Mechanism of congenital lymphocytes and intestinal immunity regulated by gut microbial metabolites via metabolite-sensing receptor Ffar2
Keywords:ILC3s; Intestinal immunity; Gut microbial metabolite; Ffar2
Objective: The DSS was utilized to construct colitis model of mouse. The colitis mice were colonized with gut microbiota. The effects of gut microbial metabolites on colitis were studied. The mechanisms of gut microbial metabolites to improve intestinal immunity were also further explored. Methods: The male BALB/c mice were selected to construct colitis mouse model with DSS and colonized with gut microbiota. The content of short-chain fatty acids in intestinal metabolites of mice during modeling were detected with GC-MS. After the mice were sacrificed, the colon tissue was stained to observe the colitis in different groups of mice. The contents of IL-22 and IL-17 in colon tissue was determined with ELISA method. To study the mechanism of relieving colitis, qRT-PCR and western blotting were used to study the horizontal of Ffar2 gene and pSTAT3 and pAKT in colon tissue, respectively. The congenital lymphocytes were isolated and purified, and the migration ability of the congenital lymphocytes was examined by cell scratch plane migration test. Results: The colonization of the gut microbiota had significant effects on the contents of short-chain fatty acids in the intestinal metabolites of colitis mice, of which the effect on the content of acetic acid and butyric acid was more significant. The colonization of gut microbiota could effectively relieve colitis in mice and effectively promote the secretion of IL-22 in colon tissue. Studying the remission mechanism indicated that colonization of gut microbiota with colitis could effectively promote the expression of Ffar2 gene in colon tissue and increase the expression of pSTAT3 and pAKT protein. The migration ability of the lymphocyte was significantly upregulated in the model group compared with the other groups, demonstrating that DSS can effectively activate the lymphocyte; The migration of congenital lymphocyte in the experimental group was significantly alleviated than that in the model group, but it was up-regulated than that in the positive control group, and the colonic tissue of the positive control group was similar to that of the normal group. Conclusion: The short-chain fatty acids in the intestinal flora metabolites can promote the gene expression of the metabolite-sensitive receptor Ffar2. The effective combination of short-chain fatty acids and Ffar2 receptors can promote the phosphorylation of STAT3 and AKT proteins, effectively promote the secretion of IL-22 in intestinal ILC3 cells, alleviate colitis in mice, and thereby improve their intestinal immune function.
Fredrik Bäckhed, Claire M Fraser, Yehuda Ringel, et al. Defining a healthy human gut microbiome: current concepts, future directions, and clinical applications[J]. Cell Host Microbe, 2012, 12(5):611-622. Doi: 10.1016/j.chom.2012.10.012.
Gerard Clarke, Roman M Stilling, Paul J Kennedy, et al. Minireview: Gut microbiota: the neglected endocrine organ[J]. Molecular endocrinology, 2014, 28(8): 1221-1238. Doi: 10.1210/me.2014-1108. Epub 2014 Jun 3.
Sittipo P, Lobionda S, Lee YK, et al. Intestinal microbiota and the immune system in metabolic diseases [J]. J Microbiol, 2018, 56(3): 154-162. Doi: 10.1007/s12275-018-7548-y. Epub 2018 Feb 28.
Max Nieuwdorp, Pim W Gilijamse, Nikhil Pai, et al. Role of the microbiome in energy regulation and metabolism[J]. Gastroenterology, 2014, 146(6): 1525-1533. Doi: 10.1053/j.gastro.2014.02.008. Epub 2014 Feb 19.
June L Round, Sarkis K Mazmanian. The gut microbiota shapes intestinal immune responses during health and disease[J]. Nat Rev Immunol, 2009, 9(5):313-323. Doi: 10.1038/nri2515.
Gil Sharon, Neha Garg, Justine Debelius, et al. Specialized metabolites from the microbiome in health and disease[J]. Cell metabolism, 2014, 20(5): 719-730. Doi: 10.1016/j.cmet.2014.10.016. Epub 2014 Nov 4.
Yin Y, Sichler A, Ecker J, et al. Gut microbiota promote liver regeneration through hepatic membrane phospholipid biosynthesis[J]. J Hepatol, 2023, 78(4): 820-835. Doi: 10.1016/j.jhep.2022.12.028. Epub 2023 Jan 18.
