Protein denature extracts of Lactobacillus crispatus KT‐11 strain promote interleukin 12p40 production via Toll‐like receptor 2 in J774.1 cell culture

• Published in: Journal of food biochemistry 2021-02, Vol.45 (2), p.e13599-n/a
• Main Authors: Tobita, Keisuke, Hoshi, Fumika, Ohki, Taeko, Watanabe, Itsuki
• Format: Article
• Language: English
• Subjects: guanidine hydrochloride extracts; interleukin 12; Lactobacillus crispatus strain KT‐11; Toll‐like receptor 2
• ISSN: 0145-8884; 1745-4514
• DOI: 10.1111/jfbc.13599

The objective of the present study is to investigate the mechanism and the cell components of Lactobacillus crispatus KT‐11 strain (KT‐11) that induce interleukin (IL)‐12p40 production. IL‐12p40 production induced by KT‐11 was decreased in the presence of inhibitors of extracellular signal‐regulated kinase or nuclear factor kappa B. Guanidine hydrochloride, urea or lithium chloride extract of KT‐11 induced IL‐12p40 production, but production was suppressed in the presence of Toll‐like receptor 2‐specific neutralizing antibody. These findings suggest that the protein denature extracts of KT‐11 promote IL‐12p40 production via Toll‐like receptor 2 in J774.1 cells. Practical applications Heat‐treated lactic acid bacteria are added to some foods because it is easier to store and transport, and have less interference with other food ingredients compared with living lactic acid bacteria. Heat‐treated Lactobacillus crispatus KT‐11 strain (KT‐11) is included in some foods because of good handling characteristics and good dispersibility in the food product. We have previously reported that the administration of KT‐11 led to beneficial health effects through the regulation of the immune system in mice, but the mechanism is not clear. We found that protein denature extracts, which may include proteins such as SLP and SLAPs, of KT‐11 cells promoted IL‐12p40 production via TLR2 in the J774.1 cell culture. This result will contribute to providing more effective lactic acid bacteria functional food. L. crispatus KT‐11 whole‐cell induces the production of cytokine such as IL‐12p40 from mouse macrophage‐like cell line, J774.1. Whole‐cell extracts of KT‐11, which may include proteins such as SLP and SLAPs, induced IL‐12p40 production in J774.1 cells, but production was suppressed in the presence of TLR 2‐specific neutralizing antibody. Cell wall proteins of KT‐11 promote IL‐12p40 production via TLR 2.