title: In vitro production of type 1 and type 2 cytokines by peripheral blood mononuclear cells from high-risk HIV-negative intravenous drug users.
abstract: OBJECTIVE
  To study type 1 and type 2 cytokine patterns in HIV-negative high-risk intravenous drug users (IVDU).
  
  
  METHODS
  We investigated interleukin (IL)-2, interferon (IFN)-gamma, IL-4, IL-6 and IL-10 production by phytohaemagglutinin (PHA)-stimulated and unstimulated peripheral blood mononuclear cell (PBMC) cultures from HIV-negative high-risk IVDU, HIV-negative controls and HIV-positive subjects.
  
  
  METHODS
  Cytokine production was measured in supernatants using enzyme-linked immunosorbent assay (ELISA) in 10 HIV-negative high-risk IVDU, 25 HIV-negative controls, and 12 HIV-positive IVDU. We also determined spontaneous in vitro immunoglobulin (Ig) G and IgM production.
  
  
  RESULTS
  HIV-negative high-risk IVDU showed increased IFN-gamma and decreased IL-4, IL-10 and IL-2, although the latter was not significant compared with HIV-negative controls. Further, HIV-negative high-risk IVDU had reduced IgG production and impaired IgM-IgG switch.
  
  
  CONCLUSIONS
  The reduced IL-2 and IL-4 production suggest an impaired CD4+ T-cell function in HIV-negative high-risk IVDU. The increased IFN-gamma production along with the decreased type 2 cytokine profile is consistent with the hypothesis that protective immunity against HIV may reside in type 1 responses and cell-mediated immunity.
authors.affiliation: Institute of Internal Medicine, Infectious Diseases and Immunopathology, University of Milan, Italy.
authors.forename: W
authors.initials: W
authors.lastname: Barcellini
authors.forename: G P
authors.initials: GP
authors.lastname: Rizzardi
authors.forename: C
authors.initials: C
authors.lastname: Velati
authors.forename: M O
authors.initials: MO
authors.lastname: Borghi
authors.forename: C
authors.initials: C
authors.lastname: Fain
authors.forename: A
authors.initials: A
authors.lastname: Lazzarin
authors.forename: P L
authors.initials: PL
authors.lastname: Meroni
mesh_terms: D000293:Adolescent; D000328:Adult; D016207:Cytokines / Q000096:biosynthesis* / Q000097:blood; D018023:HIV Seronegativity; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000097:blood; D016753:Interleukin-10 / Q000096:biosynthesis / Q000097:blood; D015847:Interleukin-4 / Q000096:biosynthesis / Q000097:blood; D015850:Interleukin-6 / Q000096:biosynthesis / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D010835:Phytohemagglutinins; D015819:Substance Abuse, Intravenous / Q000097:blood*
chemical_list: D016207:Cytokines; D015850:Interleukin-6; D010835:Phytohemagglutinins; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma