title: CD1-restricted T-cells influence IgG subclass and IgE production.
abstract: BACKGROUND
  Human CD1 has recently emerged as a third family of antigen-presenting molecules that is distinct from either major histocompatibility complex class I or class II.
  
  
  OBJECTIVE
  We investigated whether the CD1b-restricted T-cell interaction with antigen alters human IgG subclass and IgE isotype production.
  
  
  METHODS
  CD1b-restricted antigen-specific T cells derived from the skin lesion of a patient with leprosy were stimulated with their cognate antigen, lipoarabinomman (LAM) of Mycobacterium leprae, in the presence of CD1+ antigen-presenting cells and tested for their ability to alter IgG subclass and IgE production from IgD+ B cells.
  
  
  RESULTS
  CD1-restricted T cells cultured with CD1+ antigen-presenting cells in the absence of LAM induced IgG1, IgG3, IgG4, and IgE, whereas CD1b-restricted T cells cultured in the presence of LAM induced IgG1 and IgG3 and inhibited production of IgG4 and IgE. Production of IgG4 and IgE was rescued in the CD1-restricted system by the addition of anti-interferon-gamma. IgG2 production was not induced under any circumstances.
  
  
  CONCLUSIONS
  In this study we demonstrated that a specific CD1b-restricted T-cell line can behave similarly to classically-restricted Th1-type T cells. CD1b-restricted T-cells of this type may regulate immune responses to microbial pathogens by simultaneously enhancing cell-mediated immunity and downregulating IgG4 and IgE responses.
authors.affiliation: Department of Medicine, UCLA School of Medicine, Los Angeles, Calif, USA.
authors.forename: S
authors.initials: S
authors.lastname: Fujieda
authors.forename: P A
authors.initials: PA
authors.lastname: Sieling
authors.forename: R L
authors.initials: RL
authors.lastname: Modlin
authors.forename: A
authors.initials: A
authors.lastname: Saxon
mesh_terms: D000938:Antigen-Presenting Cells / Q000502:physiology; D018949:Antigens, CD1 / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification*; D007371:Interferon-gamma / Q000502:physiology; D015847:Interleukin-4 / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D018949:Antigens, CD1; D007074:Immunoglobulin G; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma