Differential regulation of lipopolysaccharide and Gram-positive bacteria induced cytokine and chemokine production in macrophages by G?iproteins

Differential regulation of lipopolysaccharide and Gram-positive bacteria induced cytokine and chemokine production in splenocytes by Galphai proteins.

Heterotrimeric Gi proteins play a role in lipopolysaccharide (LPS) and Staphylococcus aureus (SA) activated signaling leading to inflammatory mediator production. We hypothesized that genetic deletion of Gi proteins would alter cytokine and chemokine production induced by LPS and SA. LPS- and heat killed SA-induced cytokine and chemokine production in splenocytes from wild type (WT), Galpha(i2)...

Differential regulation of cytokine and chemokine production in lipopolysaccharide-induced tolerance and priming.

LPS pretreatment of human pro-monocytic THP-1 cells induces tolerance to secondary LPS stimulation with reduced TNFalpha production. However, secondary stimulation with heat-killed Staphylococcus aureus (HKSa) induces priming as evidenced by augmented TNFalpha production. The pro-inflammatory cytokine, IFNgamma, also abolishes suppression of TNFalpha in LPS tolerance. The effect of LPS toleranc...

Cytokine induction by Gram-positive bacteria.

Despite similar clinical relevance of Gram-positive and Gram-negative infections, immune activation by Gram-positive bacteria is by far less well understood than immune activation by Gram-negative bacteria. Our group has made available highly purified lipoteichoic acids (LTA) as a key Gram-positive immunostimulatory component. We have characterized the reasons for lower potency of LTA compared ...

Peritoneal Macrophages Lipopolysaccharide-Stimulated Mouse Cytokine and Chemokine Production in IL-4 Pretreatment Selectively Enhances

IL-33 enhances lipopolysaccharide-induced inflammatory cytokine production from mouse macrophages by regulating lipopolysaccharide receptor complex.

Bacterial LPS triggers monocytes and macrophages to produce several inflammatory cytokines and mediators. However, once exposed to LPS, they become hyporesponsive to a subsequent endotoxin challenge. This phenomenon is defined as LPS desensitization or tolerance. Previous studies have identified some components of the biochemical pathways involved in negative modulation of LPS responses. In par...