title: Comprehensive Characterization of the Transmitted/Founder env Genes From a Single MSM Cohort in China.
abstract: BACKGROUND
  The men having sex with men (MSM) population has become one of the major risk groups for HIV-1 infection in China. However, the epidemiological patterns, function of the env genes, and autologous and heterologous neutralization activity in the same MSM population have not been systematically characterized.
  
  
  METHODS
  The env gene sequences were obtained by the single genome amplification. The time to the most recent common ancestor was estimated for each genotype using the Bayesian Markov Chain Monte Carlo approach. Coreceptor usage was determined in NP-2 cells. Neutralization was analyzed using Env pseudoviruses in TZM-bl cells.
  
  
  RESULTS
  We have obtained 547 full-length env gene sequences by single genome amplification from 30 acute/early HIV-1--infected individuals in the Beijing MSM cohort. Three genotypes (subtype B, CRF01_AE, and CRF07_BC) were identified and 20% of the individuals were infected with multiple transmitted/founder (T/F) viruses. The tight clusters of the MSM sequences regardless of geographic origins indicated nearly exclusive transmission within the MSM population and limited number of introductions. The time to the most recent common ancestor for each genotype was 10-15 years after each was first introduced in China. Disparate preferences for coreceptor usages among 3 genotypes might lead to the changes in percentage of different genotypes in the MSM population over time. The genotype-matched and genotype-mismatched neutralization activity varied among the 3 genotypes.
  
  
  CONCLUSIONS
  The identification of unique characteristics for transmission, coreceptor usage, neutralization profile, and epidemic patterns of HIV-1 is critical for the better understanding of transmission mechanisms, development of preventive strategies, and evaluation of vaccine efficacy in the MSM population in China.
authors.affiliation: *Duke Human Vaccine Institute, Duke University, Durham, NC; †Department of Medicine, Duke University, Durham, NC; ‡Beijing You'an Hospital, Capital Medical University, Beijing, China; §Beijing Center for Disease Control and Prevention, Beijing, China; ‖Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Fudan University, Shanghai, China; ¶National Engineering Laboratory For AIDS Vaccine, College of Life Science, Jilin University, Changchun, China; #Department of Immunology, Chelsea and Westminster Hospital, Imperial College London, London, United Kingdom; and **Department of Surgery, Duke University, Durham, NC.
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Huang
authors.forename: Fangping
authors.initials: F
authors.lastname: Cai
authors.forename: Nathan
authors.initials: N
authors.lastname: Vandergrift
authors.forename: Ruolei
authors.initials: R
authors.lastname: Xin
authors.forename: Zhefeng
authors.initials: Z
authors.lastname: Meng
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Chunlai
authors.initials: C
authors.lastname: Jiang
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Xu
authors.forename: David C
authors.initials: DC
authors.lastname: Montefiori
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
mesh_terms: D002681:China / Q000453:epidemiology; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D005838:Genotype; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D015497:HIV-1 / Q000235:genetics*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D054299:env Gene Products, Human Immunodeficiency Virus
chemical_list: D054299:env Gene Products, Human Immunodeficiency Virus