Construction and characterization of an infectious molecular clone derived from the CRF01_AE primary isolate of HIV type 1.
ABSTRACT An infectious molecular clone (named p95TNIH022) was constructed using long-range polymerase chain reaction products derived from a clinical isolate (95TNIH022) of HIV-1 CRF01_AE obtained from an asymptomatic Thai carrier in 1995. The virus in the supernatant from p95TNIH022-transfected 293T cells showed infectivity in peripheral blood mononuclear cells (PBMCs) as well as in MAGIC5 cells, which express CD4 and CCR5, but not in the original MAGI cells, indicating that p95TNIH022 is an infectious molecular clone with CCR5 tropism. Interestingly, p95TNIH022-derived virus induced profound cell killing in infected PBMCs, as in cells infected with the parental isolate.
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ABSTRACT: Serosurveys conducted prior to 1988 indicated a very low level of HIV-1 infection in Thailand, even among high-risk groups. The Ministry of Health has reported a dramatic increase in HIV-1 infection during the last three years. The geographic and demographic distribution of the epidemic is broad, involving multiple provinces and risk groups. Foci of higher incidence and prevalence have been noted in the urban center of Bangkok and in the northern provinces of Chiang Mai and Chiang Rai. Here we report the results of genetic characterization of 16 HIV-1 isolates from Thailand using a combination of polymerase chain reaction (PCR) typing and DNA sequencing. The complete sequence of gp160 (env) of five isolates, partial env sequence of six additional isolates, and the gag gene of two isolates were determined. Two highly distinct HIV-1 variants were found. One variant resembled those prevalent in North America and Europe; five of the isolates were of this type. The remaining eleven isolates were very similar to one another and represented a variant unlike any previously described. Phylogenetic tree analysis of complete env and gag genes placed the two variants on widely separated branches. Protein sequence comparisons indicate both general and specific features that distinguish the Northern Thailand variant both from the Bangkok variant and from virtually all previously sequenced HIV-1 isolates. A simple PCR test for distinguishing the two variants has been developed for use in epidemiologic surveys.AIDS Research and Human Retroviruses 12/1992; 8(11):1887-95. · 2.25 Impact Factor
Article: Production of acquired immunodeficiency syndrome-associated retrovirus in human and nonhuman cells transfected with an infectious molecular clone.[show abstract] [hide abstract]
ABSTRACT: We constructed an infectious molecular clone of acquired immunodeficiency syndrome-associated retrovirus. Upon transfection, this clone directed the production of infectious virus particles in a wide variety of cells in addition to human T4 cells. The progeny, infectious virions, were synthesized in mouse, mink, monkey, and several human non-T cell lines, indicating the absence of any intracellular obstacle to viral RNA or protein production or assembly. During the course of these studies, a human colon carcinoma cell line, exquisitely sensitive to DNA transfection, was identified.Journal of Virology 09/1986; 59(2):284-91. · 5.40 Impact Factor
Article: The heterosexual human immunodeficiency virus type 1 epidemic in Thailand is caused by an intersubtype (A/E) recombinant of African origin.[show abstract] [hide abstract]
ABSTRACT: Since 1989, human immunodeficiency virus type 1 (HIV-1) has spread explosively through the heterosexual population in Thailand. This epidemic is caused primarily by viruses classified as "subtype E", which, on the basis of limited sequence comparisons, appear to represent hybrids of subtypes A (gag) and E (env). However, the true evolutionary origins of "subtype E" viruses are still obscure since no complete genomes have been analyzed, and only one full-length subtype A sequence has been available for phylogenetic comparison. In this study, we determined full-length proviral sequences for "subtype E" viruses from Thailand (93TH253) and the Central African Republic (90CR402) and for a subtype A virus from Uganda (92UG037). We also sequenced the long terminal repeat (LTR) regions from 16 virus strains representing clades A, C, E, F, and G. Detailed phylogenetic analyses of these sequences indicated that "subtype E" viruses do indeed represent A/E recombinants with multiple points of crossover along their genomes. The extracellular portion of env, parts of vif and vpr, as well as most of the LTR are of subtype E origin, whereas the remainder of the genome is of subtype A origin. The possibility that the discordant phylogenetic positions of "subtype E" viruses in gag- and env-derived trees are the result of unusual rates or patterns of evolution was also considered but was ruled out on the basis of two lines of evidence: (i) phylogenetic trees constructed for synonymous and nonsynonymous substitutions yielded the same discordant branching orders for "subtype E" gag and env gene sequences, thus excluding selection-driven evolution, and (ii) multiple crossovers in the viral genome are most consistent with the copy choice model of recombination and have been observed in other documented examples of HIV-1 intersubtype recombination. Thai and CAR "subtype E" viruses exhibited the same pattern of A/E mosaicism, indicating that the recombination event occurred in Africa prior to the spread of virus to Asia. Finally, all "subtype E" viruses were found to contain a distinctive two-nucleotide bulge in their transactivation response (TAR) elements. This feature was present only in viruses which also contained a subtype A 5' pol region (i.e., subtype A viruses or A/D and A/E recombinants), raising the possibility of a functional linkage between the TAR region and the polymerase. The implications of epidemic spread of a recombinant HIV-1 strain to viral natural history and vaccine development are discussed.Journal of Virology 11/1996; 70(10):7013-29. · 5.40 Impact Factor