Identification and genetic control of two rabbit high-density lipoprotein allotypes

Rabbits were immunized with high-density lipoprotein (HDL) isolated from the serum of other rabbits by ultracentrifugation and gel filtration. Two different precipitating antibodies were elicited which distinguished two antigenically different genetic variants, i.e., allotypes, of HDL. The allotypes were identified as HDL based on the observation that on immunoelectrophoresis the antigen-antibody precipitate formed by the reaction of each of the antiallotype antisera with electrophoresed rabbit serum appeared electrophoretically in the α₁ region and reacted with Sudan black and with β-naphthyl acetate. In addition, the precipitin bands formed by the reaction of each antiallotype antiserum with a normal rabbit serum coalesced with the precipitin band formed by the reaction of goat anti-HDL with the same normal rabbit serum. The inheritance of the two allotypes is controlled by a pair of allelic genes, as shown by genetic studies of 312 progeny from 83 rabbit families. This HDL locus, designatedLhj, was shown not to be linked to theLpq locus of low-density lipoprotein nor to any of five other loci controlling allotypic specificities of different rabbit serum proteins. The use of these allotypes for studying the structure and biosynthesis of HDL is discussed. This study was supported by Research Grant PHS AI-07043 (Dr. S. Dray) and PHS AI-09241 from the National Institutes of Allergy and Infectious Diseases. One of us (K. L. K.) is the recipient of National Institutes of Health Career Development Award (AI-28687).