Unravelling CD4+ T cell diversity and tissue adaptation of Tregs in abdominal aortic aneurysms through single-cell sequencing.

Immune cell infiltration is a significant pathological process in abdominal aortic aneurysms (AAA). T cells, particularly CD4+ T cells, are essential immune cells responsible for substantial infiltration of the aorta. Regulatory T cells (Tregs) in AAA have been identified as tissue-specific; however, the time, location, and mechanism of acquiring the tissue-specific phenotype are still unknown. Using single-cell RNA sequencing (scRNA-seq) on CD4+ T cells from the AAA aorta and spleen, we discovered heterogeneity among CD4+ T cells and identified activated, proliferating and developed aorta Tregs. These Tregs originate in the peripheral tissues and acquire the tissue-specific phenotype in the aorta. The identification of precursors for Tregs in AAA provides new insight into the pathogenesis of AAA.

Ipilimumab and nivolumab combined with anthracycline-based chemotherapy in metastatic hormone receptor-positive breast cancer: a randomized phase 2b trial.

BACKGROUND: Immune checkpoint inhibitors have shown minimal clinical activity in hormone receptor-positive metastatic breast cancer (HR+mBC). Doxorubicin and low-dose cyclophosphamide are reported to induce immune responses and counter regulatory T cells (Tregs). Here, we report the efficacy and safety of combined programmed cell death protein-1/cytotoxic T-lymphocyte-associated protein 4 blockade concomitant with or after immunomodulatory chemotherapy for HR+mBC. METHODS: Patients with HR+mBC starting first-/second- line chemotherapy (chemo) were randomized 2:3 to chemotherapy (pegylated liposomal doxorubicin 20 mg/m2 every second week plus cyclophosphamide 50 mg by mouth/day in every other 2-week cycle) with or without concomitant ipilimumab (ipi; 1 mg/kg every sixth week) and nivolumab (nivo; 240 mg every second week). Patients in the chemo-only arm were offered cross-over to ipi/nivo without chemotherapy. Co-primary endpoints were safety in all patients starting therapy and progression-free survival (PFS) in the per-protocol (PP) population, defined as all patients evaluated for response and receiving at least two treatment cycles. Secondary endpoints included objective response rate, clinical benefit rate, Treg changes during therapy and assessment of programmed death-ligand 1 (PD-L1), mutational burden and immune gene signatures as biomarkers. RESULTS: Eighty-two patients were randomized and received immune-chemo (N=49) or chemo-only (N=33), 16 patients continued to the ipi/nivo-only cross-over arm. Median follow-up was 41.4 months. Serious adverse events occurred in 63% in the immune-chemo arm, 39% in the chemo-only arm and 31% in the cross-over-arm. In the PP population (N=78) median PFS in the immune-chemo arm was 5.1 months, compared with 3.6 months in the chemo-only arm, with HR 0.94 (95% CI 0.59 to 1.51). Clinical benefit rates were 55% (26/47) and 48% (15/31) in the immune-chemo and chemo-only arms, respectively. In the cross-over-arm (ipi/nivo-only), objective responses were observed in 19% of patients (3/16) and clinical benefit in 25% (4/16). Treg levels in blood decreased after study chemotherapy. High-grade immune-related adverse events were associated with prolonged PFS. PD-L1 status and mutational burden were not associated with ipi/nivo benefit, whereas a numerical PFS advantage was observed for patients with a high Treg gene signature in tumor. CONCLUSION: The addition of ipi/nivo to chemotherapy increased toxicity without improving efficacy. Ipi/nivo administered sequentially to chemotherapy was tolerable and induced clinical responses. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT03409198.

Lower frequencies of circulating suppressive regulatory T cells and higher frequencies of CD4+ naïve T cells at baseline are associated with severe immune-related adverse events in immune checkpoint inhibitor-treated melanoma.

