title: Genetic analysis of human immunodeficiency virus type 1 and 2 (HIV-1 and HIV-2) mixed infections in India reveals a recent spread of HIV-1 and HIV-2 from a single ancestor for each of these viruses.
abstract: DNA sequences encoding the surface envelope glycoproteins of human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) were amplified by PCR from uncultured peripheral blood mononuclear cells obtained from patients with serologically defined HIV-1/HIV-2 mixed infections from Bombay, India. HIV-1-specific PCR products were obtained in seven of seven randomly chosen doubly reactive cases, while HIV-2-specific sequences were detected in five of seven cases (71%). DNA sequence analysis showed that the HIV-1 gp120 coding sequences were closely related to each other (nucleotide sequence divergence of between 3.1 and 6.8%). Phylogenetic tree analysis placed the Indian strains within the C subtype of HIV-1, being most similar to sequences previously found in East and South Africa. The HIV-2 sequences were also closely related to each other, with an overall sequence divergence of between 5.6 and 10.5%. The low level of nucleotide divergence among Indian HIV-1 and HIV-2 sequences suggests a fairly recent introduction of each virus into this population from a single point of entry in each case. The HIV-2 sequences reported here represent the first analysis of Asian HIV-2 strains and confirm the serological pattern previously detected in India. These data show that a substantial spread of HIV-2, together with HIV-1, has appeared outside Africa in a population hitherto unexposed to HIV. These findings imply that further spread of HIV-2 worldwide is to be expected and have important implications for future vaccine and therapy development.
authors.affiliation: Georg-Speyer-Haus, Chemotherapeutisches Forschungsinstitut, Frankfurt, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Grez
authors.forename: U
authors.initials: U
authors.lastname: Dietrich
authors.forename: P
authors.initials: P
authors.lastname: Balfe
authors.forename: H
authors.initials: H
authors.lastname: von Briesen
authors.forename: J K
authors.initials: JK
authors.lastname: Maniar
authors.forename: G
authors.initials: G
authors.lastname: Mahambre
authors.forename: E L
authors.initials: EL
authors.lastname: Delwart
authors.forename: J I
authors.initials: JI
authors.lastname: Mullins
authors.forename: H
authors.initials: H
authors.lastname: Rübsamen-Waigmann
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000382:microbiology; D000595:Amino Acid Sequence; D001483:Base Sequence; D016384:Consensus Sequence; D015699:HIV Envelope Protein gp120 / Q000145:classification / Q000235:genetics*; D006679:HIV Seropositivity / Q000453:epidemiology* / Q000382:microbiology; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D015498:HIV-2 / Q000145:classification / Q000235:genetics*; D006801:Humans; D007194:India / Q000453:epidemiology; D007963:Leukocytes, Mononuclear / Q000382:microbiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D015699:HIV Envelope Protein gp120