Predicted co-receptor tropism and sequence characteristics of China HIV-1 V3 loops: implications for the future usage of CCR5 antagonists and AIDS vaccine development.
BACKGROUND
The co-receptor tropism of any given HIV-1 isolate is closely associated with the progression of AIDS. Understanding the co-receptor tropism and genetic diversity of circulating HIV-1 strains is critical for AIDS treatment and vaccine development.


METHODS
All available China HIV-1 V3 sequences with known subtypes/circulating recombinant forms (CRFs) and transmission routes were retrieved from the Los Alamos HIV Sequence Database. HIV-1 co-receptor tropism was predicted using online tool HIV-1 PhenoPred.


RESULTS
All C/CRF07_BC/CRF08_BC strains appeared to use CCR5 for cell entry (R5 strains), while 61.1% of subtype B and 38.7% of CRF01_AE were also R5, indicating a higher prevalence of R5 (76.9%) than X4. The prevalence of R5 remained relatively stable over the different sample years regardless of C/CRF07_BC/CRF08_BC, B, or CRF01_AE subtypes. The co-receptor usage of HIV-1 appeared to be associated with the different subtypes, rather than transmission route. Furthermore, the V3 sequences of C/CRF07_BC/CRF08_BC were more genetically homogeneous relative to both subtypes B and CRF01_AE.


CONCLUSIONS
The higher prevalence of R5 and higher level of homogeneity of V3 sequences in C/CRF07_BC/CRF08_BC suggest that CCR5 antagonists will be promising drugs for future AIDS treatment in China, and that circulating R5 strains are valuable candidates for AIDS vaccine development.
Zhang
Chiyu
C
Institute of Life Sciences, Department of Biochemistry and Molecular Biology, Jiangsu University School of Medical Technology, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China. zhangcy1999@hotmail.com
Xu
Shungao
S
Wei
Jifu
J
Guo
Hongxiong
H
D002681:China / Q000453:epidemiology; D019295:Computational Biology / Q000379:methods; D015752:Genes, env; D014644:Genetic Variation; D015699:HIV Envelope Protein gp120 / Q000235:genetics* / Q000378:metabolism; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000235:genetics / Q000472:pathogenicity; D006801:Humans; D010446:Peptide Fragments / Q000235:genetics* / Q000378:metabolism; D011237:Predictive Value of Tests; D019713:Receptors, CCR5 / Q000378:metabolism; D015728:Receptors, HIV / Q000145:classification / Q000378:metabolism*
D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D019713:Receptors, CCR5; D015728:Receptors, HIV