scholarly journals Contrasting roles for all-trans retinoic acid in TGF-β–mediated induction of Foxp3 and Il10 genes in developing regulatory T cells

2009 ◽  
Vol 206 (2) ◽  
pp. 343-357 ◽  
Author(s):  
Craig L. Maynard ◽  
Robin D. Hatton ◽  
Whitney S. Helms ◽  
James R. Oliver ◽  
Charles B. Stephensen ◽  
...  

Extrathymic induction of regulatory T (T reg) cells is essential to the regulation of effector T cell responses in the periphery. In addition to Foxp3, T reg cell expression of suppressive cytokines, such as IL-10, is essential for peripheral tolerance, particularly in the intestines. TGF-β has been shown to induce expression of Foxp3 as well as IL10 and the vitamin A metabolite; all-trans retinoic acid (RA [at-RA]) has been found to enhance the former. We report that in contrast to its enhancement of TGF-β–mediated Foxp3 induction, at-RA potently inhibits the TGF-β–mediated induction of Il10 in naive CD4 T cells. Thus, mucosal DC subsets that are active producers of at-RA inhibit induction of Il10 in naive CD4 T cells while promoting induction of Foxp3. Accordingly, mice with vitamin A deficiency have increased numbers of IL-10–competent T reg cells. Activation of DCs by certain Toll-like receptors (TLRs), particularly TLR9, suppresses T cell induction of Foxp3 and enables induction of Il10. Collectively, our data indicate that at-RA has reciprocal effects on the induction of Foxp3 and Il10 in developing CD4+ T reg cells and suggest that TLR9-dependent inhibition of at-RA production by antigen-presenting cells might represent one mechanism to promote the development of IL-10–expressing T cells.

2004 ◽  
Vol 286 (2) ◽  
pp. L437-L444 ◽  
Author(s):  
Stephen E. McGowan ◽  
Amey Jo Holmes ◽  
Jennifer Smith

Airway hyperresponsiveness (AHR) is influenced by structural components of the bronchial wall, including the smooth muscle and connective tissue elements and the neuromuscular function. AHR is also influenced by parenchymally derived tethering forces on the bronchial wall, which maintain airway caliber by producing outward radial traction. Our previous work has shown that vitamin A-deficient (VAD) rats exhibit cholinergic hyperresponsiveness and a decrease in the expression and function of the muscarinic-2 receptors (M2R). We hypothesized that if decreases in radial traction from airway or parenchymal structures contributed to the VAD-related increase in AHR, then the radial traction would normalize more slowly than VAD-related alterations in neurotransmitter signaling. Rats remained vitamin A sufficient (VAS) or were rendered VAD and then maintained on the VAD diet in the presence or absence of supplementation with all- trans retinoic acid (RA). VAD was associated with an approximately twofold increase in respiratory resistance and elastance compared with VAS rats. Exposure to RA for 12 days but not 4 days restored resistance and elastance to control (VAS) levels. In VAD rats, AHR was accompanied by decreases in bronchial M2R gene expression and function, which were restored after 12 days of RA supplementation. Subepithelial bronchial elastic fibers were decreased by ∼50% in VAD rats and were significantly restored by RA. The increase in AHR that is associated with VAD is accompanied by decreases in M2R expression and function that can be restored by RA and a reduction in airway elastic fibers that can be partially restored by RA.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Xiaohong Sun ◽  
Yangfan Xiao ◽  
Zhuotong Zeng ◽  
Yaqian Shi ◽  
Bingsi Tang ◽  
...  

Background. Retinoic acid (RA) is an active metabolite of vitamin A and has been reported to improve the clinical symptoms of patients with systemic sclerosis (SSc). However, the mechanism of RA in the prevention of SSc remains unclear. Regulatory T cells (Tregs) are a subpopulation of T cells with immunosuppressive activity. The quantitative and functional defects of Tregs may mediate the immune dysfunction in SSc. The addition of all-trans retinoic acid (ATRA) to human naïve CD4+ cells could promote the maturation of Tregs and increase the stable expression of Foxp3. In this study, we explored the role of RA on Tregs in SSc CD4+ T cells and its possible epigenetic mechanisms, so as to further understand the mechanisms of RA on SSc. Methods. CD4+ T cells were isolated from peripheral blood of SSc and treated with or without ATRA and/or transforming growth factor-β (TGF-β). The percentage of CD4+CD25+FOXP3+ Tregs was counted by flow cytometry. FOXP3 mRNA and protein levels were measured by quantitative real-time reverse transcriptase polymerase chain reaction and Western blotting, respectively. Bisulfite sequencing was performed to determine the methylation status of the FOXP3 proximal promoter sequences. Results. The expression of Tregs and FOXP3 in CD4+ T cells from patients with SSc increased in response to ATRA. Moreover, combined stimulation with ATRA and TGF-β resulted in the enhancement of these effects. Further studies revealed that stimulation with ATRA increased the expression of FOXP3 in SSc CD4+ T cells by downregulating FOXP3 promoter methylation levels. Conclusions. ATRA acts as an inducer of Treg response in SSc CD4+ T cells via demethylation of the FOXP3 promoter and activation of FOXP3 expression. This may be one of the molecular mechanisms for ATRA, and therefore, RA can be used for the treatment of SSc.


