In silico predicted epitopes from the COOH-terminal extension of cysteine proteinase B inducing distinct immune responses during Leishmania (Leishmania) amazonensis experimental murine infection

Predicted epitopes, obtained by in silico mapping, displayed the ability to induce cell proliferation and expression of cytokines related to Th1 and Th2 responses. Furthermore, we applied in silico simulations to investigate how the MHC/epitopes interactions could be related to the immunomodulatory effects on cytokines, finding evidence that specific interaction patterns can be related to in vitro activities.Based on our results, we consider that some peptides from the CPB COOH-terminal extension may influence host immune responses in the murine infection, thus helping Leishmania survival.Leishmaniasis, a vector-borne parasitic infection, is caused by protozoans of the genus Leishmania, which present a worldwide distribution. This disease is characterized by its diversity and complexity, presenting a wide spectrum of clinical forms in humans, ranging from self-healing skin lesions to fatal visceral leishmaniasis, depending on parasite species and host factors [1,2].In Brazil, both clinical forms are present and, currently, leishmaniasis can be classified as a disease in expansion and without effective control [3]. One important etiological agent of human leishmaniasis in Brazil is Leishmania (Leishmania) amazonensis, which causes a wide spectrum of clinical diseases [4]. Interestingly, recent findings indicate that the geographical distribution of L. (L.) amazonensis is increasing, accounting for unusual clinical presentations in new transmission areas, specifically Rio de Janeiro State [5].Amastigote forms of Leishmania are intracellular parasites, inhabiting preferentially cells of the mononuclear phagocyte system, and present a series of adaptive peculiarities in this phase of the biological cycle. These adaptations allow the parasites to escape or interfere with the host immune responses and, consequently, maintain the infection. The host immunological profiles during Leishmania infections are widely studied using the murine model, as distinct leishmaniasis clin