Phlebotomus papatasi SP15: mRNA expression variability and amino acid sequence polymorphisms of field populations

Abstract

Abstract Background The Phlebotomus papatasi salivary protein PpSP15 was shown to protect mice against Leishmania major, suggesting that incorporation of salivary molecules in multi-component vaccines may be a viable strategy for anti-Leishmania vaccines. Methods Here, we investigated PpSP15 predicted amino acid sequence variability and mRNA profile of P. papatasi field populations from the Middle East. In addition, predicted MHC class II T-cell epitopes were obtained and compared to areas of amino acid sequence variability within the secreted protein. Results The analysis of PpSP15 expression from field populations revealed significant intra- and interpopulation variation.. In spite of the variability detected for P. papatasi populations, common epitopes for MHC class II binding are still present and may potentially be used to boost the response against Le. major infections. Conclusions Conserved epitopes of PpSP15 could potentially be used in the development of a salivary gland antigen-based vaccine.

Keywords

• Sand fly
• Saliva
• PpSP15
• Leishmaniasis
• Vaccine
• Expression variability