CD4 and infection: 2) WP disruption is associated to the phenomenon of immune system exhaustion; 3) IL6 may play a role in disorganization and plasma cell accumulation in the spleen.4) low CD4 T cell density and low IL15 expression may contribute to ineffective response to the parasite favoring recurrence of the disease and eventually WP disruption; 5) impaired IFNγ signaling may lead to persistence of Leishmania and chronic inflammation, thereby altering the spleen’s microenvironments and disrupting immune response to infections.