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Induction of FMLP-mediated calcium mobilization requires crosslinking of surface immunoglobulin in Daudi cells

C I Kalunta1, J S Kaptein, S J Scott

  • 1Regional Research Laboratory, Kaiser Permanente Medical Center, Los Angeles, CA 90027.

Immunology Letters
|April 1, 1992
PubMed

Insights

Anti-immunoglobulin treatment induces a specific N-formyl-methionyl-leucyl-phenylalanine (FMLP) response in Daudi cells. This requires surface immunoglobulin crosslinking and is linked to calcium mobilization, highlighting cell-type specificity.

Area of Science:

  • Immunology
  • Cell Biology
  • Signal Transduction

Background:

  • The N-formyl-methionyl-leucyl-phenylalanine (FMLP) response is crucial for immune cell activation.
  • Understanding the induction requirements of FMLP responsiveness is key to deciphering immune cell signaling pathways.

Purpose of the Study:

  • To investigate the specific conditions required for inducing the FMLP response in Daudi cells following anti-immunoglobulin treatment.
  • To identify the role of surface immunoglobulin crosslinking and calcium mobilization in this process.

Main Methods:

  • Treatment of Daudi cells with anti-immunoglobulin and its fragments (F(ab')2, Fab, Fc).
  • Assessment of FMLP responsiveness and calcium mobilization.
  • Testing various B lymphocyte regulatory agents and calcium mobilization inhibitors (W-7, PMA, colchicine).

Main Results:

  • FMLP responsiveness induction in Daudi cells was dependent on surface immunoglobulin crosslinking by anti-immunoglobulin, but not observed in Ramos or Wil-2 cells.
  • The F(ab')2 fragment was sufficient for induction, while Fab and Fc fragments were ineffective.
  • Anti-immunoglobulin was the most effective agent tested for inducing FMLP response; inhibitors of calcium mobilization blocked both anti-immunoglobulin-induced calcium flux and FMLP response induction.

Conclusions:

  • Cell type is a critical determinant for inducing a calcium-mobilizing FMLP response in B lymphocyte lineage cells.
  • Selective activation via surface immunoglobulin crosslinking is necessary for this response.
  • Calcium mobilization plays a significant role in the anti-immunoglobulin-induced FMLP response in specific B cell types.

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