The Early Immune Response in the Liver of BALB/c Mice Infected with S. typhimurium

Abstract

Gram-negative bacteria acquired through gastrointestinal infection can be a serious cause for the development of septic shock especially in immunosuppressed patients. Thus, the aim of this study was to examine the early events of the immune reaction against S. typhimurium. Bacteria were injected into mice at different concentrations. Four animals from each group were killed at five different points of time. Liver cytokine mRNA expression was determined by semiquantitative rt-PCR and liver histology was examined. Serum cytokine levels of interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-4 and IL-10 were determined. intravenous (i.v.) infection with 109 bacteria led to lethal septic shock within 24 h. A delayed production of IFN-gamma, TNF-alpha, IL-18 and IL-10 and milder histological alterations in the liver were observed in these animals. The highest expression of cytokines in the liver and the strongest histological alterations were seen after infection with 107 bacteria. Here, an increased mRNA expression of all proinflammatory cytokines began 1 h after infection. Animals infected with 1 x 102 bacteria had the highest detectable serum levels of IL-6 and IL-10. These data indicate that the immediate events in the immune reaction within the liver after infection with S. typhimurium are associated with the outcome of the subsequent sepsis.

Heterophil cytokine mRNA profiles from genetically distinct lines of chickens with differential heterophil-mediated innate immune responses

“…IL-18 is critical in initiating an inflammatory response, is associated with a T1 cytokine response, and dramatically enhances innate and acquired immunity, thereby affecting host resistance to bacterial infections (Okamura et al ., 1998;Garcia et al ., 1999;Barreiros et al ., 2000). In humans, increased IL-18 plays a protective role against systemic Salmonella infections (Mizuno et al ., 2003).…”

Differential cytokine mRNA expression in heterophils isolated from Salmonella‐resistant and ‐susceptible chickens

“…IL‐18 is an IL‐1‐related pro‐inflammatory cytokine critical in initiating an inflammatory response 42–44 . It is highly pleotropic, primarily associated with a type‐1 cytokine response and involved in determining resistance or susceptibility to bacterial infections 45,46 . An increased type‐1 cytokine response, including an up‐regulation of IL‐18 is associated with increased resistance to Mycobacterium leprae in leprosy patients 45 .…”

“…An increased type‐1 cytokine response, including an up‐regulation of IL‐18 is associated with increased resistance to Mycobacterium leprae in leprosy patients 45 . Also, in the mouse model, a sublethal dose of Salmonella typhimurium results in a rapid pro‐inflammatory cytokine response 46 . An effective type‐1 cytokine response dramatically enhances the innate and acquired immune response and enhances host resistance to infections 43,44 .…”

“…[42][43][44] It is highly pleotropic, primarily associated with a type-1 cytokine response and involved in determining resistance or susceptibility to bacterial infections. 45,46 An increased type-1 cytokine response, including an up-regulation of IL-18 is associated with increased resistance to Mycobacterium leprae in leprosy patients. 45 Also, in the mouse model, a sublethal dose of Salmonella typhimurium results in a rapid pro-inflammatory cytokine response.…”

Vitamin E Supplementation Modulates Endotoxin-induced Liver Damage in a Rat Model

“…LPS binding to immune cells initiates a cascade of events that up-regulate expression of the inflammatory cytokines including TNF- [2,4,5]. TNF- stimulates the production of reactive oxygen species (ROS) and reactive nitrogen intermediates (RNIs) by activated macrophages causing liver damage due to the oxidative stress [6][7][8][9].…”