title: Gamma delta T cells in normal spleen assist immunized alpha beta T cells in the adoptive cell transfer of contact sensitivity. Effect of Bordetella pertussis, cyclophosphamide, and antibodies to determinants on suppressor cells.
abstract: Our prior studies showed that gamma delta T cells were required to assist alpha beta T cells in the successful adoptive cell transfer of contact sensitivity (CS) responsiveness. These TCR-gamma delta+ regulatory T cells in immune spleen and lymph node were CD3+, CD4-, CD8+, nonantigen-specific, and non-MHC-restricted. In the current work, experiments were conducted to determine the mechanisms of how the gamma delta T cells were required to assist the alpha beta T cells in CS. We found that similar regulatory gamma delta T cells were in the spleen of normal mice, but not in the spleen of nude nor SCID mice, suggesting that the regulatory gamma delta T cells were present before immunization and required the thymus for differentiation, and also required rearrangements of gamma delta V gene segments. Treatment of cell transfer recipient mice with Bordetella pertussis (Bp), or with a low dose of cyclophosphamide (50 mg/kg), restored the ability of alpha beta+ gamma delta- T cells to transfer CS. This and other results suggested that Bp caused the CS-assisting gamma delta T cells to leave the lymphoid organs (such as the spleen) and enter the circulation, and only then to be able to assist the TCR-alpha beta+ CS-effector T cells. This effect needed the simultaneous i.v. injection of the CS-effector alpha beta T cells and the CS-assisting gamma delta T cells. The results also suggested that treatment with cyclophosphamide inactivated suppressor T cells in the recipients that acted to inhibit the alpha beta T cell transfer of CS, and thus that the CS-assisting gamma delta T cells acted by protecting the CS-effector alpha beta T cells from this endogenous suppression. This suppression of CS transfers also was eliminated by treatment of recipients with two different mAbs to determinants on suppressor T cells. In conclusion, we have described regulatory TCR-gamma delta+ CS-assisting/protecting T cells that are non-antigen-specific, non-MHC-restricted, CD3+, CD8+ gamma delta T cells that may assist adoptive transferring CS-effector alpha beta T cells by making these effector T cells resistant to suppressor T cells in the normal recipients.
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: P W
authors.initials: PW
authors.lastname: Askenase
authors.forename: M
authors.initials: M
authors.lastname: Szczepanik
authors.forename: M
authors.initials: M
authors.lastname: Ptak
authors.forename: V
authors.initials: V
authors.lastname: Paliwal
authors.forename: W
authors.initials: W
authors.lastname: Ptak
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D001886:Bordetella pertussis / Q000276:immunology; D003520:Cyclophosphamide / Q000494:pharmacology; D003877:Dermatitis, Contact / Q000276:immunology*; D007116:Immunization, Passive; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D013154:Spleen / Q000166:cytology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D003520:Cyclophosphamide