title: HIV infection alters the production of both type 1 and 2 cytokines but does not induce a polarized type 1 or 2 state.
abstract: OBJECTIVE
  To test the T-helper (TH)1/TH2 cytokine paradigm in HIV infection.
  
  
  METHODS
  Cytokine profiles in two separate studies of HIV patients and controls are presented: (i) a longitudinal study of HIV patients with CD4 counts > 500 x 10(6)/l tested at three timepoints compared with controls; (ii) a blinded cross-sectional study of controls and patients with high (> 500 x 10(6)/l) and low (< 500 x 10(6)/l) CD4 counts. Peripheral blood mononuclear cells (PBMC) from patients and controls were tested for the production of two type 1 [interleukin (IL)-2, interferon (IFN)-gamma] and two type 2 (IL-4, IL-10) cytokines by enzyme-linked immunosorbent assay. Both spontaneous and mitogen-induced cytokine production was measured.
  
  
  RESULTS
  HIV infection was noted to have the following effects on cytokine production: (i) it led to the in vivo activation of type 2 cytokines in a small group of individuals with high CD4 numbers characterized by the spontaneous release of IL-4 and IL-10. Longitudinal data showed high spontaneous IL-4 and IL-10 to be a consistent feature of the patient group (at each timepoint some patients were high producers) but to be variable in a given individual; (ii) HIV infection impaired the ability of PBMC to respond to stimuli (selected for their ability to optimally induce each cytokine) in terms of IL-2, IL-4 and IL-10 production in patients with both high and low CD4 cell counts; and (iii) conversely, HIV infection led to an overproduction of IFN-gamma in patients with high CD4 counts; patients with low CD4 produced normal levels of IFN-gamma.
  
  
  CONCLUSIONS
  Our observations did not suggest polarization of the type 1/type 2 cytokine profile in HIV patients. Instead, the data suggested more complex changes to type 1/type 2 cytokine patterns in HIV infection than originally proposed by the TH1/TH2 dichotomy.
authors.affiliation: Department of Sexually Transmitted Diseases, University College London Medical School, UK.
authors.forename: A
authors.initials: A
authors.lastname: Fakoya
authors.forename: P M
authors.initials: PM
authors.lastname: Matear
authors.forename: E
authors.initials: E
authors.lastname: Filley
authors.forename: G A
authors.initials: GA
authors.lastname: Rook
authors.forename: J
authors.initials: J
authors.lastname: Stanford
authors.forename: R J
authors.initials: RJ
authors.lastname: Gilson
authors.forename: N
authors.initials: N
authors.lastname: Beecham
authors.forename: I V
authors.initials: IV
authors.lastname: Weller
authors.forename: A
authors.initials: A
authors.lastname: Vyakarnam
mesh_terms: D018791:CD4 Lymphocyte Count; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis*; D015658:HIV Infections / Q000276:immunology*; D018023:HIV Seronegativity; D015497:HIV-1; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008137:Longitudinal Studies; D008934:Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D016207:Cytokines; D007376:Interleukin-2; D008934:Mitogens; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma