Enhancement of macrophage-mediated tumor cell killing by bacterial outer membrane proteins (porins).
Published
Journal Article
Various microbial products are known to influence the function of mouse peritoneal macrophages. Lipopolysaccharide (LPS) and certain lipid A-associated proteins are known to enhance the tumoricidal effects of macrophages. The purpose of this study was to determine whether porins (outer membrane proteins) of Salmonella typhimurium G30/C21 would influence the activity of macrophages from lipid A-responsive and -unresponsive mice. Porins, extracted by a combined sodium dodecyl sulfate-EDTA method from cell walls, were free of LPS as determined by Limulus amebocyte lysate assay and appeared as a band at approximately 36,000 molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In tumor cell killing assays done under LPS-free conditions, the porins in doses of 1 to 10 ng/ml enhanced the tumoricidal effect of macrophages from bacillus Calmette-Guérin-infected C3H/HeN or C3H/HeJ mice. Protein-free LPS enhanced the tumoricidal activity of macrophages from bacillus Calmette-Guérin-infected C3H/HeN but not C3H/HeJ mice. The tumoricidal-enhancing activity of protein-free LPS was blocked by the lipid A-binding antibiotic polymyxin B sulfate, but the effects of porins were not altered by the polymyxin B sulfate. These results suggest that porins, proteins known to alter membrane function, may alter macrophage function by interaction with macrophage membranes.
Full Text
Duke Authors
Cited Authors
- Weinberg, JB; Ribi, E; Wheat, RW
Published Date
- October 1, 1983
Published In
Volume / Issue
- 42 / 1
Start / End Page
- 219 - 223
PubMed ID
- 6311745
Pubmed Central ID
- 6311745
International Standard Serial Number (ISSN)
- 0019-9567
Digital Object Identifier (DOI)
- 10.1128/IAI.42.1.219-223.1983
Language
- eng
Conference Location
- United States