title: Antigen-specific mouse lymphocyte stimulation by DNP-conjugated T-independent antigens studied by photobleaching recovery.
abstract: Fluorescence photobleaching recovery techniques have allowed us to measure the lateral mobility of T-independent antigens bound to antigen-specific mouse B cells. The in vitro immunogenicity or tolerogenicity of antigens we have examined, DNP-polymerized flagellin (DNP-POL), and DNP-linear dextran (DNP-DEX), depend upon the antigen dose and epitope density. These factors also determine the mobility of antigen bound to B cell surfaces. For DNP-POL bound to DNP-specific cells, the observed diffusion constants D decrease monotonically with increasing antigen dose and epitope density. Values of D range from 10.4 X 10(-11) cm2 sec-1 for DNP0.4-POL at 0.15 microgram/ml to 0.8 X 10(-11) cm2 sec-1 for DNP3.5-POL at 30 microgram/ml. For receptor bound DNP-DEX, D depends strongly on antigen epitope density but not observably on antigen concentration. For epitope densities of 1.2 or less, D is close to the value of 21 X10(-11) cm2 sec-1 observed for single sIg receptors. By an epitope density of 4.8, D has fallen to 2.1 X 10(-11) cm2 sec-1. Peak immunogenicities for DNP-POL and DNP-DEX are observed when antigen-receptor aggregates have mobilities 14-fold and 3-fold lower, respectively, than a single sIg molecule.
mesh_terms: D000818:Animals; D000941:Antigens; D001402:B-Lymphocytes / Q000276:immunology*; D003911:Dextrans / Q000276:immunology; D004140:Dinitrophenols; D005260:Female; D005408:Flagellin / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D010777:Photochemistry; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods
chemical_list: D000941:Antigens; D003911:Dextrans; D004140:Dinitrophenols; D005408:Flagellin