TNF and infection: The bacteria in plaque produce a variety of toxins and enzymes that irritate the gums, causing them to become red, swollen, and bleed easily.4The immune system then responds to the bacterial invasion by releasing macrophage, neutrophils, and various inflammatory mediators, such as prostaglandins, cytokines, and chemokines, to combat the infection.5Tumor necrosis factor-alpha (TNF-α) and prostaglandin E2 (PGE2) are both mediators of inflammation that have been found to be elevated in periodontal disease.