Related Experiment Videos
Effects of E. coli 0111.B4 lipopolysaccharide on spin-labelled murine macrophage and hepatocyte membranes
S K Jackson1, P E James, C C Rowlands
1Dept Medical Microbiology, University of Wales College of Medicine, Cardiff.
Abstract:
Macrophages and hepatocytes from normal and BCG-primed mice have been spin-labelled in their membranes with 5- and 16-doxyl stearic acid. Incubation of spin-labelled cells from BCG-primed animals with lipopolysaccharide from E. coli 0111.B4 produced a detectable and transient disturbance in the cell membranes as reflected by an increase in the order parameter measured from the electron spin resonance spectra of 5-doxyl-stearate. This membrane disturbance was maximal at 3-4 hours of incubation and was only detected with cells from mice primed with BCG. Spectra obtained from the 16-doxyl-stearate-labelled cells showed no change in order parameter on incubation with lipopolysaccharide.
Insights
Bacillus Calmette-Guérin (BCG)-primed immune cells show transient membrane disturbances upon lipopolysaccharide exposure. This effect, detected via electron spin resonance, highlights immune cell membrane dynamics during immune response.
Area of Science:
- Immunology
- Cell Biology
- Biophysics
Background:
- Macrophages and hepatocytes are key immune and metabolic cells.
- Bacillus Calmette-Guérin (BCG) vaccination primes the immune system.
- Lipopolysaccharide (LPS) is a major component of Gram-negative bacterial outer membranes.
Purpose of the Study:
- To investigate the effect of lipopolysaccharide (LPS) on the cell membranes of macrophages and hepatocytes from normal and BCG-primed mice.
- To assess changes in membrane fluidity and order using spin-labelling techniques.
Main Methods:
- Spin-labelling of cell membranes with 5- and 16-doxyl stearic acid.
- Incubation of labelled cells with Escherichia coli (E. coli) lipopolysaccharide (LPS).
- Analysis of cell membrane order parameter using electron spin resonance (ESR) spectroscopy.
Main Results:
- BCG-primed cells exhibited a transient increase in membrane order parameter when incubated with LPS, indicating membrane disturbance.
- This membrane disturbance was maximal at 3-4 hours post-incubation.
- No significant changes in the order parameter were observed in 16-doxyl-stearate labelled cells or cells from non-primed mice.
Conclusions:
- BCG priming induces a specific, transient alteration in macrophage and hepatocyte membrane properties upon LPS challenge.
- Electron spin resonance spectroscopy is a sensitive method for detecting immune-induced membrane changes.
- These findings contribute to understanding the biophysical basis of immune memory at the cellular level.