New insights about cross-reactive epitopes of six trypanosomatid genera revealed that Crithidia and Leptomonas have antigenic similarity to L. (L.) chagasi

• Published in: Acta tropica 2014-03, Vol.131, p.41-46
• Main Authors: Ferreira, Leandro Rodrigues, Kesper, Norival, Teixeira, Marta M.G., Laurenti, Marcia Dalastra, Barbieri, C.L., Lindoso, José Angelo, Umezawa, Eufrosina S.
• Format: Article
• Language: English
• Subjects: Animals; Antigens, Protozoan - chemistry; Antigens, Protozoan - immunology; Chagas Disease - immunology; Chagas Disease - parasitology; Crithidia; Crithidia - chemistry; Crithidia - immunology; Crithidia fasciculata; Cross Reactions; Cross-reactivity; Dogs; Epitopes - chemistry; Epitopes - immunology; Humans; Immune Sera - chemistry; L. (L.) chagasi; Leishmania chagasi; Leishmania donovani - chemistry; Leishmania donovani - immunology; Leishmania mexicana - chemistry; Leishmania mexicana - immunology; Leishmaniasis, Cutaneous - immunology; Leishmaniasis, Cutaneous - parasitology; Leishmaniasis, Visceral - diagnosis; Leishmaniasis, Visceral - immunology; Leishmaniasis, Visceral - parasitology; Leptomonas; Leptomonas seymouri; Male; Phytomonas serpens; Trypanosoma cruzi; Trypanosoma cruzi - chemistry; Trypanosoma cruzi - immunology; Trypanosomatids; Trypanosomatina - chemistry; Trypanosomatina - immunology
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2013.11.010

Human VL samples with Abs492nm1.00 to L. (L.) chagasi (A2) showed similar titers with all of them. •Insect and plant trypanosomatids revealed antigenic similarity to L. (L.) chagasi.•Crithidia and Leptomonas showed 100% positivity with VL cases.•34% of VL cases showed higher titers with insect parasites than to L. (L.) chagasi. We investigated whether ELISA using crude antigens from insect and plant trypanosomatids, which are non-pathogenic and easily cultivated in large scale, has the same positivity data as Leishmania (Leishmania) chagasi, the etiological agent of human visceral leishmaniasis (VL) or canine leishmaniasis (CanL), or as Trypanosoma cruzi, the etiological agent of Chagas disease (CD). The antigens from Crithidia fasciculata, Crithidia luciliae, and Leptomonas seymouri showed 100% cross-reactivity with VL and CanL samples, with no statistically titers differences from L. (L.) chagasi, however, 34% (17/50) of VL samples revealed higher titers using the insect trypanosomatids than the homologous antigen. On the other hand, antigens from Strigomonas culicis, Angomonas deanei, and Phytomonas serpens showed low cross-reactivity with VL and CanL samples. The sera from patients with American tegumentary leishmaniasis showed low levels of cross-reactivity with all trypanosomatids investigated, even with L. (L) chagasi, without titers dissimilarity among them. These parasites were also worthless as antigen source for detection of CD cases, which required homologous antigens to reach 100% positivity. This study showed, by ELISA, that crude extract of Crithidia and Leptomonas have epitopes similar to L. (L.) chagasi, which supports the idea of using them as antigens source for the serodiagnosis of visceral leishmaniasis.