Plant sterols may induce a Th1 shift in humans. However, whether plant stanols have similar effects as well as the underlying mechanism are unknown. We have now shown that (like sitosterol) sitostanol, both 4-desmethylsterols, induces a Th1 shift when added in vitro at physiological concentrations to human PBMCs. This conclusion was based on a higher IFNgamma production, with no change in the production of IL-4 and IL-10. alpha-Amyrin, a 4.4-dimethylsterol, had comparable effects. Because 4.4-dimethylsterols cannot activate transcription factor LXR, this finding indicates that LXR activation was not involved. Sitosterol and sitostanol did not alter the production of IL-12 and IL-18 in PBMCs as well as in monocyte-derived U937 cells, suggesting that plant sterols directly affect T-helper cells, without activating APCs. However, in PBMCs treated with a TLR2 blocker (T2.5), IFNgamma production was completely inhibited, whereas blocking TLR4 with HTA125 had no such effect. To confirm these findings, PBMCs from TLR2(-/-) mice were cultured in the presence of sitosterol and sitostanol. In these cells, no Th1 shift was observed. Our results, therefore, indicate that TLR2 activation is essential to induce a Th1 shift in human PBMCs by plant stanols and plant sterols.
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http://dx.doi.org/10.1074/jbc.M109.036343 | DOI Listing |
Allergy Asthma Proc
January 2025
From the Department of Microbiology-Immunology, Georgetown University Medical Center, Washington, D.C.
Allergen immunotherapy (AIT) is currently the most effective immunologic form of treatment for patients with atopic allergic diseases commonly used by allergist/immunologists to reduce allergic symptoms by gradually desensitizing the immune system to specific allergens. Currently, the primary mechanism of AIT emphasizes the crucial role of immune regulation, which involves a shift from a T-helper type 2 (Th2) cell response, which promotes allergy, to a T-regulatory (Treg) cell population, which inhibits the allergic inflammatory response through the production of immunosuppressive cytokines interleukin 10 and transforming growth factor β, which play pivotal roles in suppressing the allergic reaction. In a series of previous in vitro and in vivo experiments, we have demonstrated the capacity of synthetic methylated cytosine-phosphate-guanine (CpG) oligodeoxynucleotide (ODN) moieties as well as methylated genomic DNA ODN motifs from Bifidobacterium longum subspecies infantis to activate Treg cell differentiation in contrast to the unmethylated ODN moiety, which promotes proinflammatory responses driven by Th17-mediated responses.
View Article and Find Full Text PDFJ Dent Res
December 2024
Department of Immunology and Molecular Microbiology in Dental Science, Seoul National University School of Dentistry, Seoul, Republic of Korea.
Oral lichen planus (OLP) is a chronic T cell-mediated inflammatory mucosal disease of unknown etiology. The lack of suitable animal models has hampered understanding of its etiopathogenesis. This study aimed to clarify the contribution of bacterial infection and zinc deficiency (ZD) in OLP pathogenesis by developing a murine model.
View Article and Find Full Text PDFElife
December 2024
Trinity Translational Medicine Institute, St James's Hospital, Trinity College Dublin, The University of Dublin, Dublin, Ireland.
J Agric Food Chem
December 2024
School of Food and Biological Engineering, Engineering Research Center of Bio-process of Ministry of Education, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei 230009, Anhui, P. R. China.
The ingestion of red kidney bean products is hindered by the persistent allergenicity of lectins, even after autoclaving. This study examined the modification of lectin allergenicity in red kidney beans by pH-shifting and autoclaving treatments, utilizing BALB/c mouse sensitization, recirculating perfusion, and a bone marrow-derived dendritic cell (BMDC) model for allergenicity evaluation. Compared to autoclaving alone, combined pH-shifting and autoclaving reduced allergic symptoms in BALB/c mice, as evidenced by lower serum IgE, mMCPT-1, GM-CSF, HIS, IL-2, IL-4, IL-9, IL-13, and IL-17 levels and higher IgG1, IgG2a, IL-10, IFN-γ, and IFN-α cytokine release.
View Article and Find Full Text PDFBMC Infect Dis
November 2024
Departments of Medical Parasitology Faculty of Medicine, Cairo University, Cairo, Egypt.
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