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

✍ Scribed by Beatrice H. Hahn; George M. Shaw; Mikulas Popovic; Anita Lo Monico; Robert C. Gallo; Flossie Wong-Staal

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: French
• Weight: 655 KB
• Volume: 34
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910340505

✦ Synopsis

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.