title: Regulatory T cells in the control of host-microorganism interactions (*).
abstract: Each microenvironment requires a specific set of regulatory elements that are finely and constantly tuned to maintain local homeostasis. Various populations of regulatory T cells contribute to the maintenance of this equilibrium and establishment of controlled immune responses. In particular, regulatory T cells limit the magnitude of effector responses, which may result in failure to adequately control infection. However, regulatory T cells also help limit collateral tissue damage caused by vigorous antimicrobial immune responses against pathogenic microbes as well as commensals. In this review, we describe various situations in which the balance between regulatory T cells and effector immune functions influence the outcome of host-microorganism coexistence and discuss current hypotheses and points of polemic associated with the origin, target, and antigen specificity of both endogenous and induced regulatory T cells during these interactions.
authors.affiliation: Mucosal Immunology Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA. ybelkaid@niaid.nih.gov
authors.forename: Yasmine
authors.initials: Y
authors.lastname: Belkaid
authors.forename: Kristin
authors.initials: K
authors.lastname: Tarbell
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D016207:Cytokines / Q000276:immunology* / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000276:immunology / Q000378:metabolism; D006706:Homeostasis / Q000276:immunology; D054884:Host-Pathogen Interactions / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D007155:Immunologic Factors / Q000276:immunology / Q000378:metabolism; D007239:Infections / Q000276:immunology* / Q000382:microbiology / Q000469:parasitology; D008213:Lymphocyte Activation / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000382:microbiology / Q000469:parasitology
chemical_list: D016207:Cytokines; D051858:Forkhead Transcription Factors; D007155:Immunologic Factors