Smith PM, Howitt MR, Panikov N, et al. The microbial metabolites, short-chain fatty acids, regulate colonic Treg cell homeostasis[J]. Science, 2013, 341(6145): 569-573. Doi: 10.1126/science.1241165. Epub 2013 Jul 4.
Campbell C, McKenney PT, Konstantinovsky D, et al. Bacterial metabolism of bile acids promotes generation of peripheral regulatory T cells [J]. Nature, 2020, 581(7809): 475-479. Doi: 10.1038/s41586-020-2193-0. Epub 2020 Apr 15.
Takahashi D, Hoshina N, Kabumoto Y, et al. Microbiota-derived butyrate limits the autoimmune response by promoting the differentiation of follicular regulatory T cells [J]. EBioMedicine, 2020, 58:102913. Doi: 10.1016/j.ebiom.2020.102913. Epub 2020 Jul 22.
Nagendra Singh, Ashish Gurav, Sathish Sivaprakasam, et al. Activation of Gpr109a, receptor for niacin and the commensal metabolite butyrate, suppresses colonic inflammation and carcinogenesis[J]. Immunity, 2014, 40(1): 128-139. Doi: 10.1016/j.immuni.2013.12.007. Epub 2014 Jan 9.
Frolova MS, Suvorova IA, Iablokov SN, et al. Genomic reconstruction of short-chain fatty acid production by the human gut microbiota [J]. Front Mol Biosci, 2022, 9: 949563. Doi: 10.1016/j.immuni.2013.12.007. Epub 2014 Jan.
Jian K Tan, Craig McKenzie, Eliana Mariño, et al. Metabolite-sensing G protein-coupled receptors-facilitators of diet-related immune regulation[J]. Annual Review of Immunology, 2017, 35(1): 371-402. Doi: 10.1146/annurev-immunol-051116-052235.
Colonna M. Innate lymphoid cells: Diversity, plasticity, and unique functions in immunity[J]. Immunity, 2018, 48(6): 1104-1117. Doi: 10.1016/j.immuni.2018.05.013.
Vivier E, Artis D, Colonna M, et al. Innate Lymphoid Cells: 10 Years On[J]. Cell, 2018, 174(5): 1054-1066. Doi: 10.1016/j.cell.2018.07.017.
Artis D, Spits H. The biology of innate lymphoid cells[J]. Nature, 2015, 517(7534): 293-301. Doi: 10.1038/nature14189.
David R Withers, Matthew R Hepworth. Group 3 innate lymphoid cells: Communications hubs of the intestinal immune system[J]. Front Immunol, 2017, 8:1298. Doi: 10.3389/fimmu.2017.01298. eCollection 2017.
Peng G, Sinkko HM, Alenius H, et al. Graphene oxide elicits microbiome-dependent type 2 immune responses via the aryl hydrocarbon receptor [J]. Nat Nanotechnol, 2023, 18(1):42-48. Doi: 10.1038/s41565-022-01260-8. Epub 2022 Dec 12.
Lisa A Mielke, Sarah A Jones, Mathilde Raverdeau, et al. Retinoic acid expression associates with enhanced IL-22 production by γδ T cells and innate lymphoid cells and attenuation of intestinal inflammation[J]. J Exp Med, 2013, 210(6):1117-1124. Doi: 10.1084/jem.20121588. Epub 2013 May 20.
Eunyoung Chun, Sydney Lavoie, Diogo Fonseca-Pereira, et al. Metabolite-sensing receptor Ffar2 regulates colonic group 3 innate lymphoid cells and gut immunity[J]. Immunity, 2019, 51(5):871-884.e6. Doi: 10.1016/j.immuni.2019.09.014. Epub 2019 Oct 15.
Andrew J Brown, Susan M Goldsworthy, Ashley A Barnes, et al. The Orphan G protein-coupled receptors GPR41 and GPR43 are activated by propionate and other short chain carboxylic acids[J]. J Biol Chem, 2003, 278(13):11312-11319. Doi: 10.1074/jbc.M211609200. Epub 2002 Dec 19.
Xiaohuan Guo, Ju Qiu, Tony Tu, et al. Induction of innate lymphoid cell-derived interleukin-22 by the transcription factor STAT3 mediates protection against intestinal infection[J]. Immunity, 2014, 40(1):25-39. Doi: 10.1016/j.immuni.2013.10.021. Epub 2014 Jan 9.