Production of Macrophage Inflammatory Protein (MIP)-1α and MIP-1β by Human Polymorphonuclear Neutrophils Stimulated with Porphyromonas endodontalis Lipopolysaccharide

Abstract

This study was undertaken to investigate the capacity of polymorphonuclear neutrophils (PMNs) to secrete Macrophage Inflammatory Protein (MIP)-1alpha and MIP-1beta after stimulation with Porphyromonas endodontalis lipopolysaccharide (LPS). Escherichia coli LPS was used as a positive control. Venous blood was collected and PMNs were isolated from healthy volunteers. Cells were cultured with various concentrations of LPS for different periods of time. Cell supernatants were assayed by enzyme-linked immunosorbent assay. The levels of chemokine secretion in PMNs stimulated with each LPS were found to be significantly higher than in the unstimulated control cells (p < 0.05), and this expression occurred in a time- and dose-dependent manner. E. coli LPS induced higher levels of cytokines than P. endodontalis LPS. These findings demonstrated that P. endodontalis LPS is capable of stimulating PMNs to produce chemotactic cytokines and suggested that PMNs stimulated with P. endodontalis LPS may play a crucial role in the inflammatory and immunopathological reactions of pulpal and periapical diseases.

Direct stimulatory effects of the TLR2/6 ligand bacterial lipopeptide MALP-2 on neutrophil granulocytes

“…Neutrophils have been shown to release MIP-1 beta after exposure to lipopolysaccharide and cytokines [16,20]. Our present Wndings clearly indicate that neutrophils exposed to TLR2-ligand bacterial lipopeptides secrete MIP-1 beta.…”

Neutrophils secrete MIP‐1β after adhesion to laminin contained in basement membrane of blood vessels

“…In this study, we demonstrated that neutrophils secreted MIP-1b after adhering to laminin. This result suggests that neutrophils transmigrating from the intravascular space into inflammatory tissues traverse the basement membrane, which contains abundant laminin, and then secrete MIP-1b soon after the transmigration, whereas previous reports showed that neutrophils secreted MIP-1b after stimulation with lipopolysaccharide or cytokines (Kasama et al, 1994;Ko & Lim, 2002). Since the survival time of neutrophils is very short, our reasoning seems logical enough to explain the intervention of neutrophils between innate immune response and specific immune response.…”

Comparison of Endotoxin Levels Found in Primary and Secondary Endodontic Infections

“…Typical results were shown by Schein and Schilder (3) and Horiba et al (24). It has long been known that oral bacterial LPSs are potent stimuli for proinflammatory cytokines involved in periapical tissue destruction (6,8,26,27). Martinho et al (6) showed that higher levels of endotoxins were followed by an increased production of interleukin-1b in teeth with a larger area of bone resorption.…”

“…The selection criteria for the investigation of P. nigrescens, P. endodontalis, F. nucleatum, T. denticola, and T. socranskii were based on the frequent occurrence of these species in endodontic infections (6,(8)(9)(10)(11)(12)(13)(21)(22)(23) and their LPS toxicity (5,7,26,27). Recently, a great interindividual variation in the composition of the apical microbiota has been disclosed by pyrosequencing analyses (28,29).…”