title: In situ studies of the primary immune response to (4-hydroxy-3-nitrophenyl)acetyl. I. The architecture and dynamics of responding cell populations.
abstract: After primary immunization with an immunogenic conjugate of (4-hydroxy-3-nitrophenyl)acetyl, two anatomically and phenotypically distinct populations of antibody-forming cells arise in the spleen. As early as 2 d after immunization, foci of antigen-binding B cells are observed along the periphery of the periarteriolar lymphoid sheaths. These foci expand, occupying as much as 1% of the splenic volume by day 8 of the response. Later, foci grow smaller and are virtually absent from the spleen by day 14. A second responding population, germinal center B cells, appear on day 8-10 and persist at least until day 16 post-immunization. Individual foci and germinal centers represent discrete pauciclonal populations that apparently undergo somatic evolution in the course of the primary response. We suggest that foci may represent regions of predominantly interclonal competition for antigen among unmutated B cells, while germinal centers are sites of intraclonal clonal competition between mutated sister lymphocytes.
authors.affiliation: Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore 21201.
authors.forename: J
authors.initials: J
authors.lastname: Jacob
authors.forename: R
authors.initials: R
authors.lastname: Kassir
authors.forename: G
authors.initials: G
authors.lastname: Kelsoe
mesh_terms: D000818:Animals; D000906:Antibodies / Q000235:genetics / Q000276:immunology / Q000502:physiology; D000917:Antibody Formation / Q000187:drug effects*; D000941:Antigens / Q000235:genetics / Q000276:immunology / Q000502:physiology; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000235:genetics; D007132:Immunoglobulin Isotypes / Q000235:genetics / Q000276:immunology; D007134:Immunoglobulin Switch Region / Q000235:genetics / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology; D007146:Immunoglobulin lambda-Chains / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009596:Nitrophenols / Q000276:immunology / Q000494:pharmacology*; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D010648:Phenylacetates; D013154:Spleen / Q000166:cytology / Q000276:immunology
chemical_list: D000906:Antibodies; D000941:Antigens; D007132:Immunoglobulin Isotypes; D007135:Immunoglobulin Variable Region; D007146:Immunoglobulin lambda-Chains; D009596:Nitrophenols; D010648:Phenylacetates; C026242:4-hydroxy-5-nitrophenyl acetic acid; D004247:DNA