Differential Recruitment of Dendritic Cells Subsets to Lymph Nodes Correlates with a Protective or Permissive T-Cell Response duringLeishmania(Viannia)BraziliensisorLeishmania(Leishmania)AmazonensisInfection

Abstract

Leishmania (L.) amazonensis(La) andL. (V.) braziliensis(Lb) are responsible for a large clinical and immunopathological spectrum in human disease; whileLamay be responsible for anergic disease,Lbinfection leads to cellular hypersensitivity. To better understand the dichotomy in the immune response caused by theseLeishmaniaspecies, we evaluated subsets of dendritic cells (DCs) and T lymphocyte in draining lymph nodes during the course ofLaandLbinfection in BALB/c mice. Our results demonstrated a high involvement of DCs inLainfection, which was characterized by the greater accumulation of Langerhans cells (LCs); conversely,Lbinfection led to an increase in dermal DCs (dDCs) throughout the infection. Considering the T lymphocyte response, an increase of effector, activated, and memory CD4+T-cells was observed inLbinfection. Interleukin- (IL-) 4- and IL-10-producing CD4+and CD8+T-cells were present in bothLaandLbinfection; however, interferon- (IFN-)γ-producing CD4+and CD8+T-cells were detected only inLbinfection. The results suggest that duringLbinfection, the dDCs were the predominant subset of DCs that in turn was associated with the development of Th1 immune response; in contrastLainfection was associated with a preferential accumulation of LCs and total blockage of the development of Th1 immune response.