Lactobacilli-based postbiotic differentially affects chicken macrophage-like HD11 cells depending on stimulatory lipopolysaccharide dosage.

BACKGROUND: This study investigated the dose-dependent effects of a lactobacilli-based postbiotic (Post) on the transcriptional reprogramming of the chicken macrophage-like HD11 cell line when exposed to Escherichia coli lipopolysaccharide (LPS). First, the HD11cells were treated with 0, 3, 30 and 300 ng/mL LPS in combination with 0, 0.2, 0.4, 0.6 and 0.8% v/v Post. Nitric oxide (NO) production was quantified at 20 h incubation and the early transcriptome reprogramming was analysed in a subset of treatments at 5 h incubation. RESULTS: Post increased NO production dose-dependently and an LPS-postbiotic interaction was present, with the cells eliciting a higher NO production in response to Post at 30 and 300 ng/ml LPS compared to the zero and 3 ng/ml LPS. To further understand this interaction, the early transcriptome reprogramming was investigated for treatments with 0, 3 and 300 ng/mL LPS and 0 and 0.8% v/v Post. A number of differentially expressed genes were identified and gene set enrichment analysis of KEGG pathways revealed that Post at 0 and 300 ng/mL LPS influenced similar inflammation-related pathways, until Post at 3 ng/mL LPS which had a minimal effect. Expression of transcription factors (TFs) and immune-related genes revealed differential effects induced by Post depending on LPS concentration which would have likely influenced the inflammatory response. Specifically, the only TFs affected by Post at 300 ng/ml LPS were STAT2, SMAD3 and IFR8, which all showed increased expression. The TFs consistently affected by Post at the zero and 3 ng/ml LPS increased and were JUN, ZFP36L2, SMAD1 and E2F3. CONCLUSION: Our results showed that Post had a pro-inflammatory effect, which was exacerbated in the presence of a 300 but not 3 ng/ml LPS. Furthermore, the dose of LPS affected the sensitivity of the cells to Post. Dose-response studies should be performed when investigating the effects of dietary compounds on inflammation in chicken macrophages.