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Rous sarcoma virus-transformed avian cells express four different cell surface antigens that are distinguishable by a
Abstract:
Japanese quails bearing avian sarcoma virus-induced tumors develop immune spleen cells that are cytotoxic in vitro against virally and chemically transformed cells, as well as against embryonic cells. The cell-mediated cytotoxicity can be blocked by soluble antigens extracted from in vitro cultured cells. The existence of partial as well as total blocking effects in tests with extracts from various transformed and untransformed virus-producing cells makes it possible to distinguish up to four different kinds of antigens expressed on sarcoma virus transformed cells: a) a subgroup-specific determinant of the virus-envelope glycoprotein gp85 (s-gp85) is expressed at the surface of productively infected, tranformed as well as untransformed cells; b) a group-specific determinant of gp85 (g-gp85) that is only expressed on the surface of virus-transformed cells; c) embryonic antigens, also detectable on chemically transformed as well as on primary normal embryonic cells, and finally; d) a sarcoma virus transformation-specific antigen (TSSA) that is not a structural constituent of the virus.
Insights
Japanese quails develop immune cells targeting tumor cells. These cells recognize specific viral and embryonic antigens on transformed cells, aiding in cancer research.
Area of Science:
- Immunology
- Virology
- Oncology
Background:
- Avian sarcoma virus (ASV)-induced tumors in Japanese quails elicit an immune response.
- Immune spleen cells from affected quails exhibit cytotoxic activity against various transformed cells.
Purpose of the Study:
- To characterize the antigens recognized by ASV-transformed cell-specific cytotoxic T lymphocytes.
- To differentiate between viral, embryonic, and transformation-specific antigens on ASV-transformed cells.
Main Methods:
- In vitro cytotoxicity assays using immune spleen cells from ASV-bearing quails.
- Soluble antigen blocking assays with extracts from various cultured cells (transformed, untransformed, embryonic).
Main Results:
- Cytotoxicity was blocked by soluble antigens, indicating specific antigen recognition.
- Four distinct antigen types were identified: subgroup-specific gp85 (s-gp85), group-specific gp85 (g-gp85), embryonic antigens, and a transformation-specific antigen (TSSA).
- s-gp85 is present on both transformed and untransformed virus-producing cells, while g-gp85 is specific to transformed cells.
Conclusions:
- ASV-transformed cells express a complex array of antigens, including viral structural and non-structural components, as well as embryonic antigens.
- The identified antigens provide targets for understanding cell-mediated immunity in viral oncogenesis.