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Updated: Aug 7, 2026
In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells
Published on: May 16, 2011
The characteristics of binding of Corynebacterium parvum to glass-adherent mouse peritoneal exudate cells
Abstract:
Corynebacterium parvum, strain 10390, whole organisms were shown to bind to the surface of glass-adherent mouse peritoneal exudate cells in vitro. An HCl extract and a lipid extract of the organism were both capable of inhibiting this binding. The attachment of organisms was not affected by trypsin treatment of the cells, indicating that the plasma membrane receptor is not cell-bound antibody in nature. The binding was inhibited by various sugars, most of which are major components of the cell wall of C. parvum. Removal of divalent cations prevented binding. At room temperature some binding occurred in the presence of magnesium ions alone, whereas both calcium and magnesium ions were required at 4 degrees C. The possibility is discussed that the attachment of C. parvum to the plasma membrane of macrophages may lead directly to their activation.
Insights
Corynebacterium parvum organisms bind to mouse immune cells. Inhibitors and cell wall components suggest specific binding mechanisms involving sugars and divalent cations, potentially activating macrophages.
Area of Science:
- Immunology
- Microbiology
- Cell Biology
Background:
- Corynebacterium parvum (C. parvum) is an immunostimulant.
- Understanding C. parvum's interaction with host cells is crucial for immunotherapy.
- Previous studies suggest C. parvum can activate macrophages.
Purpose of the Study:
- To investigate the in vitro binding mechanism of C. parvum to mouse peritoneal exudate cells.
- To identify factors influencing the attachment of C. parvum to host immune cells.
Main Methods:
- In vitro binding assays using glass-adherent mouse peritoneal exudate cells and C. parvum (strain 10390).
- Treatment of cells with trypsin to assess the role of cell surface receptors.
- Inhibition studies using HCl and lipid extracts of C. parvum, various sugars, and divalent cations (magnesium and calcium).
Main Results:
- Whole C. parvum organisms bound to mouse peritoneal exudate cells.
- HCl and lipid extracts of C. parvum inhibited this binding.
- Trypsin treatment of cells did not affect organism attachment, ruling out antibody-mediated binding.
- Binding was inhibited by sugars, many of which are C. parvum cell wall components.
- Divalent cations were required for binding; magnesium sufficed at room temperature, while both calcium and magnesium were needed at 4°C.
Conclusions:
- C. parvum attachment to macrophages involves specific interactions with cell surface components, likely mediated by organism-derived molecules and influenced by sugars and divalent cations.
- The binding mechanism is not dependent on cell-bound antibodies.
- This specific binding may be an initial step in C. parvum-induced macrophage activation.
