Differential inflammatory responses associated with Leishmania major and Ltropica in culture.

Abstract

Anthroponotic cutaneous leishmaniasis (ACL) due to Leishmania tropica and zoonotic CL (ZCL) due to Lmajor have different clinical and epidemiological features. To determine whether pro-inflammatory cytokines are involved in diverse pathogenicity of Leishmania species causing CL. The capacity of Lmajor/Ltropica to modulate expression of IL-1β, IL-8 (CXCL8), IFN-γ, TNF-α and MCP-1 (CCL2) in peripheral blood mononuclear cells (PBMCs) and monocyte-derived macrophages (MDMs) was evaluated by real-time RT-PCR technique. PBMCs from both ZCL and ACL cases expressed significantly higher IFN-γ (P<.001) and TNF-α (P<.05) compared with healthy controls (HC). PBMCs from ACL patients expressed significantly higher IL-1β and IL-8 compared with ZCL patients and HC when stimulated with live Lmajor or Ltropica promastigotes (P<.001). After 4 and 10hours, Lmajor-infected MDMs expressed significantly higher IFN-γ (P<.05), and after 10hours, Ltropica-infected MDMs expressed significantly higher IL-1β, IFN-γ and IL-8 compared with noninfected cells (P<.05). This study shows differential parasite-mediated stimulations of the inflammatory response with Lmajor vs Ltropica ex vivo. Pro-inflammatory cytokines particularly IL-8 (CXCL8) and IL-1β might contribute in diverse clinical features of CL such as longer duration of lesion persistence in ACL patients.