Leptin activates pro-inflammatory cells promoting a Th1 immune response.42 Hence, to characterize the immune response induced by leptin treatment during L. donovani infection in mice, we analyzed L. donovani Ag–specific cytokine secretion by splenocytes from untreated L. donovani-infected and leptin-treated infected mice at 60 days after infection. Here, LEP is linked to infection.