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Isolation and Characterization of Neutrophils with Anti-Tumor Properties
Published on: June 19, 2015
Fusobacterium nucleatum T18 aggregates human mononuclear cells and inhibits their PHA-stimulated proliferation
S Kinder Haake1, R A Lindemann
1Section of Periodontics Biology, UCLA School of Dentistry, USA.
Abstract:
In previous studies Fusobacterium nucleatum has been shown to induce either stimulatory or inhibitory effects on human mononuclear cells. We examined the interaction of human mononuclear cells with human and cynomolgus monkey strains of F. nucleatum. Peripheral blood mononuclear cells (PBMCs) isolated from normal donors were aggregated in the presence of cells of F. nucleatum but not control bacteria. The aggregation of PBMCs and F. nucleatum T18 was inhibited by either L-arginine, L-lysine, or pretreatment of the bacterial cells with heat, but was unaffected by the presence of sugars or normal human serum. Strain T18 aggregated purified T-cells and monocytes at approximately equal concentrations. When F. nucleatum T18 was incubated with PHA-stimulated PBMCs, DNA synthesis in the PBMCs was significantly inhibited and detection of IL-2R alpha on the PBMCs was reduced. These studies indicate that F. nucleatum aggregates PBMCs, and that this interaction is associated with both an inhibition of PBMC proliferation and a decrease in IL-2 receptor expression. The ability of F. nucleatum to inhibit mononuclear cell proliferation may be significant in the pathogenesis of periodontal diseases.
Insights
Fusobacterium nucleatum aggregates human mononuclear cells, inhibiting their proliferation and IL-2 receptor expression. This interaction may play a role in periodontal disease pathogenesis.
Area of Science:
- Immunology
- Microbiology
- Periodontology
Background:
- Fusobacterium nucleatum exhibits variable effects on human mononuclear cells.
- Understanding F. nucleatum's interaction with immune cells is crucial for periodontal disease research.
Purpose of the Study:
- To investigate the interaction between human mononuclear cells and F. nucleatum.
- To determine the impact of F. nucleatum on mononuclear cell proliferation and immune marker expression.
Main Methods:
- Peripheral blood mononuclear cells (PBMCs) were isolated from healthy donors.
- PBMC aggregation with F. nucleatum strains was assessed.
- Inhibition assays using L-arginine, L-lysine, and heat-treated bacteria were performed.
- DNA synthesis and IL-2 receptor alpha expression in PHA-stimulated PBMCs were measured.
Main Results:
- F. nucleatum, but not control bacteria, induced PBMC aggregation.
- Aggregation was inhibited by L-arginine, L-lysine, and heat treatment.
- F. nucleatum T18 inhibited DNA synthesis and reduced IL-2 receptor alpha expression in PHA-stimulated PBMCs.
- Strain T18 aggregated purified T-cells and monocytes.
Conclusions:
- F. nucleatum aggregates PBMCs, inhibiting their proliferation and decreasing IL-2 receptor expression.
- This immune modulation by F. nucleatum may contribute to the pathogenesis of periodontal diseases.
