title: Identification and characterization of B cell precursors in rat lymphoid tissues. I. Adoptive transfer assays for precursors of TI-1, TI-2, and TD antigen-reactive B cells.
abstract: Quantitative adoptive transfer assays were developed to detect the precursors of TI-1, TI-2, and TD antigen-reactive B cells in rat lymphoid tissues. Studies on the immune responses in normal and athymic nude rats validate the use of TNP-lipopolysaccharide as a TI-1 antigen, TNP-Ficoll as a TI-2 antigen, and SRBC as a TD antigen in rats. The precursors to these immunologically competent B cells are detected, following transfer into irradiated histocompatible recipients, by their ability to generate expanded populations of antigen-reactive B cells capable of mounting antibody responses (splenic IgM plaque-forming cells) to these antigens. Maximal numbers of antigen-reactive B cells emerge in antigenically naive rats after an interval of 7-12 days following transfer of donor lymphoid cells and decline rapidly thereafter. The delayed responses in adoptive recipients reconstituted with spleen cells are proportional to the numbers of spleen cells transferred and are shown to be primarily donor derived using histocompatible Ig kappa chain alloantigen disparate rat strain combinations. The precursors of TI-1, TI-2, and TD antigen-reactive B cells are present in both donor spleen and bone marrow. However, precursor cells to TI-1 and TD antigens are largely absent from donor lymph node cells, whereas precursors to the TI-2 antigen are as prevalent in donor lymph node as in donor spleen. These results support the hypothesis that newly formed virginal B cells represent transient populations of precursor cells that undergo further proliferation and differentiation in the spleen before acquiring immunological competence. The results also suggest that the precursors of TI-2 antigen-reactive B cells differ developmentally from those of TI-1 and TD antigen-reactive B cells, and that the antigen-reactive progeny of these precursors require additional stimulation in order to join the pool of long-lived peripheral B cells.
authors.affiliation: Department of Pathology, University of Connecticut Health Center, Farmington 06030-3105.
authors.forename: B J
authors.initials: BJ
authors.lastname: Whalen
authors.forename: I
authors.initials: I
authors.lastname: Goldschneider
mesh_terms: D000818:Animals; D000955:Antigens, T-Independent / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D005362:Ficoll / Q000031:analogs & derivatives / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006462:Hemolytic Plaque Technique; D007075:Immunoglobulin M / Q000096:biosynthesis; D016219:Immunotherapy, Adoptive; D008070:Lipopolysaccharides / Q000276:immunology; D008221:Lymphoid Tissue / Q000166:cytology*; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D011919:Rats, Inbred Strains; D011923:Rats, Nude; D012756:Sheep / Q000276:immunology; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D000955:Antigens, T-Independent; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; C020529:TNP-ficoll; D014301:Trinitrobenzenes; C048761:trinitrophenyl-lipopolysaccharide; D005362:Ficoll