Upon stimulation with anti-CD3, suppressor T-cell (Ts) hybridomas and homologous transfectants of T-cell receptor α (TCRα) cDNA in the T-cell hybridoma formed a 55-kDa TCRα chain derivative that bound both the monoclonal anti-TCRα chain and polyclonal antibodies against glycosylation inhibiting factor (GIF). The peptide is a subunit of antigen-specific suppressor T-cell factor (TsF), and is considered to be a posttranslationally-formed conjugate of TCRα chain with GIF peptide. The TCRα derivative is synthesized by the transfectant after stimulation with anti-CD3, and not derived from TCR present on the cell surface. Stimulation of the stable homologous transfectants with anti-CD3 induced translocation of the 13-kDa GIF peptide into endoplasmic reticulum (ER). When a helper Ts hybridoma or a stable transfectant of the same TCRα cDNA in a helper cell-derived TCRα- clone was stimulated with anti-CD3, translocation of GIF peptide was not detected, and these cells failed to secrete a TCRα derivative. However, further transfection of a chimeric cDNA encoding a procalcitonin-GIF fusion protein into the helper cell-derived stable transfectant of TCRα cDNA resulted in translocation of the GIF protein and formation of bioactive 55-kDa GIF. The results indicated that translocation of GIF peptide through ER is unique for Ts cells, and that this process is essential for the formation/secretion of the soluble form derivative of TCRα chain by T cells.
|Number of pages
|Proceedings of the National Academy of Sciences of the United States of America
|Published - Jul 9 1996
- Antigen-specific suppressor T-cell factor
- Endoplasmic reticulum
- Glycosylation inhibiting factor
ASJC Scopus subject areas