ABSTRACT In Aggregatibacter actinomycetemcomitans, different serotypes have been described based on LPS antigenicity. Recently, our research group has reported a differential immunogenicity when T lymphocytes were stimulated with these different serotypes. In particular, it was demonstrated that the serotype b of A. actinomycetemcomitans has a stronger capacity to trigger Th1- and Th17-type cytokine production. Objective This study aimed to quantify the expression of different CC chemokines (CCLs) and receptors (CCRs) in T lymphocytes stimulated with the different A. actinomycetemcomitans serotypes. In addition, the expression of the transcription factors T-bet, GATA-3, RORC2, and Foxp3, master-switch genes implied in the Th1, Th2, Th17, and T-regulatory differentiation, respectively, was analyzed in order to determine T-cell phenotype-specific patterns of CCL and CCR expression upon A. actinomycetemcomitans stimulation. Material and Methods Human naïve CD4+ T lymphocytes were obtained from healthy subjects and stimulated with autologous dendritic cells primed with the different A. actinomycetemcomitans serotypes. The expression levels for the chemokines CCL1, CCL2, CCL3, CCL5, CCL11, CCL17, CCL20, CCL21, CCL25, and CCL28, as well as the chemokine receptors CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CCR9, and CCR10 were quantified by qPCR. Similarly, the expression levels for the transcription factors T-bet, GATA-3, RORC2, and Foxp3 were quantified and correlated with the CCL and CCR expression levels. Results Higher expression levels of CCL2, CCL3, CCL5, CCL20, CCL21, CCL28, CCR1, CCR2, CCR5, CCR6, CCR7, and CCR9 were detected in T lymphocytes stimulated with the serotype b of A. actinomycetemcomitans compared with the other serotypes. In addition, these higher expression levels of CCLs and CCRs positively correlated with the increased levels of T-bet and RORC2 when T lymphocytes were stimulated with the serotype b. Conclusion A T-lymphocyte response biased towards a Th1- and Th17-pattern of CCL and CCR expression was detected under stimulation with the serotype b of A. actinomycetemcomitans.

In Aggregatibacter actinomycetemcomitans, different serotypes have been described based on LPS antigenicity. Recently, our research group has reported a differential immunogenicity when T lymphocytes were stimulated with these different serotypes. In particular, it was demonstrated that the serotype b of A. actinomycetemcomitans has a stronger capacity to trigger Th1- and Th17-type cytokine production. Objective This study aimed to quantify the expression of different CC chemokines (CCLs) and receptors (CCRs) in T lymphocytes stimulated with the different A. actinomycetemcomitans serotypes. In addition, the expression of the transcription factors T-bet, GATA-3, RORC2, and Foxp3, master-switch genes implied in the Th1, Th2, Th17, and T-regulatory differentiation, respectively, was analysed in order to determine T-cell phenotype-specific patterns of CCL and CCR expression upon A. actinomycetemcomitans stimulation. Material and Methods Human naïve CD4+ T lymphocytes were obtained from healthy subjects and stimulated with autologous dendritic cells primed with the different A. actinomycetemcomitans serotypes. The expression levels for the chemokines CCL1, CCL2, CCL3, CCL5, CCL11, CCL17, CCL20, CCL21, CCL25, and CCL28, as well as the chemokine receptors CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CCR9, and CCR10 were quantified by qPCR. Similarly, the expression levels for the transcription factors T-bet, GATA-3, RORC2, and Foxp3 were quantified and correlated with the CCL and CCR expression levels. Results Higher expression levels of CCL2, CCL3, CCL5, CCL20, CCL21, CCL28, CCR1, CCR2, CCR5, CCR6, CCR7, and CCR9 were detected in T lymphocytes stimulated with the serotype b of A. actinomycetemcomitans compared with the other serotypes. In addition, these higher expression levels of CCLs and CCRs positively correlated with the increased levels of T-bet and RORC2 when T lymphocytes were stimulated with the serotype b. Conclusion A T-lymphocyte response biased towards a Th1- and Th17-pattern of CCL and CCR expression was detected under stimulation with the serotype b of A. actinomycetemcomitans.

Parasitic cowbirds lay their eggs in the nest of other species, the host, depending on the host's parental care for their successful reproduction. It has been suggested that cowbirds modified some life-history traits as adaptations to brood parasitism. Specifically, they would have developed small-sized eggs with thicker eggshells, would have shortened their incubation periods, and would have accelerated nestling growth. A previous analysis with independent phylogenetic contrasts found that observed values of those life-history traits in parasitic cowbirds only differ from the predicted ones by their non-parasitic relatives in their thicker eggshell. In this work, we reanalyzed these traits as potential adaptations to brood parasitism in cowbirds by reconstructing ancestral values under two models of character evolution. By comparing the ancestors reconstructed from the parasitic cowbirds with those reconstructed from their non-parasitic relatives, we only found differences in eggshell thickness. This demonstrates that both techniques (ancestor reconstruction and independent phylogenetic contrasts) are consistent, and that the increase in eggshell thickness as a potential adaptation to brood parasitism is a robust result.

Los tordos parásitos de cría ponen sus huevos en los nidos de otras especies (hospederos), dependiendo de ellos para su reproducción. Se ha propuesto que los tordos habrían modificado ciertas características de historia de vida como adaptaciones para desarrollar este comportamiento. Específicamente, poseerían menor peso del huevo, menor período de incubación, mayor grosor de la cáscara del huevo, mayor tasa de crecimiento de los pichones y menor peso de los pichones cuando abandonan el nido. Un análisis reciente utilizando contrastes independientes filogenéticos encontró que los valores observados de estas características en los tordos solo difieren de los valores predichos para las especies no parásitas en el grosor de la cáscara del huevo. En este trabajo reanalizamos si estas características son potenciales adaptaciones al parasitismo de cría en los tordos a partir de la reconstrucción de ancestros bajo dos modelos de evolución de caracteres. Al comparar los valores ancestrales reconstruidos a partir de los tordos con los obtenidos a partir de las especies no parásitas, solo encontramos diferencias en el grosor de la cáscara del huevo. Esto demuestra que ambas técnicas (la reconstrucción de ancestros y los contrastes independientes filogenéticos) son consistentes, por lo cual el hecho de que solo el mayor grosor de la cáscara del huevo puede ser una adaptación potencial es un resultado muy robusto.