title: Reduced cellular susceptibility to in vitro HIV infection is associated with CD4+ T cell quiescence.
abstract: BACKGROUND
  HIV preferentially establishes productive infection in activated CD4+ T cells. Since proportions of activated CD4+ T cells vary between individuals, this study aimed to determine if individuals with a greater proportion of activated CD4+ T cells would be more susceptible to in vitro HIV infection.
  
  
  RESULTS
  Unstimulated peripheral blood mononuclear cells (PBMC) from various donors were inoculated with HIV(ML1956)in vitro. HIV replication was evaluated by HIV p24 ELISA of culture supernatants and intracellular staining for HIV p24, which was detected by flow cytometry. Baseline T cell phenotypes and infected cell phenotypes were also evaluated by flow cytometry. Ex vivo phenotyping at the time of blood draw showed that elevated T cell activation and reduced Tregs were associated with increased cellular susceptibility to in vitro infection. Furthermore, the infected CD4+ T cell population was enriched for activated cells.
  
  
  CONCLUSIONS
  These data suggest that CD4+ T cell quiescence provides an environment less conducive to the establishment of HIV infection by limiting the pool of activated target cells.
authors.affiliation: Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Card
authors.forename: W John
authors.initials: WJ
authors.lastname: Rutherford
authors.forename: Suzie
authors.initials: S
authors.lastname: Ramdahin
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Yao
authors.forename: Makobu
authors.initials: M
authors.lastname: Kimani
authors.forename: Charles
authors.initials: C
authors.lastname: Wachihi
authors.forename: Joshua
authors.initials: J
authors.lastname: Kimani
authors.forename: Francis A
authors.initials: FA
authors.lastname: Plummer
authors.forename: T Blake
authors.initials: TB
authors.lastname: Ball
authors.forename: Keith R
authors.initials: KR
authors.lastname: Fowke
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000502:physiology / Q000821:virology*; D015331:Cohort Studies; D060467:Disease Resistance; D015658:HIV Infections / Q000276:immunology / Q000473:pathology* / Q000821:virology; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D010641:Phenotype; D050378:T-Lymphocytes, Regulatory / Q000502:physiology / Q000821:virology; D014779:Virus Replication