title: HIV-1 strains from India are highly divergent from prototypic African and US/European strains, but are linked to a South African isolate.
abstract: OBJECTIVE
  To gain molecular insights into different HIV-1 strains present in two different states of India, nucleotide sequences derived from the env region of four HIV-1 strains were analysed.
  
  
  METHODS
  HIV-1 was isolated from high-risk patients from the states of Maharashtra (city of Bombay) and Goa. The molecular analysis of the env region encompassed all variable domains of the external glycoprotein, gp120.
  
  
  METHODS
  Genomic DNA from cultured cells infected with each of the four Indian HIV-1 strains independently was amplified by polymerase chain reaction (PCR). PCR fragments were cloned and sequenced and a phylogenetic tree constructed.
  
  
  RESULTS
  All four Indian HIV-1 sequences were closely related to each other. The closest related sequence to them was from a South African isolate, HIV-1NOF, with a homology of 85-87%. In the phylogenetic tree, the Indian and the South African HIV-1 sequences cluster together and constitute a subtype different from the North American/European, Central African, Uganda/Rwanda and Northern Thailand subtypes. Interestingly, the viruses of this subtype are characterized by an additional potential N-glycosylation site C-terminal to the CD4-binding domain.
  
  
  CONCLUSIONS
  The low variation between the HIV-1 sequences from randomly chosen individuals from high-risk cohorts in two Indian states suggests a rapid and recent spread of HIV and, possibly, introduction of the virus by the same route, most probably heterosexual transmission. The rapid spread of HIV-1 variants in India, which form a subgroup of their own together with a South African strain, necessitate consideration of these strains in vaccine development.
authors.affiliation: Chemotherapeutisches Forschungsinstitut Georg-Speyer-Haus, Frankfurt, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Dietrich
authors.forename: M
authors.initials: M
authors.lastname: Grez
authors.forename: H
authors.initials: H
authors.lastname: von Briesen
authors.forename: B
authors.initials: B
authors.lastname: Panhans
authors.forename: M
authors.initials: M
authors.lastname: Geissendörfer
authors.forename: H
authors.initials: H
authors.lastname: Kühnel
authors.forename: J
authors.initials: J
authors.lastname: Maniar
authors.forename: G
authors.initials: G
authors.lastname: Mahambre
authors.forename: W B
authors.initials: WB
authors.lastname: Becker
authors.forename: M L
authors.initials: ML
authors.lastname: Becker
mesh_terms: D000349:Africa; D000595:Amino Acid Sequence; D005060:Europe; D015686:Gene Products, env / Q000235:genetics; D015752:Genes, env; D015658:HIV Infections / Q000382:microbiology; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007194:India; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014481:United States
chemical_list: D015686:Gene Products, env