title: Genetic and biochemical characterization of human lymphocyte cell surface antigens. The A-1A5 and A-3A4 determinants.
abstract: The genes that code for the human lymphocyte cell surface determinants defined by monoclonal antibodies A- 1A5 and A- 3A4 have been genetically mapped. All human chromosomes, except Y, were included in a series of human less than mouse lymphocyte hybrid populations that retained expression of lymphocyte-specific surface markers. Expression of the A- 1A5 and A- 3A4 antigens was quantitated by indirect immunofluorescence and fluorescence-activated cell sorter (FACS) analysis. Hybrid populations heterogeneous for antigen expression were sorted to yield antigenically homogeneous subpopulations. Isozyme analysis indicated concordant segregation of the A- 1A5 determinant with chromosome 10, and the A- 3A4 determinant with chromosome 4. In contrast to the unhybridized human parent cell line (MOLT-4), from which A- 1A5 immunoprecipitated two proteins (160,000 and 125,000 Mr), A- 1A5 only immunoprecipitated a single band (125,000 Mr) from an A- 1A5 -expressing human less than mouse hybrid. The genetic disassociation of these two proteins from the A- 1A5 -reactive complex suggests that the appearance of the 160,000 Mr protein requires a gene locus that is unlinked to the locus for the 125,000 Mr protein on chromosome 10. A third component of the A- 1A5 -reactive protein complex (210,000 Mr), which is recognized by the monoclonal antibody TS2/7, was not expressed on the parent MOLT-4 cells, but was weakly expressed on MOLT-4 less than mouse BW5147 hybrids. This allowed preliminary mapping of that determinant to either chromosome 10 or 15. The A- 3A4 antigen (approximately 45,000 Mr) is a novel cell surface structure expressed on all hematopoietic cell lines tested, and represents the first cell surface marker mapped to chromosome 4.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000145:classification / Q000235:genetics* / Q000276:immunology; D002460:Cell Line; D002874:Chromosome Mapping; D002905:Chromosomes, Human, 4-5; D002906:Chromosomes, Human, 6-12 and X; D000939:Epitopes / Q000235:genetics* / Q000276:immunology; D005819:Genetic Markers; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D007621:Karyotyping; D051379:Mice; D008970:Molecular Weight; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000939:Epitopes; D005819:Genetic Markers; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7