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.
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.
Gharu
Lavina
L
Department of Molecular Virology, National AIDS Research Institute, Indian Council of Medical Research, G-73, MIDC, Bhosari, Pune 411026, Maharashtra, India.
Ringe
Rajesh
R
Pandey
Sudhanshu
S
Paranjape
Ramesh
R
Bhattacharya
Jayanta
J
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics*; D016000:Cluster Analysis; D005838:Genotype; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007194:India; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010802:Phylogeny; D015728:Receptors, HIV / Q000378:metabolism*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D055672:Static Electricity; D053585:Virus Attachment; D054299:env Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000235:genetics*
D015728:Receptors, HIV; D054299:env Gene Products, Human Immunodeficiency Virus