title: Altered affinity maturation in primary response to (4-hydroxy-3-nitrophenyl) acetyl (NP) after autologous reconstitution of irradiated C57BL/6 mice.
abstract: Immune responses developing in irradiated environment are profoundly altered. The memory anti-arsonate response of A/J mice is dominated by a major clonotype encoded by a single gene segment combination called CRIA. In irradiated and autoreconstituted A/J mice, the level of anti-ARS antibodies upon secondary immunization is normal but devoid of CRIA antibodies. The affinity maturation process and the somatic mutation frequency are reduced. Isotype switching and development of germinal centers (GC) are delayed. The primary antibody response of C57BL/6 mice to the hapten (4-hydroxy-3-nitrophenyl) acetyl (NP)-Keyhole Limpet Hemocyanin (KLH) is dominated by antibodies encoded by a family of closely related VH genes associated with the expression of the lambda1 light chain.We investigated the anti-NP primary response in irradiated and autoreconstituted C57BL/6 mice. We observed some splenic alterations as previously described in the irradiated A/J model. Germinal center reaction is delayed although the extrafollicular foci appearance is unchanged. Irradiated C57BL/6 mice are able to mount a primary anti-NP response dominated by lambda1 positive antibodies but fail to produce high affinity NP-binding IgG1 antibodies. Following a second antigenic challenge, irradiated mice develop enlarged GC and foci. Furthermore, higher affinity NP-binding IgG1 antibodies are detected.
authors.affiliation: Universite Libre de Bruxelles, Institut de Biologie et de Médecine Moléculaires, Laboratory of Animal Physiology, 12 rue des Profs Jeener et Brachet, Gosselies 6041, Belgium.
authors.forename: Carl
authors.initials: C
authors.lastname: de Trez
authors.forename: Annette
authors.initials: A
authors.lastname: van Acker
authors.forename: Georgette
authors.initials: G
authors.lastname: Vansanten
authors.forename: Jacques
authors.initials: J
authors.lastname: Urbain
authors.forename: Maryse
authors.initials: M
authors.lastname: Brait
mesh_terms: D000818:Animals; D000906:Antibodies / Q000097:blood / Q000276:immunology*; D000915:Antibody Affinity / Q000528:radiation effects; D001402:B-Lymphocytes / Q000276:immunology / Q000528:radiation effects; D018858:Germinal Center / Q000276:immunology / Q000528:radiation effects; D006241:Haptens / Q000276:immunology; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009596:Nitrophenols / Q000008:administration & dosage / Q000276:immunology*; D010648:Phenylacetates; D011828:Radiation Chimera; D013154:Spleen / Q000276:immunology / Q000528:radiation effects; D013601:T-Lymphocytes / Q000276:immunology / Q000528:radiation effects
chemical_list: D000906:Antibodies; D006241:Haptens; D007074:Immunoglobulin G; D009596:Nitrophenols; D010648:Phenylacetates; C026242:4-hydroxy-5-nitrophenyl acetic acid