title: Qa-12--a novel determinant of activated T and B lymphocytes.
abstract: Investigation of the antigenic phenotype of activated lymphocytes using the broadly cross-reactive mAb 6.3.4 revealed two phenotypic alterations as compared with the resting lymphocytes. The Qa specificity Qa-m208 disappears after lectin activation of Qa-m208-positive T lymphocytes. Analysis of Q7 and Q9 transfectants expressing the Qa-2 polypeptides shows that Qa-m208 is an epitope of the Qa-2 antigen. Because the Qa-2 antigens are still expressed on T lymphoblasts which have lost Qa-m208, changes of the Qa-2 molecules occur and result in the loss of certain epitopes. The second phenotypic change that we observed is the appearance of a novel specificity, Qa-12. Its expression is induced by lymphocyte activation and it is expressed on lymphoblasts of both T and B cell origin. The presence of this novel non-ubiquitous antigenic specificity is determined by the Tla region.
authors.affiliation: Department of Molecular Genetics, The Netherlands Cancer Institute, Amsterdam.
authors.forename: M
authors.initials: M
authors.lastname: Oudshoorn-Snoek
authors.forename: P
authors.initials: P
authors.lastname: Demant
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000276:immunology*; D003208:Concanavalin A / Q000494:pharmacology; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008198:Lymph Nodes / Q000166:cytology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D010835:Phytohemagglutinins / Q000494:pharmacology; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D015395:Histocompatibility Antigens Class I; D008070:Lipopolysaccharides; D010835:Phytohemagglutinins; C032907:Q surface antigens; D003208:Concanavalin A