Allelic exclusion in rat kappa immunoglobulin chains: extent of Jk rearrangement in normal B lymphocytes.

Abstract

The frequency of normal rat peripheral B lymphocytes stained for surface immunoglobulin kappa allotypes a and b in (a X b) F1 heterozygotes was assessed by two‐colour immunofluorescence on a fluorescence‐activated cell sorter. The upper limit to the frequency of double‐ stainers was 8% among all kappa‐positive cells, though it was not resolved how far cytophilic antibody accounted for these. Cells expressing each allotype singly were isolated and the extent of rearrangement of the genes encoding the joining‐kappa segment on the expressed and non‐expressed chromosome were independently assessed. The expressed allele was found to be virtually completely rearranged while the non‐expressed allele showed approximately 45‐60% rearrangement. The implications of this substantial non‐productive rearrangement for models of allelic exclusion are discussed.

The Protection: The Unit of Humoral Immunity Selected by Evolution

“…Thus, there were 4 (13 x y^) [K"K''-|-H] true doubles found per 146 hybridomas. This represents 2.7% doubles under conditions that would have been assayed using the FACS analysis described by Tsukamoto et al (1984) where 5.6% doubles were reported. As an aside, the calculations of Cherepakhin et al (1987) -showing that aberrant rearrangement alone in the absence of branching ratios and STOP signals accounts for haplotype exclusion -are not valid, as we have discussed in Part Two.…”

“…An analogous situation exists for doubles of the [2L -I-1H] type. There are two studies in rats using allelic markers of C^ (Tsukamoto et al 1984, Cherepakhin et al 1987. Tsukamoto et al (1984) using FACS analysis found that doubles of the type [K"«:''-I-H] were expressed at 5.6 + 2.6% (corrected for chimera background) of Ig"^ B cells.…”

“…There are two studies in rats using allelic markers of C^ (Tsukamoto et al 1984, Cherepakhin et al 1987. Tsukamoto et al (1984) using FACS analysis found that doubles of the type [K"«:''-I-H] were expressed at 5.6 + 2.6% (corrected for chimera background) of Ig"^ B cells. Cherepakhin et al (1987) using hybridoma analyses on 4-to 5-d-old rat splenic cells describe 17 double-producers [KV^] out of 146 Kproducers (il.6Vo).…”

How One Thing Led to Another

“…Only the surviving SP cells upregulated the tissue-homing receptors for LNs [L-selectin, CD62L (57)] and for PP HEVs [integrin α 4 β 7 (58,59)]. During these studies my fellows and I had discovered the homing receptors (59)(60)(61)(62)(63)(64)(65)(66)(67) and the essential regions of lymphoid organs by finding out how to stain tissue sections for cell membrane antigens (31 chains (68)(69)(70). The timing of IgH chain rearrangement occurred in distinct pro-B dividing cells, which was prior to light chain rearrangement in nondividing pre-B cells (68,71).…”

Antibody regulation of B cell development

“…Evidence for light chain allelic exclusion was first obtained in rabbits and rats using antibodies to allotype 43,94 . However, light chain allelic exclusion has never been measured precisely and, in contrast to the heavy chain, many of the experiments with transgenic mice show only partial light chain allelic exclusion 95,96 .…”