Antigenic Heterogeneity of Qa-2 Antigens in C57BL/6

• Published in: MICROBIOLOGY and IMMUNOLOGY 1993, Vol.37(9), pp.743-752
• Main Authors: Park, Eunkyue, Shinohara, Nobukata, Arn, J. Scott, Sharrow, Susan O., Waneck, Gerry L., Sacks, David H.
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Monoclonal; Antibody Specificity; Antigens; Biological and medical sciences; Cross Reactions; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Genes, MHC Class I - genetics; Genetic Variation; H-2 Antigens - immunology; Heterogeneity; Histocompatibility antigens (hla, h-2 and other systems); Histocompatibility Antigens Class I - immunology; MHC class I antigen; Mice; Mice, Inbred BALB C - immunology; Mice, Inbred C3H - immunology; Mice, Inbred C57BL - immunology; Mice, Inbred Strains - immunology; Molecular immunology; Multigene; PI linkage; Precipitin Tests; Qa-2; Spleen - immunology; Transfection
• ISSN: 0385-5600; 1348-0421
• DOI: 10.1111/j.1348-0421.1993.tb01700.x

The Qa-2 antigens are class I-like molecules encoded by genes mapped telomeric to the H-2D region on chromosome 17 in the mouse. A panel of 8 new monoclonal anti-Qa-2 antibodies derived from a C3H.KBR anti-C3H. SW immunization was studied. Immunoprecipitation of 125I-labeled C57BL/6 splenocyte antigens showed that all of these antibodies precipitated 40kDa molecules which could be completely precleared by the monoclonal antibody 20-8-4, which had previously been shown to crossreact with Qa-2. One of the monoclonal antibodies (1-12-1), however, was found not to completely preclear Qa-2 antigens precipitable by the other 7 antibodies or by 20-8-4, suggesting the existence of at least two different species of Qa-2 molecules. Cell lines transfected with Q7 or Q9 genes were reactive with all 9 antibodies and the Qa-2 antigens expressed on surface membranes of these cells were completely precleared by both 20-8-4 and 1-12-1. Therefore, the observed heterogeneity of these molecules cannot be explained by an antigenic difference between the Q7 and Q9 gene products. 2D gel analyses showed identical pI spectra between Qa-2 molecules precipitated with 20-8-4 and 1-12-1. In addition, all of the monoclonal antibodies reacted with labeled antigen preparations following treatment with Endo F or neuraminidase, indicating that carbohydrate moieties are probably not responsible for the antigenic difference between the two species of Qa-2 antigen.