Protective immunogenicity of the paraflagellar rod protein 2 ofLeishmania mexicana

Paraflagellar rod proteins (PFR) are a potent immunogen against experimentalTrypanosoma cruziinfection. PFR are highly conserved among kinetoplastid parasites. We therefore evaluated the immunogenicity of theLeishmania mexicana pfr-2gene and protein product in the hamster model of American cutaneous leishmaniasis. Immunization withpfr-2DNA-induced specific antibody, confirming immunogenicity. Subsequent challenge with 10,000 and 500 stationary phaseL. mexicanapromastigotes respectively, resulted in delayed appearance of lesions, and significant reduction in lesions post infection in male hamsters, yet exacerbated lesions in female hamsters. Immunization with recombinant PFR-2 protein (rPFR-2) prevented lesion development in female hamsters challenged withL. panamensis, but was ineffective againstL. mexicana. Nevertheless, prime boost immunization of female hamsters with rPFR andpfr-2DNA significantly reduced lesion size following challenge with 500L. mexicanapromastigotes, supporting the relevance of PFR-2 as a potential vaccine constituent.