Molecular Investigation of Pro-inflammatory and Anti- Inflammatory Cytokines Gene Expression in Macrophages Exposed to Leishmania major.

INTRODUCTION: Cutaneous leishmaniasis (CL) is an infectious skin disease that affects people all over the world. The innate and adaptive immune response generated against the parasite in the host is effective during the treatment period and wound healing process. The production of pro-inflammatory and anti-inflammatory cytokines plays a central role in susceptibility and resistance to the pathogen. MATERIALS & METHODS: Peritoneal macrophage cells were harvested from the peritoneal cavity of BALB/C mice and exposed to Leishmania major parasite (MHOM/IR/75/ER) at three time points (24, 48, and 72 hours). Gene expression of TNF-α, IL-12, CXCL-9, CXCL-10, IL-10, and TGF-β cytokines was analyzed by real-time PCR. RESULTS: The expression of IL-10 as an anti-inflammatory cytokine was higher than that of inflammatory cytokines during the three treatment periods (24, 48, and 72). The expression of IL-p35 was also high, but not IL-p40. The expression of CXCL-9 (crucial for the recruitment of immune T cells) was also upregulated (P≤0.05). The gene expression of TNF-α was low at three different time points, especially after 72 hours of exposure, and the level of TGF-β expression increased significantly after 72 hours, and anti-inflammatory cytokine expression was higher than that of pro-inflammatory cytokines (P≤0.05). CONCLUSION: Pro-inflammatory and anti-inflammatory cytokines have a critical role in the treatment of L. major infections. Pro- and anti-inflammatory cytokine production is related to the mechanism of suppression of cellular immune responses mediated by Th2 lymphocytes during disease progression. Evaluation of macrophage cytokine gene expression may be indicative of cytokine expression by macrophage cells as a major factor in the host defense involved in CL and is important for studies on the pathogenesis of the disease.