title: Brief Report: Increased Expression of the Type I Interferon Receptor on CD4+ T Lymphocytes in HIV-1-Infected Individuals.
abstract: BACKGROUND
  Type I interferons (IFN1s; eg, interferon-alpha and interferon-beta) are potent cytokines that inhibit the replication of human immunodeficiency virus-1 (HIV-1) and other viruses. The antiviral and immunoregulatory activities of IFN1 are mediated through ligand-receptor interactions with the IFN1 receptor complex (IFNAR). Variation in the cell-surface density of IFNAR could play a role in HIV-1 pathogenesis.
  
  
  METHODS
  In this cross-sectional study of fresh whole blood, we used flow cytometry to evaluate the expression of IFNAR2 on lymphocyte subsets from HIV-1-infected (n = 33) and HIV-1-uninfected (n = 22) individuals.
  
  
  RESULTS
  In comparison with healthy blood bank donors, we observed that the HIV-1-infected individuals, particularly those having advanced to disease, exhibited the increased expression of IFNAR2 on CD4 T cells (relative fluorescence intensity 6.9 vs. 9.0; P = 0.027). The CD4:CD4 T-cell IFNAR2 expression-level ratio provides an internally standardized measure of this alteration. The observed increased expression of IFNAR2 was largely restricted to CD4 T cells that expressed the chemokine receptor CXCR4 and lacked the expression of CCR5.
  
  
  CONCLUSIONS
  HIV-1-infected individuals exhibit an increased expression of the IFN1 receptor on CD4 T cells. The level of IFNAR2 expression seems to increase with disease progression. These findings provide insight for the immunologic alterations associated with HIV-1 infection and possibly new therapeutic approaches.
authors.affiliation: *Departments of Basic Biomedical Sciences and Public Health, Sanford School of Medicine, University of South Dakota, Vermillion, SD; and †Department of Medicine, University of California San Francisco, San Francisco, CA.
authors.forename: M Scott
authors.initials: MS
authors.lastname: Killian
authors.forename: Sue H
authors.initials: SH
authors.lastname: Fujimura
authors.forename: Ramu G
authors.initials: RG
authors.lastname: Sudhagoni
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005434:Flow Cytometry; D018023:HIV Seronegativity / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D053633:Receptor, Interferon alpha-beta / Q000097:blood*; D019713:Receptors, CCR5 / Q000097:blood*; D019718:Receptors, CXCR4 / Q000097:blood*; D019562:Viral Load
chemical_list: C508033:IFNAR2 protein, human; D019713:Receptors, CCR5; D019718:Receptors, CXCR4; D053633:Receptor, Interferon alpha-beta