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On-line version ISSN 1678-8060
Mem. Inst. Oswaldo Cruz vol.103 no.7 Rio de Janeiro Nov. 2008
The utility of rhesus monkey (Macaca mulatta) and other non-human primate models for preclinical testing of Leishmania candidate vaccines
Gabriel Grimaldi Jr
Laboratório de Pesquisas em Leishmaniose, Instituto Oswaldo Cruz-Fiocruz, Av. Brasil 4365, 21045-900 Rio de Janeiro, RJ, Brasil
Leishmaniasis causes significant morbidity and mortality, constituting an important global health problem for which there are few effective drugs. Given the urgent need to identify a safe and effective Leishmania vaccine to help prevent the two million new cases of human leishmaniasis worldwide each year, all reasonable efforts to achieve this goal should be made. This includes the use of animal models that are as close to leishmanial infection in humans as is practical and feasible. Old world monkey species (macaques, baboons, mandrills etc.) have the closest evolutionary relatedness to humans among the approachable animal models. The Asian rhesus macaques (Macaca mulatta) are quite susceptible to leishmanial infection, develop a human-like disease, exhibit antibodies to Leishmania and parasite-specific T-cell mediated immune responses both in vivo and in vitro, and can be protected effectively by vaccination. Results from macaque vaccine studies could also prove useful in guiding the design of human vaccine trials. This review summarizes our current knowledge on this topic and proposes potential approaches that may result in the more effective use of the macaque model to maximize its potential to help the development of an effective vaccine for human leishmaniasis.
Key words: non-human primates - experimental leishmaniasis - Leishmania vaccine development
Leishmaniasis is one of the major infectious diseases primarily affecting some of the poorest regions of the world. The disease is endemic in 88 countries, and the World Health Organization estimates that it is a threat to 350 million people with a worldwide prevalence of 12 million cases. Among the annual incidence of 2 million new cases of human infections, 0.5 million are life-threatening visceral leishmaniasis (VL) (www.who.int/tdr/diseases). Cutaneous leishmaniasis (CL) caused by highly pathogenic parasites is also characterized by its chronicity, latency and tendency to metastasize, resulting in recurrent skin lesions with the potential for mucosal involvement. It should be noted that an estimated 2.4 million disability adjust life years, in addition to 59,000 lives, were lost to leishmaniasis in 2001 alone (Davies et al. 2003). Concerns about chemotherapy failure for both VL and CL are exacerbated by geographical variation in antimonial treatment regimens, severity of disease and sensitivity of Leishmania species. In addition, no proven successful vaccine for controlling human leishmaniasis is in routine use (Davies et al. 2003, Kedzierski et al. 2006). Moreover, at least 20 genetically heterogeneous Leishmania species infect humans and each of them has a unique epidemiological pattern, such that two or more parasite species are often sympatric in sylvan areas of the Neotropics (Grimaldi & Tesh 1993). These data explain the limited success of current control strategies based on conventional measures (such as vector reduction and elimination of infected reservoir) for American leishmaniasis.
The solid protective immunity observed in humans following convalescence to CL formed the basis for practice of active immunization, beginning with deliberate inoculation of virulent organisms ("leishmanization") in centuries past and continuing with vaccination using a crude antigen preparation obtained from inactivated ("killed") promastigotes of one or various species of Leishmania, formulated either with or without BCG (bacillus of Calmette and Guerin) as an adjuvant (Grimaldi 1995). While accumulated experience with mass vaccination both in the ex-USSR and in Israel has clearly shown that a virulent strain of Leishmania must be used for vaccination to succeed (Gunders 1987), several Phase III trials testing the potential efficacy of various crude vaccine approaches have given conflicting results. Overall, the results vary from 0-75% efficacy against CL and little (< 6%) or no protection against VL (Grimaldi 1995, Coler & Reed 2005). Although host genetics can have dramatic effects on T-cell responses to existing vaccines (Lambert et al. 2005), several technical problems (including inadequate information about the quality, stability and potency of the antigens) may provide explanation for some of the variation in efficacy observed in those human vaccine studies. Nevertheless, most experts believe that a preventive vaccine will be essential if this disease is ever to be controlled worldwide (Coler & Reed 2005, Tabbara 2006, Kedzierski et al. 2006, Palatnik-de-Souza 2008, Silvestre et al. 2008).
The current effort to develop improved vaccines for leishmaniasis has led to the need for appropriate animal models in which to test candidate vaccines (Hein & Griebel 2003). There are reminders that the results from rodent models do not automatically translate to humans (MacGregor et al. 1998). The use of non-human primates (NHP) as animal models for the study of human diseases (including immunological studies and drug and vaccine-development studies against infectious diseases) has become increasingly important (Campos-Neto et al. 2001, Delgado et al. 2005, Giavedoni 2005, Gibbs et al. 2007, Nikolich-ugich 2007, Souza-Lemos et al. 2008). For instance, the SIV-macaque model is widely used for testing vaccine and therapeutic strategies prior to conducting human clinical trials (Nathansson et al. 1999, Hu 2005). This review aims to provide insight into the current knowledge on vaccine studies against leishmaniasis, with emphasis on studies involving vaccination and experimental infection in monkeys.
Vaccine studies against leishmaniasis
A major international research effort over the past 20 years has resulted in the identification of various Leishmania antigen candidates for second and third-generation vaccines (Coler & Reed 2005, Palatnik-de-Souza 2008). Information about a multitude of immunization approaches representing all of the major vaccine design strategies, including vaccines using live genetically attenuated parasites, subunit proteins/peptides in adjuvants, naked DNA and infectious vectored vaccines expressing genes coding for specific leishmanial antigens and combinations thereof has been given in recent review articles (Coler & Reed 2005, Tabbara 2006, Kedzierski et al. 2006, Palatnik-de-Souza 2008, Silvestre et al. 2008). Many of these vaccines have been tested for immunogenicity and protective efficacy in a variety of experimental models (such as inbred laboratory rodents, dogs and NHP). Depending on the particular vaccine approach and animal model used, varying degrees of protective immunity have been achieved, as determined by the level of parasite burden in infected sites and/or lesion size following infectious challenge.
Vaccination strategies are based on the immunology of Leishmania infection (Vanloubbeeck & Jones 2004, Von Stebut 2007). On the basis of compelling evidence that both CD4+ (including multifunctional Th1 cells and central memory CD4+ T-cells) and CD8+ T-cells are key players in the immune response to leishmaniasis (Reed & Scott 2000, Zaph et al. 2004, Darrah et al. 2007), the scientific community has focused considerable efforts on the development of prophylactic vaccines that elicit T-cell responses (Rhee et al. 2002, Tapia et al. 2003, Sharma et al. 2006, Dondji et al. 2008) with the premise that such interventions will confer protective effects in these conditions. In this regard, sustained protective immunity against both murine CL and VL has been achieved by DNA vaccines encoding antigen candidates (Gurunathan et al. 2000, Mendez et al. 2001, Campos-Neto et al. 2002, Zanin et al. 2007, Dondji et al. 2008) or leishmanial recombinant protein(s) formulated with improved vaccine adjuvants (Pashine et al. 2005), including cytosine phosphate guanosine oligodeoxynucleotides, CpG ODN (Rhee et al. 2002, Iborra et al. 2005) and cationic distearoyl phosphatidylcholine (DSPC) liposomes (Bhowmick et al. 2007). Of note, long-term immunity elicited by those vaccines corresponded to, in addition to the presence of leishmania-specific Th1, CD8+ T-cells responses (Gurunathan et al. 2000, Rhee et al. 2002, Sharma et al. 2006). Additionally, heterologous prime-boost vaccination regimes, such as combining DNA priming with a live vectored boost (Gonzalo et al. 2002, Ramiro et al. 2003), or two different live vectors to prime and boost a response (Dondji et al. 2005, Ramos et al. 2008) have been explored as a means of raising protective T-cell responses (Hu 2005).
