Induction of tumor necrosis factor α and interleukin-1β in subcutaneously implanted chamber by lipopolysaccharide

Abstract

Lipopolysaccharide (LPS) is the major component of the outermost membrane of Gram-negative bacteria and is considered to be one of the major virulence factors of these bacteria. While the effect of systemic injection of LPS is well characterized, the characterization of cytokine secretion in response to local injection of LPS is lacking. The present study was designed to determine the local production of tumor necrosis factor α (TNFα) and interleukin-1β (IL1β) over a 4 day period following injection of LPS into subcutaneous implanted chambers in mice. Mice were challenged by a single or repeated injection of Salmonella typhosa LPS into the chambers. Chamber fluids were aspirated at different time intervals and were used for assessment of leukocyte and cytokine levels. A single injection of LPS was found to induce cell influx into the chamber which peaked after 4 h. TNFα and IL-1β levels increased rapidly, reaching their maximum levels within 4 h. After 24 h, TNFα levels declined markedly and were undetectable at 48 and 96 h. TNFα mRNA levels in the sedimented cells followed a similar pattern. In contrast, IL-1β showed a more gradual decrease with levels significantly different from baseline still being present 96 h post-LPS challenge. Four consecutive daily injections of LPS into the chambers resulted in undetectable levels of TNFα in the chamber fluid, while significant levels of IL-1β were detected. These levels were significantly higher than the levels of IL-1β in the chamber fluid 96 h after a single injection and approximately 60% of the levels measured 24 h after a single intra-chamber injection of LPS. The results emphasize the difference between single and repeated exposure to LPS in vivo, and suggest a role for TNFα in the initial phase of the local inflammatory response and for IL-1β in the later phase.

Immunization to Porphyromonas gingivalis enhances the local pro‐inflammatory response to subcutaneous bacterial challenge

“…To try to explain this apparent contradiction between protective immune response represented by high antibody titers, and disease progression, we hypothesize that immunization against P. gingivalis leads to antibody production on one hand, but to up‐regulation of tissue‐destructive cytokines on the other hand. To test this hypothesis, we investigated the effect of pre‐immunization to P. gingivalis on a P. gingivalis ‐induced inflammatory response in the subcutaneous chamber model in mice (Genco & Arko 1994, Shapira et al 1997). 2 different adjuvants were used for immunization, incomplete Freund’s Adjuvant (IFA) and Alum.…”

Repeat bacterial challenge in a subcutaneous chamber model results in augmented tumour necrosis factor‐α and interferon‐γ response, and suppression of interleukin‐10

“…To test this hypothesis, we used a P. gingivalis induced in¯ammatory response in the subcutaneous chamber model in mice. 13,14 This model provides a localized in¯amma-tory exudate that is easily accessible for sampling and quanti®cation of its contents. We followed the development of the in¯ammatory response by measuring leucocyte recruitment and the local accumulation of TNF-a, IFN-c, and IL-10, after a single challenge compared to two repeated challenges with P. gingivalis.…”

Citrus Oil and MgCl2 as Antibacterial and Anti‐Inflammatory Agents

“…The aim of this study was to investigate the antibacterial and anti‐inflammatory properties of citrus oil, magnesium salt, and their combination with respect to their potential use for treatment of oral infections and inflammation. The antibacterial effect was evaluated on in vitro cultures of P. gingivalis , and the anti‐inflammatory effect was evaluated in vivo using a subcutaneous chamber model in mice 24 …”

“…The antibacterial effect was evaluated on in vitro cultures of P. gingivalis, and the anti-inflammatory effect was evaluated in vivo using a subcutaneous chamber model in mice. 24 MATERIALS AND METHODS Antibacterial Activity P. gingivalis (ATCC 33277) was cultured in sterile Wilkins bedding for 2 to 3 days and standardized with a spectrophotometer to an optical density of 0.8. The minimal inhibitory concentration (MIC) of the substance being examined was determined using serial broth dilutions.…”