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Macrophages stimulated with lipopolysaccharide release a selective neutrophil chemotactic factor: an in vivo

F Q Cunha1, G E Souza, S H Ferreira

  • 1Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, USP, Brasil.

Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Medicas E Biologicas
|January 1, 1986
PubMed

Insights

A specific chemotactic factor from endotoxin-primed macrophages attracts neutrophils but not macrophages into rat abdomens. Other agents like carrageenan, thioglycolate, or endotoxin attract both cell types.

Area of Science:

  • Immunology
  • Cell Biology

Background:

  • Macrophage activation by endotoxin is crucial for immune responses.
  • Understanding directed cell migration (chemotaxis) is key to inflammatory processes.

Purpose of the Study:

  • To investigate the differential migration of neutrophils and macrophages induced by specific factors.
  • To compare the chemotactic effects of an endotoxin-induced macrophage factor with known inflammatory agents.

Main Methods:

  • Rats received intraperitoneal injections.
  • Macrophage monolayers were preincubated with endotoxin.
  • Chemotactic factors were isolated or agents were directly injected.
  • Cellular infiltration into the abdominal cavity was analyzed.

Main Results:

  • A factor from endotoxin-primed macrophages selectively induced neutrophil migration.
  • This factor did not induce macrophage migration.
  • Carrageenan, thioglycolate, and endotoxin stimulated the migration of both neutrophils and macrophages.

Conclusions:

  • Endotoxin-primed macrophages release a specific factor that recruits neutrophils.
  • This contrasts with general inflammatory stimuli that recruit both neutrophils and macrophages.
  • Suggests distinct mechanisms regulate neutrophil versus macrophage recruitment in inflammation.

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