title: Molecular cloning and analysis of a new variant of human T-cell leukemia virus (HTLV-ib) from an African patient with adult T-cell leukemia-lymphoma.
abstract: We report the identification and characterization of a new variant of HTLV-I in an African patient with adult T-cell leukemia/lymphoma (ATL). Proviral sequences were detected by Southern blot analysis in three T-cell lines established from this patient's peripheral blood lymphocytes (PBL) and lymph-node cells. We molecularly cloned and analyzed proviruses from two of these cells lines, one established by direct culture of PBL and one established by co-cultivation of PBL with cord-blood T cells. These two HTLV clones contained full-length proviruses which were identical to each other in 44 out of 44 restriction enzyme sites. They were closely related to, but distinct from, the prototype HTLV-I, having divergence in their envelope and 5' pX regions and therefore represented a new variant of HTLV-I. We designated it as HTLV-Ib. Despite the genomic differences, however, HTLV-Ib retained its tropism for OKT4+ lymphocytes as well as its ability to initiate and maintain transformation of these cells. The finding of a variant of HTLV-I in this African ATL patient, along with the results of recent seroepidemiological studies, extends to the African continent the prevalence of HTLV-I associated malignancy previously identified in the Caribbean and Japan.
mesh_terms: D000328:Adult; D001483:Base Sequence; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000032:analysis; D017977:Deltaretrovirus / Q000235:genetics* / Q000302:isolation & purification; D015023:Democratic Republic of the Congo / Q000208:ethnology; D005814:Genes, Viral; D014644:Genetic Variation; D006801:Humans; D007938:Leukemia / Q000382:microbiology*; D008223:Lymphoma / Q000382:microbiology*; D008297:Male
chemical_list: D004279:DNA, Viral; D004262:DNA Restriction Enzymes