title: TCR stimulation with modified anti-CD3 mAb expands CD8+ T cell population and induces CD8+CD25+ Tregs.
abstract: Modified anti-CD3 mAbs are emerging as a possible means of inducing immunologic tolerance in settings including transplantation and autoimmunity such as in type 1 diabetes. In a trial of a modified anti-CD3 mAb [hOKT3gamma1(Ala-Ala)] in patients with type 1 diabetes, we identified clinical responders by an increase in the number of peripheral blood CD8+ cells following treatment with the mAb. Here we show that the anti-CD3 mAb caused activation of CD8+ T cells that was similar in vitro and in vivo and induced regulatory CD8+CD25+ T cells. These cells inhibited the responses of CD4+ cells to the mAb itself and to antigen. The regulatory CD8+CD25+ cells were CTLA4 and Foxp3 and required contact for inhibition. Foxp3 was also induced on CD8+ T cells in patients during mAb treatment, which suggests a potential mechanism of the anti-CD3 mAb immune modulatory effects involving induction of a subset of regulatory CD8+ T cells.
authors.affiliation: Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
authors.forename: Brygida
authors.initials: B
authors.lastname: Bisikirska
authors.forename: John
authors.initials: J
authors.lastname: Colgan
authors.forename: Jeremy
authors.initials: J
authors.lastname: Luban
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Bluestone
authors.forename: Kevan C
authors.initials: KC
authors.lastname: Herold
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology*; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D060908:CTLA-4 Antigen; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D051858:Forkhead Transcription Factors / Q000276:immunology; D006801:Humans; D007166:Immunosuppressive Agents / Q000276:immunology / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D016853:Muromonab-CD3 / Q000276:immunology / Q000494:pharmacology*; D015375:Receptors, Interleukin-2 / Q000276:immunology*; D014180:Transplantation; D023001:Transplantation Tolerance / Q000187:drug effects / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D007166:Immunosuppressive Agents; D016853:Muromonab-CD3; D015375:Receptors, Interleukin-2