T-cell-activating monoclonal antibodies, reacting with both leukocytes and erythrocytes, recognize the guinea pig Thy-1 differentiation antigen: Characterization and cloning of guinea pig CD90

Item Type:	Article
Title:	T-cell-activating monoclonal antibodies, reacting with both leukocytes and erythrocytes, recognize the guinea pig Thy-1 differentiation antigen: Characterization and cloning of guinea pig CD90
Creators Name:	Schaefer, H. and Bartels, T. and Hahn, G. and Otto, A. and Burger, R.
Abstract:	A glycophosphatidylinositol (GPI)-linked differentiation antigen expressed on guinea pig T and B lymphocytes was identified by several monoclonal antibodies; it has been shown previously that this membrane protein induced strong polyclonal T cell proliferation upon antibody binding and costimulation by PMA. Purification by immunoadsorption and microsequencing revealed that this T-cell-activating protein is the homologue of Thy-1 or CD90. In contrast to the Thy-1 antigen of most other species, guinea pig Thy-1 has a much higher molecular weight, which is due to a more extensive N-linked glycosylation, bringing the molecular weight of the total antigen up to 36 kDa. Molecular cloning of guinea pig Thy-1 indicated that the deduced molecular weight of the protein backbone is 12,777 after removal of an N-terminal 19-amino-acid leader peptide and cleavage of the 31 amino acids for GPI anchoring the C-terminal end. Sequence comparison showed that guinea pig Thy-1 has an 82% homology to human and a 72% homology to mouse Thy-1 on the amino acid level. Immunohistological staining of cryostat sections revealed intensive staining with the monoclonal antibody H154 on fibroblasts, fibrocytes, Kupffer cells, alveolar macrophages, and mesangial cells. As observed in the human, mouse, and rat, Thy-1 is abundant in the guinea pig brain. Unlike Thy-1 expression in other species, guinea pig Thy-1 is strongly expressed on most resting, nonactivated B cells and, to a lesser extent, on erythrocytes. While treatment of erythrocytes and lymphocytes with GPI-specific phospholipase C largely decreased reactivity with mAb H154, T cells retained the proliferative response to antibody and phorbol esters.
Keywords:	Amino Acid Sequence, Amino Acid Sequence Homology, B-Lymphocytes, Cell Line, Complementary DNA, Culture Media, Erythrocytes, Glycosylation, Lymphocyte Activation, Molecular Cloning, Molecular Sequence Data, Monoclonal Antibodies, Mononuclear Leukocytes, Phosphatidylinositol Diacylglycerol-Lyase, Phosphatidylinositols, Pronase, Staining and Labeling, T-Lymphocytes, Thy-1 Antigens, Transfection, Type C Phospholipases, Western Blotting, Animals, Guinea Pigs, Mice, Rats
Source:	Cellular Immunology
ISSN:	0008-8749
Volume:	197
Number:	2
Page Range:	116-128
Date:	1 November 1999
Official Publication:	https://doi.org/10.1006/cimm.1999.1564
PubMed:	View item in PubMed

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