Trypanossoma cruzi: course of infection in platelets-depleted mice

Fernandes, Margareth; Irulegui, Ione; Deane, Maria P.; Ruiz, Rita de Cassia

doi:10.1590/S0036-46651992000100002

Abstracts

The effect of platelet depletion on the course of Trypanosoma cruzi infection in BALB/c mice was investigated. Thrombocytopenia was achieved by inoculation of rabbit anti-platelet IgG during the parasitemic phase of the infection. The number of parasites in the blood of anti-platelet IgG treated was significantly higher than that of non-treated control mice, during the phase of high parasitemia. Cumulative mortality of platelet-depleted mice was consistently but not significantly higher than that of control mice up to the 32nd day of infection; from the 33rd day on they were equivalent, no mortalities occurring from then on, until observations were discontinued on the 60th day. These results suggest that platelets participate of the mechanisms of parasites removal from the bloodstream, but do not have an effective role in the mechanisms of defence against T. cruzi, during the acute phase of infection.

Trypanosoma cruzi; platelets depletion

O efeito do esgotamento de plaquetas sobre o curso da infecção pelo Trypanosoma cruzi em camundongos BALB/c foi estudado. A trombocitopenia foi provocada por inoculação de IgG de coelho anti-plaquetas durante a fase parasitêmica da infecção. O número de parasitas no sangue dos camundongos tratados com IgG anti-plaquetas foi significantemente maior que aquele dos controles não tratados, no período de maior parasitemia. A mortalidade cumulativa dos camundongos esgotados de plaquetas foi consistente mas não significativamente maior que a dos controles até o 32º dia de infecção; do 33º dia em diante elas foram equivalentes, nenhuma morte ocorrendo a partir de então, até o 60º dia, quando as observações foram interrompidas. Estes resultados sugerem que as plaquetas participam dos mecanismos de remoção dos parasitas da circulação, mas que não desempenham um papel efetivo nos mecanismos de defesa contra o T. cruzi na fase aguda da infecção.

ORIGINAL ARTICLES

Trypanossoma cruzi: course of infection in platelets-depleted mice

Trypanosoma cruzi: curso da infecção em camundongos depletados de plaquetas

Margareth Fernandes^I; Ione Irulegui^I; Maria P. Deane^II; Rita de Cassia Ruiz^I

^IInstituto de Medicina Tropical de São Paulo - Laboratório de Investigação Médica 06 - Brasil

^IIInstituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro - Brasil

^{Address for correspondence} Address for correspondence: Margareth Fernandes Instituto de Medicina Tropical de São Paulo Av. Dr. Enéas de Carvalho Aguiar 470 CEP. 05403. São Paulo, SP, Brasil

SUMMARY

The effect of platelet depletion on the course of Trypanosoma cruzi infection in BALB/c mice was investigated. Thrombocytopenia was achieved by inoculation of rabbit anti-platelet IgG during the parasitemic phase of the infection. The number of parasites in the blood of anti-platelet IgG treated was significantly higher than that of non-treated control mice, during the phase of high parasitemia.

Cumulative mortality of platelet-depleted mice was consistently but not significantly higher than that of control mice up to the 32^nd day of infection; from the 33^rd day on they were equivalent, no mortalities occurring from then on, until observations were discontinued on the 60^th day. These results suggest that platelets participate of the mechanisms of parasites removal from the bloodstream, but do not have an effective role in the mechanisms of defence against T. cruzi, during the acute phase of infection.

Key words: Trypanosoma cruzi, infection; platelets depletion.

RESUMO

O efeito do esgotamento de plaquetas sobre o curso da infecção pelo Trypanosoma cruzi em camundongos BALB/c foi estudado. A trombocitopenia foi provocada por inoculação de IgG de coelho anti-plaquetas durante a fase parasitêmica da infecção. O número de parasitas no sangue dos camundongos tratados com IgG anti-plaquetas foi significantemente maior que aquele dos controles não tratados, no período de maior parasitemia.

A mortalidade cumulativa dos camundongos esgotados de plaquetas foi consistente mas não significativamente maior que a dos controles até o 32º dia de infecção; do 33º dia em diante elas foram equivalentes, nenhuma morte ocorrendo a partir de então, até o 60º dia, quando as observações foram interrompidas. Estes resultados sugerem que as plaquetas participam dos mecanismos de remoção dos parasitas da circulação, mas que não desempenham um papel efetivo nos mecanismos de defesa contra o T. cruzi na fase aguda da infecção.

Full text available only in PDF format.

Texto completo disponível apenas em PDF.

ACKNOWLEDGEMENT

The authors thank Dr. Euthymia Brandão Almeida Prado for the CH50 determination as well as for the useful suggestions and Drs. Junko Takano Osaka and Luci Ebisui, of the Central Animal House of Faculdade de Medicina da Universidade de São Paulo, for the animals supplied.

