Analysis of T cell signaling by class I MHC molecules: the cytoplasmic domain is not required for signal transduction.
The structural requirements for signal transduction by class I major histocompatibility complex (MHC) molecules were examined. Native or mutant HLA-A2 or HLA-B27 constructs lacking most of their cytoplasmic domains were co-transfected with pSV2neo into Jurkat cells. Transfection of either native or mutant constructs resulted in a comparable expression of the gene products. Stimulation of transfectants expressing either native or truncated A2 or B27 molecules with specific mAb evoked an increase in [Ca2+]i upon crosslinking. Moreover, crosslinking native or truncated A2 or B27 induced IL-2 production upon co-stimulation with phorbol myristate acetate. These results confirm that crosslinking class I MHC molecules transduces an activation signal to human T cells. Effective signaling was observed when all but four of the intracytoplasmic residues were deleted, indicating that signal transduction does not require this portion of the molecule.
Gur
H
H
Harold C. Simmons Arthritis Research Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235.
el-Zaatari
F
F
Geppert
T D
TD
Wacholtz
M C
MC
Taurog
J D
JD
Lipsky
P E
PE
D000818:Animals; D002118:Calcium / Q000032:analysis; D003593:Cytoplasm / Q000502:physiology; D015789:HLA-A2 Antigen / Q000235:genetics / Q000502:physiology*; D015796:HLA-B27 Antigen / Q000235:genetics / Q000502:physiology*; D007376:Interleukin-2 / Q000096:biosynthesis; D051379:Mice; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015789:HLA-A2 Antigen; D015796:HLA-B27 Antigen; D007376:Interleukin-2; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium