title: Innate immune responses support adaptive immunity: NKT cells induce B cell activation.
abstract: Invariant NKT cells are a peculiar subset of T lymphocytes whose features, highly conserved both in the mouse and the human system, strongly recall those of other "innate lymphocytes". Following recognition of CD1d-presented glycosphingolipid antigens invariant NKT promptly release high amount of diverse cytokines concurring to the activation of the actors of both innate and acquired immune responses. For this reason, in recent years NKT cells have been the object of intensive study, aimed to understand their role in diverse patho-physiological conditions and to exploit the possibility to take advantage of their "adjuvant-like" activity in the formulation of new vaccines. As antibodies are an essential part of many immune responses, we focused our attention on invariant NKT-B cell interactions analyzing their influences on B cell activation and effector functions. The results of this study demonstrate that human invariant NKT cells can provide direct help for B cell proliferation and antibody production through CD1d-restricted mechanisms. Remarkably, help to B lymphocytes by invariant NKT cells is delivered also in the absence of exogenous antigen, suggesting the existence of an endogenous ligand presented by CD1d on B cells.
authors.affiliation: IRIS Research Center, Chiron Vaccines, Via Fiorentina 1, I-53100 Siena, Italy.
authors.forename: Grazia
authors.initials: G
authors.lastname: Galli
authors.forename: Sandra
authors.initials: S
authors.lastname: Nuti
authors.forename: Simona
authors.initials: S
authors.lastname: Tavarini
authors.forename: Luisa
authors.initials: L
authors.lastname: Galli-Stampino
authors.forename: Claudia
authors.initials: C
authors.lastname: De Lalla
authors.forename: Giulia
authors.initials: G
authors.lastname: Casorati
authors.forename: Paolo
authors.initials: P
authors.lastname: Dellabona
authors.forename: Sergio
authors.initials: S
authors.lastname: Abrignani
mesh_terms: D018949:Antigens, CD1 / Q000502:physiology; D055610:Antigens, CD1d; D001402:B-Lymphocytes / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation
chemical_list: D018949:Antigens, CD1; D055610:Antigens, CD1d; C526877:CD1D protein, human