Immune Responsiveness to the Immunodominant Recombinant Envelope Epitopes of Human T Lymphotropic Virus Types I and II in Diverse Geographic Populations

Abstract

The heterogeneity of immune responsiveness to the immunodominant epitopes of human T lymphotropic virus (HTLV) types I (MTA-1^162–209) and II (K-55^162–205) were determined in natural infections with HTLV-I and -II from diverse geographic areas (n = 285). Of the HTLV-I specimens confirmed by polymerase chain reaction (PCR), all North American (n = 37) and Peruvian (n = 19) specimens reacted with MTA-1. Of HTLV-II specimensconfirmed by PCR, 44 (96%) of 46 from North American blood donors, 28 (97%) of 29 from native Americans, and all from intravenous drug users (n = 29) reacted with K-55. Specimens from other geographic areas (Peru, 30; Brazil, 4; Mexico, 10; Italy, 5; Somalia, 13; Ethiopia, 17; Japan, 32; and Jamaica, 15) all reacted either with MTA-1 or K-55. By synthetic peptide-based serologic typing, all of these specimens could be typed as HTLV-I or -II. In addition to the direct implications of these findings for diagnostic purposes, these data provide indirect evidencefor the conservation of immunodominant HTLV^env epitopes in diverse geographic populations.