title: Cooperation between platelet-derived CD154 and CD4+ T cells for enhanced germinal center formation.
abstract: It has been demonstrated previously that platelet-derived CD154 communicates with the adaptive immune compartment, enhancing B and T cell responses in CD154(-/-) mice. The presence of platelets was also shown to be necessary for optimal production of immunoglobulin G (IgG) in normal C57BL/6 mice. These data led us to hypothesize that platelets perform a sentinel function, quickly relaying activating signals to the adaptive immune compartment. Here, we report that platelet-derived CD154 increases serum IgG levels and germinal center formation under conditions where antigen-specific CD4(+) T cell numbers are limiting. We propose that in the physiologic setting where antigen-specific B and T cells are rare, platelets function to enhance signals required for robust adaptive humoral immunity.
authors.affiliation: Department of Urology, Iowa City, IA 52242, USA.
authors.forename: Bennett D
authors.initials: BD
authors.lastname: Elzey
authors.forename: Julieann F
authors.initials: JF
authors.lastname: Grant
authors.forename: Haley W
authors.initials: HW
authors.lastname: Sinn
authors.forename: Bernhard
authors.initials: B
authors.lastname: Nieswandt
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Waldschmidt
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Ratliff
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D023201:CD40 Ligand / Q000276:immunology*; D002450:Cell Communication / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D018858:Germinal Center / Q000166:cytology / Q000276:immunology*; D007111:Immunity, Cellular / Q000276:immunology; D007113:Immunity, Innate / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood / Q000276:immunology; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D015398:Signal Transduction / Q000276:immunology; D015854:Up-Regulation / Q000276:immunology*
chemical_list: D000939:Epitopes; D007074:Immunoglobulin G; D023201:CD40 Ligand