A Molecular Basis for the Ia.2 and Ia.19 Antigenic Determinants

• Published in: Proceedings of the National Academy of Sciences - PNAS 1985-05, Vol.82 (9), p.2930-2934
• Main Authors: Landais, Didier, Matthes, Hans, Benoist, Christophe, Mathis, Diane
• Format: Article
• Language: English
• Subjects: Alleles; Amino Acid Sequence; Amino acids; Animals; Antibodies; Antigens; Base Sequence; Biological and medical sciences; Cloning, Molecular; Complementary DNA; DNA - genetics; Epitopes; Epitopes - genetics; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Haplotypes; Histocompatibility Antigens Class II - genetics; Mice; Molecular immunology; Molecules; Sequencing; T lymphocytes; T-Lymphocytes - immunology
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.82.9.2930

The murine Ia antigens, heterodimeric glycoproteins on the surface of immunocompetent cells, restrict immune recognition by their influence on cell-cell interactions. Many serological specificities have been mapped to these molecules, and monoclonal antibodies directed against some of these determinants block antigen presentation to T lymphocytes. As a step toward a better understanding of Ia function, we sought to define the molecular basis of Ia.2 and Ia.19, specificities found on the Aαchain of only the k or of both k and r haplotypes, respectively. We report nucleotide sequences for the Aαchain cDNAs of the k, r, and s haplotypes, which, when compared to previously published Aαsequences, demonstrate the existence of one k-specific amino acid residue and of another present only in the k and r haplotypes. These residues must thus play an important role in the generation of Ia.2 and Ia.19 specificities.