Pro-Inflammatory Cytokine Interleukin-1 Beta (Il-1 Beta) Controls Leishmania Infection

Leishmania is an obligate intracellular parasite uses low pH phagolysosomal compartments of host macrophages as their final abode. IL-1 beta is a pro inflammatory cytokine, which is secreted by immune cells to trigger inflammation and this has been found profoundly in the lesions caused by Leishmania pathogens. But the specific role of this cytokine on host cell macrophages during infection has not been fully explored. Here in, we have showed that prolonged exposure of IL-1 beta on macrophages increases the parasite burden. Pre-treatment of bone marrow derived macrophages (BMDM) with IL-1 beta also generates significantly higher amount of anti-inflammatory cytokine IL-10. As IL-10 plays crucial role in the establishment of infection, enhanced production of IL-10 observed upon IL-1 beta treatment could contribute to the progression of the disease. By quantifying the production of Nitric oxide (NO), we further report that the pretreatment of IL-1 beta fails to produce the nitric oxide. By measuring the footpad thickness in two different mice strains of differential susceptibility we showed IL-1 beta treatment increases parasitic burden. As our results shows that the exposure of IL-1 beta helps in disease progression, IL-1 beta signalling may be an attractive target for future therapeutic intervention.