title: Relative sensitivity of fetal and newborn mice to induction of hapten-specific B cell tolerance.
abstract: Mice were rendered tolerant to the hapten fluorescein (FLU) by a single injection of FLU-human gamma globulin (FLU5HGG) 2-3 d after birth or via the maternal circulation at 14.5 d of fetal life. After 7-9 d, the degree of functional nonresponsiveness induced in vivo among splenic FLU-specific B cells of tolerized mice was assessed by limiting-dilution analysis in vitro, and the serum levels of trace-labeled tolerogen were determined. When tolerogen was introduced before the appearance of any B cells, and was thus present during the pre-B to B cell transition stage, a concentration of 5.4 x 10(-13) M effectively silenced 50% of the clonable anti-FLU PFC precursors; but a similar reduction on newborns required a minimal tolerogen concentration of 1.3 x 10(-10) M, > 300-fold less than has previously been shown to equally affect adult B cells, but at least 240-fold more than in the in utero situation. Neonatally induced tolerance using a relatively high tolerogen dose lasted approximately 12 wk.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001402:B-Lymphocytes / Q000276:immunology*; D005260:Female; D006241:Haptens / Q000276:immunology*; D007108:Immune Tolerance; D051379:Mice; D008808:Mice, Inbred CBA; D011247:Pregnancy; D011947:Receptors, Antigen, B-Cell / Q000276:immunology
chemical_list: D006241:Haptens; D011947:Receptors, Antigen, B-Cell