One week of multifactorial high-stress military ranger training affects Gram-negative signalling.

Background: Toll-like receptor 4 (TLR4), especially expressed on monocytes/macrophages, connects microbial and sterile innate immune activation. Lipopolysaccharide (LPS) from Gram-negative bacteria and several endogenous molecules, among others saturated fatty acids (SFAs), are able to induce signalling through this receptor. Downstream inflammatory cytokines orchestrate the immune response.

The impact of hyaluronan on monocyte Toll-like receptor expression in term infant cord blood.

Aim: To explore the possible effects of hyaluronan, an endogenous mediator of inflammation, on monocyte surface expression of Toll-like receptors 2 and 4 in human umbilical cord blood ex vivo, and in a model mimicking Gram-negative neonatal sepsis.

Methods: Term infant cord blood was obtained after elective caesarean sections, n = 15. Both unstimulated and lipopolysaccharide-stimulated (10 ng/mL) blood was incubated with 500 μg/mL high- or low-molecular-weight hyaluronan for 6 h.

Moderate temperature alterations affect Gram-negative immune signalling in ex vivo whole blood.

Background: Alterations in body temperature may influence immune system function and consequently affect the risk of infection and inflammatory diseases. Lipopolysaccharide (LPS) from gram-negative bacteria induces production of inflammatory cytokines after ligand binding to Toll-like receptor 4 (TLR4) on immune cells (especially monocytes/ macrophages). Our aim was to explore how clinically relevant hypo- and hyperthermia affect this signalling in an ex vivo whole blood model, and investigate if the cytokine response was correlated with monocyte TLR4 expression level.