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Biomedical subjects

M E Kamarck

Publications and source records attributed to M E Kamarck.

24 records · Page 2Linked to original sources
PubMed1982

Somatic cell genetic analysis of HLA-A, B, C and human beta 2-microglobulin expression.

We have examined the cell surface expression of the human histocompatibility antigens HLA-A, B, C and beta 2-microglobulin (beta 2m) on a human-mouse somatic cell hybrid line. Using specific antibodies and the fluorescence-activated cell sorter (FACS), we viably fractionated and characterized four separate hybrid subpopulations (HLA+,beta 2m+; HLA+,beta 2m-; HLA-,beta 2m+; HLA-,beta 2m-). Hybrid selection based on surface antigen expression resulted in corresponding genetic selection for and against human chromosomes 6 and 15. Studies of the homogeneous hybrid sublines revealed that the presence of human beta 2m in a hybrid cell dramatically increased the surface expression of human HLA-A, B, C and mouse H-2Kk antigens. The results demonstrate the importance of human chromosome-specific surface markers and the fluorescence-activated cell sorter in somatic cell genetic analysis.

Animals↗
PubMed1982

Genetic and biochemical characterization of a human surface determinant on somatic cell hybrids: the 4F2 antigen.

We have mapped the gene which codes the species-specific determinant defined by monoclonal antibody 4F2 to human chromosome 11. All human chromosomes, except Y, were included in a group of four human-mouse hybrid lines. Hybrids heterogeneous for 4F2 antigen expression were sorted using the fluorescence-activated cell sorter (FACS) to yield populations homogeneous with respect to the presence or absence of this determinant. Isozyme analysis indicated corresponding genetic selection for or against human chromosome 11. This map assignment was confirmed using a hybrid line which contained only human chromosome 11. Immunoprecipitation of the 4F2 determinant from the 11 only hybrid resulted in a heavy subunit of molecular weight (Mr) = 100,000 and a light subunit of Mr = 41,000. This contrasts with results obtained from nonhybrid human cells of different lineages. These results demonstrate the importance of FACS techniques in the rapid mapping of genes which code human cell surface antigens.

Animals↗
PubMed1982

Identification of human genomic clones coding the major histocompatibility antigens HLA-a2 and HLA-B7 by DNA-mediated gene transfer.

We have screened a large number of isolated human genomic clones that hybridize to a cloned HLA cDNA probe for their ability to direct the synthesis of HLA-A, -B, and -C surface antigens on mouse L cells following DNA-mediated gene transfer. The surface expression of human histocompatibility antigens, monitored by indirect immunofluorescence and the fluorescence-activated cell sorter, was examined at 60 hr after transfection and on hypoxanthine/aminopterin/thymidine-resistant (HATR) populations derived from cotransfer with the herpes simplex virus thymidine kinase gene. Two unique genomic clones designated JY B3.2 and JY 158, isolated from the human lymphoblastoid cell line JY (homozygous HLA-A2, -B7), were shown to contain gene sequences capable of directing expression of an HLA-A, -B, -C determinant. By using allo-specific antibodies, the gene products of these clones were identified as HLA-A2 and HLA-B7, respectively. HATR clonal populations isolated from cotransfections with these genomic clones displayed varying levels of surface HLA expression that correlated with the number of intact donor HLA sequences present in the cells. In general, these levels of expression were stable during 3 months in culture. This system provides a powerful tool for the study of human surface antigen gene structure, expression, and function on a mouse cell background.

Antigens, Surface↗