Up-regulated expression of MICA on activated T lymphocytes involves Lck and Fyn kinases and signaling through MEK1/ERK, p38 MAP kinase, and calcineurin

J Leukoc Biol. 2003 Jun;73(6):815-22. doi: 10.1189/jlb.0602329.


Major histocompatibility complex class I-related chain (MICA) is a cell stress-regulated molecule recognized by cytotoxic cells expressing the NKG2D molecule. MICA can be induced on T cells after CD3 or CD28 engagement. Here, we investigated the intracellular pathways leading to activation-induced expression of MICA. The Src kinase inhibitor PP1 inhibited up-regulated expression of MICA on anti-CD3-stimulated T cells. Downstream signaling routes involved mitogen-activated protein kinase (MAPK) kinase (MEK)1/extracellular signal-regulated kinase (ERK), p38 MAPK, and calcineurin, as MICA expression was prevented by U0126, SB202190, cyclosporin A, and FK506. Also, Lck and Fyn as well as MEK1/ERK and p38 MAPK were found to regulate MICA expression in anti-CD28/phorbol 12-myristate 13-acetate-stimulated T cells. Expression of MICA on activated T cells involved interleukin-2-dependent signaling routes triggered by Janus tyrosine kinases/signal transducer and activators of transcription and p70(S)(6) kinase, as it could be inhibited by AG490 and rapamycin. This is the first demonstration of the intracellular pathways involved in activation-induced expression of MICA, which may reveal potential targets for immune intervention to modulate MICA expression in pathological disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcineurin / metabolism
  • Cells, Cultured
  • Enzyme Inhibitors / pharmacology
  • Histocompatibility Antigens Class I / biosynthesis*
  • Humans
  • Interleukin-2 / physiology
  • Lymphocyte Activation
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / antagonists & inhibitors
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / physiology
  • MAP Kinase Kinase 1
  • MAP Kinase Signaling System*
  • Mitogen-Activated Protein Kinase Kinases / antagonists & inhibitors
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • Mitogen-Activated Protein Kinases / metabolism
  • Protein Serine-Threonine Kinases / antagonists & inhibitors
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / antagonists & inhibitors
  • Proto-Oncogene Proteins / physiology
  • Proto-Oncogene Proteins c-fyn
  • Ribosomal Protein S6 Kinases, 70-kDa / antagonists & inhibitors
  • Ribosomal Protein S6 Kinases, 70-kDa / physiology
  • Signal Transduction
  • T-Lymphocytes / enzymology*
  • T-Lymphocytes / immunology*
  • Up-Regulation*
  • p38 Mitogen-Activated Protein Kinases


  • Enzyme Inhibitors
  • Histocompatibility Antigens Class I
  • Interleukin-2
  • MHC class I-related chain A
  • Proto-Oncogene Proteins
  • FYN protein, human
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
  • Proto-Oncogene Proteins c-fyn
  • Protein Serine-Threonine Kinases
  • Ribosomal Protein S6 Kinases, 70-kDa
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • MAP Kinase Kinase 1
  • MAP2K1 protein, human
  • Mitogen-Activated Protein Kinase Kinases
  • Calcineurin