Due to the genetic variability of human T-cell responses (across HLA haplotypes), T-cell vaccines can elicit variable protective immunity (Robinson & Amara 2005). A second limitation of T-cell vaccines is the potential for T-cells to become exhausted by high levels of persisting antigens (Kostense et al. 2002). Another challenge is the ability of leishmanial parasites to modulate their antigens to evade immune responses (Vanloubbeeck & Jones 2004). Therefore, a successful DNA or subunit protein-based vaccine will likely require a cocktail of proven immunogens. Accordingly, there is increasing emphasis on strategies for combining protective antigen candidates in the same regimen (Campos-Neto et al. 2002, Skeiky et al. 2002, Iborra et al. 2004, Zadeh-Vakili et al. 2004, Moreno et al. 2007, Rodriguez-Cortés et al. 2007, Zanin et al. 2007). It should be noted that a triple fusion protein vaccine (termed Leish-111f-MPL®-SE), consisting of the T-cell adjuvant antigens thiol-specific antioxidant, Leishmania major stress-inducible protein 1 and Leishmania elongation initiation factor formulated in monophosphoryl lipid A plus squalene, which confers protection in the mouse model against L. major, Leishmania amazonensis (Coler & Reed 2005) and Leishmania infantum infections (Coler et al. 2007) is now within reach. Whether prophylactic immunization using this vaccine can achieve similar levels of immunity against all parasite species that cause disease in genetically diverse human subjects (who also may differ significantly in their nutritional status and previous immunological experience) has yet to be determined.
Additionally, the potential efficacy of the Leish-111f/GM-CSF adjuvant vaccine in a post-exposure paradigm is currently being tested in cases of drug-refractory disease with encouraging results (Badaró et al. 2006). On the other hand, the potential for immunomodulatory factors of sandfly saliva to serve as vaccine targets to prevent pathogen transmission (Titus et al. 2006) has received increased attention by investigators. In this regard, two candidates are the Lutzomyia longipalpis salivary gland protein maxadilan (Brodie et al. 2007) and the recombinant protein SP15; a vaccine composed of the latter antigen confers protection in the mouse model against L. major challenge infection (Valenzuela et al. 2001).
Natural and experimental leishmanial infections in NHP
Table I summarizes the published studies on natural leishmanial infections in NHP. At least four species of Neotropical monkeys are susceptible to natural infection with human pathogenic Leishmania (Viannia) species (Herrer et al. 1973, Lainson et al. 1988, 1989). In contrast, only one species of old world monkeys was found to be naturally infected with L. major (Binhazim et al. 1987).
Monkeys have varying degrees of susceptibility to leishmanial parasites and the specific disease course depends on the challenge parasite (Amaral et al. 1996, 2001, Teva et al. 2003), host species or individual (Dennis et al. 1986, Porrozzi et al. 2006) challenge dose and route of exposure (Lujan et al. 1986a, Amaral et al. 1996). Moreover, sand fly saliva immunomodulators are known to exacerbate leishmanial infection in rodents (Lima & Titus 1996). Accordingly, when rhesus macaques are infected with L. major transmitted by Phlebotomus papatasi (Probst et al. 2001), they developed skin lesions that lasted longer (12-28 weeks post-infection) than typical infections (11 weeks) induced by needle inoculation with larger numbers (1 x 107) of L. major culture metacyclics (Amaral et al. 2001).
Table II summarizes the essential features of the published studies on experimental infection of NHP by various Leishmania species. Different NHP species have become useful in studying the biology of infection and in dissecting the host response to these parasites. Those reported as being highly susceptible to Leishmania donovani complex parasites include the Neotropical simians Aotus trivirgatus (Chapman et al. 1981, Broderson et al. 1986), Saimiri sciureus (Chapman & Hanson 1981, Dennis et al. 1985, 1986) and Callithrix jacchus jacchus (Marsden et al. 1981). All of these species have since been used as NHP models of VL for anti-leishmanial chemotherapy studies (Dietze et al. 1985, Madindou et al. 1985, Berman et al. 1986). Conversely, East African primates such as Sykes monkeys (Cercopithecus mitis) and baboons (Papio cynocephalus) all supported low-grade L. donovani infections for periods ranging between 4-8 months and subsequently showed evidence of self-cure (Githure et al. 1986). Furthermore, disease mimicking human VL was established in langur monkeys (Presbytis entellus) (Dube et al. 1999), vervet monkeys (Cercopithecus aethiops) (Binhazim et al. 1993, Gicheru et al. 1995) and macaques (Macaca mulatta) (Porrozzi et al. 2006). The L. donovani-langur monkey model has also been explored to assess different vaccine formulations against VL (Dube et al. 1998, Misra et al. 2001).
Consistent with documented cases of human CL caused by L. major, experimental infection in macaques induced by the same parasite species causes a self-limiting CL of moderate severity (Fig. 1), which resolves within three months (Fig. 2) and provides the most ethically acceptable model for vaccine testing (Amaral et al. 2001, 2002, Campos-Neto et al. 2001). When infected with L. amazonensis, macaques developed greater lesion size with longer duration (Amaral et al. 1996). In both experiments, active skin lesions contained amastigotes with a mononuclear infiltrate of macrophages, plasma cells and lymphocytes and formation of tuberculoid-type granulomas. In L. amazonensis-infected macaques it was demonstrated that CD4+/CD8+ T-cell ratios favour CD8+ cells in both active and healing skin lesions (Amaral et al. 2000). A more marked variation in the clinical course of infection was found when groups of macaques were inoculated with different Leishmania braziliensis strains (Teva et al. 2003, Souza-Lemos et al. 2008). The inocula produced lesions of variable severity, ranging from localized self-healing CL to non-healing disease (Figs 3A, C). Pathological findings included a typical cell-mediated immunity-induced granulomatous reaction (Fig. 3D), which consisted of all cell types found within human granulomas, including the presence of both IFN-γ- or TNF-α-producing CD4+ and CD8+ T-cells, as well as IL-10-producing CD4+CD25+ T-cells (Souza-Lemos et al. 2008). While several groups have described that ML (mucosa lesions) has not been observed in Neotropical monkey models of CL (Lainson & Shaw 1977, Lujan et al. 1986a, 1990, Cuba Cuba et al. 1990), in our own studies (Teva et al. 2003, G Grimaldi Jr, unpublished data) two of 30 (6.7%) L. braziliensis-infected macaques developed nasal ML (Fig. 3C). In the original model description (Marques da Cunha 1944), ML was observed in two of seven (28.5%) monkeys infected with L. braziliensis. Of note, therapeutic responses of L. braziliensis-infected macaques to the reference drug N-methylglucamine antimoniate (Glucantime®) were consistent with those reported in human disease (Teva et al. 2005).
Contrary to the traditional belief that human self-resolution of CL confers life-long immunity against further infection by the same parasite (Gunders 1987), Killick-Kendrick et al. (1985) and Saraiva et al. (1990) provided evidence that immunity conferred by prior self-resolving leishmanial infection may not always be complete in humans. Likewise, in L. amazonensis (Amaral et al. 1996) or L. major-infected out-bred macaques (Amaral et al. 2001) both the level of resistance and the acquired immune response to subsequent homologous challenge(s) are variable. The mechanism causing partial protection in primates is not yet clear, but may be related to differential performance of memory T cells (Zaph et al. 2004). In addition, IL-10-producing CD4+CD25+T cells are known to control acquired immunity in mice (Belkaid et al. 2002) and macaques (Souza-Lemos et al. 2008) with leishmanial infections.
The findings from cross-immunity experiments between different species or strains of Leishmania in monkeys (Table III) may give important clues to vaccine reseach. The relative variability in protection after self-cure or drug-cured experimental leishmaniasis to challenge by heterologous parasites appears to reflect both the nature (i.e., etiologic agent) and the course of primary infection or disease tempo (i.e., the progression and resolution of leishmanial lesions). Another factor that can influence acquired immunity is the time between recovery from primary infection and re-challenge. For example, a self-healing CL following infection with L. major induces significant protection for L. amazo-nensis and Leishmania guyanensis and was dependent on time of re-challenge by L. amazonensis after animals had recovered from primary lesions, but lacked protection against L. braziliensis. Conversely, macaques immune to either L. braziliensis or Leishmania chagasi (syn. L. infantum) were found to be fully protected to challenge with L. braziliensis or L. amazonensis (Porrozzi et al. 2004).
All infected animals responded with increased production of immunoglobulins capable of binding to cross-reacting parasite antigens (Lujan et al. 1987, Porrozzi et al. 2004). Although an antigen-specific Th1-like response appears critical for mediating protection in a variety of primate models of CL (Olobo et al. 1992, Olobo & Reid 1993, Amaral et al. 2001, Teva et al. 2003) and VL (Porrozzi et al. 2006), the current parameters of cell-mediated immunity [i.e., by measuring delayed-type hypersensitivity reaction (DHT) to the leishmanin skin test (LST) in vitro lymphocyte proliferation and IFN-γ production] do not always correlate with clinical recovery and resistance to infectious re-challenge (Amaral et al. 2001, Porrozzi et al. 2004, 2006). Certainly, further studying the immune response in primates may clarify what is required to develop and maintain protective immunity to re-challenge(s).
Use of primate models to assess leishmaniasis vaccines
Divergent evolution (~ 210 million year divergence between rodents and humans) limits the relevance of murine models in guiding the design of human vaccine trials (Nikolich-ugich 2007). In this regard, old world simian species which diverged from humans approximately 25 million years ago (Gibbs et al. 2007) are emerging as invaluable in vivo models of pathogenesis and immunity to infectious diseases requiring cellular immunity, but are also a key tool for conducting comparative studies of vaccine approaches (Nathansson et al. 1999, Jonhston 2000). Because of the homology between the M. mulatta and human immune systems (Kennedy et al. 1997b, Shearer et al. 1999, Pahar et al. 2003, Giavedoni 2005), the NHP model is frequently used to determine which vaccine candidates are most worthy of accelerated development (Johnston 2000, Nikolich-ugich 2007).
A variety of NHP models for both CL and VL have been used to assess the safety (to verify whether vaccination itself causes adverse effects), immunogenicity (including evaluation of potential correlates of immune protection) and protective efficacy (to determine whether vaccination protects the animal host against infective challenge) of vaccine formulations (Table IV). To date, the only way to determine acquired resistance afforded by a candidate vaccine is to challenge the vaccinated animals with virulent leishmanial parasites. However, because of (i) the limited number of monkeys per experimental group and (ii) the fact that stationary-phase promastigotes can have varying numbers of the infectious form of metacyclic promastigotes within each preparation, researchers use a high inoculum dose to achieve uniform infection for challenge, which may account for the relative variability in the levels of vaccine-induced protection. On the other hand, the use of a short interval between the last boost and the infectious challenge (as short as 3-5 weeks in some studies), makes it difficult to interpret the results in terms of the ability of the vaccine to induce a sustained memory T-cell response (Pitcher et al. 2002). In addition, in most studies of this nature, it is difficult to accurately assess partial host immunity during infection since lesion size, a highly variable parameter (due to the out-bred nature of monkeys used for such studies) is commonly used as a correlate of protection.
The results from primate vaccine studies are summarized in Table IV. Protective efficacy with crude vaccine approaches against CL in macaques was achieved only when the inactivated parasites were combined with alum plus recombinant human IL-12 (Kenney et al. 1999) or CpG ODN (Verthelyi et al. 2002) as adjuvants. In addition, successful vaccination against L. donovani visceral infection in langur monkeys was obtained using alum-precipitated autoclaved L. major with BCG (Misra et al. 2001). In our previous studies (Amaral et al. 2002) we have compared the potential efficacy of two L. major vaccines, one genetically attenuated (DHFR-TS deficient organisms), the other inactivated organisms (autoclaved promastigotes with BCG), in protecting macaques against homologous challenge. While a positive antigen-specific recall proliferative response was observed in those vaccinated (79% in attenuated parasite-vaccinated monkeys, versus 75% in ALM-plus-BCG-vaccinated animals), none of these animals exhibited either augmented in vitro INF-γ production or a positive DTH response to the leishmanin skin test prior to challenge. Following challenge, significant differences in blastogenic responses were found between attenuated-vaccinated monkeys and naïve controls. Protective immunity did not follow vaccination, in that monkeys exhibited skin lesions at the site of challenge in all experimental groups. In contrast, vaccination using a mix of the recombinant antigens LmSTI1 and TSA (Webb et al. 1996, 1998) formulated with rhIL-12 and alum as adjuvants induced excellent protection in the high dose L. major-macaque model (Campos-Neto et al. 2001). Likewise, vervet monkeys, when immunized with recombinant histone H1 antigen using Montanide as an adjuvant, mounted good protection against challenge with L. major (Masina et al. 2003).
Ample evidence supports the notion that different prime-boost vaccination regimens can elicit greater immune responses than single immunization modalities. The use of heterologous prime-boost approaches was originally explored as a means to overcome vector-specific immunity elicited against the priming immunogen and to augment antigen-specific responses by subunit protein boost (Hu et al. 1991). This approach was found to enhance antigen-specific antibody responses in mice, macaques and humans primed with a recombinant vaccinia virus and boosted with recombinant HIV-1 envelope protein (Hu 2005). Conversely, immunization with DNA priming and recombinant virus boosting elicited strong T-cell responses (Schneider et al.1999, Barouch & Letvin 2000). The effect regarding the order of DNA versus recombinant vector for priming or boosting can have in eliciting protective immunity has been debated (Hanke et al. 1998, McClure et al. 2000). Over the past three years, several primate studies have been performed in our laboratory to establish vaccination procedures, improve vaccine immunogenicity and minimize vector-specific immunity. Indeed, it is now clear that detectable Leishmania-specific T-cell responses can be induced safely in primates by vaccination, but, depending on the particular regimen used, varying degrees of acquired immunity have been achieved (ranging from non-existent to full protection after the infectious challenge). Further experiments are in progress in the Leishmania-macaque model to comparatively examine the potential efficacy of various vaccine approaches afforded by vaccine candidates.
Determining correlates of immune protection to Leishmania
While the functional heterogeneity (across HLA haplotypes) of T-cell cytokine responses to existing vaccines is undoubtedly of importance (Robinson & Amara 2005), they have not been extensively analyzed. In fact, T-cell vaccines for microbial infections have been developed without a clear understanding of their mechanism(s) of protection (Lambert et al. 2005). With regard to leishmaniasis, most vaccine studies measure the frequency of IFN-γ-producing Th1 cells as the primary immune correlate of protection (Coller & Reed 2005), but in vitro IFN- γ production as a single immune parameter may not be sufficient to predict protection (Elias et al. 2005, Oliveira et al. 2005). Recent data have shed important insight on the potential correlates of protection, showing that the magnitude, potency and durability of a multifunctional CD4+ Th1-cell cytokine response can be a crucial determinant in whether a vaccine is protective (Darrah et al. 2007). Conversely, it is likely that IL-10-producing CD4+CD25+ T regulatory cells are functional in determining vaccine failure (Stober et al. 2005). In another study (Stäger et al. 2000), vaccine-induced protection, using the recombinant hydrophilic acylated surface protein B1 (HASPB1) of L. donovani, correlates with the presence of rHASPB1-specific, IFN-γ -producing CD8+ T cells.
Neither study in the L. amazonensis (Kenney et al. 1999) or L. major-macaque model (Campos-Neto et al. 2001, Amaral et al. 2002), nor those in the L. major-vervet monkey model (Gicheru et al. 2001), have resulted in a clear definition of what T-cell responses will be required for vaccine-induced protective immunity. Without such knowledge, vaccine design strategies will remain largely empirical, and further failures are likely to occur. This is due, in part, to the high degree of variability in the antigen-specific recall blastogenic and IFN-γ responses detected among primates (Campos-Neto et al. 2001, Pahar et al. 2003). This appears to result from the outbred genetics of macaques used for such studies, which indeed makes them the most appropriate model when predicting the diversity of responses that could be expected in the human population. Increasing the number of monkeys per experimental group can help address this condition. Unfortunately, by definition this is not feasible. On the other hand, using macaques with defined genotypes with respect to immune response genes (MHC class I and II) would minimize individual variability, but unfortunately this approach introduces bias into the results (Johnston 2000, Hu 2005).
Finally, the application of ELIspot and cytokine flow cytometry assays has provided new insights into the attributes of both CD4+ and CD8+ T cells that mediate protection in macaques (Mäkitalo et al. 2002, Keeney et al. 2003). This technology should help to identify correlates of protection in future primate vaccine studies.
Clinical development of the available subunit protein or DNA-based vaccines against leishmaniasis may not be fully protective across all HLA haplotypes and Leishmania species. This is due, in part, to the inherent difficulties that hinder full characterization of the determinants of successful T-cell immunity in humans (Robinson & Amara 2005, Appay et al. 2008). Nevertheless, most experts believe that a successful Leishmania vaccine will likely require (i) selection of a cocktail of protective immunogens; (ii) identification of efficient prime-boost strategies in order to provide broad, cross-reactive and long-lasting protection; and (iii) selection or identification of an adjuvant formulations or delivery systems that can be used in human clinical trials. Nonetheless, given these intrinsic vaccine development requirements, regulatory authorities are willing to regulate safety data on infectious vectored vaccines generated from primates.
