Research Article Dynamic of the Cellular Immune Response at the Dermal Site of Leishmania (L.) amazonensis and Leishmania (V.) braziliensis Infection in Sapajus apella Primate Márcia Dalastra Laurenti, 1 Luiz Felipe Domingues Passero, 1 Thaise Yumie Tomokane, 1 Fernanda de Camargo Francesquini, 1 Mussya Cisotto Rocha, 1 Claudia Maria de Castro Gomes, 1 Carlos Eduardo Pereira Corbett, 1 and Fernando Tobias Silveira 2,3 1 Infectious Diseases Laboratory (LIM-50), Pathology Department, Medical School of S˜ ao Paulo University, Avenida Dr. Arnaldo, 455-1 ∘ Andar, Sala 1209, 01246-903 S˜ ao Paulo, SP, Brazil 2 Leishmaniasis Laboratory, Evandro Chagas Institute, Ministry of Health, Rodovia BR 316 s/n, 67030-000 Ananindeua, PA, Brazil 3 Tropical Medicine Nucleus, Par´ a Federal University, Avenida General´ ıssimo Deodoro 92, 66055-240 Bel´ em, PA, Brazil Correspondence should be addressed to M´ arcia Dalastra Laurenti; mdlauren@usp.br Received 10 February 2014; Revised 21 June 2014; Accepted 13 August 2014; Published 28 August 2014 Academic Editor: Amogh A. Sahasrabuddhe Copyright © 2014 M´ arcia Dalastra Laurenti et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. he purpose of this study was to characterize the immunopathological response in the skin of S. apella infected with Leishmania (L.) amazonensis and L. (V.) braziliensis parasites, the main causative agents of localized cutaneous leishmaniasis in South America. In infected animals, amastigote forms of L. (L.) amazonensis could be detected till 120 days postinfection (PI), while, in L. (V.) braziliensis infection, parasites could be detected until 180 days PI in the skin sections. CD20 + cells were detected throughout the experimental time in both groups as well as in CD3 + cells, which appeared to be activated because high densities of inducible nitric oxide synthase (iNOS + ) cells were detected at 60 and 90 days PI in both studied groups. Ater 60 and 120 days PI, decrease in iNOS + cells was observed in L. (L.) amazonensis and L. (V.) braziliensis, respectively, which was associated with parasite clearance. Increase in lysozyme + cells was observed during the experimental infections, which also can be associated with parasite killing. 1. Introduction Leishmaniasis is an infectious disease caused by diferent species of protozoa parasites, which is transmitted by sand ly bites. hese protozoa are able to cause cutaneous and visceral form of the disease. Several reports have examined the pathogenesis of leishmaniasis in murine models aiming to characterize the mechanisms by which Leishmania para- sites induce disease [1–5]. However, other reports state that some aspects of leishmaniasis immunopathogenesis cannot be completely represented using murine models since they are not the natural hosts for the parasites. hus, a more reliable experimental model that mimics human infection is required. Nonhuman primates may represent an interest- ing tool for analyzing the aspects of human leishmaniasis immunopathology since they share 85–92% of their DNA with humans, indicating their close phylogenetic relationship with humans [6]. he Sapajus apella primate, previously known as Cebus apella, has been successfully used in experimental studies to analyze the dynamics of clinical and histological lesions during L. (L.) amazonensis, L. (V.) braziliensis, and L. (V.) lainsoni infections [7–9]. In these reports, all species of parasites were able to infect the primates. In addition, animals infected with L. (L.) amazonensis presented an apparent lesion 20 days postinfection (PI) with a nodular aspect Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 134236, 8 pages http://dx.doi.org/10.1155/2014/134236