| Autor: |
Kos FJ; Department of Microbiology and Immunology, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298-0037, USA., Bear HD |
| Jazyk: |
angličtina |
| Zdroj: |
Immunology [Immunology] 1998 Aug; Vol. 94 (4), pp. 575-9. |
| DOI: |
10.1046/j.1365-2567.1998.00558.x |
| Abstrakt: |
Ligation of CD28 molecules expressed on the surface of human leukaemic natural killer-like YT cells triggers intracellular signals leading to cytolysis of target cells expressing CD80 or CD86 molecules. Known intracellular events include tyrosine phosphorylation, activation of phosphatidylinositol 3-kinase, and protein kinase C (PKC). In this study, we report that PKC-delta isoenzyme activity is required for CD28-triggered cytotoxicity mediated by YT cells and we also demonstrate that one of the primary targets of bryostatin 1, a modulator of PKC activity, is PKC-delta. Treatment of YT cells with bryostatin 1 caused degradation of PKC-delta, but not other PKC isoenzymes, and completely blocked the cytolytic activity of YT cells. In addition, PKC-delta-specific antibody introduced into YT cells by electroporation inhibited partially the YT cell-mediated cytotoxicity of B-lymphoblastoid cell line JY. This effect was specific, since addition of anti-PKC-delta antibody-blocking peptide in combination with anti-PKC-delta antibody to YT cells for electroporation, neutralized the effect of this antibody. These results demonstrate that YT cell cytolytic activity is dependent on PKC-delta, which is selectively down-regulated by bryostatin 1. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
