1. The RT6 system of the rat: developmental, molecular and functional aspects.
- Author
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Thiele, Heinz-Gunter and Haag, Friedrich
- Subjects
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CELL membranes , *ADENOSINE diphosphate , *T cells , *KILLER cells - Abstract
RT6 is a developmentally regulated cell-surface membrane adenosine 5′-diphosphate-ribosyltransferase/nicotinamide adenine dinucleotide-glycohydrolase inserted within the membrane by a glycophosphatidylinositol anchor. In the rat it is restricted to mature T lymphocytes and a subpopulation of natural killer cells. With respect to the data now available, three aspects concerning the function of RT6 are discussed: first, the meaning of the marked polymorphisms; second, its enzymatic activity; third, its possible role concerning T-cell survival. The observation that the rat RT6 gene contains two transcription start sites suggests their different use by distinct subpopulations of T cells. The fact that the expression of RT6 is defective in lymphopenic diabetes prone (DP-BB) rats, although the RT6 gene is structurally not grossly altered in these animals, makes this rat strain a promising model to study the biological meaning of RT6. While it mostly is believed that the RT6 expression defect of the DP-BB rat is a consequence of the lymphopenia, the present paper discusses the possibility that the RT6 expression defect is causally involved in the lymphopenia, and that a normal expression of RT6 may protect the recent thymic emigrants from apoptosis. [ABSTRACT FROM AUTHOR]
- Published
- 2001
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