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.
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.
Grez
M
M
Georg-Speyer-Haus, Chemotherapeutisches Forschungsinstitut, Frankfurt, Germany.
Dietrich
U
U
Balfe
P
P
von Briesen
H
H
Maniar
J K
JK
Mahambre
G
G
Delwart
E L
EL
Mullins
J I
JI
Rübsamen-Waigmann
H
H
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
D015699:HIV Envelope Protein gp120