title: T lymphocyte recognition of human group 1 CD1 molecules: implications for innate and acquired immunity.
abstract: Recent evidence has established that non-MHC-encoded molecules of the CD1 family mediate MHC-independent pathways for antigen presentation and T cell activation. Human group 1 CD1 molecules (CD1a, CD1b, CD1c) are expressed mainly on professional antigen-presenting cells, and mediate presentation of microbial lipid and glycolipid antigens to T cells. These group 1 CD1 molecules differentially sample distinct endocytic compartments that may contain different sets of lipid antigens derived from intracellular microbes, and activate antigen-specific T cells. These T cells lyse infected antigen-presenting cells and secrete Th1 cytokines, such as interferon- gamma, and granulysin, a potent antimicrobial protein, and thus can control microbial infection. Reactivity to CD1a, b, and c molecules in the absence of foreign antigen has also been detected in T cells bearing alphabeta and gammadelta TCRs. These T cells may recognize self-lipid antigens and are considered to be autoreactive. In particular, the main tissue subset of gammadelta T cells (V delta 1(+)subset) show prominent reactivity to CD1c, and produce interferon- gamma and granulysin. These CD1c directly reactive T cells may mediate immunity against microbial infection even before antigen-specific T cells differentiate and expand. Together, human CD1a, b and c molecules elicit T cell-dependent immunity to the universe of foreign and self-lipid antigens in both innate and acquired immunity settings.
authors.affiliation: Lymphocyte Biology Section, Division of Rheumatology, Immunology, and Allergy, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: M
authors.initials: M
authors.lastname: Sugita
authors.forename: M B
authors.initials: MB
authors.lastname: Brenner
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D018949:Antigens, CD1 / Q000378:metabolism*; D006801:Humans; D007110:Immunity, Active; D007113:Immunity, Innate; D008213:Lymphocyte Activation / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*
chemical_list: D018949:Antigens, CD1