However, primate testing should be reserved for the final stages of evaluation of vaccine candidates that have already shown consistent induction of significant protective immunity in conventional mouse models. Considerations for employing the primate M. mulatta to evaluate vaccine safety and protective efficacy should also include costs and availability (Kennedy et al. 1997a). Available data indicates that vaccine trials in macaques will not be hindered due to divergence of MHC class I and class II molecules (Watkins et al. 1988, Klein et al. 1993, Doxiadis et al. 2001). Moreover, rhesus macaques have been successfully infected with a variety of human pathogenic Leishmania species either by syringe or sandfly challenge and develop a human-like disease (including the non-curing L. braziliensis granulomata ML). Most of the published information on the course of primary or secondary infection, clinicopathological changes, immune responses and vaccination data was gained using outbred macaques. Although the predictive value for any animal model in vaccine development ultimately depends on validating data from human trials, further development of the Leishmania-macaque model should prove useful in guiding the design of human vaccine trials.
To Dr. Antonio Campos-Neto, for critically reviewing this manuscript.
Amaral VF, Pirmez C, Ferreira AJS, Ferreira V, Grimaldi Jr G 2000. Cell populations in lesions of cutaneous leishmaniasis of Leishmania (L.) amazonensis-infected rhesus macaques, Macaca mulatta. Mem Inst Oswaldo Cruz 95: 209-216. [ Links ]
Amaral VF, Ransatto VAO, Conceição-Silva F, Molinaro E, Ferreira V, Coutinho SG, McMahon-Pratt D, Grimaldi G Jr 1996. Leishmania amazonensis: the Asian rhesus macaques (Macaca mulatta) as an experimental model for study of cutaneous leishmaniasis. Exp Parasitol 82: 34-44. [ Links ]
Amaral VF, Teva A, Oliveira-Neto MP, Silva AJ, Pereira MS, Cupolillo E, Porrozzi R, Coutinho SG, Pirmez C, Beverley SM, Grimaldi G Jr 2002. Study of the safety, immunogenicity and efficacy of attenuated and killed Leishmania (Leishmania) major vaccines in a rhesus monkey (Macaca mulatta) model of the human disease. Mem Inst Oswaldo Cruz 97: 1041-1048. [ Links ]
Amaral VF, Teva A, Porrozzi R, Silva AJ, Pereira MS, Grimaldi G Jr 2001. Leishmania (Leishmania) major-infected rhesus macaques (Macaca mulatta) develop varying levels of resistance against homologous reinfections. Mem Inst Oswaldo Cruz 96: 795-804. [ Links ]
Anuradha R, Pal R, Zehra K, Katiyar JC, Sethi N, Bhatia G, Singh RK 1992. The Indian langur: preliminary report of a new non-human primate host for visceral leishmaniasis. WHO Bulletin 70: 63-72. [ Links ]
Anuradha D, Sharma P, Skrivastava JK, Misra A, Naik S 1998. Vaccination of langur monkey (Presbytis entellus) against Leishmania donovani with autoclaved L. major plus BCG. Parasitology 116: 219-221. [ Links ]
Appay V, Douek DC, Price DA 2008. CD8+ T cell efficacy in vaccination and disease. Nature Med 14: 623-628. [ Links ]
Badaró R, Lobo I, Munos A, Netto EM, Modabber F, Campos-Neto A, Coler RN, Reed SG 2006. Immunotherapy for drug-refractory mucosal leishmaniasis. J Infect Dis 194: 1151-1159. [ Links ]
Barouch DH, Letvin NL 2000. DNA Vaccination for HIV-1 and SIV. Intervirology 43: 282-287. [ Links ]
Belkaid Y, Piccirillo CA, Mendez S, Shevach EM, Sacks DL 2002. CD4+CD25+ regulatory T cells control Leishmania major persistence and immunity. Nature 420: 502-507. [ Links ]
Berman JD, Hanson WL, Chapman WL, Alving CR, Lopez-Berestein G 1986. Antileishmanial activity of liposome-encapsulated Amphotericin B in hamsters and monkeys. Antimicrob Agents Chemother 30: 847-851. [ Links ]
Bhowmick S, Ravindran R, Ali N 2007. Leishmanial antigens in liposomes promote protective immunity and provide immunotherapy against visceral leishmaniasis via polarized Th1 response. Vaccine 25: 6544-6556. [ Links ]
Binhazim AA, Githure JI, Muchemi GK, Reid GD 1987. Isolation of Leishmania major from a naturally infected vervet monkey (Cercopithecus aethiops) caught in Kiambu District, Kenya. Parasitology 73: 1278-1279. [ Links ]
Binhazim AA, Shin SS, Chapman WL Jr, Olobo J 1993. Comparative susceptibility of African green monkeys (Cercopithecus aethiops) to experimental infection with Leishmania leishmania donovani and Leishmania leishmania infantum. Lab Anim Sci 43: 37-47. [ Links ]
Broderson JR, Chapman WL Jr, Hanson WL 1986. Experimental visceral leishmaniasis in the owl monkey. Vet Pathol 23: 293-302. [ Links ]
Brodie TM, Smith MC, Morris RV, Titus RG 2007. Immunomodulatory effects of the Lutzomyia longipalpis salivary gland protein Maxadilan on mouse macrophages. Infect Immun 75: 2359-2365. [ Links ]
Campos-Neto A, Porrozzi R, Greeson K, Coler RN, Webb JR, Seiky YA, Reed SG, Grimaldi G Jr 2001. Protection against cutaneous leishmaniasis induced by recombinant antigens in murine and non-human primate models of the human disease. Infect Immun 69: 4103-4108. [ Links ]
Campos-Neto A, Webb JR, Greeson K, Coler RN, Skeiky YA, Reed SG 2002. Vaccination with plasmid DNA encoding TSA/LmSTI1 leishmanial fusion proteins confers protection against Leishmania major infection in susceptible BALB/c mice. Infect Immun 70: 2828-2836. [ Links ]
Chapman WL Jr, Hanson WL 1981. Visceral leishmaniasis in the squirrel monkey (Saimiri sciurea). J Parasitol 67: 740-741. [ Links ]
Chapman WL Jr, Hanson WL, Hendricks LD 1981. Leishmania donovani in the owl monkey (Aotus trivirgatus). Trans R Soc Trop Med Hyg 75: 124-125. [ Links ]
Christensen HA, de Vasquez AM 1981. Susceptibility of Aotus trivirgatus to Leishmania braziliensis and L. mexicana. Am J Trop Med Hyg 30: 54-56. [ Links ]
Coler RN, Goto Y, Bogatzki L, Raman V, Reed SG 2007. Leish-111f, a recombinant polyprotein vaccine that protects against visceral leishmaniasis by elicitation of CD4+ T cells. Infect Immun 75: 4648-4654. [ Links ]
Coler RN, Reed SG 2005. Second-generation vaccines against leishmaniasis. Trends Parasitol 21: 244-248. [ Links ]
Cuba-Cuba CA, Ferreira V, Bampi M, Magalhães A, Marsden P, Vexenat A, Mello MT 1990. Experimental infection with Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis in marmoset (Callithrix penicillata) (Primates, Callithricidae). Mem Inst Oswaldo Cruz 85: 459-467. [ Links ]
Cuba-Cuba CA, Marsden PD 1992. Failure to develop homologous immunity to a second challenge with Leishmania (Viannia) braziliensis in the black-plumed marmoset (Callithrix penicillata). Trans R Soc Trop Med Hyg 86: 37-45. [ Links ]
Darrah PA, Patel DT, De Luca PM, Lindsay RWB, Davey DF, Flynn BJ, Hoff ST, Andersen P, Reed SG, Morris SL, Roederer M, Seder RA 2007. Multifunctional TH1 cells define a correlate of vaccine-mediated protection against Leishmania major. Nature Med 13: 843-850. [ Links ]
Davies CR, Kaye P, Croft SL, Sundar S 2003. Leishmaniasis: new approaches to disease control. BMJ 326: 377-382. [ Links ]
