Induction of tolerogenic porcine antigen presenting cells by immunobiotic Lactobacillus jensenii: impact on pathogen-induced inflammatory damage

JULIO VILLENA; HITOMI FUJIE; RIE SUZUKI; SYOICHI HOSOYA; YOSHIHITO SUDA; ERIKO CHIBA; HISASHI ASO; MASANORI TOHNO; SHUJI IKEGAMI; HIROYUKI ITOH; TADAO SAITO; SUSANA ALVAREZ; HARUKI KITAZAWA

Geneva

Congreso; 4th Congress of European Microbiologists; 2011

We studied the effect of Lactobacillus jensenii strain (Lj) on porcine antigen presenting cells (pAPCs) from Peyer´s patches (PP). The effect of Lj was evaluated in PP tissue cultures and PP adherent cells. Three subsets of pAPCs were defined by flow cytometric analysis: CD172a+CD11R1-MHCII+, CD172a-CD11R1lowMHCII+ and CD172a+CD11R1highMHCII+ cells. Stimulation of PP with Lj up-regulated MHCII, CD80/86, TLR2 and IL-10 expression in CD172a+CD11R1high and CD172a+CD11R1- cells, while TGF-β was increased only in CD172a+CD11R1high cells. These results were confirmed in CD172a+ cells obtained by MACS cell separation system (magnetic cell labeling). In addition, we evaluated the immunoregulatory activity of Lj on pAPCs during the generation of an inflammatory response triggered by enterotoxigenic Escherichia coli (ETEC). Inflammatory challenge increased MHCII, CD80/86, TNF-α, IL-6 and IFN-γ levels in pAPCs while IL-10 and TGF-β were down-regulated in CD172a+CD11R1- and CD172a+CD11R1high cells respectively. No changes were observed in CD14, TLR2 and TLR4. PP pAPCs stimulated with Lj before ETEC challenge showed lower levels of TNF-α and IL-6 than ETEC control cells. Moreover, immunoregulatory cytokines were higher in CD172a+ pAPCs. These results were confirmed in CD172a+ MACS separated cells. In this work we have effectively implement the use of pAPCs as laboratory tools for in vitro studies. In addition, we have deepened in the understanding of the mechanisms involved in the protective activity of Lj against pathogen-induced inflammatory damage, demonstrating that Lj exerts its immunoregulatory action through CD172a+ cells by stimulating their maturation (MHCII and CD80/86) and inducing the expression of immunoregulatory cytokines (TGF-β and IL-10).