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Integrins Influence the Size and Dynamics of Signaling Microclusters in a Pyk2-dependent Manner

Maria Steblyanko1, Nadia Anikeeva1, Kerry S Campbell2

  • 1From the Departments of Microbiology and Immunology and.

The Journal of Biological Chemistry
|March 18, 2015
PubMed

Insights

Integrin signaling regulates immune cell killing by influencing receptor microclusters and degranulation speed. This finding reveals how integrins impact the efficiency of antibody-dependent cell-mediated cytotoxicity (ADCC).

Area of Science:

  • Immunology
  • Cellular Biology
  • Molecular Signaling

Background:

  • Integrin engagement on lymphocytes triggers outside-in signaling, crucial for cytoskeleton remodeling and forming the synaptic interface.
  • The precise mechanism linking outside-in signaling to intracellular pathways regulating granule delivery and cytolytic activity remains unclear.

Purpose of the Study:

  • To investigate how integrin ligation on effector cells influences the kinetics of cytolytic activity.
  • To elucidate the molecular events at the cell-contact area that mediate integrin-regulated intracellular signaling in CD16.NK-92 cells.

Main Methods:

  • Analysis of molecular events in CD16.NK-92 cells interacting with planar lipid bilayers displaying varying densities of integrin ligands and CD16-specific antibodies.
  • Assessment of changes in integrin ligation extent and its impact on activating receptor microclusters and Pyk2-dependent signaling.
  • Evaluation of the effect of integrin-mediated signaling on degranulation kinetics in CD16.NK-92 cells.

Main Results:

  • Variations in ICAM-1 expression on tumor cells affected killing kinetics by CD16.NK-92 cells, suggesting integrin ligation influences effector cell activity.
  • Integrin ligation extent modulated the size and dynamics of activating receptor microclusters in a Pyk2-dependent manner.
  • Integrin-mediated intracellular signaling significantly altered degranulation kinetics, impacting the rate of target cell destruction in ADCC.

Conclusions:

  • Integrins play a critical role in regulating the kinetics of cytolytic activity by CD16.NK-92 cells.
  • Integrin signaling influences key molecular events, including receptor microcluster formation and degranulation, thereby controlling the efficiency of antibody-dependent cell-mediated cytotoxicity (ADCC).

Keywords:
ADCCCytotoxic lymphocytesIntegrin receptorscellular immune responseimmunologykilling kineticslymphocytenatural killer cells (NK cells)signalingsignaling microclusters

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