title: A periarteriolar lymphoid sheath-associated B cell focus response is not observed during the development of the anti-arsonate germinal center reaction.
abstract: The behavior of p-azophenylarsonate (Ars)-specific B cell clones during the primary T cell-dependent splenic response of A/J mice was investigated using an immunohistochemical approach. The earliest Ars-specific B cells were observed as isolated cells in the red pulp by day 3 after immunization with Ars-keyhole limpet hemocyanin, (KLH) and at day 6, large clusters of Ars-specific B cells were first detected in germinal centers, which continued to be observed for an additional 8 to 15 days. Surprisingly, no Ars-specific B cell foci were observed in or near the CD4 T cell-rich periarteriolar lymphoid sheath (PALS) during the entire primary response. Nevertheless, A/J mice immunized with (4-hydroxy-3-nitrophenyl)acetyl-chicken gamma globulin (NP-CGG) or Ars-CGG mounted robust splenic (4-hydroxy-3-nitrophenyl)acetyl or CGG-specific PALS-associated focus reactions, respectively. In contrast, no Ars-specific PALS B cell foci were detected in A/J mice immunized with Ars-CGG. These data add to a growing body of evidence indicating that B cell proliferation and differentiation in CD4 T cell-rich microenvironments are not prerequisites for the GC reaction. Taken together with previous results obtained using other model Ags, the data suggest that the specificity of the B cell Ag receptor may strongly influence the lymphoid microenvironment in which a B cell clone first undergoes Ag-driven clonal expansion and differentiation.
authors.affiliation: Department of Microbiology and Immunology, Thomas Jefferson Medical College, Philadelphia, PA 19107, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Vora
authors.forename: K M
authors.initials: KM
authors.lastname: Tumas-Brundage
authors.forename: T
authors.initials: T
authors.lastname: Manser
mesh_terms: D000818:Animals; D001160:Arterioles; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D002645:Chickens; D000939:Epitopes / Q000276:immunology; D018858:Germinal Center / Q000166:cytology / Q000276:immunology*; D008221:Lymphoid Tissue / Q000098:blood supply* / Q000166:cytology / Q000276:immunology*; D051379:Mice; D008805:Mice, Inbred A; D009596:Nitrophenols / Q000276:immunology; D010648:Phenylacetates; D005719:gamma-Globulins / Q000276:immunology; D010132:p-Azobenzenearsonate / Q000276:immunology*
chemical_list: D000939:Epitopes; D009596:Nitrophenols; D010648:Phenylacetates; D005719:gamma-Globulins; C026242:4-hydroxy-5-nitrophenyl acetic acid; D010132:p-Azobenzenearsonate