Important note: Information in this article was accurate in 1991. The state of the art may have changed since the publication date.
Small regions of the env and tat genes control cellular tropism, cytopathology and replicative properties of HIV-1.
Int Conf AIDS. 1991 Jun 16-21;7(1):21 (abstract no. M.A.5). Unique Identifier : AIDSLINE ICA7/1000591 Cheng-Mayer C; Shioda T; Levy JA; Cancer Research Institute, University of California, School of; Medicine, San Francisco, California 94143-0128
Abstract:
OBJECTIVE: To identify genetic regions of HIV-1 that control the pathogenic properties of the virus. METHODS: Recombinant viruses were generated between two sequential isolates (HIV-1SF2, HIV-1SF13) that are highly related at the genomic level and yet display distinct in vitro biological properties. RESULTS: The sequential isolates (HIV-1SF2, HIV-1SF13), molecularly cloned and sequenced, were found to be closely related at the genomic level (greater than 97% overall sequence homology). However, when compared to the earlier isolate (HIV-1SF2mc), the later isolate (HIV-1SF13mc) replicated faster and to higher titers in PMC, Hut78, MT-4 and Jurkat cells and was highly cytopathic. It induced plaque in the MT-4 cell line. Moreover, HIV-1SF13mc displayed a wide host range; productively infected primary macrophages, the CEM and U937 cell lines, and CD4-negative fibroblastoid cells. Studies with recombinants showed that a 0.48kb StuI/MstII fragment, encompassing the V3 domain of gp120, determines cytopathogenicity in PMC and the Hut78 and MT-4 cell lines. This same region also contains the major determinant of macrophage tropism. A 0.39kb MstII/StyI fragment, encompassing the V4, V5 and CD4 binding domains of gp120, contains the major determinant for entry into the Jurkat, CEM and U937 cells. A 0.29kb RI/Hind III fragment, encompassing the first coding exons of tat and rev, determines the rate of virus replication in the Hut78, Jurkat and MT-4 cell lines. A single aa change in this region of tat, however, appears to be responsible for the difference observed between HIV-1SF2mc and HIV-1SF13mc. CONCLUSIONS: Our studies showed that small genetic regions of HIV-1 control biological properties of the virus that correlate with its virulence in the host. Specifically, a single aa change in tat appears to affect the replicative rate of HIV-1. Studies with other site-directed mutants are in progress to identify specific amino acid changes in the envelope gp120 that determine the different host range properties of HIV-1.
Keywords: Antigens, CD4/ANALYSIS Cell Line Genes, env Genes, tat Genes, Viral HIV Envelope Protein gp120 HIV-1/*GENETICS/PHYSIOLOGY/PATHOGENICITY Plaque Assay Virulence *Virus Replication ABSTRACT 912130
M91C4064
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