Understanding Resistance vs. Susceptibility in Visceral Leishmaniasis Using Mouse Models of Leishmania infantum Infection

Frontiers in Cellular and Infection Microbiology

Anabela Cordeiro-da-Silva²  Pedro Cecílio²  Fátima Gärtner⁵  Rita Vasconcellos⁶  Tiago Bordeira Gaspar⁷  Begoña Pérez-Cabezas⁹ 

[1] Cancer Signalling and Metabolism Group, Institute of Molecular Pathology and Immunology of University of Porto, Porto, Portugal;Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal;Department of Molecular Pathology and Immunology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal;Faculdade de Medicina, Universidade do Porto, Porto, Portugal;Glycobiology in Cancer Group, Institute of Molecular Pathology and Immunology of University of Porto, Universidade do Porto, Porto, Portugal;Immunobiology Department, Biology Institute, Universidade Federal Fluminense, Rio de Janeiro, Brazil;Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal;Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal;Parasite Disease Group, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal;

关键词: Leishmania;    visceral leishmaniasis;    mouse models;    susceptibility vs. resistance;    immune regulation;   

DOI  :  10.3389/fcimb.2019.00030

来源: DOAJ

【 摘 要 】

Every year, up to 90,000 new cases of Visceral Leishmaniasis and 30,000 resultant deaths are estimated to occur worldwide. Such numbers give relevance to the continuous study of this complex form of the disease: a zoonosis and an anthroponosis; two known etiological agents (Leishmania infantum and L. donovani, respectively); with an estimated average ratio of 1 symptomatic per 10 asymptomatic individuals; and sometimes associated with atypical clinical presentations. This complexity, which results from a long co-evolutionary process involving vector-host, host-pathogen, and pathogen-vector interactions, is still not completely understood. The determinants of visceralization are not fully defined and the dichotomy resistance vs. susceptibility remains unsolved, translating into obstacles that delay the progress of global disease control. Inbred mouse models, with different susceptibility patterns to Leishmania infection, have been very useful in exploring this dichotomy. BALB/c and C57BL/6 mice were described as susceptible strains to L. donovani visceral infection, while SV/129 was considered resistant. Here, we used these three mouse models, but in the context of L. infantum infection, the other Leishmania species that cause visceral disease in humans, and dynamically compared their local and systemic infection-induced immune responses in order to establish a parallel and to ultimately better understand susceptibility vs. resistance in visceral leishmaniasis. Overall, our results suggest that C57BL/6 mice develop an intermediate “infection-phenotype” in comparison to BALB/c and SV/129 mouse strains, considering both the splenic parasite burden and the determined target organs weights. However, the immune mechanisms associated with the control of infection seem to be different in each mouse strain. We observed that both BALB/c and SV/129, but not C57BL/6 mice, show an infection-induced increase of splenic T follicular helper cells. On the other hand, differences detected in terms of CD21 expression by B cells early after infection, together with the quantified anti-Leishmania specific antibodies, suggest that SV/129 are faster than BALB/c and C57BL/6 mice in the assembly of an efficient B-cell response. Additionally, we observed an infection-induced increase in polyfunctional CD4+ T cells in the resistant SV/129 model, opposing an infection-induced increase in CD4+IL-10+ cells in susceptible BALB/c mice. Our data aligns with the observations reported for L. donovani infection and suggest that not only a single mechanism, but an interaction of several could be necessary for the control of this parasitic disease.

【 授权许可】

Unknown