Allotype B4 Research Articles

Light chains of restricted allotype: Electrophoretic distribution of b4 and b5 markers of light chains of rabbit anti- p-azobenzoate antibody

The electrophoretic distribution (on acrylamide gel, pH 8·6) of allotypes b4 and b5 of L chains isolated from individual preparations of rabbit anti- p-azobenzoate antibody as well as from normal IgG was investigated. Each examined rabbit showed an individual electrophoretic pattern of specific L chains. Several fractions were eluted from the gel and the allotypes were quantitated in the eluates by means of specific anti-allotype sera. The pool of L chains was resolved into a number of components in which the b4/b5 ratio varied markedly from fraction to fraction and in comparison with the same ratio in the unfractionated preparations. Moreover, in some fractions an almost complete predominance of one allotype over the other was found. The results are discussed in relation to the hypothesis that the heterogeneity of ordinary anti-hapten antibodies is far less broad than previously assumed.

Electron Microscopic Localization of Rabbit Immunoglobulin Allotype b4 on Blood Lymphocytes by an Indirect Ferritin Immune Complex Labeling Technique

Abstract Immunoglobulin allotypic determinant b4 may be detected on the surface of rabbit peripheral blood lymphocytes by electron microscopy. Soluble complexes of ferritin and rabbit antiferritin of a given allotype were incubated with lymphocytes coated with anti-allotype antibody to form labeled lymphocytes. Seventy to 80% of the lymphocytes examined demonstrated specific focal ferritin-immune complex labeling scattered over the membrane surface. This technique should provide a sensitive and relatively simple method for the ultra structural detection of other immunoglobulin determinants.

Communications

Abstract In rabbits, the immunoglobulin allotypes b4, b5, b6 and b9 are associated with antigenic determinants on light polypeptide chains (2). Genes which behave as alleles at the “b locus” appear to control at least part of the amino acid sequence of these antigenically distinct forms of light chains. It is possible that the “b locus” actually represents a genetic region consisting of several closely linked and related cistrons. However, to date no one has detected production of more than two of the four known “b locus allotypes” in an individual rabbit. On the other hand, the c7 allotype (originally designated “P” (3)) is detectable in the sera of numerous rabbits, no matter whether they are heterozygous or homozygous at the a and b loci (3, 4). The c7 antigenic determinants are detected with specific isoantisera on molecules which have the immunoelectrophoretic characteristics of rabbit IgG.