Characterizing cellular immune response to kinetoplastid membrane protein‐11 (KMP‐11) during Leishmania (Viannia) panamensis infection using dendritic cells (DCs) as antigen presenting cells (APCs)

SUMMARY In vitro peptide binding assays and DCs pulsed with recombinant KMP‐11 (rKMP‐11) plus six 20‐mer overlapping peptides covering the entire protein of Leishmania (Viannia) panamensis (L(V)p) promastigotes were used to identify T‐cell epitopes in this protein. Such in vitro binding assays, using HLA DRB1* 0101, ‐0401, ‐0701 and ‐1101 alleles, demonstrated that two peptide sequences ( DEEFNKKMQEQNAKFFADKP and FKHKFAELLEQQKAAQYPSK) exhibited high HLA DRB1* 0401 allele binding capacity. rKMP‐11 specific T‐cell proliferation and cytokine production, derived from 13 volunteers exposed to the parasite, suggested that using autologous DCs as APCs becomes advantageous in uncovering T‐cell epitopes promoting proliferation and differences in IFN‐γ and IL‐4 production in T‐cells from volunteers with ACTIVE and CURED undetectable disease when other APCs were used. The two peptides which bound in vitro to the HLA DRB1* 0401 allele were immunogenic in HLA DRB1* 04 volunteers, thus validating the use of in vitro binding assays for predicting epitopes in this protein. The experimental approach used here may prove useful for characterizing T‐cell epitopes in a protein useful in designing peptide‐based vaccine candidates for Leishmania and other intracellular pathogens.