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Effects of the Bacterial Extract OM-85 on Phagocyte Functions and the Stress Response

S Baladi1, S Kantengwa, Y R Donati

  • 1Allergy Unit University Hospital 1211 Geneva 14 Switzerland.

Mediators of Inflammation
|January 1, 1994
PubMed

Insights

The bacterial extract OM-85 boosts superoxide production and calcium mobilization in monocytes but does not induce classical heat shock/stress proteins. It does, however, upregulate a glucose-regulated protein (GRP78) and interleukin-1 beta precursor.

Area of Science:

  • Immunology
  • Cellular Biology
  • Microbiology

Background:

  • Phagocytosis by monocytes involves a respiratory burst, linked to heat shock/stress protein synthesis.
  • Bacterial extracts can modulate immune cell responses.

Purpose of the Study:

  • To investigate the effects of the bacterial extract OM-85 on human monocyte responses.
  • To assess OM-85's impact on respiratory burst, intracellular calcium, and stress protein induction.

Main Methods:

  • Human peripheral blood monocytes from normal donors were treated with OM-85.
  • Measurements included superoxide production, intracellular calcium mobilization, and heat shock protein (HSP) synthesis.
  • Interleukin-1 beta precursor expression was also analyzed.

Main Results:

  • OM-85 stimulated superoxide production and increased intracellular calcium mobilization.
  • Classical HSP synthesis was not induced by OM-85, even with iron potentiation.
  • A 75-78 kDa protein, likely GRP78, was induced, along with enhanced interleukin-1 beta precursor expression.

Conclusions:

  • OM-85 modulates key monocyte functions like respiratory burst and calcium signaling.
  • The extract's effect on stress protein synthesis is complex, inducing GRP78 but not classical HSPs.
  • OM-85 enhances the expression of interleukin-1 beta precursor, suggesting immunomodulatory potential.

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