Demonstration of double allelic expression (allelic inclusion) of rabbit κ light chain allotypes on heterozygous lymphocytes by double allotype sequential stimulation

Abstract

The hypothesis that individual lymphoid cells from rabbits heterozygous for genetically controlled immunoglobulin antigenic determinants (allotypes) are able to express only one of the allelic specificities (allelic exclusion) has been tested by double anti-allotypic sequential stimulation (DASS). DASS refers to stimulation by anti-allotypic serum directed to one specificity, followed, after blocking, by stimulation with an anti-allotypic serum directed to a different allotypic specificity. Previously published data reveal that most lymphocytes from the peripheral blood (PBLs) may be stimulated to undergo “blast transformation” by the addition of anti-immunoglobulin (anti-Ig) or anti-allotype antiserum and that this stimulation is mediated through surface immunoglobulin on the responding cells. In addition, the process of transformation may be reversed (blocked) by the addition of serum immunoglobulin which reacts with the stimulating antiserum. Such “blocked” cultures may be restimulated by removal of the blocking immunoglobulin and readdition of the stimulating antiserum. The present report demonstrates that lymphocyte cultures from heterozygous donors prestimulated by antiserum to one of the allelic specificities, after blocking and subsequent stimulation by antiserum directed towards the other allelic specificity, respond to a greater extent than do cultures stimulated by one antiserum only. This suggests that some individual PBLs of a heterozygous rabbit express both allelic Ig allotypes on their surface. The data suggest that it is possible that doubly expressing cells may produce both allelic markers sequentially or alternatively.