Introduction: Protozoa of the genus Leishmania cause a wide range of pathologies from self-healing skin lesions to visceral pathology. The outcome of infection depends on the species of the infecting Leishmania parasite, the quality and quantity of the host immune response and the host genetic background.
Objective: This study aimed to determine the differential expression of TL2, TL4, TL9, IFN-γ and IL-10 cytokine genes of Human THP1 cell line following in vitro infection with Leishmania donovani isolates from different clinical forms.
Methods: Human THP1 cells were infected by live promastigotes of leishmania donovani isolates from visceral (VL), cutaneous (CL), Post Kala-Azar dermal Leishmaniasis (PKDL) and mucosal Leishmaniasis (ML) Patients. The expression of Tolls like receptor TL2, TL4 and TL9 and the expression of IFN-γ and IL-10 cytokine were measured using Real Time PCR.
Results: A significant increase in the expression of TLR 2, TLR4 and TLR9 by THP-1 was detected following infection of THP-1 cells with L. donovani isolates from ML and PKDL patients. A high expression IL-10 mRNA by THP-1 cells was detected in cells infected by Leishmania donovani isolates from mucosal lesions.
Conclusion: Leishmania donovani isolates from different clinical forms of Leishmaniasis induce different cytokine responses.