title: Survival of long-lived plasma cells is independent of antigen.
abstract: Recent studies have shown that persistent specific antibody titer is provided by long-lived plasma cells (PC) which constitute a new kind of 'memory-providing cells'. In the present study, we examine the role of antigen for the long-term survival of PC and the maintenance of specific serum antibody titers. Using a novel cytometric technology, to identify and isolate antigen-specific PC, we analyzed long-lived PC of BALB/c mice, during their development (between day 1 and 10) after secondary immunization with ovalbumin (OVA) and in the phase of the established immune reaction. Most if not all OVA-specific PC were generated within a few days after immunization. Within approximately 3 weeks, they matured, as indicated by down-regulation of expression of MHC class II. These PC are long lived and located in spleen and bone marrow. Upon adoptive transfer, OVA-specific PC from bone marrow, but not memory B cells, conferred specific and long-lasting antibody titers to antigen-free IgH syngeneic recipients. In response to antigenic challenge, new OVA-specific antibody-secreting cells were generated from transferred memory B cells. Antibody secretion by long-lived PC was not affected. Our results confirm that persistent antibody titers are provided by long-lived PC, independent of memory B cells and demonstrate that this humoral memory is inert to antigen.
authors.affiliation: Deutsches Rheuma-Forschungszentrum, Berlin, Germany.
authors.forename: R A
authors.initials: RA
authors.lastname: Manz
authors.forename: M
authors.initials: M
authors.lastname: Löhning
authors.forename: G
authors.initials: G
authors.lastname: Cassese
authors.forename: A
authors.initials: A
authors.lastname: Thiel
authors.forename: A
authors.initials: A
authors.lastname: Radbruch
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000906:Antibodies / Q000097:blood; D000941:Antigens / Q000276:immunology*; D001402:B-Lymphocytes; D001854:Bone Marrow Cells / Q000276:immunology; D002470:Cell Survival; D005434:Flow Cytometry; D006681:HLA-D Antigens / Q000378:metabolism; D007117:Immunization, Secondary; D007156:Immunologic Memory; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D010950:Plasma Cells / Q000166:cytology* / Q000276:immunology*; D013154:Spleen / Q000166:cytology
chemical_list: D000906:Antibodies; D000941:Antigens; D006681:HLA-D Antigens; D010047:Ovalbumin