Newly Isolated B1/1 Modulates the Expression of Cytokines and Antimicrobial Proteins in a Porcine Model.

BACKGROUND

The epithelia of the intestine perform various functions, playing a crucial role in providing a physical barrier and an innate immune defense against infections. By generating a "three-dimensional" (3D) model of cell co-cultures using the IPEC-J2 cell line and porcine blood monocyte-derived macrophages (MDMs), we are getting closer to mimicking the porcine intestine Methods: The effect of B1/1 and CCM 7158 (indicator strain) on the relative gene expression of interleukins (IL-1β, IL-6, IL-8, IL-18 and IL-10), genes encoding receptors for TLR4 and TLR2, tight junction proteins such as claudin-1 (CLDN1), occludin (OCLN) and important antimicrobial proteins such as lumican (LUM) and olfactomedin-4 (OLMF-4) was monitored in this model.

RESULTS

The results obtained from this pilot study point to the immunomodulatory potential of newly isolated B1/1, as it was able to suppress the enhanced pro-inflammatory response to lipopolysaccharide (LPS) challenge in both cell types. B1/1 was even able to up-regulate the mRNA levels of genes encoding antimicrobial proteins LUM and OLFM-4 and to increase tight junction (TJ)-related genes and , which were significantly down-regulated in LPS-induced IPEC-J2 cells. Conversely, CCM 7158, chosen as an indicator lactic acid bacteria (LAB) strain, increased the mRNA levels of the investigated pro-inflammatory cytokines (IL-18, IL-6, and IL-1β) in MDMs when LPS was simultaneously applied to basally deposited macrophages. Although CCM 7158 induced the production of pro-inflammatory cytokines, synchronous up-regulation of the anti-inflammatory cytokine IL-10 was detected in both LAB strains used in both cell cultures.

CONCLUSIONS

The obtained results suggest that the recently isolated LAB strain B1/1 has the potential to alleviate epithelial disruption caused by LPS and to influence the production of antimicrobial molecules by enterocytes.