HIV-1 clade C env clones obtained from an Indian patient exhibiting expanded coreceptor tropism are presented with naturally occurring unusual amino acid substitutions in V3 loop

Virus Res. 2009 Sep;144(1-2):306-14. doi: 10.1016/j.virusres.2009.04.020. Epub 2009 May 4.

Abstract

HIV-1 subtype C is predominantly circulating in India and has been reported to be strictly CCR5 tropic irrespective of disease stages. In the present study, we examined env clones obtained from a late stage Indian patient with a history of multiple sexual partners and opportunistic infections for coreceptor usage and V3 loop sequence. The env clones were found to exploit several coreceptors in addition to CCR5 in a cell-associated and cell-free manner. Analysis of V3 loop sequence revealed that the NARI-VB105 env clones were presented with unique amino acid substitutions with GPGR motif, atypical of clade C envelope. Further genetic analysis showed the V3 sequences albeit belonging to subtype C; however clustered distinctly to that of other clade C envelopes originated in different geographical regions. Modelling data revealed that NARI-VB105 V3 loop contained several basic residues giving rise a high net positive charge of +8 to these envelopes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acid Substitution / genetics*
  • Cluster Analysis
  • Genotype
  • HIV Infections / virology*
  • HIV-1 / genetics*
  • HIV-1 / isolation & purification
  • Humans
  • India
  • Molecular Sequence Data
  • Mutation, Missense*
  • Phylogeny
  • Receptors, HIV / metabolism*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Static Electricity
  • Virus Attachment*
  • env Gene Products, Human Immunodeficiency Virus / chemistry
  • env Gene Products, Human Immunodeficiency Virus / genetics*

Substances

  • Receptors, HIV
  • env Gene Products, Human Immunodeficiency Virus

Associated data

  • GENBANK/EU521729
  • GENBANK/EU622014
  • GENBANK/EU760892