Delgado G, Parra-López C, Spinel C, Patarroyo ME 2005. Phenotypical and functional characterization of non-human primate Aotus spp. dendritic cells and their use as a tool for characterizing immune response to protein antigens. Vaccine 23: 3386-3395. [ Links ]
Dennis VA, Chapman WL Jr, Hanson WL, Lujan R 1985. Leishmania donovani: clinical, haematological and hepatic changes in squirrel monkeys (Saimiri sciureus). J Parasitol 71: 576-582. [ Links ]
Dennis VA, Lujan R, Chapman WL Jr, Hanson WL 1986. Leishmania donovani: Cellular and humoral immune responses after primary and challenge infections in squirrel monkeys, Saimiri sciureus. Exp Parasitol 61: 319-334. [ Links ]
Dietze R, Araújo RC, Lima MLR, Vexenat JA, Marsden PD, Barreto AC 1985. Ensaio terapêutico com glucantime em sagüis (Callithrix jacchus) infectados com uma cepa de Leishmania donovani aparentemente resistente ao tratamento. Rev Soc Bras Med Trop 18: 39-42. [ Links ]
Dondji B, Deak E, Goldsmith-Pestana K, Perez-Jimenez E, Esteban M, Miyake S, Yamamura T, McMahon-Pratt D 2008. Intradermal NKT cell activation during DNA priming in heterologous prime-boost vaccination enhances T cell responses and protection against Leishmania. Eur J Immunol 38: 706-719. [ Links ]
Dondji B, Pérez-Jimenez E, Goldsmith-Pestana K, Esteban M, McMahon-Pratt D 2005. Heterologous prime-boost vaccination with the LACK antigen protects against murine visceral leishmaniasis. Infect Immun 73: 5286-5289. [ Links ]
Doxiadis GGM, Otting NG, Natasja G, Bontrop RE 2001. Differential evolutionary MHC class II strategies in humans and rhesus macaques: relevance for biomedical studies. Non-human primate models for human disease and immunobiology. Immunol Rev 183: 76-85. [ Links ]
Dube A, Sharma P, Srivastava JK, Misra A, Naik S, Katiyar JC 1998. Vaccination of langur monkeys (Presbytis entellus) against Leishmania donovani with autoclaved L. major plus BCG. Parasitology 116: 219-221. [ Links ]
Dube A, Srivastava JK, Sharma P, Chaturvedi A, Katiyar JC, Naik S 1999. Leishmania donovani: cellular and humoral immune responses in Indian langur monkeys, Presbytis entellus. Acta Trop 73: 37-48. [ Links ]
Elias D, Akuffo H, Britton S 2005. PPD induced in vitro interferon gamma production is not a reliable correlate of protection against Mycobacterium tuberculosis. Trans R Soc Trop Med Hyg 99: 363-368. [ Links ]
Freidag BL, Mendez S, Cheever AW, Kenney RT, Flynn B, Sacks DL, Seder RA 2003. Immunological and pathological evaluation of rhesus macaques infected with Leishmania major. Exp Parasitol 103: 160-168. [ Links ]
Garcez LM, Silveira FT, El Harith A, Lainson R, Shaw JJ 2002. Experimental cutaneous leishmaniasis IV. The humoral response of Cebus apella (Primates: Cebidae) to infections of Leishmania (Leishmania) amazonensis, L. (Viannia) lainsoni and L. (V.) braziliensis using the direct agglutination test. Acta Trop 68: 65-76. [ Links ]
Giavedoni LD 2005. Simultaneous detection of multiple cytokines and chemokines from nonhuman primates using luminex technology. J Immunol Methods 301: 89-101. [ Links ]
Gibbs RA, Rogers J, Katze MG, Bumgarner R, Weinstock GM, Mardis ER, Remington KA, Strausberg RL, Venter JC, Wilson RK, Batzer MA, Bustamante CD, Eichler EE, Hahn MW, Hardison RC, Makova KD, Miller W, Milosavljevic A, Palermo RE, Siepel A, Sikela JM, Attaway T, Bell S, Bernard KE, Buhay CJ, Chandrabose MN, Clay Davis DM, Delehaunty KD, Ding Y, Dinh HH, Dugan-Rocha S, Fulton LA, Gabisi RA, Garner TT, Godfrey J, Hawes AC, Hernandez J, Hines S, Holder M, Hume J, Jhangiani SN, Joshi V, Khan ZM, Kirkness EF, Cree A, Fowler RG, Lee S, Lewis LR, Li Z, Liu Y, Moore SM, Muzny D, Nazareth LV, Ngo DN, Okwuonu GO, Pai G, Parker D, Paul HA, Pfannkoch C, Pohl CS, Rogers Y-H, Ruiz SJ, Sabo A, Santibanez J, Schneider BW, Smith SM, Sodergren E, Svatek AF, Utterback TR, Vattathil S, Warren W, White CS, Chinwalla AT, Feng Y, Halpern AL, Hillier LW, Huang X, Minx P, Nelson JO, Pepin KH, Qin X, Sutton GG, Venter E, Walenz BP, Wallis JW, Worley KC, Yang S-P, Jones SM, Marra MA, Rocchi M, Schein JE, Baertsch R, Clarke L, Csürös M, Glasscock J, Harris RA, Havlak P, Jackson AR, Jiang H, Liu Y, Messina DN, Shen Y, Xing-Zhi Song H, Wylie T, Zhang L, Birney E, Han K, Konkel MK, Lee J, Smit AFA, Ullmer B, Wang H, Xing J, Burhans R, Cheng Z, Karro JE, Ma J, Raney B, She X, Cox MJ, Demuth JP, Dumas LJ, Han S-G, Hopkins J, Karimpour-Fard A, Kim YH, Pollack JR, Vinar T, Addo-Quaye C, Degenhardt J, Denby A, Hubisz MJ, Indap A, Kosiol C, Lahn BT, Lawson HA, Marklein A, Nielsen R, Vallender EJ, Clark AG, Ferguson B, Hernandez RD, Hirani K, Kehrer-Sawatzki H, Kolb J, Patil S, Pu L-L, Ren Y, Smith DG, Wheeler DA, Schenck I, Ball EV, Chen R, Cooper DN, Giardine B, Hsu F, Kent FW, Lesk A, Nelson DL, O'Brien WE, Prüfer K, Stenson PD, Wallace JC, Ke H, Liu X-M, Wang P, Xiang AP, Yang F, Barber GP, Haussler D, Karolchik D, Kern AD, Kuhn RM, Smith KE, Zwieg AS 2007. Rhesus macaque genome sequencing and analysis consortium. Evolutionary and biomedical insights from the rhesus macaque genome. Science 316: 222-234. [ Links ]
Gicheru MM, Olobo JO, Anjili CO 1997. Heterologous protection by Leishmania donovani for Leishmania major infections in the vervet monkey model of the disease. Exp Parasitol 85: 109-116. [ Links ]
Gicheru MM, Olobo JO, Anjili CO, Orago AS, Modabber F, Scott P 2001. Vervet monkeys vaccinated with killed Leishmania major parasites and interleukin-12 develop a type 1 immune response but are not protected against challenge infection. Infect Immun 69: 245-251. [ Links ]
Gicheru MM, Olobo JO, Kariuki TM, Adhiambo C 1995. Visceral leishmaniasis in vervet monkeys: immunological responses during asymptomatic infections. Scand J Immunol 41: 202-208. [ Links ]
Githure JI, Reid GD, Binhazim AA, Anjili CO, Shatry AM, Hendricks LD 1987. Leishmania major: the suitability of East African nonhuman primates as animal models for cutaneous leishmaniasis. Exp Parasitol 64: 438-447. [ Links ]
Githure JI, Shatry AM, Tarara R, Chulay JD, Suleman MA, Chunge CN, Else JG 1986. The suitability of East African primates as animal models of visceral leishmaniasis. Trans R Soc Trop Med Hyg 80: 575-576. [ Links ]
Gonzalo RM, del Real G, Rodriguez JR, Rodriguez D, Heljasvaara R, Lucas P, Larraga V, Esteban M 2002. A heterologous prime-boost regime using DNA and recombinant vaccinia virus expressing the Leishmania infantum P36/LACK antigen protects BALB/c mice from cutaneous leishmaniasis. Vaccine 20: 1226-1231. [ Links ]
Grimaldi G Jr 1995. Meeting on vaccine studies towards the control of leishmaniasis. Mem Inst Oswaldo Cruz 90: 553-556. [ Links ]
Grimaldi G Jr, Tesh RB 1993. Leishmaniasis of the New World: Current concepts and implications for future research. Clin Microbiol Rev 6: 230-250. [ Links ]
