Key points are not available for this paper at this time.
Apoptosis (programmed cell death) is a mechanism by which superfluous or damaged cells undergo changes that lead to selective removal from organ systems by phagocytic cells. Certain bacterial products delay apoptosis in neutrophils (PMNs). In this study, PMNs were incubated for up to 8 h with varying concentrations of lipopolysaccharide (LPS), lipid A or capsular polysaccharide isolated from 3 strains of Porphyromonas gingivalis (Pg) (strains HG-184, A7A1-28 and 381). Assay runs included controls containing cells and medium but no bacterial products. Fluorescence microscopy was used to evaluate apoptotic changes. PMNs exhibited a time-dependent increase in the number of apoptotic cells. When cells were cultured in the presence of LPS from any of the 3 Pg strains, apoptosis was delayed in a dose-dependent fashion (p 0.05). Thus, LPS and lipid A from P. gingivalis appear to modulate the functional lifespan of PMNs. This could potentiate the inflammatory and destructive components of periodontal diseases.
Preshaw et al. (Sat,) studied this question.