Recebido para publicação em 14/8/1991

Aceito para publicação em 5/12/1991

This project was sponsored by "Fundação de Amparo à Pesquisa do Estado de São Paulo" - FAPESP

1. ALBRIGHT, J.W. & ALBRIGHT, J.F. - Basis of the specificity of rodent trypanosomes for their natural hosts. Infect. Immun., 33: 355-363, 1981.
2. ALCANTARA, A. & BRENER, Z. - The in vitro interaction of Trypanosoma cruzi bloodstream forms and mouse peritoneal macrophages. Acta trop. (Basel), 35: 209-219,1978.
3. BRENER, Z. - Therapeutic activity and criterion of cure on mice experimentally infected with Trypanosoma cruzi. Rev. Inst. Med. trop. S. Paulo, 4: 389 396, 1962.
4. CARDOSO, J.E. & BRENER, Z. - Hematological changes in mice experimentally infected with Trypanosoma cruzi. Mem. Inst. Oswaldo Cruz, 75: 97-104, 1980.
5. DAVIS, C.E. - Thrombocytopenia: a uniform complication of African trypanosomiasis. Acta trop. (Basel), 39: 123-133, 1982.
6. DUFFEY, L.M.; ALBRIGHT, J.W. & ALBRIGHT, J.F. - Trypanosoma musculi: Population dynamics of erythrocytes and leukocytes during the course of murine infections. Exp. Parasit., 59: 375-389,1985.
7. EMERIBE, A.O. & ANOSA, V.O. - Haematology of experimental Gambiense trypanosomiasis, I. Platelet and other haemostatic changes. Centr. Afr. J. Med., 34: 286-290, 1988.
8. JAMRA, M.; AMATO NETO, V.; FREITAS, J.L. de; SILVA, L.H.P. da & TARTARI, J.T.A. - Aspectos hematológicos da doença de Chagas nas fases iniciais. Rev. paul. Med., 45: 52-60, 1954.
9. TANOWITZ, H.P.; BURNS, E.R.; SINHA, A.K.; KAHN, N.N.; MORRIS, S.A.; FACTOR, S.M.; HATCHER, V.B.; BIELEZIKIAN, J.P.; BAUM, S.G. & WITTNER, M. - Enhanced platelets adherence and aggregation in Chagas' disease: a potential pathogenic mechanism for cardiomyopathy. Amer. J. trop. Med. Hyg., 43: 274-281, 1990.
10. UMEKITA, L.F. & MOTA, I. - In vitro lysis of sensitized Trypanosoma cruzi by platelets: role of C3b receptors. Paras. Immunol., 11: 561-566,1989.
11. UMEKITA L. & MOTA, I. - Role of platelets in the in vivo removal of T. cruzi from circulation. Braz. J. med. biol. Res., 23: 593-596, 1990.
12. VIENS, P.; DUBOIS, R. & KONGSHAVN, P.A.L. - Platelet activity in immune lysis of Trypanosoma musculi. Int. J. Parasit., 13: 527-530, 1983.

Address for correspondence:

Margareth Fernandes

Instituto de Medicina Tropical de São Paulo

Av. Dr. Enéas de Carvalho Aguiar 470

CEP. 05403. São Paulo, SP, Brasil

Publication Dates

Publication in this collection
06 Sept 2006
Date of issue
Feb 1992

History

Received
14 Aug 1991
Accepted
05 Dec 1991

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] 1. ALBRIGHT, J.W. & ALBRIGHT, J.F. - Basis of the specificity of rodent trypanosomes for their natural hosts. Infect. Immun., 33: 355-363, 1981.

[2] 2. ALCANTARA, A. & BRENER, Z. - The in vitro interaction of Trypanosoma cruzi bloodstream forms and mouse peritoneal macrophages. Acta trop. (Basel), 35: 209-219,1978.

[3] 3. BRENER, Z. - Therapeutic activity and criterion of cure on mice experimentally infected with Trypanosoma cruzi. Rev. Inst. Med. trop. S. Paulo, 4: 389 396, 1962.

[4] 4. CARDOSO, J.E. & BRENER, Z. - Hematological changes in mice experimentally infected with Trypanosoma cruzi. Mem. Inst. Oswaldo Cruz, 75: 97-104, 1980.

[5] 5. DAVIS, C.E. - Thrombocytopenia: a uniform complication of African trypanosomiasis. Acta trop. (Basel), 39: 123-133, 1982.

[6] 6. DUFFEY, L.M.; ALBRIGHT, J.W. & ALBRIGHT, J.F. - Trypanosoma musculi: Population dynamics of erythrocytes and leukocytes during the course of murine infections. Exp. Parasit., 59: 375-389,1985.

[7] 7. EMERIBE, A.O. & ANOSA, V.O. - Haematology of experimental Gambiense trypanosomiasis, I. Platelet and other haemostatic changes. Centr. Afr. J. Med., 34: 286-290, 1988.

[8] 8. JAMRA, M.; AMATO NETO, V.; FREITAS, J.L. de; SILVA, L.H.P. da & TARTARI, J.T.A. - Aspectos hematológicos da doença de Chagas nas fases iniciais. Rev. paul. Med., 45: 52-60, 1954.

[9] 9. TANOWITZ, H.P.; BURNS, E.R.; SINHA, A.K.; KAHN, N.N.; MORRIS, S.A.; FACTOR, S.M.; HATCHER, V.B.; BIELEZIKIAN, J.P.; BAUM, S.G. & WITTNER, M. - Enhanced platelets adherence and aggregation in Chagas' disease: a potential pathogenic mechanism for cardiomyopathy. Amer. J. trop. Med. Hyg., 43: 274-281, 1990.

[10] 10. UMEKITA, L.F. & MOTA, I. - In vitro lysis of sensitized Trypanosoma cruzi by platelets: role of C3b receptors. Paras. Immunol., 11: 561-566,1989.

[11] 11. UMEKITA L. & MOTA, I. - Role of platelets in the in vivo removal of T. cruzi from circulation. Braz. J. med. biol. Res., 23: 593-596, 1990.

[12] 12. VIENS, P.; DUBOIS, R. & KONGSHAVN, P.A.L. - Platelet activity in immune lysis of Trypanosoma musculi. Int. J. Parasit., 13: 527-530, 1983.

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