DNA from <i>Lactobacillus paragasseri</i> SBT2055 Activates Plasmacytoid Dendritic Cells and Induces IFN-α via TLR9

Previously, we reported that <i>Lactobacillus paragasseri</i> SBT2055 (LG2055) activates plasmacytoid dendritic cells (pDCs) and induces interferon alpha (IFN-α) in vitro. Our clinical trial suggested that LG2055 intake may enhance pDC activity, supporting immune maintenance and reducing...

Full description

Saved in:
Bibliographic Details
Main Authors: Eiji Kobatake, Toshinobu Arai
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Microorganisms
Subjects:
Online Access:https://www.mdpi.com/2076-2607/13/7/1440
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850071709883826176
author Eiji Kobatake
Toshinobu Arai
author_facet Eiji Kobatake
Toshinobu Arai
author_sort Eiji Kobatake
collection DOAJ
description Previously, we reported that <i>Lactobacillus paragasseri</i> SBT2055 (LG2055) activates plasmacytoid dendritic cells (pDCs) and induces interferon alpha (IFN-α) in vitro. Our clinical trial suggested that LG2055 intake may enhance pDC activity, supporting immune maintenance and reducing subjective common cold symptoms. However, the precise mechanisms remain unclear. In this study, we investigated how LG2055 engages with pDCs to stimulate IFN-α production. We evaluated LG2055-induced pDC activation using flow cytometry, ELISA, and phagocytosis assays. Human peripheral blood mononuclear cells (PBMCs) were stimulated with LG2055 and its components to evaluate immune responses. An in vitro M cell model was used to examine LG2055 translocation. We found that DNA extracted from LG2055 activated pDCs and enhanced IFN-α production via Toll-like receptor 9 (TLR9). Phagocytosis assays demonstrated that LG2055 DNA was internalized by PBMC-derived pDCs, enabling TLR9-mediated signaling. Additionally, LG2055 translocated across M cells in vitro, suggesting potential transport into Peyer’s patches, where it may interact with pDCs. These findings demonstrate that intestinal LG2055 can translocate across M cells, interact with pDCs, and exert immune-stimulatory effects to enhance host antiviral immunity. This study provides mechanistic insight into how dietary components support immune health and could inform the development of novel functional foods or therapeutic strategies.
format Article
id doaj-art-f38d8ff57fed4e7c936090aa0fb0e31b
institution DOAJ
issn 2076-2607
language English
publishDate 2025-06-01
publisher MDPI AG
record_format Article
series Microorganisms
spelling doaj-art-f38d8ff57fed4e7c936090aa0fb0e31b2025-08-20T02:47:14ZengMDPI AGMicroorganisms2076-26072025-06-01137144010.3390/microorganisms13071440DNA from <i>Lactobacillus paragasseri</i> SBT2055 Activates Plasmacytoid Dendritic Cells and Induces IFN-α via TLR9Eiji Kobatake0Toshinobu Arai1Milk Science Research Institute, MEGMILK SNOW BRAND Co., Ltd., Saitama 350-1165, JapanMilk Science Research Institute, MEGMILK SNOW BRAND Co., Ltd., Saitama 350-1165, JapanPreviously, we reported that <i>Lactobacillus paragasseri</i> SBT2055 (LG2055) activates plasmacytoid dendritic cells (pDCs) and induces interferon alpha (IFN-α) in vitro. Our clinical trial suggested that LG2055 intake may enhance pDC activity, supporting immune maintenance and reducing subjective common cold symptoms. However, the precise mechanisms remain unclear. In this study, we investigated how LG2055 engages with pDCs to stimulate IFN-α production. We evaluated LG2055-induced pDC activation using flow cytometry, ELISA, and phagocytosis assays. Human peripheral blood mononuclear cells (PBMCs) were stimulated with LG2055 and its components to evaluate immune responses. An in vitro M cell model was used to examine LG2055 translocation. We found that DNA extracted from LG2055 activated pDCs and enhanced IFN-α production via Toll-like receptor 9 (TLR9). Phagocytosis assays demonstrated that LG2055 DNA was internalized by PBMC-derived pDCs, enabling TLR9-mediated signaling. Additionally, LG2055 translocated across M cells in vitro, suggesting potential transport into Peyer’s patches, where it may interact with pDCs. These findings demonstrate that intestinal LG2055 can translocate across M cells, interact with pDCs, and exert immune-stimulatory effects to enhance host antiviral immunity. This study provides mechanistic insight into how dietary components support immune health and could inform the development of novel functional foods or therapeutic strategies.https://www.mdpi.com/2076-2607/13/7/1440plasmacytoid dendritic cellstype I interferoninterferon-αlactic acid bacteria<i>Lactobacillus paragasseri</i> SBT2055Toll-like receptor 9
spellingShingle Eiji Kobatake
Toshinobu Arai
DNA from <i>Lactobacillus paragasseri</i> SBT2055 Activates Plasmacytoid Dendritic Cells and Induces IFN-α via TLR9
Microorganisms
plasmacytoid dendritic cells
type I interferon
interferon-α
lactic acid bacteria
<i>Lactobacillus paragasseri</i> SBT2055
Toll-like receptor 9
title DNA from <i>Lactobacillus paragasseri</i> SBT2055 Activates Plasmacytoid Dendritic Cells and Induces IFN-α via TLR9
title_full DNA from <i>Lactobacillus paragasseri</i> SBT2055 Activates Plasmacytoid Dendritic Cells and Induces IFN-α via TLR9
title_fullStr DNA from <i>Lactobacillus paragasseri</i> SBT2055 Activates Plasmacytoid Dendritic Cells and Induces IFN-α via TLR9
title_full_unstemmed DNA from <i>Lactobacillus paragasseri</i> SBT2055 Activates Plasmacytoid Dendritic Cells and Induces IFN-α via TLR9
title_short DNA from <i>Lactobacillus paragasseri</i> SBT2055 Activates Plasmacytoid Dendritic Cells and Induces IFN-α via TLR9
title_sort dna from i lactobacillus paragasseri i sbt2055 activates plasmacytoid dendritic cells and induces ifn α via tlr9
topic plasmacytoid dendritic cells
type I interferon
interferon-α
lactic acid bacteria
<i>Lactobacillus paragasseri</i> SBT2055
Toll-like receptor 9
url https://www.mdpi.com/2076-2607/13/7/1440
work_keys_str_mv AT eijikobatake dnafromilactobacillusparagasseriisbt2055activatesplasmacytoiddendriticcellsandinducesifnaviatlr9
AT toshinobuarai dnafromilactobacillusparagasseriisbt2055activatesplasmacytoiddendriticcellsandinducesifnaviatlr9