Related Experiment Videos
Selective induction of the glucose-regulated protein grp78 in human monocytes by bacterial extracts (OM-85): a role
M R Jacquier-Sarlin1, D Dreher, B S Polla
1Laboratoire de Physiologie Respiratoire, UFR Cochin Port-Royal, Paris, France.
Abstract:
Heat shock/stress proteins (HSP) act as molecular chaperones, protect cells from injury, and are involved in the immune response. We investigated the effects of the immunomodulating bacterial extracts OM-85 on the stress response in normal human peripheral blood monocytes. While OM-85 did not induce the classical HSP, we show here, using 2D gel electrophoresis combined with immunoblotting, the induction of the glucose regulated protein grp78 (the immunoglobulin heavy chain binding protein BiP) along with the described accumulation of pro-interleukin-1 beta. The increased Ca2+ mobilization observed with OM-85 is the likely second messenger for grp78 induction. Recent studies are in favor of a protective role of grp78 against cytokine-mediated cytotoxicity and apoptosis. We suggest that grp78 induction following exposure to OM-85 explains, at least in part, the immunodulatory and protective effects of the bacterial extracts.
Insights
Bacterial extract OM-85 does not induce heat shock proteins (HSP) but increases glucose-regulated protein grp78 in monocytes. This grp78 induction may explain OM-85
Area of Science:
- Immunology
- Cell Biology
- Molecular Biology
Background:
- Heat shock proteins (HSP) function as molecular chaperones, cellular protectors, and immune modulators.
- The bacterial extract OM-85 is known for its immunomodulatory properties.
Purpose of the Study:
- To investigate the effects of OM-85 on the stress response in human monocytes.
- To elucidate the molecular mechanisms underlying OM-85's immunomodulatory effects.
Main Methods:
- Utilized 2D gel electrophoresis and immunoblotting to analyze protein expression in monocytes.
- Measured calcium ion (Ca2+) mobilization.
- Assessed pro-interleukin-1 beta accumulation.
Main Results:
- OM-85 did not induce classical HSP but significantly induced glucose-regulated protein grp78 (also known as BiP).
- Pro-interleukin-1 beta also accumulated in response to OM-85.
- Increased Ca2+ mobilization was observed, suggesting it acts as a second messenger for grp78 induction.
Conclusions:
- The induction of grp78 by OM-85 may contribute to its immunomodulatory and protective effects.
- Grp78's known protective role against cytotoxicity and apoptosis supports this hypothesis.
- OM-85's impact on monocyte stress response involves grp78 upregulation.