Gunders AE 1987. Vaccination: past and future role in control. In W Peters, R Killick-Kendrick (eds.), The leishmaniasis in Biology and Medicine, Vol. 2, Academic Press, London, p. 928-941. [ Links ]
Gurunathan S, Stobie L, Prussin C, Sacks DL, Glaichenhaus N, Fowell DJ, Locksley RM, Chang JT, Wu C-Y, Seder RA 2000. Requirements for the maintenance of Th1 immunity in vivo following DNA vaccination: a potential immunoregulatory role for CD8+ T cells. J Immunol 165: 915-924. [ Links ]
Hanke T, Blanchard TJ, Schneider J, Hannan CM, Becker M, Gilbert SC, Hill AVS, Smith GL, McMichael A 1998. Enhancement of MHC class I-restricted peptide-specific T cell induction by a DNA prime/MVA boost vaccination regime. Vaccine 16: 439-445. [ Links ]
Hein WR, Griebel PJ 2003. A road less traveled: large animal models in immunological research. Nat Rev Immunol 3: 79-84. [ Links ]
Herrer A, Christensen HA, Beumer RJ 1973. Reservoir hosts of cutaneous leishmaniasis among Panamanian forest mammals. Am J Trop Med Hyg 22: 585-591. [ Links ]
Hu S-L 2005. Non-human primate models for AIDS vaccine research. Curr Drug Targets Infect Disord 5: 193-201. [ Links ]
Hu S-L, Klaniecki J, Dykers T, Sridhar P, Travis BM 1991. Neutralizing antibodies against HIV-1 BRU and SF2 isolates generated in mice immunized with recombinant vaccinia virus expressing HIV-1 (BRU) envelope glycoproteins and boosted with homologous gp160. AIDS Res Hum Retroviruses 7: 615-620. [ Links ]
Iborra S, Carrión J, Anderson C, Alonso C, Sacks D, Soto M 2005. Vaccination with the Leishmania infantum acidic ribosomal P0 protein plus CpG oligodeoxynucleotides induces protection against cutaneous leishmaniasis in C57BL/6 mice but does not prevent progressive disease in BALB/c mice. Infect Immun 73: 5842-5852. [ Links ]
Iborra S, Soto M, Carrión J, Alonso C, Requena JM 2004. Vaccination with a plasmid DNA cocktail encoding the nucleosomal histones of Leishmania confers protection against murine cutaneous leishmaniosis. Vaccine 22: 3865-3876. [ Links ]
Johnston MI 2000. The role of non-human primate models in AIDS vaccine development. Mol Med Today 6: 267-270. [ Links ]
Kedzierski L, Zhu Y, Handman E 2006. Leishmania vaccines: progress and problems. Parasitology 133 (Suppl.): 87-112. [ Links ]
Keeney TS, Nomura LE, Maecker HT, Sastry KJ 2003. Flow cytometric analysis of macaque whole blood for antigen-specific intracellular cytokine production by T lymphocytes. J Med Primatol 32: 23-30. [ Links ]
Kennedy RC, Shearer MH, Hildebrand WH 1997a. Nonhuman primate models to evaluate vaccine safety and immunogenicity. Vaccine 15: 903-908. [ Links ]
Kennedy RC, Shearer MH, Hildebrand WH, Simmonds RS 1997b. Non-human primates and their use in immunologically based investigations. The Immunologist 5/5: 150-156. [ Links ]
Kenney RT, Sacks DL, Sypek JP, Vilela L, Gam AA, Evans-Davis K 1999. Protective immunity using recombinant human IL-12 and alum as adjuvants in a primate model of cutaneous leishmaniasis. J Immunol 163: 4481-4488. [ Links ]
Killick-Kendrick R, Bryceson ADM, Peter W, Evans DA, Leaney AJ, Rioux JA 1985. Zoonotic cutaneous leishmaniasis in Saudi Arabia: Lesions healing naturally in man followed by a second infection with the same zymodeme of Leishmania major. Trans R Soc Trop Med Hyg 79: 363-365. [ Links ]
Klein J, Satta Y, O'Huigin C, Takahata N 1993. The molecular descent of the major histocompatibility complex. Immunol Reviews 11: 213-244. [ Links ]
Kostense S, Vandenberghe K, Joling J, Van Baarle D, Nanlohy N, Manting E, Miedema F 2002. Persistent numbers of tetramer+ CD8+ T cells, but loss of interferon-+ HIV-specific T cells during progression to AIDS. Blood 99: 2505-2511. [ Links ]
Lainson R, Braga RR, de Souza AAA, Povoa MM, Ishikawa EAY, Silveira FT 1989. Leishmania (Viannia) shawi sp. n., a parasite of monkeys, sloths and procyo-nids in Amazonian Brazil. Ann Parasitol Hum Comp 64: 200-207. [ Links ]
Lainson R, Bray RS 1966. Studies on the immunology and serology of leishmaniasis. II. Cross-immunity experiments among different forms of American cutaneous leishmaniasis in monkeys. Trans R Soc Trop Med Hyg 60: 526-532. [ Links ]
Lainson R, Shaw JJ 1966. Studies on the immunology and serology of leishmaniasis. III. Cross-immunity between Panamenian cutaneous leishmaniasis and Leishmania mexicana infection in man. Trans R Soc Trop Med Hyg 60: 533-535. [ Links ]
Lainson R, Shaw JJ 1977. Leishmaniasis in Brazil: XII. Observations on cross-immunity in monkeys and man infected with Leishmania mexicana mexicana, L. m. amazonensis, L. braziliensis braziliensis, L. b. guyanensis and L. b. panamensis. J Trop Med 80: 29-35. [ Links ]
Lainson R, Shaw JJ, Braga RR, Sacawa EAY, Souza AA, Silveira FT 1988. Isolation of Leishmania from monkeys in the Amazon region of Brazil. Trans R Soc Trop Med Hyg 82: 132. [ Links ]
Lambert P-H, Liu M, Siegrist C-A 2005. Can successful vaccines teach us how to induce efficient protective immune responses? Nature Med 11 (Suppl.): 54-62. [ Links ]
Lawyer PG, Ghiture JI, Anjili CO, Olobo JO, Koech DK, Reid GDF 1990. Experimental transmission of Leishmania major to vervet monkeys (Cercopithecus aethiops) by bites of Phlebotomus duboscqi (Diptera: Psychodidae). Trans R Soc Trop Med Hyg 84: 229-232. [ Links ]
Levinson G, Hughes AL, Letvin NL 1992. Sequence and diversity of rhesus monkey T-cell receptor beta chain genes. Immunogenetics 35: 75-88. [ Links ]
Lima HC, Titus RG 1996. Effects of sand fly vector saliva on development of cutaneous lesions and the immune response to Leishmania braziliensis in BALB/c mice. Infect Immun 64: 5442-5445. [ Links ]
Lujan R, Chapman WL Jr, Hanson WL, Dennis VA 1986a. Leishmania braziliensis: development of primary and satellite lesions in the experimentally infected owl monkey, Aotus trivirgatus. Exp Parasitol 61: 348-358. [ Links ]
Lujan R, Chapman WL Jr, Hanson WL, Dennis VA 1990. Leishmania braziliensis in the squirrel monkeys: development of primary and satellite lesions and lack of cross-immunity with Leishmania donovani. J Parasitol 76: 594-597. [ Links ]
Lujan R, Dennis VA, Chapman WL Jr, Hanson WL 1986b. Blastogenic responses of peripheral blood leukocytes from owl monkeys experimentally infected with Leishmania braziliensis panamensis. Am J Trop Med Hyg 35: 1103-1109. [ Links ]
Lujan R, Hanson WL, Chapman WL Jr, Dennis VA 1987. Antibody responses, as measured by the enzyme-linked immunosorbent assay (ELISA), in owl monkeys experimentally infected with Leishmania braziliensis panamensis. J Parasitol 73: 430-432. [ Links ]
MacGregor RR, Boyer JD, Ugen KE, Lacy KE, Gluckman SJ, Bagarazzi ML, Chattergoon MA, Baine Y, Higgins TJ, Ciccarelli RB, Coney LR, Ginsberg RS, Weiner DB 1998. First human trial of a DNA-based vaccine for treatment of human immunodeficiency virus type 1 infection: safety and host response. J Infect Dis 178: 92-100. [ Links ]
