Immunotherapeutic efficacy of Th1 stimulatory epitopes derived from Leishmania donovani enolase and triose phosphatase isomerase in experimental visceral leishmaniasis.

Visceral leishmaniasis is a lethal systemic disease which cannot be controlled by drugs alone given asymptomatic reservoirs and must include alternatives to modulate immune responses of the endemic contacts. Our previous studies have yielded potential immunomodulatory proteins by proteomic approach and their peptides showed significant immunomodulation and prophylactic efficacies. The current study has been intended to evaluate immunotherapeutic potential of the lead peptides (P10, P14 and P15) and their combinations with BCG as adjuvant. Results indicated P10 + 14 as well as P10 + P15 to be the most potential therapeutic peptides cocktails as both these combinations reduced parasite burden by > 65 % eliciting remarkable cellular response. High level of IFN-γ, TNF-α and IL-12 with decreased TGF-β expression suggested skewing of immune response towards Th1 type. These results were further supported by strong DTH and lymphoproliferative responses indicating therapeutic potential of the peptide combinations and possibilities in Kala-azar elimination program.