BACKGROUND: Immune-related adverse events (irAEs) are major barriers of clinical management and further development of immune checkpoint inhibitors (ICIs) for cancer therapy. Therefore, biomarkers associated with the onset of severe irAEs are needed. In this study, we aimed to identify immune features detectable in peripheral blood and associated with the development of severe irAEs that required clinical intervention. METHODS: We used a 43-marker mass cytometry panel to characterize peripheral blood mononuclear cells from 28 unique patients with melanoma across 29 lines of ICI therapy before treatment (baseline), before the onset of irAEs (pre-irAE) and at the peak of irAEs (irAE-max). In the 29 lines of ICI therapy, 18 resulted in severe irAEs and 11 did not. RESULTS: Unsupervised and gated population analysis showed that patients with severe irAEs had a higher frequency of CD4+ naïve T cells and lower frequency of CD16+ natural killer (NK) cells at all time points. Gated population analysis additionally showed that patients with severe irAEs had fewer T cell immunoreceptor with Ig and ITIM domain (TIGIT+) regulatory T cells at baseline and more activated CD38+ CD4+ central memory T cells (TCM) and CD39+ and Human Leukocyte Antigen-DR Isotype (HLA-DR)+ CD8+ TCM at peak of irAEs. The differentiating immune features at baseline were predominantly seen in patients with gastrointestinal and cutaneous irAEs and type 1 diabetes. Higher frequencies of CD4+ naïve T cells and lower frequencies of CD16+ NK cells were also associated with clinical benefit to ICI therapy. CONCLUSIONS: This study demonstrates that high-dimensional immune profiling can reveal novel blood-based immune signatures associated with risk and mechanism of severe irAEs. Development of severe irAEs in melanoma could be the result of reduced immune inhibitory capacity pre-ICI treatment, resulting in more activated TCM cells after treatment.

Hypertension-Driven Regulatory T-Cell Perturbations Accelerate Myocardial Ischemia-Reperfusion Injury.

BACKGROUND: Patients with a history of hypertension have elevated inflammation and a worse prognosis after acute myocardial infarction (AMI). Regulatory T cells (Tregs) are reported to lose their immunosuppressive capacity under pathological conditions. However, whether hypertension leads to Treg dysfunction, thus accelerating myocardial ischemia-reperfusion injury, is still unknown. METHODS: Studies were performed in hypertensive rats and mice with myocardial ischemia-reperfusion injury. The frequencies and phenotypes of Tregs were analyzed by flow cytometry and immunohistochemistry. Reconstruction Treg experiments were performed to evaluate the effect of Tregs on ischemia-reperfusion injury. Patients with AMI were enrolled to assess circulating Tregs, inflammatory cytokines, and cardiac function. RESULTS: In this study, we found that hypertension leads to proinflammatory Th1 (T helper 1 cell)-like Treg subsets with compromised suppressive capacity. Reconstruction Treg experiments identified that dysfunctional Tregs induced by hypertension play a pathogenic role in the progression of myocardial ischemia-reperfusion injury. In particular, we identified HDAC6 (histone deacetylase 6) as a central regulator in the perturbed Tregs. Clinical studies revealed that the hypertension-induced reduction in circulating Tregs strongly correlated with the higher occurrence rate of microvascular obstruction in AMI patients with hypertension. CONCLUSIONS: Our study provided promising clues to explain the poor prognosis of hypertensive AMI patients due to alterations in Tregs. Targeting disturbed Tregs may be a new strategy to treat AMI patients with hypertension.

CTLA-4 Pathway Is Instrumental in Giant Cell Arteritis.