Madindou TJ, Hanson WL, Chapman WL Jr 1985. Chemotherapy of visceral leishmaniasis (Leishmania donovani) in the squirrel monkey (Saimiri sciureus). Ann Trop Med Parasitol 79: 13-19. [ Links ]
Mäkitalo B, Andersson M, Areström I, Karlén K, Villinger F, Ansari A, Paulie S, Throstensson R, Ahlborg N 2002. ELISpot and ELISA analysis of spontaneous, mitogen-induced and antigen-specific cytokine production in cynomolgus and rhesus macaques. J Immunol Methods 270: 85-97. [ Links ]
Marques da Cunha A 1938. Infecções experimentais na leishmaniose visceral americana. Mem Inst Oswaldo Cruz 33: 581-598. [ Links ]
Marques da Cunha A 1944. Infecções experimentais na leishmaniose tegumentar americana. Mem Inst Oswaldo Cruz 41: 263-282. [ Links ]
Marsden PD, Cuba CC, Vexenat A, Costa e Silva M, Costa e Silva A, Barreto AC 1981. Experimental Leishmania chagasi infections in the marmoset Callithrix jacchus jacchus. Trans R Soc Trop Med Hyg 75: 314-315. [ Links ]
Massina S, Gicheru MM, Dempts SO, Fasel NJ 2003. Protection against cutaneous leishmaniasis in outbred vervet monkeys, using a recombinant histone H1 antigen. J Infect Dis 188: 1250-1257. [ Links ]
McClure J, Schmidt AM, Rey-Cuille M-A, Bannink J, Misher L, Tsai C-C, Anderson DM, Morton WR, Hu S-L 2000. Derivation and characterization of a highly pathogenic isolate of human immunodeficiency virus type 2 that causes rapid CD4+ cell depletion in Macaca nemestrina. J Med Primatol 29: 114-126. [ Links ]
Méndez S, Gurunathan S, Kamhawi S, Belkaid Y, Moga MA, Skeiky YA, Campos-Neto A, Reed S, Seder RA, Sacks D 2001. The potency and durability of DNA- and protein-based vaccines against Leishmania major evaluated using low-dose, intradermal challenge. J Immunol 166: 5122-5128. [ Links ]
Misra A, Dube A, Srivastava B, Sharma P, Srivastava JK, Katiyar JC, Naik S 2001. Successful vaccination against Leishmania donovani infection in Indian langur using alum-precipitated autoclaved Leishmania major with BCG. Vaccine 19: 3485-3492. [ Links ]
Moreno J, Nieto J, Masina S, Cañavate C, Cruz I, Chicharro C, Carrillo E, Napp S, Reymond C, Kaye PM, Smith DF, Fasel N, Alvar J 2007. Immunization with H1, HASPB1 and MML Leishmania proteins in a vaccine trial against experimental canine leishmaniasis. Vaccine 25: 5290-5300. [ Links ]
Nathansson N, Hirsch VM, Mathieson BJ 1999. The role of non-human primates in thedevelopment of an AIDS vaccine. AIDS 13 (Suppl. A): 113-120. [ Links ]
Nikolich-ugich J 2007. Non-human primates models of T-cell reconstitution. Semin Immunol 19: 310-317. [ Links ]
Oliveira MR, Tafuri WL, Afonso LCC, Oliveira MAP, Nicoli JR, Vieira EC, Scott P, Melo MN, Vieira LQ 2005. Germ-free mice produce high levels of interferon-gamma in response to infection with Leishmania major but fail to heal lesions. Parasitology 131: 477-488. [ Links ]
Olobo JO, Anjili CO, Gicheru MM, Mbati PA, Kariuki TM, Githure JI, Koech DK, McMaster 1995. Vaccination of vervet monkeys against cutaneous leishmaniasis using recombinant Leishmania "major surface glycoporotein" (gp63). Vet Parasitol 60: 199-212. [ Links ]
Olobo JO, Reid GDF 1993. Delayed-type hypersensitivity responses in vervet monkeys self-cured from experimental cutaneous leishmaniasis. Acta Trop 52: 309-311. [ Links ]
Olobo JO, Reid GDF, Githure JI, Anjili CO 1992. IFN-gamma and delayed-type hypersensitivity are associated with cutaneous leishmaniasis in vervet monkeys following secondary rechallenge with Leishmania major. Scand J Immunol (Suppl.) 11: 48-52. [ Links ]
Pahar B, Li J, Rourke T, Miller CJ, McChesney MB 2003. Detection of antigen-specific T cell interferon- expression by ELISPOT and cytokine flow cytometry assays in rhesus macaques. J Immunol Methods 282: 103-115. [ Links ]
Palatnik-de-Souza CB 2008. Vaccines for leishmaniasis in the fore coming 25 years. Vaccine 26: 1709-1724. [ Links ]
Parrot L, Donatien A, Lestoquard F 1927. Notes expérimentales sur le bouton d'Orient et sur la leishmaniose canine viscérale. Arch Inst Pasteur Alger 5: 120-130. [ Links ]
Pashine A, Valiente NM, Ulmer JB 2005. Targeting the innate immune response with improved vaccine adjuvants. Nature Med 11 (Suppl.): 63-68. [ Links ]
Pitcher CJ, Hagen SI, Walker JM, Lum R, Mitchell BL, MainoVC, Axthelm MK, Picker LJ 2002. Development and homeostasis of T cell memory in rhesus macaque. J Immunol 168: 29-43. [ Links ]
Porrozzi R, Pereira MS, Teva A, Volpini AC, Pinto MA, Marchevsky RS, Barbosa AA Jr, Grimaldi G Jr 2006. Leishmania infantum-induced primary and challenge infections in rhesus monkeys (Macaca mulatta): a primate model for visceral leishmaniasis. Trans R Soc Trop Med Hyg 100: 926-937. [ Links ]
Porrozzi R, Teva A, Amaral VF, Santos da Costa MV, Grimaldi G Jr 2004. Cross-immunity experiments between different species or strains of Leishmania in rhesus macaques (Macaca Mulatta). Am J Trop Med Hyg 71: 297-305. [ Links ]
Probst RJ, Wellde BT, Lawyer PG, Stiteler JS, Rowton ED 2001. Rhesus monkey model for Leishmania major transmitted by Phlebotomus papatasi sandfly bites. Med Vet Entomol 15: 12-21. [ Links ]
Pung OJ, Hulsebos LH, Kuhn RE 1988. Experimental American leishmaniasis and Chagas' disease in the Brazilian squirrel monkey: cross immunity and electrocardiographic studies of monkeys infected with Leishmania braziliensis and Trypanosoma cruzi. Internat J Parasitol 18: 1053-1059. [ Links ]
Pung OJ, Kuhn RE 1987. Experimental leishmaniasis in the Brazilian squirrel monkey (Saimiri sciureus): lesions, hematology, cellular and humoral immune responses. J Med Primatol 16: 165-174. [ Links ]
Ramiro MJ, Zárate JJ, Hanke T, Rodriguez D, Rodriguez JR, Esteban M, Lucientes J, Castillo JA, Larraga V 2003. Protection in dogs against visceral leishmaniasis caused by Leishmania infantum is achieved by immunization with a heterologous prime-boost regime using DNA and vaccinia recombinant vectors expressing LACK. Vaccine 21: 2474-2484. [ Links ]
Ramos I, Alonso A, Marcen JM, Peris A, Castillo JA, Colmenares M, Larraga V 2008. Heterologous prime-boost vaccination with a non-replicative vaccinia recombinant vector expressing LACK confers protection against canine visceral leishmaniasis with a predominant Th1-specific immune response. Vaccine 26: 333-344. [ Links ]
Ranque J, Depieds R, Nicole RM 1960. Les phénomènes d'immunité dans les leishmanioses. Path Biol 8: 99-107. [ Links ]
Reed SG, Scott P 2000. Immunologic mechanisms in Leishmania. MW Cunningham, RS Fujinami (eds.), Effects of microbes on the immune system. Lippincott Williams & Wilkins, Philadelphia, p. 537-554. [ Links ]
Rhee EG, Mendez S, Shah JA, Wu C, Kirman JR, Turon TN, Davey DF, Davis H, Klinman DM, Coler RN, Sacks DL, Seder RA 2002. Vaccination with heat-killed Leishmania antigen or recombinant leishmanial protein and CpG oligodeoxynucleotides induces long-term memory CD4+ and CD8+ T cell responses and protection against Leishmania major infection. J Exp Med 195: 1565-1573. [ Links ]
