Abstract
The CD99 antigen has been implicated in various cellular processes, including apoptosis in T cells. Previously, we reported two monoclonal antibodies that recognize different epitopes of the CD99 molecule, named DN16 and YG32. In this study, we investigated the role of each CD99 epitope in T cell apoptosis. Unlike the DN16 epitope, CD99 ligation via the YG32 epitope failed to induce T cell death. Surprisingly, however, the YG32 signal enhanced Fas-mediated apoptosis in Jurkat T cells. Augmentation of Fas-mediated apoptosis by YG32 ligation was inhibited by treatment with either of the caspase inhibitors z-VAD-fmk or z-IETD-fmk, and YG32 ligation appeared to induce Fas oligomerization. These results suggest that each CD99 epitope plays a distinct role in T cell biology, especially in T cell apoptosis.
Publication types
-
Comparative Study
-
Research Support, Non-U.S. Gov't
MeSH terms
-
12E7 Antigen
-
Amino Acid Chloromethyl Ketones / pharmacology
-
Antibodies, Monoclonal / chemistry
-
Antibodies, Monoclonal / immunology
-
Antigens, CD / chemistry
-
Antigens, CD / immunology
-
Antigens, CD / metabolism*
-
Apoptosis / physiology*
-
Caspase Inhibitors
-
Caspases / metabolism
-
Cell Adhesion Molecules / chemistry
-
Cell Adhesion Molecules / immunology
-
Cell Adhesion Molecules / metabolism*
-
Cell Aggregation / drug effects
-
Enzyme Inhibitors / pharmacology
-
Epitopes, T-Lymphocyte / immunology
-
Epitopes, T-Lymphocyte / metabolism
-
Epitopes, T-Lymphocyte / pharmacology
-
Humans
-
Immunohistochemistry / methods
-
Jurkat Cells
-
Membrane Potentials / drug effects
-
Membrane Potentials / physiology
-
Microscopy, Confocal
-
Mitochondria / drug effects
-
Mitochondria / physiology
-
Signal Transduction / physiology
-
T-Lymphocytes / cytology*
-
T-Lymphocytes / metabolism
-
fas Receptor / chemistry
-
fas Receptor / metabolism*
-
fas Receptor / ultrastructure
Substances
-
12E7 Antigen
-
Amino Acid Chloromethyl Ketones
-
Antibodies, Monoclonal
-
Antigens, CD
-
CD99 protein, human
-
Caspase Inhibitors
-
Cell Adhesion Molecules
-
Enzyme Inhibitors
-
Epitopes, T-Lymphocyte
-
benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone
-
fas Receptor
-
Caspases