title: B-cell fate decisions following influenza virus infection.
abstract: Rapidly induced, specific Ab generated in extrafollicular foci are important components of early immune protection to influenza virus. The signal(s) that prompt B cells to participate in extrafollicular rather than germinal center responses are incompletely understood. To study the regulation of early B-cell differentiation events following influenza infection, we exploited earlier findings of a strong contribution of C12 idiotype-expressing B cells to the primary HA-specific response against influenza A/PR/8/34. Using an idiotype-specific mAb to C12 and labeled HA, in conjunction with multicolor flow cytometry, we followed the fate of C12Id-expressing influenza HA-specific B cells in WT BALB/c mice, requiring neither genetic manipulation nor adoptive cell transfer. Our studies demonstrate that HA-specific C12Id(+) B cells are phenotypically indistinguishable from follicular B cells. While they induced both extrafollicular and germinal center responses, extrafollicular responses were strongly predominant. Provision of increased HA-specific T-cell help increased the magnitude of the extrafollicular response, but did not shift the C12Id(+) response toward germinal center formation. Collectively the data are consistent with the hypothesis that B-cell fate determination following activation is a stochastic process in which infection-induced innate signals might drive the preferential expansion of the early extrafollicular response.
authors: The Graduate Group Immunology, University of California-Davis, Davis, CA, USA.
authors: Kristina
authors: K
authors: Rothaeusler
authors: Nicole
authors: N
authors: Baumgarth
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology; D000914:Antibodies, Viral / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D018858:Germinal Center / Q000276:immunology / Q000378:metabolism; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology; D007130:Immunoglobulin Idiotypes / Q000235:genetics / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000235:genetics / Q000276:immunology; D009980:Influenza A virus / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009976:Orthomyxoviridae Infections / Q000276:immunology* / Q000821:virology
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007130:Immunoglobulin Idiotypes; D007132:Immunoglobulin Isotypes