title: Leukocyte homing, fate, and function are controlled by retinoic acid.
abstract: Although vitamin A was recognized as an "anti-infective vitamin" over 90 years ago, the mechanism of how vitamin A regulates immunity is only beginning to be understood. Early studies which focused on the immune responses in vitamin A-deficient (VAD) animals clearly demonstrated compromised immunity and consequently increased susceptibility to infectious disease. The active form of vitamin A, retinoic acid (RA), has been shown to have a profound impact on the homing and differentiation of leukocytes. Both pharmacological and genetic approaches have been applied to the understanding of how RA regulates the development and differentiation of various immune cell subsets, and how RA influences the development of immunity versus tolerance. These studies clearly show that RA profoundly impacts on cell- and humoral-mediated immunity. In this review, the early findings on the complex relationship between VAD and immunity are discussed as well as vitamin A metabolism and signaling within hematopoietic cells. Particular attention is focused on how RA impacts on T-cell lineage commitment and plasticity in various diseases.
authors.affiliation: Department of Microbiology and Immunology, Dartmouth Medical School, Norris Cotton Cancer Center, Lebanon, New Hampshire; and Medical Research Council Centre of Transplantation, Guy's Hospital, King's College London, King's Health Partners, London, United Kingdom.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Department of Microbiology and Immunology, Dartmouth Medical School, Norris Cotton Cancer Center, Lebanon, New Hampshire; and Medical Research Council Centre of Transplantation, Guy's Hospital, King's College London, King's Health Partners, London, United Kingdom.
authors.forename: Chrysothemis
authors.initials: C
authors.lastname: Brown
authors.affiliation: Department of Microbiology and Immunology, Dartmouth Medical School, Norris Cotton Cancer Center, Lebanon, New Hampshire; and Medical Research Council Centre of Transplantation, Guy's Hospital, King's College London, King's Health Partners, London, United Kingdom.
authors.forename: Carla
authors.initials: C
authors.lastname: Ortiz
authors.affiliation: Department of Microbiology and Immunology, Dartmouth Medical School, Norris Cotton Cancer Center, Lebanon, New Hampshire; and Medical Research Council Centre of Transplantation, Guy's Hospital, King's College London, King's Health Partners, London, United Kingdom.
authors.forename: Randolph J
authors.initials: RJ
authors.lastname: Noelle
mesh_terms: D000818:Animals; D006801:Humans; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007962:Leukocytes / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D015398:Signal Transduction; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D014212:Tretinoin