title: Concurrent induction of antitumor immunity and autoimmune thyroiditis in CD4+ CD25+ regulatory T cell-depleted mice.
abstract: When CD4+ CD25+ regulatory T cells are depleted or inactivated for the purpose of enhancing antitumor immunity, the risk of autoimmune disease may be significantly elevated because these regulatory T cells control both antitumor immunity and autoimmunity. To evaluate the relative benefit and risk of modulating CD4+ CD25+ regulatory T cells, we established a new test system to measure simultaneously the immune reactivity to a tumor-associated antigen, neu, and an unrelated self-antigen, thyroglobulin. BALB/c mice were inoculated with TUBO cells expressing an activated rat neu and treated with anti-CD25 monoclonal antibody to deplete CD25+ cells. The tumors grew, then regressed, and neu-specific antibodies and IFN-gamma-secreting T cells were induced. The same mice were also exposed to mouse thyroglobulin by chronic i.v. injections. These mice produced thyroglobulin-specific antibody and IFN-gamma-secreting T cells with inflammatory infiltration in the thyroids of some mice. The immune responses to neu or thyroglobulin were greater in mice undergoing TUBO tumor rejection and thyroglobulin injection than in those experiencing either alone. To the best of our knowledge, this is the first experimental system to assess the concurrent induction and possible synergy of immune reactivity to defined tumor and self-antigens following reduction of regulatory T cells. These results illustrate the importance of monitoring immune reactivity to self-antigens during cancer immunotherapy that involves immunomodulating agents, and the pressing need for novel strategies to induce antitumor immunity while minimizing autoimmunity.
authors.affiliation: Karmanos Cancer Institute, Wayne State University, Detroit, Michigan 48201, USA. weiw@karmanos.org
authors.forename: Wei-Zen
authors.initials: WZ
authors.lastname: Wei
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Jacob
authors.forename: John F
authors.initials: JF
authors.lastname: Zielinski
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Flynn
authors.forename: K David
authors.initials: KD
authors.lastname: Shim
authors.forename: Ghazwan
authors.initials: G
authors.lastname: Alsharabi
authors.forename: Alvaro A
authors.initials: AA
authors.lastname: Giraldo
authors.forename: Yi-chi M
authors.initials: YC
authors.lastname: Kong
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D007156:Immunologic Memory; D008325:Mammary Neoplasms, Experimental / Q000276:immunology* / Q000517:prevention & control; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000276:immunology; D013954:Thyroglobulin / Q000096:biosynthesis / Q000276:immunology; D013967:Thyroiditis, Autoimmune / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D018719:Erb-b2 Receptor Tyrosine Kinases; D015375:Receptors, Interleukin-2; D013954:Thyroglobulin