BACKGROUND: Giant cell arteritis (GCA) causes severe inflammation of the aorta and its branches and is characterized by intense effector T-cell infiltration. The roles that immune checkpoints play in the pathogenesis of GCA are still unclear. Our aim was to study the immune checkpoint interplay in GCA. METHODS: First, we used VigiBase, the World Health Organization international pharmacovigilance database, to evaluate the relationship between GCA occurrence and immune checkpoint inhibitors treatments. We then further dissected the role of immune checkpoint inhibitors in the pathogenesis of GCA, using immunohistochemistry, immunofluorescence, transcriptomics, and flow cytometry on peripheral blood mononuclear cells and aortic tissues of GCA patients and appropriated controls. RESULTS: Using VigiBase, we identified GCA as a significant immune-related adverse event associated with anti-CTLA-4 (cytotoxic T-lymphocyte-associated protein-4) but not anti-PD-1 (anti-programmed death-1) nor anti-PD-L1 (anti-programmed death-ligand 1) treatment. We further dissected a critical role for the CTLA-4 pathway in GCA by identification of the dysregulation of CTLA-4-derived gene pathways and proteins in CD4+ (cluster of differentiation 4) T cells (and specifically regulatory T cells) present in blood and aorta of GCA patients versus controls. While regulatory T cells were less abundant and activated/suppressive in blood and aorta of GCA versus controls, they still specifically upregulated CTLA-4. Activated and proliferating CTLA-4+ Ki-67+ regulatory T cells from GCA were more sensitive to anti-CTLA-4 (ipilimumab)-mediated in vitro depletion versus controls. CONCLUSIONS: We highlighted the instrumental role of CTLA-4 immune checkpoint in GCA, which provides a strong rationale for targeting this pathway.

Repetitive Antigen Responses of LDL-Reactive CD4+ T Cells Induce Tr1 Cell-Mediated Immune Tolerance.

BACKGROUND: Inflammation triggered by the deposition of LDL (low-density lipoprotein) in the arterial wall leads to the development of atherosclerosis. Regulatory T (Treg) cells inhibit vascular inflammation through the induction of immune tolerance toward LDL-related antigens. However, tolerogenic mechanisms that promote the generation of LDL-specific Treg cells in vivo remain unclear. METHODS: We identified LDL-specific T cells by activation-induced marker expression and analyzed expression profiles and suppressive functions of TCR (T-cell antigen receptor)-transgenic T cells upon repetitive transfer into antigen-transgenic mice via flow cytometry. RESULTS: We investigated the naturally occurring Treg-cell response against human LDL in standard chow diet-fed mice that are transgenic for human ApoB100 (apolipoprotein B100). We found that IL (interleukin)-10 expression in LDL-specific T cells from spleen increases with age, albeit LDL-specific populations do not enlarge in older mice. To investigate the generation of IL-10-producing LDL-specific T cells, we transferred naive CD4+ T cells recognizing human ApoB100 from TCR-transgenic mice into human ApoB100-transgenic mice. Adoptive transfer of human ApoB100-specific T cells induced immune tolerance in recipient mice and effectively inhibited activation of subsequently transferred naive T cells of the same specificity in vivo. Moreover, repetitive transfers increased the population of Treg type 1 cells that suppress ApoB100-specific responses via IL-10. In a translational approach, LDL-specific Treg type 1 cells from blood of healthy donors suppressed the activation of monocytic THP-1 cells in an IL-10-dependent manner. CONCLUSIONS: We show that repetitive transfer of naive ApoB100-specific T cells and recurrent LDL-specific T-cell stimulation induces Treg type 1 cell-mediated immune tolerance against LDL in vivo. Our results provide insight into the generation of autoantigen-specific anti-inflammatory T cells under tolerogenic conditions.

