Characterization of extracellular vesicles from Lactiplantibacillus plantarum

Researchers at Kindai University, Japan investigated the characteristics and functionalities of extracellular vesicles (EVs) from Lactiplantibacillus plantarum (previously Lactobacillus plantarum) towards host immune cells. Lplantarum produces EVs that have a cytoplasmic membrane and contain cytoplasmic metabolites, membrane and cytoplasmic proteins, and small RNAs, but not bacterial cell wall components, namely, lipoteichoic acid and peptidoglycan. In the presence of Lplantarum EVs, Raw264 cells inducibly produced the pro-inflammatory cytokines IL-1β and IL-6, the anti-inflammatory cytokine IL-10, and IF-γ and IL-12, which are involved in the differentiation of naive T-helper cells into T-helper type 1 cells. IgA was produced by PP cells following the addition of EVs. Therefore, Lplantarum EVs activated innate and acquired immune responses. Lplantarum EVs are recognized by Toll-like receptor 2 (TLR2), which activates NF-κB, but not by other TLRs or NOD-like receptors. N-acylated peptides from lipoprotein19180 (Lp19180) in Lplantarum EVs were identified as novel TLR2 ligands. Therefore, Lplantarum induces an immunostimulation though the TLR2 recognition of the N-acylated amino acid moiety of Lp19180 in EVs. Additionally, the researchers detected a large amount of EVs in the rat gastrointestinal tract for the first time, suggesting that EVs released by probiotics function as a modulator of intestinal immunity.

Properties of EVs produced by Lplantarum and their effects on host immune cells

Figure 1

(a) Biochemical components of L. plantarum EVs. (b) Schematic sketch of NF-κB activation by Lp19180 via TLR2 and the subsequent stimulation of innate and adaptive immunities.

Kurata A, Kiyohara S, Imai T et al. (2022) Characterization of extracellular vesicles from Lactiplantibacillus plantarum. Sci Rep 12, 13330. [article]

Leave a Reply

Your email address will not be published. Required fields are marked *