title: Imaging of germinal center selection events during affinity maturation.
abstract: The germinal center (GC) is an important site for the generation and selection of B cells bearing high-affinity antibodies, yet GC cell migration and interaction dynamics have not been directly observed. Using two-photon microscopy of mouse lymph nodes, we revealed that GC B cells are highly motile and extend long cell processes. They transited between GC dark and light zones and divided in both regions, although these B cells resided for only several hours in the light zone where antigen is displayed. GC B cells formed few stable contacts with GC T cells despite frequent encounters, and T cells were seen to carry dead B cell blebs. On the basis of these observations, we propose a model in which competition for T cell help plays a more dominant role in the selection of GC B cells than previously appreciated.
authors.affiliation: Howard Hughes Medical Institute and Department of Microbiology and Immunology, University of California, San Francisco, CA 94143, USA.
authors.forename: Christopher D C
authors.initials: CD
authors.lastname: Allen
authors.forename: Takaharu
authors.initials: T
authors.lastname: Okada
authors.forename: H Lucy
authors.initials: HL
authors.lastname: Tang
authors.forename: Jason G
authors.initials: JG
authors.lastname: Cyster
mesh_terms: D000818:Animals; D000915:Antibody Affinity; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000502:physiology; D002453:Cell Cycle; D016923:Cell Death; D002465:Cell Movement; D020566:Dendritic Cells, Follicular / Q000166:cytology / Q000502:physiology; D018858:Germinal Center / Q000166:cytology / Q000276:immunology*; D008264:Macrophages / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008853:Microscopy / Q000379:methods; D018448:Models, Immunological; D009154:Mutation; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000502:physiology