T helper cell and regulatory T-cell related cytokines changes in vaginal lavage fluid of patients with high risk-human papilloma virus 16 positive and the predictive effect on the development of cervical neoplasms / 肿瘤研究与临床

Objective:To investigate the changes of T helper cell (Th), regulatory T-cell (Treg cell) related cytokines in vaginal lavage fluid of patients with high risk-human papilloma virus 16 (HR-HPV16) positive and its predictive effect on the development of cervical neoplasms.Methods:A total of 200 cases of HR-HPV16 positive patients who admitted to Xingtai People's Hospital from January 2022 to December 2022 were selected as the experimental group. According to the results of pathological examination, all patients in the experimental group were divided into non pathological group (78 cases), low grade squamous intraepithelial lesion (LSIL) group (49 cases), high grade squamous intraepithelial lesion (HSIL) group (39 cases) and cervical cancer group (34 cases); and 100 healthy people undergoing the physical examination in the same period were taken as the healthy control group. Enzyme-linked immunosorbent assay (ELISA) double-antibody sandwich method was used to detect the levels of interleukin (IL)-2, IL-4, IL-6, IL-10, IL-12, IL-17, tumor necrosis factor α (TNF-α), interferon γ (IFN-γ) and transforming growth factor β (TGF-β) in vaginal lavage fluid of patients in different groups. Multivariate logistics regression was used to analyze the risk factors of cervical cancer, and a nomogram model was established. The receiver operating characteristics (ROC) curve was drawn with pathological results as the gold standard, and the area under the curve (AUC) was calculated to evaluate the predictive ability of the nomogram model.Results:The levels of IL-6, IL-10, IL-17, TNF-α, TGF-β in vaginal lavage fluid of patients in the experimental group were higher than those in the healthy control group, while the levels of IL-2, IL-12 and IFN-γ in the experimental group were lower than those in the healthy control group, and the differences were statistically significant (all P < 0.05); the difference in IL-4 level of both groups was not statistically significant ( P > 0.05). There were statistically significant differences in IL-6, IL-10, IL-17, TNF-α, TGF-β, IL-2, IL-12 and IFN-γ among non pathological group, LSIL group, HSIL group and cervical cancer group (all P < 0.05); the levels of IL-6, IL-10, IL-17, TNF-α, TGF-β in cervical cancer group were the highest, the levels of IL-2, IL-12 and IFN-γ were the lowest; the level of IL-4 in non pathological group, LSIL group, HSIL group and cervical cancer group had no statistically significant difference ( P > 0.05). Logistics regression analysis showed that low IL-2, high IL-4, high IL-6, high IL-10, low IL-12, high IL-17, high TNF-α, low IFN- γ and low TGF-β expressions in vaginal lavage fluid of patients with HR-HPV16 positive were independent risk factors for the development of cervical cancer (all P < 0.05). The results of nomogram analysis showed that IL-6, IL-10, IL-17, TNF-α, TGF-β in vaginal lavage fluid were the factors predicting the development of cervical cancer in HR-HPV16 positive patients. The ROC curve analysis showed that the AUC of nomogram model in predicting the development of cervical cancer in HR-HPV16 positive patients was 0.945 (95% CI 0.901-0.988), and the predictive efficacy was good. Conclusions:Th and Treg cell related cytokines levels in vaginal lavage fluid of patients with HR-HPV16 positive show pathological changes in cervical cancer patients and the above indicators have a high value in predicting the development of cervical cancer.

Investigation on the incidence of IRIS in HIV patients with TB infection and its relationship with Th17/Treg, CD4 + T lymphocyte levels / 中国医师杂志

