| Abstract: |
Thy-1 is a cell surface differentiation marker which shows distinct patterns of tissue-specific expression in different species. In man, the Thy-1 antigen is encoded by chromosome 11. We have examined the regulatory signals determining human Thy-1 expression through serologic analysis of rodent-human somatic cell hybrids retaining human chromosome 11 in which the fusion partners belong to distinct differentiation lineages. Cell surface expression of human Thy-1 was determined by mixed hemadsorption assays with two monoclonal antibodies (mAb), K117 and L127, shown to detect authentic human Thy-1 through analysis of COS-7 monkey kidney cells transfected with a cloned human Thy-1 gene. Three different patterns of human Thy-1 expression were observed when hybrid cells, constructed with different human and rodent cell types, were tested with mAb K117 and L127. Hybrids formed between Thy-1+ human neuroblastoma cells and Thy-1- mouse neuroblastoma cells, or hybrids between Thy-1+ human fibroblasts and the Thy-1- mouse kidney carcinoma, RAG, retain human Thy-1 expression. In contrast, hybrids formed between either Thy-1+ human neuroblastoma cells or Thy-1+ human fibroblasts and Thy-1- mouse L cells lose expression of human Thy-1 even though chromosome 11 is retained. Finally, hybrids formed between Thy-1- human peripheral lymphocytes or a Thy-1- lymphoblastoid B cell line and Thy-1- Chinese hamster fibroblasts begin to express human Thy-1. These studies suggest that both positive and negative trans-acting signals may play a role in the tissue-specific regulation of the human Thy-1 gene. |
| Keywords: |
human cell; genetics; nonhuman; mouse; animal; mice; heredity; gene expression; in vitro study; pathology; cercopithecus aethiops; tumor antigen; kidney carcinoma; b lymphocyte; monoclonal antibody; gene expression regulation; membrane antigen; biosynthesis; immunology; antibodies, monoclonal; antigens, neoplasm; genetic engineering; neuroblastoma; organ specificity; cercopithecus; gene control; antibody specificity; rodent; chromosome 11; chromosomes, human, pair 11; antigens, surface; nervous system; cricetulus; thy 1 antigen; hybrid cell; hybrid cells; hamster; antigens, thy-1; human; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; hamsters; l cells (cell line); l cell; blood and hemopoietic system; antigens, thy 1
|
