Duringactive viscerocutaneous leishmaniasis theanti-P2humoralresponse is specifically triggered bytheparasite P proteins

SUMMARY Inthis workwe showthatintheserafromdogsnaturally infected withtheprotozoanparasite Leishmania infantum there are antibodies thatreactspecifically against theparasite acidic ribosomal proteins LiP2aandLiP2b, andthateachone oftheLeishmania P proteins elicits a specific humoral immuneresponse.Usingsynthetic peptides, theantigenic epitope ofthese proteins hasbeenmappedina single region located adjacent totheC-terminal domainhighly conserved among theeukaryotic Pproteins. Theanti-P antibodies elicited during theLeishmania infection donotrecognize theconserved C-terminal domainoftheparasite Pproteins, incontrast withthefindings reported inChagas' disease or systemic lupuserythematosus. Theantigenic epitopes oftheLiP2aandLiP2b arealmost identical inaminoacid sequence.Noreactivity against Trypanosoma cruzi andhumanPproteins was foundinserafromL.infantum-infected dogs.