Objective:To investigate the incidence of immune reconstitution inflammatory syndrome (IRIS) in patients with HIV (HIV) and tuberculosis (TB) infection, and analyze the relationship between Th17/Treg cytokines, CD4 + T lymphocytes and IRIS. Methods:HIV patients with TB infection admitted to Public Health Clinical Center of Chengdu from June 2020 to June 2022 were divided into IRIS group (31 cases) and non IRIS group (93 cases) according to whether IRIS occurred after highly active antiretroviral therapy (HAART). The Demography data, clinical data and laboratory indicators of the two groups were compared. Multivariate logistic regression analysis was conducted to investigate the influencing factors of IRIS in HIV patients with TB infection.Results:There was no significant difference in Demography data between the two groups ( P>0.05). There was a statistically significant difference in the history of opportunistic infection between the IRIS group and the non IRIS group (χ 2=5.194, P<0.05). The levels of HIV RNA, interleukin (IL)-17, and IL-23 in the IRIS group were higher than those in the non IRIS group (all P<0.05). The levels of the γ interferon (IFN- γ), the transforming growth factor-β (TGF- β) and baseline CD4 + T lymphocyte count were lower than those in the non IRIS group (all P<0.05). The results of multivariate logistic regression analysis showed that IL-17 ( OR: 1.266, 95% CI: 1.095-1.464), IL-23( OR: 1.384, 95% CI: 1.120-1.710), and TGF- β( OR: 0.589, 95% CI: 0.436-0.797) were influencing factors for the occurrence of IRIS in HIV patients with TB infection (all P<0.05). Conclusions:For patients with high IL-17 levels, high IL-23 levels, and low TGF- β level of HIV complicated with TB infection, clinical prevention and control should be carried out as soon as possible to prevent the occurrence of IRIS.

Efficacy of Zhibitai capsules combined with low-dose atorvastatin in the treatment of cervical arteriosclerosis and its effects on high-sensitivity C-reactive protein and regulatory T cells in the peripheral blood / 中国基层医药

Objective:To investigate the efficacy of Zhibitai capsules combined with low-dose atorvastatin in the treatment of cervical arteriosclerosis and its effects on high-sensitivity C-reactive protein and regulatory T cells in the peripheral blood. Methods:A total of 104 patients with carotid arteriosclerosis admitted to Fenyang Hospital from January 2021 to April 2022 were retrospectively included in this study. They were divided into a control group ( n = 52) and an observation group ( n = 52) according to different treatment methods. The control group was orally given atorvastatin calcium tablets 20 mg once a day. The observation group was orally given atorvastatin calcium tablets 10 mg once a day, and Zhibitai capsules 0.24 g, one capsule in the morning and one capsule in the evening. After 8 weeks of treatment, changes in total cholesterol, triacylglycerol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high-sensitivity C-reactive protein, and regulatory T cell proportion in the peripheral blood were evaluated. Results:After treatment, high-density lipoprotein cholesterol level and regulatory T cell proportion in the observation group were (1.53 ± 0.29) mmol/L and (5.52 ± 1.38)%, respectively, which were significantly higher than (1.19 ± 0.21) mmol/L and (4.48 ± 0.86)% respectively in the control group ( t = 6.84, 4.61, both P < 0.05). Total cholesterol, triacylglycerol, low-density lipoprotein cholesterol, and high-sensitivity C-reactive protein levels in the observation group were (2.88 ± 0.27) mmol/L, (1.21 ± 0.15) mmol/L, (2.01 ± 0.19) mmol/L, (2.58 ± 0.43) mg/L, respectively, which were significantly lower than (3.68 ± 0.41) mmol/L, (1.33 ± 0.19) mmol/L, (2.69 ± 0.31) mmol/L, (3.70 ± 0.25) mg/L, respectively in the control group ( t = 11.75, 3.57, 12.31, 17.23, all P < 0.05). There was no significant difference in carotid plaque size pre-treatment between the two groups, but the plaque size decreased after treatment compared with before treatment. The efficacy of Zhibitai capsules combined with low-dose atorvastatin in the treatment of cervical arteriosclerosis in the observation group was superior to that in the control group ( P < 0.05). Conclusion:Oral administration of Zhibitai capsules combined with low-dose atorvastatin for the treatment of cervical arteriosclerosis is safe and has few adverse reactions. The combined therapy can decrease serum high-sensitivity C-reactive protein levels, increase the proportion of regulatory T cells in the peripheral blood, help stabilize plaques, and reduce plaque size.

