Lactobacillus plantarum RS-09 Induces M1-Type Macrophage Immunity Against Salmonella Typhimurium Challenge via the TLR2/NF-κB Signalling Pathway

Abstract

Lactobacillus plantarum can interact with macrophages against bacterial enteropathy due to its potential ability to modulate macrophage polarization. However, this mechanism is not completely understood. TLR2 can recognize microbial components and trigger macrophage cytokine responses to different gram-positive strains. The aim of this study was to investigate whether probiotic Lactobacillus plantarum RS-09 can induce macrophage polarization against Salmonella Typhimurium infection via TLR2 signalling. BALB/c mice were preadministered RS-09 continuously for 7 days and then infected with Salmonella Typhimurium ATCC14028. Mouse RAW264.7 mononuclear macrophages were stimulated with RS-09 and coincubated with ATCC14028 or PBS controls. The results of the in vivo study indicated that RS-09 could relieve S. Typhimurium-induced splenomegaly, body weight loss and death rate. RS-09 also limited the colonization and translocation of S. Typhimurium in the gastrointestinal tract and thereby protected against infection. We also observed that RS-09 upregulated the production of M1 macrophage characteristics (e.g., CD11c and IL-6) against S. Typhimurium. Furthermore, RS-09 induced the expression of TLR2 in macrophages. In an in vitro study, treatment of RAW264.7 cells with RS-09 either concurrently with or before S. Typhimurium challenge enhanced the secretion of Reactive oxygen species and Nitric oxide. This effect was related to TLR2 and NF-κB activation. Based on these findings, Lactobacillus plantarum RS-09 was shown to modulate M1 macrophage polarization and induce TLR2-linked NF-κB signalling activity in the innate immune response to S. Typhimurium infection.

Lactobacillus plantarum synergistically regulates M1 macrophage polarization in resistance against Salmonella enterica serovar Typhimurium infection

“…Therefore, LP itself might slightly modulate M1 macrophage polarization, but it is uncertain. These results are partly consistent with those of previous studies on LGG, Lactobacillus plantarum RS-09, and Lactobacillus johnsonii polarizing M1 macrophages against pathogen infection (Affar et al, 2018 ; Wang et al, 2020 ; Zhao et al, 2022 ). LGG triggers M1 polarization and induces both pro-inflammatory and anti-inflammatory cytokines in BMM, which aid in maintaining immune balance and homeostasis (Wang et al, 2020 ).…”

“…Bacterial co-culture of RAW 264.7 was performed according to previous studies (Fu et al, 2019 ; Duan et al, 2021 ; Zhao et al, 2022 ). RAW 264.7 was seeded on 96-, 12-, or 6-well plates.…”

Akebia Saponin D Inhibits the Inflammatory Reaction by Inhibiting the IL-6-STAT3-DNMT3b Axis and Activating the Nrf2 Pathway

“…Macrophage polarization plays a key role in the inflammatory process. M1 macrophages (classically activated macrophages), which mainly enhance inflammation, are defined as proinflammatory macrophages, whereas those that decrease inflammation are called M2 macrophages (alternatively activated macrophages) [8,9]. Overall, the high expression of DNMT3b is positively correlated with inflammation, suggesting that DNMT3b-regulated macrophage phenotypes participate in the regulation of inflammation [10].…”

PP19128R, a Multiepitope Vaccine Designed to Prevent Latent Tuberculosis Infection, Induced Immune Responses In Silico and In Vitro Assays

“…Linkers such as GPGPG, AAY, and KK were used to link HTL, CTL, and B-cell epitopes. Toll-like receptor 2 (TLR2) agonist Porin B (PorB) [33] (IALTLAALPVAAMADVTLYGTIKAGVETSRSVAHNGAQAASVETGT-GIVDLG-SKIGFKGQEDLGNGLKAIWQVEQ) and TLR-4 agonist RS-09 [34] (APPHALS) were used as adjuvants to enhance the immunogenicity of MEV. A pan HLA DR binding epitope (PADRE) (AGLFQRHGEGTKATVGEPV) was added to induce a more robust HTL response [35].…”