Phenotypic and genotypic characterization of human immunodeficiency virus type 1 CRF07_BC strains circulating in the Xinjiang Province of China.
BACKGROUND
HIV-1 CRF07_BC recombinant previously circulated mainly among the intravenous drug users (IDUs) in Xinjiang province of China and is currently spreading in the entire country. The aim of this study is to characterize the genotypic and phenotypic properties of HIV-1 CRF07_BC isolates in comparison with those of the subtype B' (Thailand B) which is prevalent in the former plasma donors (FPDs) in China.


RESULTS
Twelve HIV-1 CRF07_BC variants were isolated from the blood of the HIV-1-infected IDUs in Xinjiang province, and 20 subtype B' isolates were obtained from the FPDs in Anhui and Shanxi provinces of China. All the CRF07_BC viruses utilized CCR5 co-receptor, whereas 12 subtype B' viruses were R5-tropic, and the remaining B' isolates were dual (R5X4) tropic. CRF07_BC viruses had lower net charge value in the V3 loop and exhibited slower replication kinetics than subtype B' viruses. The number and location of the potential N-linked glycosylation sites in V1/V2 and the C2 region of the CRF07_BC viruses were significantly different from those of the subtype B' viruses.


CONCLUSIONS
The HIV-1 CRF07_BC recombinant strains with relatively lower net charges in the V3 loop exclusively utilize CCR5 co-receptor for infection and exhibit slow replication kinetics in the primary target cells, suggesting that CRF07_BC may be superior over B' and other HIV-1 subtypes in initiating infection in high-risk population. These findings have molecular implications for the adaptive evolution of HIV-1 circulating in China and the design of tailored therapeutic strategy for treatment of HIV-1 CRF07_BC infection.
State Key Laboratory for Infectious Disease Control and Prevention, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, PR China. liyingma5566@chinaaids.cn
Liying
L
Ma
Yanfang
Y
Guo
Lin
L
Yuan
Yang
Y
Huang
Jianping
J
Sun
Shuiling
S
Qu
Xiaoling
X
Yu
Zhefeng
Z
Meng
Xiang
X
He
Shibo
S
Jiang
Yiming
Y
Shao
D000328:Adult; D000595:Amino Acid Sequence; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D055030:Drug Users; D005838:Genotype; D006031:Glycosylation; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D015728:Receptors, HIV / Q000032:analysis; D017385:Sequence Homology; D015819:Substance Abuse, Intravenous / Q000150:complications; D053585:Virus Attachment; D014779:Virus Replication
D015699:HIV Envelope Protein gp120; D015728:Receptors, HIV; C514793:gp120 protein, Human immunodeficiency virus 1