Efficacy of lenalidomide in treatment of multiple myeloma and its effect on levels of regulatory T cells and natural killer cells of patients / 白血病·淋巴瘤

Objective:To investigate the clinical efficacy of lenalidomide combined with bortezomib and dexamethasone (RVd) regimen in treatment of newly diagnosed multiple myeloma (NDMM) patients and its effect on the levels of regulatory T cells (Treg cells) and natural killer (NK) cells.Methods:Thirty-eight NDMM patients who were admitted to the Second Affiliated Hospital of Bengbu Medical College from September 2019 to May 2022 were selected for a prospective study, and were divided into control group (18 cases) and observation group (20 cases) according to random number table method. The control group was treated with bortezomib+epirubicin+dexamethasone (VAd) regimen, and the observation group was treated with RVd regimen. The efficacy and safety were compared between the two groups. The levels of Treg cells (CD4 + CD25 + FOXP3 +) and NK cells (CD3 - CD56 + CD16 +) before and after treatment in the two groups were detected by flow cytometry, and the results were compared. Results:After 4 courses of treatment, the objective response rate (ORR) of the observation group was 95.0% (19/20), which was higher than that of the control group [77.8% (14/18)], and the difference was statistically significant ( P = 0.016). Before treatment, there was no statistical difference in the levels of Treg cells and NK cells between the two groups ( P values were 0.381 and 0.650). After treatment, the level of Treg cells in the control group increased from (1.5±0.5)% before treatment to (4.7±1.3)% ( P = 0.008), while the level of Treg cells in the observation group increased from (1.4±0.5)% before treatment to (6.8±1.5)% ( P = 0.001), and the level in the observation group was higher than that in the control group ( P = 0.027); the level of NK cells in the control group increased from (16±6)% before treatment to (20±5)% ( P = 0.004), while the level of NK cells in the observation group increased from (16±6)% before treatment to (24±6)% ( P = 0.006), and the level in the observation group was higher than that in the control group ( P = 0.032). The incidence rates of thrombocytopenia and neutropenia in the observation group were higher than those in the control group, and the differences were statistically significant ( P values were 0.012 and 0.027), which was reversible after active treatment. There was no statistical difference in the incidence rates of other adverse reactions (all P>0.05). Conclusions:RVd regimen for NDMM is clinically effective, safe and reliable, and the patients' levels of Treg cells and NK cells elevate after treatment.

Bone marrow CD3+ CD56+ regulatory T lymphocytes (TR3 -56 cells) are inversely associated with activation and expansion of bone marrow cytotoxic T cells in IPSS-R very-low/low risk MDS patients.

BACKGROUND: Emergence of dysplastic haematopoietic precursor/s, cytopenia and variable leukaemia risk characterise myelodysplastic syndromes (MDS). Impaired immune-regulation, preferentially affecting cytotoxic T cells (CTL), has been largely observed in MDS. Recently, we described the TR3-56 T cell subset, characterised by the co-expression of CD3 and CD56, as a novel immune-regulatory population, able to modulate cytotoxic functions. Here, we address the involvement of TR3-56 cells in MDS pathogenesis/progression. OBJECTIVES: To analyse the relationship between TR3-56 and CTL activation/expansion in bone marrow (BM) of very-low/low-risk MDS subjects. METHODS: Peripheral blood and BM specimens, obtained at disease onset in a cohort of 58 subjects, were analysed by immune-fluorescence and flow cytometry, to preserve the complexity of the biological sample. RESULTS: We observed that a trend-increase of BM TR3-56 in high/very-high MDS stage, as compared with very-low/low group, associates with a decreased activation of BM resident CTL; significant correlation of TR3-56 with BM blasts has been also revealed. In addition, in very-low/low-risk subjects the TR3-56 amount in BM inversely correlates with the presence of activated BM CTL showing a skewed Vß T-cell repertoire. CONCLUSIONS: These data add TR3-56 to the immune-regulatory network involved in MDS pathogenesis/progression. Better knowledge of the immune-mediated processes associated with the disease might improve MDS clinical management.

