title: Massive number of antigen-specific CD4 T cells during vaccination with live attenuated Salmonella causes interclonal competition.
abstract: The clonal burst size of CD4 T cells is predicted to be less than that of CD8 T cells. In this study, we demonstrate that massive numbers of Ag-specific CD4 T cells respond during vaccination of mice with live attenuated Salmonella, reaching a peak frequency of approximately 50% of CD4 T cells. Salmonella-specific T cells persisted at high frequency for several weeks and could be detected in the memory population for months after infection. Surprisingly, the expansion of endogenous Salmonella-specific CD4 T cells prevented the persistence of adoptively transferred Salmonella-specific T cells in vivo, demonstrating interclonal competition for access to the memory compartment.
authors.affiliation: Department of Medicine, Division of Immunology, University of Connecticut Health Center, Farmington, CT 06030, USA.
authors.forename: Aparna
authors.initials: A
authors.lastname: Srinivasan
authors.forename: Joseph
authors.initials: J
authors.lastname: Foley
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: McSorley
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D040881:CD11a Antigen / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D022562:Salmonella Vaccines / Q000276:immunology*; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000276:immunology
chemical_list: D040881:CD11a Antigen; D011948:Receptors, Antigen, T-Cell; D022562:Salmonella Vaccines; D014613:Vaccines, Attenuated; D007371:Interferon-gamma