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The MAGUK family protein CARD11 is essential for lymphocyte activation

Hiromitsu Hara1, Teiji Wada, Chris Bakal

  • 1Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Dr. Bohr Gasse 7, A-1030, Vienna, Austria.

Immunity
|June 24, 2003
PubMed

Insights

Genetic inactivation of CARD11 protein blocks T and B cell immunity by disrupting antigen receptor signaling. This MAGUK family protein is crucial for both adaptive and innate immune responses.

Area of Science:

  • Immunology
  • Molecular Biology
  • Neuroscience

Background:

  • MAGUK family proteins are known to organize signaling complexes at neuronal synapses.
  • The role of MAGUK proteins in immune cell function is largely unexplored.

Purpose of the Study:

  • To investigate the function of the MAGUK family protein CARD11 in immune responses.
  • To determine CARD11's role in T and B cell activation and signaling pathways.

Main Methods:

  • Genetic inactivation of CARD11 in immune cells.
  • Analysis of T and B cell proliferation and cytokine production.
  • Assessment of JNK and NF-kappaB signaling pathways activation.
  • Stimulation of B cells with lipopolysaccharide (LPS) via TLR4.

Main Results:

  • Complete blockade of T and B cell immunity upon CARD11 genetic inactivation.
  • Impaired T and B cell proliferation and cytokine production due to defects in JNK and NF-kappaB activation.
  • Impaired B cell proliferation and JNK activation upon TLR4 stimulation, indicating involvement in innate immunity.

Conclusions:

  • CARD11 is essential for adaptive immune responses mediated by T and B cells.
  • CARD11 plays a critical role in both innate and adaptive immune signaling pathways.
  • MAGUK proteins are key regulators in both neuronal and immune receptor signaling.

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