Efficacy of Wumei Baijiang prescription on regulatory T cells / helper T cells Immune balance in mice with ulcerative coliti.

OBJECTIVE: To observe the therapeutic effect of Wumei Baijiang prescription empirical prescription of Lu Zhizheng, on experimental ulcerative colitis (UC) mice, and to investigate the mechanism of the prescription in UC from the perspective of the immune balance of regulatory T cells (Treg) and helper T cells (Th17). METHODS: Sixty C57BL/6 mice were randomly divided into 6 groups: normal group, model group, Chinese medicine group (high, medium and low dose group of Wumei Baijiang prescription) and control group (mesalazine sustained-release granules). Except for the normal group, the other groups used 2.5% dextran sulfate sodium to induce UC mice model. At the end of the model, the Chinese medicine group was given high, medium and low dose administration of Wumei Baijiang prescription, the control group was given slow-release granules of mesalazine, and the model group was given equal volume saline for 10 d. The changes of food intake, body weight, disease activity index (DAI) score, length of large intestine and histopathology were observed. The number of Treg, Th17, CD4+, CD8+ cells in spleen was detected by flow cytometry. The expression of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) and C-reactive protein (CRP) in serum was detected by enzyme-linked immunosorbent assay. RESULTS: The middle and high-dose groups of Wumei Baijiang prescription were superior to the model group in terms of increasing food intake and body weight of colitis mice, restoring colon morphology, improving pathological damage, and reducing DAI (P < 0.05). There was no statistical difference with the mesalazine group (P > 0.05). Compared with the model group, the spleen Treg and CD4+ of the mice in the high and middle dose groups of Wumei Baijiang prescription were higher, while Th17 and CD8+ were lower (P < 0.05), and there was no statistical difference compared with the mesalazine group (P > 0.05). In addition, compared with the model group, the serum levels of TNF- and CRP in mice with high and middle doses of Wumei Baijiang prescription and mesalazine group were lower (P < 0.05), and IL-10 content was higher ( P < 0.05). CONCLUSIONS: Wumei Baijiang prescription can improve the general conditions of colitis mice, such as diarrhea, hematochezia, weight loss, and mucosal damage. The mechanism may be related to the regulation of Treg/Th17 immune balance.

CCL17 Aggravates Myocardial Injury by Suppressing Recruitment of Regulatory T Cells.

BACKGROUND: Recent studies have established that CCR2 (C-C chemokine receptor type 2) marks proinflammatory subsets of monocytes, macrophages, and dendritic cells that contribute to adverse left ventricle (LV) remodeling and heart failure progression. Elucidation of the effector mechanisms that mediate adverse effects of CCR2+ monocytes, macrophages, and dendritic cells will yield important insights into therapeutic strategies to suppress myocardial inflammation. METHODS: We used mouse models of reperfused myocardial infarction, angiotensin II and phenylephrine infusion, and diphtheria toxin cardiomyocyte ablation to investigate CCL17 (C-C chemokine ligand 17). We used Ccl17 knockout mice, flow cytometry, RNA sequencing, biochemical assays, cell trafficking studies, and in vivo cell depletion to identify the cell types that generate CCL17, define signaling pathways that controlled its expression, delineate the functional importance of CCL17 in adverse LV remodeling and heart failure progression, and determine the mechanistic basis by which CCL17 exerts its effects. RESULTS: We demonstrated that CCL17 is expressed in CCR2+ macrophages and cluster of differentiation 11b+ conventional dendritic cells after myocardial infarction, angiotensin II and phenylephrine infusion, and diphtheria toxin cardiomyocyte ablation. We clarified the transcriptional signature of CCL17+ macrophages and dendritic cells and identified granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling as a key regulator of CCL17 expression through cooperative activation of STAT5 (signal transducer and activator of transcription 5) and canonical NF-κB (nuclear factor κ-light-chain-enhancer of activated B cells) signaling. Ccl17 deletion resulted in reduced LV remodeling, decreased myocardial fibrosis and cardiomyocyte hypertrophy, and improved LV systolic function after myocardial infarction and angiotensin II and phenylephrine infusion. We observed increased abundance of regulatory T cells (Tregs) in the myocardium of injured Ccl17 knockout mice. CCL17 inhibited Treg recruitment through biased activation of CCR4. CCL17 activated Gq signaling and CCL22 (C-C chemokine ligand 22) activated both Gq and ARRB (ß-arrestin) signaling downstream of CCR4. CCL17 competitively inhibited CCL22 stimulated ARRB signaling and Treg migration. We provide evidence that Tregs mediated the protective effects of Ccl17 deletion on myocardial inflammation and adverse LV remodeling. CONCLUSIONS: These findings identify CCL17 as a proinflammatory mediator of CCR2+ macrophages and dendritic cells and suggest that inhibition of CCL17 may serve as an effective strategy to promote Treg recruitment and suppress myocardial inflammation.

