FREQUENCY OF PARA-AZOPHENYLARSONATE AND DIMETHYLAMINONAPTHALENE-SULFONYL-SPECIFIC B-CELLS IN NEONATAL AND ADULT BALB-C MICE

Abstract

The limiting cell dilution splenic focus technique was used to determine the frequency of p-azophenylarsonate (Ars) and 5-dimethylaminonaphthalene-sulfonyl (Dansyl)-specific B [bone marrow-derived] cells in neonatal and adult mice. The adult frequencies for Ars and Dansyl in conventionally reared BALB/c mice are 1.5 .+-. 0.3/105 B cells and 9.4 .+-. 3.3/105 B cells, respectively. Dansyl-specific precursor cells are present in high frequencies at birth and reach adult precursor frequency levels during the 1st wk of life. This finding mirrors the ontogenetic development previously described for dinitrophenyl (DNP) and trinitrophenyl (TNP), but contrasts with the results obtained for fluorescein (FL) and phosphorylcholine (PC), for which precursors arise later in development. The kinetics of appearance of B cells specific for Ars is unique in that the precursor frequency appears to decrease during the 1st wk of life. There apparently is a highly ordered, rigorously predetermined acquisition of the specificity repertoire during ontogeny. By increasing the flexibility of the splenic focus technique to allow analysis of other, chemically diverse haptens, results were obtained that confirm and extend observations made with DNP, TNP, FL and PC.