Robinson HL, Amara RR 2005. T cell vaccines for microbial infections. Nature Med 11 (Suppl.): 25-32. [ Links ]
Rodríguez-Cortés A, Ojeda A, López-Fuertes L, Timón M, Altet L, Solano-Gallego L, Sánchez-Robert E, Francino O, Alberola J 2007. Vaccination with plasmid DNA encoding KMPII, TRYP, LACK and GP63 does not protect dogs against Leishmania infantum experimental challenge. Vaccine 25: 7962-7971. [ Links ]
Saravia NG, Weigle K, Segura I, Giannini SH, Pacheco R, Labrada LA, Gonçalves A 1990. Recurrent lesions in humans Leishmania braziliensis infection - reactivation or reinfection? Lancet 336: 398-402. [ Links ]
Schneider J, Gilbert SC, Hannan CM, Degano P, Prieur E, Sheu EG, Plebanski M, Hill AVS 1999. Induction of CD8+ T cells using heterologous prime-boost immunisation strategies. Vaccines and vaccination - Part I. Immunol Rev 170: 29-38. [ Links ]
Sharma SK, Dube A, Nadeem A, Khan S, Saleem I, Garg R, Mohammad O 2006. Non PC liposome entrapped promastigote antigens elicit parasite specific CD8+ and CD4+ T-cell immune response and protect hamsters against visceral leishmaniasis. Vaccine 24: 1800-1810. [ Links ]
Shearer MH, Dark RD, Chodosh J, Kennedy RC 1999. Comparison and caracterization of immunoglobulin G subclasses among primate species. Clin Diagn Lab Immunol 6: 953-958. [ Links ]
Silveira FT, Lainson R, Shaw JJ, Garcez LM, Souza AA, Braga RR, Ishikawa EA 1989. Experimental cutaneous leishmaniasis: I - On the susceptibility of the primate Cebus apella (Cebidae) to the infection caused by Leishmania (Viannia) lainsoni Silveira, Shaw and Ishikawa, 1987. Rev Soc Bras Med Trop 22: 125-130. [ Links ]
Silveira FT, Lainson R, Shaw JJ, Garcez LM, Souza AA, Braga RR, Ishikawa EA 1990. Experimental skin leishmaniasis: I. Course of the infection in the Cebus apella primate (Cebidae) caused by Leishmania (V.) braziliensis and L. (L.) amazonensis. Rev Soc Bras Med Trop 23: 5-12. [ Links ]
Silvestre R, Cordeiro-da-Silva A, Quaissi A 2008. Live attenuated Leishmania vaccines: a potential strategic alternative. Arch Immunol Ther Exp 56: 123-126. [ Links ]
Skeiky YAW, Coler RN, Brannon M, Stromberg E, Greeson K, Crane RT, Campos-Neto A, Reed SG 2002. Protective efficacy of a tandemly linked, multi-subunit recombinant leishmanial vaccine (Leish-111f) formulated in MPL® adjuvant. Vaccine 20: 3292-3303. [ Links ]
Souza-Lemos C, de-Campos SN, Teva A, Côrte-Real S, Fonseca EC, Porrozzi R, Grimaldi G Jr 2008. Dynamics of immune granuloma formation in a Leishmania braziliensis-induced self-limiting cutaneous infection in the primate Macaca mulatta. J Pathol 216: 375-386. [ Links ]
Stäger S, Smith DF, Kaye PM 2000. Immunization with a recombinant stage-regulated surface protein from Leishmania donovani induces protection against visceral leishmaniasis. J Immunol 165: 7064-7071. [ Links ]
Stober CB, Lange UG, Roberts MT, Alcami A, Blackwell JM 2005. IL-10 from regulatory T cells determines vaccine efficacy in murine Leishmania major infection. J Immunol 175: 2517-2524. [ Links ]
Tabbara KS 2006. Progress towards a Leishmania vaccine. Saudi Med J 27: 942-950. [ Links ]
Tapia E, Pérez-Jiménez E, López-Fuertes L, Gonzalo R, Gherardi MM, Esteban M 2003. The combination of DNA vectors expressing IL-12 + IL-18 elicits high protective immune response against cutaneous leishmaniasis after priming with DNA-p36/LACK and the cytokines, followed by a booster with a vaccinia virus recombinant expressing p36/LACK. Microbes Infect 5: 73-84. [ Links ]
Teva A, Porrozzi R, Cupolillo E, Oliveira-Neto MP, Grimaldi G Jr 2005. Responses of Leishmania (Viannia) braziliensis cutaneous infection to N-methylglucamine antimoniate in the rhesus monkey (Macaca mulatta) model. J Parasitol 91: 976-978. [ Links ]
Teva A, Porrozzi R, Cupolillo E, Pirmes C, Oliveira-Neto MP, Grimaldi G Jr 2003. Leishmania (Viannia) braziliensis-induced chronic granulomatous cutaneous lesions affecting the nasal mucosa in the rhesus monkey (Macaca mulatta) model. Parasitology 127: 437-447. [ Links ]
Titus RG, Bishop JV, Mejia JS 2006. The immunomodulatory factors of arthropod saliva and the potential for these factors to serve as vaccine targets to prevent pathogen transmission. Parasite Immunol 28: 131-141. [ Links ]
Valenzuela JG, Belkaid Y, Garfield MK, Mendez S, Kamhawi S, Rowton ED, Sacks DL, Ribeiro JMC 2001. Toward a defined anti-Leishmania vaccine targeting vector antigens: characterization of a protective salivary protein. J Exp Med 194: 331-342. [ Links ]
Vanloubbeeck Y, Jones DE 2004. The immunology of Leishmania infection and the implications for vaccine development. Ann N Y Acad Sci 1026: 267-272. [ Links ]
Verthelyi D, Kenney RT, Seder RA, GamAA, FriedagB, Klinman DM 2002. CpG Oligodeoxynucleotides as vaccine adjuvants in primates. J Immunol 168: 1659-1663. [ Links ]
Von Stebut E 2007. Immunology of cutaneous leishmaniasis: the role of mast cells, phagocytes and dendritic cells for protective immunity. Eur J Dermatol 17: 115-122. [ Links ]
Vouldoukis I, Ogunkolade W, Strazielle L, Ploton I, Monjour L 1986. Susceptibility of Cebus nigrivittatus to Leishmania infantum. J Parasitol 72: 472-473. [ Links ]
Watkins DI, Kannagi M, Stone ME, Letvin NL 1988. Major histocompatibility complex class I molecules of nonhuman primates. Eur J Immunol 18: 1425-1432. [ Links ]
Webb JR, Campos-Neto, Ovendale PJ, Martin TI, Stromberg EJ, Badaro R, Reed SG 1998. Human and murine immune responses to a novel Leishmania major recombinant protein encoded by members of a multicopy gene family. Infec Immun 66: 3279-3289. [ Links ]
Webb JR, Kaufmann D, Campos-Neto, Reed SG 1996. Molecular cloning of a novel protein antigen of Leishmania major that elicits a potent immune response in experimental murine leishmaniasis. J Immunol 157: 5034-5041. [ Links ]
Wolf RE 1976. Immune response to Leishmania tropica in Macaca mulatta. J Parasitol 62: 209-214. [ Links ]
Zadeh-Vakili A, Taheri T, Taslimi Y, Doustdari F, Salmanian AH, Rafati S 2004. Immunization with the hybrid protein vaccine, consisting of Leishmania major cysteine proteinases Type I (CPB) and Type II (CPA), partially protects against leishmaniasis. Vaccine 22: 1930-1940. [ Links ]
Zanin FH, Coelho EA, Tavares CA, Marques-da-Silva EA, Silva Costa MM, Rezende SA, Gazzinelli RT, Fernandes AP 2007. Evaluation of immune responses and protection induced by A2 and nucleoside hydrolase (NH) DNA vaccines against Leishmania chagasi and Leishmania amazonensis experimental infections. Microbes Infect 9: 1070-1077. [ Links ]
Zaph C, Uzonna J, Beverley SM, Scott P 2004. Central memory T cells mediate long-term immunity to Leishmania major in the absence of persistent parasites. Nature Med 10: 1104 -1110. [ Links ]
Received 15 October 2008
Accepted 22 October 2008
Financial support: Millennium Institute for Vaccine Development and Technology (MCT/CNPq-420067/2005-1).
Corresponding author: firstname.lastname@example.org