EVALUATION OF CHANGES IN CELL MICROENVIRONMENT IN MICE SPENIC MICROENVIRONMENTS
DURING THE PROGRESSION OF VISCERAL LEISHMANIASIS
Visceral Leishmaniasis; Immunohistochemistry; Splenocytes; Mice.
ABSTRACT INTRODUCTION: Visceral leishmaniasis (VL) is a parasitic disease caused by a protozoan of the genus Leishmania. Among affected organs, the spleen is highlighted for being involved in all cases of the disease, contributing to immunopathogenesis. Disorganization of the splenic white pulp (WP) compartment is reported, with changes in the organ's cellularity in severe forms of VL. OBJECTIVE: Determine frequency and distribution of mice splenic cells in the different compartments of the spleen during experimental VL. MATERIAL AND METHODS: Were used 40 spleens from infected mice or control group. Animals were euthanized 30, 60 and 90 days after injection. An immunohistochemical study was performed in the spleen to detect T lymphocytes (TL), B lymphocytes (BL), plasma cells and Leishmania. Counting was performed in different splenic compartments. RESULTS: Mice undergo maintenance of the splenic organization, slight histological changes, and absence of clinical signs, except for splenomegaly. Disease’s progression is associated with decrease of LT, BL and plasma cells in PV. While infected macrophages progressively increase in all compartments of the spleen. Despite of presence of macrophage infected in WP, the proportion of TL and BL at site was maintained for almost the entire course of the infection. CONCLUSIONS: Splenic disorganization is not observed in course of murine VL. Disease progression in mice is associated with subclinical profile, with persistence of the parasite and significant decrease in splenic leukocytes.