title: IL-10 and TGF-beta induce alloreactive CD4+CD25- T cells to acquire regulatory cell function.
abstract: We previously reported that interleukin-10 (IL-10) and transforming growth factor (TGF)-beta treatment of primary mixed lymphocyte reaction (MLR) cultures resulted in secondary alloantigen-specific hyporesponsiveness and protection from graft-versus-host disease (GVHD) lethality. Here, we report that CD4+ T cells recovered from the IL-10- and TGF-beta-treated primary MLR cultures have immunoregulatory function. Tolerized cells significantly inhibited proliferation of naive alloreactive CD4+ T cells in a primary MLR. Inhibition of the naive alloresponse was observed with as few as 1 tolerized cell to 10 naive responder cells. Tolerized cells were able to significantly reduce GVHD lethality when injected with naive alloreactive CD4+ T cells into major histocombatibility class (MHC) II disparate recipients. Rigorous CD25 depletion of the primary MLR had no effect on generation of a regulatory capacity, suggesting that the regulatory cells likely originated from CD4+CD25- T cells. Immune suppression was mediated independently of IL-10 and TGF-beta production, as neutralizing antibodies for IL-10, IL-10R, and TGF-beta were unable to revert suppression, and IL-10- deficient CD4+ T cells were able to mediate in vitro and in vivo suppression. The generation of immunoregulatory cells from a CD4+CD25- population during tolerization with IL-10 and TGF-beta provides an additional mechanism to prevent GVHD lethality by T cells that may escape full tolerance induction.
authors.affiliation: University of Minnesota Cancer Center and Department of Pediatrics, Division of Bone Marrow Transplantation, Minneapolis, MN 55455, USA.
authors.forename: Zong-ming
authors.initials: ZM
authors.lastname: Chen
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: O'Shaughnessy
authors.forename: Irene
authors.initials: I
authors.lastname: Gramaglia
authors.forename: Angela
authors.initials: A
authors.lastname: Panoskaltsis-Mortari
authors.forename: William J
authors.initials: WJ
authors.lastname: Murphy
authors.forename: Satwant
authors.initials: S
authors.lastname: Narula
authors.forename: Maria G
authors.initials: MG
authors.lastname: Roncarolo
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Blazar
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D006086:Graft vs Host Disease / Q000401:mortality / Q000517:prevention & control; D007108:Immune Tolerance; D016753:Interleukin-10 / Q000276:immunology / Q000494:pharmacology*; D007519:Isoantigens / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008810:Mice, Inbred C57BL; D018123:Receptors, Interleukin / Q000276:immunology; D053701:Receptors, Interleukin-10; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000494:pharmacology*
chemical_list: D000906:Antibodies; D007519:Isoantigens; D018123:Receptors, Interleukin; D053701:Receptors, Interleukin-10; D015375:Receptors, Interleukin-2; D016212:Transforming Growth Factor beta; D016753:Interleukin-10