Lipopolysaccharide-Activated Leukocytes Enhance Thymic Stromal Lymphopoietin Production in a Mouse Air-Pouch-Type Inflammation Model

Abstract

Thymic stromal lymphopoietin (TSLP) is a key cytokine that exacerbates allergic and fibrotic reactions. Several microbes and virus components have been shown to induce TSLP production, mainly in epithelial cells. TLR4 activators, such as lipopolysaccharide (LPS), induce TSLP production in vivo, although the underlying mechanisms remain unclear. In this study, we investigated the contribution of LPS-activated leukocytes to the production of TSLP in a mouse air-pouch-type inflammation model. LPS induced the production of TSLP in this model but not in the mouse keratinocyte cell line PAM212. Transfer of the infiltrated leukocytes collected from an LPS-injected air pouch to the air pouch of another mouse enhanced TSLP production. Further, the LPS-activated leukocytes produced tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β); a deficiency in these cytokines attenuated the LPS-induced production of TSLP. TSLP production was induced by TNF-α and enhanced by IL-1β and LPS in the PAM212 cells. These results demonstrated that TNF-α and IL-1β, which are partly produced by LPS-activated leukocytes, contribute to TSLP production via TLR4 activation in vivo.

Renoprotective effect of erythropoietin via modulation of the STAT6/MAPK/NF-κB pathway in ischemia/reperfusion injury after renal transplantation

“…These data suggest that EPO not only suppressed the expression of pro-inflammatory cytokines, but also increased the level of anti-inflammatory cytokines. TLSP is a critical cytokine that exacerbates allergic and fibrotic reactions ( 37 ). TLSP is mainly produced by epithelial cells and its production is induced by inflammatory cytokines ( 38 ).…”

Bromamine T, a stable active bromine compound, prevents the LPS‑induced inflammatory response

“…In the experiments presented herein, the potential protective action of agents was examined 8 h following the LPS administration, since a significant neutrophil accumulation was only observed 8 h after the LPS injection in mice bearing an air pouch (44). A similar pattern of LPS challenge was also used in another study (53). In the present study, pouches were injected with a single dose of 1 ml (1 µg/ml) LPS alone (positive control) or a single dose of 1 ml (1 µg/ml) LPS plus a single dose of (3 or 6 or 9 mg/mouse) BAT concurrently or a single dose of 1 ml (1 µg/ml) LPS plus a single dose of (9 mg/mouse) taurine concurrently, inside the air pouch of mice for 8 h, 10 days after air pouch formation (44).…”