10.1038/7417 ◽  
1999 ◽  
Vol 5 (4) ◽  
pp. 418-422 ◽  
Author(s):  
Zengquan Wang ◽  
Mohamed Boudjelal ◽  
Sewon Kang ◽  
John J. Voorhees ◽  
Gary J. Fisher

2021 ◽  
Author(s):  
Mahmoud Ramadan Elkazzaz ◽  
Yousry Esam-Eldin Abo-Amer ◽  
Amr Ahmed ◽  
Tamer Haydara

Abstract The COVID-19 pandemic caused by SARS-CoV-2 has become a global health crisis. Patients with haematological malignancies (blood cancers) as B-cell chronic lymphocytic leukemia (CLL) have an increased risk of severe infections due to disease- and treatment-related immunodeficiency. In addition to impaired COVID-19 viral evolution and clearance was commonly seen in patients with haematological malignancies. Moreover, in patients with haematological malignancies, Covid-19 is associated with a mortality rate of 33-37%. As a result, patients with hematologic malignancies have been given priority for primary COVID-19 vaccination. After receiving COVID-19 vaccination, about one out of every four patients with blood cancer fails to produce detectable antibodies. Many studies have suggested that patients with haematological malignancies who have been fully vaccinated can develop severe and often fatal complications. COVID-19 is a virus that causes disease. A recent study by Oxford University scientists showed that leucine zipper transcription factor-like 1(LZTFL1), as a candidate causal gene and its enhancer the rs17713054 A risk allele was significantly responsible for the twofold increased risk of respiratory failure from COVID-19 associated with 3p21.31. LZTFL1 gene is widely up regulated in respiratory epithelial cells, including ciliated epithelial cells, which have been found as one of the main cellular targets for COVID-19. The scientists in this study used a combined multiomics and machine learning approach and identified that the gain-of-function risk A allele of an SNP, rs17713054G>A, was a causative variant. With gene-expression analysis and chromosome conformation capture oxford scientists showed that the rs17713054-affected enhancer induces the interacting gene, LZTFL1. The rs17713054 A risk allele causes increased transcription by enhancing an epithelial–endothelial–fibroblast enhancer, which is aided by the addition of a second CEBPB binding motif. The risk allele generates a second CCAAT/enhancer binding protein beta (CEBPB) motif in the enhancer, according to sequence analysis.. As a result, the rs17713054 risk allele must generate a CCAAT/enhancer binding protein beta motif in order to increase covidm-19 risk by interacting with LZTFL1, according to this study. This study discovered that rs17713054 is an active enhancer of LZTFL1 in the lungs, which is linked to an increased risk of COVID-19, but not in immune cells, where CCR9 is expressed.. According to this study, LZTFL1 variants that increase the risk of severe COVID-19 disease are not found in immune cells. Here, we propose attestable hypothesis that the casual gene(LZTFL1) induced by all trans retinoic acid could be enhance the immune response in vaccinated patients with haematological malignancies SARS-CoV-2 mRNA vaccines have been shown to induce broad CD4+ T cell responses that recognize SARS-CoV-2 variants and HCoV-NL63. Fortunately, LZTFL1 has been discovered to potentially activate CD4 T cells and induce their immune response, as well as enhance IL-5 production under the control of all trans retinoic acid (ATRA). LZTFL1 expression is induced by ATRA in human primary CD4+ T cells. LZTFL1 has been found to be downregulated in a variety of cancers. TNM (tumour (T), node (N), and metastasis (M) stages of the tumour, as well as the number of metastasized lymph nodes, were found to have significant inverse correlations with loss of LZTFL1 expression (mLN). The T cell activation signal was further enhanced by overexpression of LZTFL1 in CD4+ T cells, as evidenced by increased NFAT activity. Furthermore, knocking down LZTFL1 reduced Th2 cytokine production, particularly IL-5 mRNA and protein, and suppressed ATRA-induced IL-5 production. In addition, retinoic acid is required for T cell migration in vitro and in vivo. Furthermore, trans retinoic acid was discovered to potentially downregulate EBP (CCAAT/enhancer binding protein beta motif) in the lungs, which could be used by the active enhancer rs17713054 of LZTFL1. Conclusions Haematological malignancies (blood cancers) patients are more vulnerable to COVID-19 disuse severity and mortality. Un fortunately mRNA vaccine seem to be less effective with weak immune response and insufficient level of generated antibodies in this category of patients. Therefore we suggest all trans retinoic acid is a good candidate as mRNA COVID-19 vaccine adjuvant via inducing LZTFL1 gene in CD4Tcells and this activation could improve the immune response and increase the level of the generated antibodies. Moreover LZTFL1 gene in CD4 T cells is not associated with increasing risk of COVID-19 infection because of absence of its enhancer(The risk allele of the SNP, rs17713054 A) in immune cells according to oxford recent study. In addition to all trans retinoic acid could inhibit CCAAT/enhancer binding protein beta motif that is generated by The risk allele of the SNP, rs17713054 A


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