title: B cell-specific expression of B7-2 is required for follicular Th cell function in response to vaccinia virus.
abstract: Follicular Th (T(FH)) cells are specialized in provision of help to B cells that is essential for promoting protective Ab responses. CD28/B7 (B7-1 and B7-2) interactions are required for germinal center (GC) formation, but it is not clear if they simply support activation of naive CD4 T cells during initiation of responses by dendritic cells or if they directly control T(FH) cells and/or directly influence follicular B cell differentiation. Using a model of vaccinia virus infection, we show that B7-2 but not B7-1 deficiency profoundly impaired T(FH) cell development but did not affect CD4 T cell priming and Th1 differentiation. Consistent with this, B7-2 but not B7-1 was required for acquisition of GC B cell phenotype, plasma cell generation, and virus-specific neutralizing Ab responses. Mixed adoptive transfer experiments indicated that bidirectional interactions between CD28 expressed on activated T cells and B7-2 expressed on follicular B cells were essential for maintenance of the T(FH) phenotype and GC B cell development. Our data provide new insight into the source and nature of molecules required for T(FH) cells to direct GC B cell responses.
authors: Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, San Diego, CA 92037, USA.
authors: Samira
authors: S
authors: Salek-Ardakani
authors: Youn Soo
authors: YS
authors: Choi
authors: Mohammed
authors: M
authors: Rafii-El-Idrissi Benhnia
authors: Rachel
authors: R
authors: Flynn
authors: Ramon
authors: R
authors: Arens
authors: Stephen
authors: S
authors: Shoenberger
authors: Shane
authors: S
authors: Crotty
authors: Michael
authors: M
authors: Croft
authors: Shahram
authors: S
authors: Salek-Ardakani
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D051940:B7-2 Antigen / Q000096:biosynthesis / Q000276:immunology*; D018106:CD28 Antigens / Q000096:biosynthesis / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002469:Cell Separation; D005260:Female; D005434:Flow Cytometry; D018858:Germinal Center / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010950:Plasma Cells / Q000166:cytology / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014615:Vaccinia / Q000276:immunology*; D014616:Vaccinia virus / Q000276:immunology
chemical_list: D051940:B7-2 Antigen; D018106:CD28 Antigens