Research Reveals Unique Immune Evasion Strategy of Bacterium Linked to Periodontal Disease

Researchers have recently identified a new mechanism through which Porphyromonas gingivalis (P. gingivalis), a key bacterium associated with periodontitis, evades the immune system. This discovery could lead to novel strategies for enhancing bacterial clearance and improving both periodontal health and overall wellness.

A recent study led by Professor Gabriel Nussbaum from the Faculty of Dental Medicine at the Hebrew University of Jerusalem has uncovered a unique way in which P. gingivalis manipulates the immune system. The findings, published in PNAS, reveal how this pathogen persists in inflamed oral tissues and increases risks for various systemic diseases including cardiovascular disease, Alzheimer’s, and cancer.

The research team found that P. gingivalis exploits CD47, an integrin-associated protein known as a “don’t eat me” signal in cancer cells. By interfering with the body’s immune response through CD47, the bacterium is protected from destruction by immune cells. Furthermore, the study uncovered that P. gingivalis induces the production of thrombospondin-1 (TSP-1), another ligand that suppresses immune activity, particularly neutrophil-mediated bacterial clearance.

“Our findings suggest that P. gingivalis uses CD47 to hijack immune signaling pathways,” explained Prof. Gabriel Nussbaum, “effectively disabling the host’s ability to clear the infection.” This mechanism helps explain why this bacterium thrives in inflammatory environments and is linked to chronic periodontitis as well as systemic diseases.

Using both laboratory and animal models, researchers demonstrated that blocking CD47 or TSP-1 significantly enhanced bacterial clearance by immune cells. Mice lacking CD47 showed a higher ability to eliminate P. gingivalis, indicating that targeting this pathway could be a promising strategy for treating periodontal disease.

“Current treatments for periodontitis focus on reducing bacterial load mechanically,” Prof. Nussbaum added, “but understanding how these bacteria evade immune responses opens up new therapeutic possibilities.” Targeting CD47-TLR2 signaling or TSP-1 could represent a novel approach to managing chronic infections linked to oral and systemic health.

Given the strong correlation between periodontitis and various conditions such as cardiovascular disease, Alzheimer’s, and cancer, this discovery holds broad implications beyond dentistry. Future research will aim to translate these findings into clinical therapies that improve immune responses against persistent bacterial infections.