title: Immunologic cross-reactivity between structural proteins of human T-cell lymphotropic virus type I and the blood stage of Plasmodium falciparum.
abstract: To determine the serologic cross-reactivity between human T-cell lymphotropic virus type I (HTLV-I) and parasite antigens, we measured antibody responses against HTLV-I, Plasmodium falciparum, Plasmodium vivax, and Brugia malayi in serum specimens obtained from regions where malaria (n = 482) and filariasis (n = 101) are endemic. Analysis of immune reactivity to HTLV-I antigens showed that specimens from regions where malaria is endemic had significantly higher rates of enzyme immunoassay (EIA) reactivity (76 of 482 [15.8%] than those from regions where filariasis is endemic (0 of 101 [0%]). Western blot (immunoblot) analysis of the HTLV-I EIA-reactive specimens demonstrated predominant Gag reactivity (HTLV-Iind). Only two specimens each from Indonesia and Brazil and four specimens from Papua New Guinea had Env reactivity by radioimmunoprecipitation analysis. Furthermore, a positive correlation between HTLV-EIA and titers of antibody to the blood stage of P. falciparum (rs = 0.24, P < 0.005) was discerned; no correlation was observed between antibodies to the blood stage or the circumsporozoite protein of P. vivax and the circumsporozoite protein of P. falciparum. In addition, P. falciparum-infected erythrocyte lysate specifically abrogated binding of Gag-specific antibodies in HTLV-Iind specimens from regions where malaria is endemic without affecting binding in HTLV-I-seropositive specimens, suggesting that the immunologic cross-reactivity between HTLV Gag proteins and malaria parasites is restricted to the blood-stage antigens of plasmodia in specimens from regions where malaria is endemic. However, HTLV-seroindeterminate specimens from the United States did not demonstrate serologic cross-reactivity, suggesting that antigenic mimicry of HTLV proteins extends to other nonplasmodial antigens as well.
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood / Q000276:immunology*; D001666:Binding Sites, Antibody; D001667:Binding, Competitive / Q000276:immunology; D003429:Cross Reactions; D004912:Erythrocytes / Q000276:immunology; D015481:HTLV-I Antibodies / Q000097:blood; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood* / Q000276:immunology / Q000469:parasitology; D010963:Plasmodium falciparum / Q000254:growth & development / Q000276:immunology*; D015678:Viral Structural Proteins / Q000097:blood / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan; D015481:HTLV-I Antibodies; D015678:Viral Structural Proteins