title: Analysis of antigen-stimulated B cell migration into germinal centers during the early stage of a T-dependent immune response.
abstract: The quasimonoclonal (QM) mouse provides a model to analyze B cell selection because major B cell antigen receptors (BCR) are composed of the knockin V(H)DJ(H) 17.2.25 (V(H)T) encoded H chain and the lambda1 or lambda2 L chain, thereby being specific for (4-hydoxy-3-nitrophenyl)acetyl (NP). We have reported that during a T-dependent antibody (Ab) response for a low-affinity NP analog p-nitrophenylacetyl (pNP), although V(H)T/lambda1 and V(H)T/lambda2 IgM were equally produced, V(H)T/lambda2 IgG almost exclusively underwent affinity maturation toward pNP. The initial affinity of V(H)T/lambda2 B cells for pNP was approximately 50-100-fold higher than that of V(H)T/lambda1 B cells, suggesting a role of BCR affinity in recruiting B cells to affinity maturation processes. Here, we investigated whether the intensity of BCR signals could contribute to the selection of V(H)T/lambda2 B cells for affinity maturation. V(H)T/lambda2 B cells were more responsive to pNP than V(H)T/lambda1 B cells in vitro. When CFSE-labeled QM B cells were transferred into the wild type mice where T cells had been primed with chicken gamma-globulin (CGG), QM B cells challenged by pNP-conjugated CGG could be observed to get activated and migrate to GCs in the early phase of the T-dependent response to pNP-CGG. Adoptive transfer of sorted populations revealed that the V(H)T/lambda2 B cell population was more potent in migration into GCs than the V(H)T/lambda1 counterpart. Thus, it is suggested that the higher BCR affinity of V(H)T/lambda2 B cells may be an initial cue for their recruitment to GCs during a T-dependent Ab response.
authors.affiliation: Department of Bioscience and Biotechnology, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-Naka, Okayama 700-8530, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Kouyama
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishikawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Okazawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Magari
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ohmori
authors.forename: Naoki
authors.initials: N
authors.lastname: Kanayama
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology*; D018858:Germinal Center / Q000276:immunology*; D007143:Immunoglobulin Heavy Chains / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D009596:Nitrophenols / Q000737:chemistry / Q000276:immunology; D010648:Phenylacetates; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D007143:Immunoglobulin Heavy Chains; D009596:Nitrophenols; D010648:Phenylacetates; D011947:Receptors, Antigen, B-Cell; C026242:4-hydroxy-5-nitrophenyl acetic acid