L. plantarum WCFS1 enhances Treg frequencies by activating DCs even in absence of sampling of bacteria in the Peyer Patches

Abstract

Probiotics such as L. plantarum WCFS1 can modulate immune responses in healthy subjects but how this occurs is still largely unknown. Immune-sampling in the Peyer Patches has been suggested to be one of the mechanisms. Here we studied the systemic and intestinal immune effects in combination with a trafficking study through the intestine of a well-established immunomodulating probiotic, i.e. L. plantarum WCFS1. We demonstrate that not more than 2–3 bacteria were sampled and in many animals not any bacterium could be found in the PP. Despite this, L. plantarum was associated with a strong increase in infiltration of regulatory CD103+ DCs and generation of regulatory T cells in the spleen. Also, a reduced splenic T helper cell cytokine response was observed after ex vivo restimulation. L. plantarum enhanced Treg cells and attenuated the T helper 2 response in healthy mice. We demonstrate that, in healthy mice, immune sampling is a rare phenomenon and not required for immunomodulation. Also in absence of any sampling immune activation was found illustrating that host-microbe interaction on the Peyer Patches was enough to induce immunomodulation of DCs and T-cells.

Lactiplantibacillus plantarum–Nomad and Ideal Probiotic

“…This result was confirmed and expanded upon in a subsequent study which also observed that administration of L. plantarum WCSF1 to healthy mice increased splenic infiltration of regulatory dendritic cells and Tregs and attenuated T helper 2 type responses (Bermudez-Brito et al, 2018). This study expanded upon the previous report by demonstrating that hostmicrobe interaction at the Peyer's patches was enough to induce immunomodulation of host DCs and T cells.…”

Comparative colloidal stability, antitumor efficacy, and immunosuppressive effect of commercial paclitaxel nanoformulations

“…For immunophenotype analysis of T cells, CD4+ and CD8+ T cell levels were calculated as a ratio of the entire CD3+ population. For DC maturation analysis, The DCs were stained with CD11c and MHC II, and the expression levels of MHC I, CD40, CD80, and CD86 on DCs were examined [ 32 , 33 ].…”

The Role of Gut Microbiota Biomodulators on Mucosal Immunity and Intestinal Inflammation

“…Probiotics may be sampled by M cells in the Peyer's patches [114] and modulate the activity of APC [115]. The interaction between probiotics and DCs may influence the subsequent antigen-specific T cell response towards Th1, Th2, Th17 or Treg cells, although some strains of lactobacilli (L. plantarum) regulates Treg frequency and DCs activation even in the absence of M-dependent sampling [73]. Different strains of Lactobacillus and Bifidobacterium showed significant capability to reduce pro-inflammatory IL-6 and IL-17 levels [74], to restore the Treg/Th17 balance [75] via inhibition of the NF-κB signalling pathway in macrophages and epithelial cells and to control the overgrowth of pathobionts belonging to Enterobacteriaceae [76,77].…”