Inflammation Resolution: Implications for Atherosclerosis.

Resolution is an active and highly coordinated process that occurs in response to inflammation to limit tissue damage and promote repair. When the resolution program fails, inflammation persists. It is now understood that failed resolution is a major underlying cause of many chronic inflammatory diseases. Here, we will review the major failures of resolution in atherosclerosis, including the imbalance of proinflammatory to pro-resolving mediator production, impaired clearance of dead cells, and functional changes in immune cells that favor ongoing inflammation. In addition, we will briefly discuss new concepts that are emerging as possible regulators of resolution and highlight the translational significance for the field.

The correlation between diamine oxidase and T helper cells 17/regulatory T cell immune balance in rheumatoid arthritis / 中华风湿病学杂志

Objective:To investigate the changes of intestinal mucosal barrier function related indexes [diamine oxidase and secretory immunoglobulin A (sIgA)] in peripheral blood of patients with rheumatoid arthritis (RA) and their correlation with peripheral immune function.Methods:A total of 40 patients with RA who admitted to the Rheumatology and Immunology department of the Second Hospital of the Shanxi Medical University were enrolled. We collected their clinical and laboratory data, and selected 20 age and gender matched people as the control group. Enzyme-linked immunosorbnent assay (ELISA) was used to detect the level of DAO and sIgA in the peripheral blood, the lymphocytes and CD4 + T subsets were detected by flow cytometry. Then t-test, rank sum test and correlation analysis were conducted for statistical analysis. Results:① The level of DAO in patients with RA was higher than that of healthy controls [205(164, 251) ng/ml vs 364 (276, 483) ng/ml, Z=-4.48, P<0.001], while the level of sIgA was decreased [3.64 (2.76, 4.83)×10 5 ng/ml vs 6.83 (4.80, 9.44)×10 5, Z=-3.84, P<0.001]. ② The absolute number of B and CD4 + T cells were increased in RA, the difference were statistically significant, but the absolute number of T, natural killer cells (NK) and CD8 + T cells were not significantly different between the two groups. For CD4 + T subsets, the absolute number of T helper cells (Th)1 and Treg cells in RA group were significantly decreased than healthy controls, but there were no statistical significant difference in the number of Th2 and Th17 cells. ③ The level of DAO was positively correlated with absolute number of Th17 cells in patients with RA ( r=0.36 P=0.038), and positively correlated with age and white blood cell count ( r=0.40, P=0.021; r=0.40, P=0.020), but no significant correlation among other indicators were found. ④ The serum sIgA level of RA patients in antimutated citrullinated vimentin antibody (MCV), antiperinuclear factor (APF) and antikeratin antibody (AKA) positive group were higher than those in the negative group [3.99(2.99, 5.58)×10 5 ng/ml vs 2.73(2.29, 3.05)×10 5 ng/ml, Z=-2.55, P=0.011; 5.49 (3.26, 5.70)×10 5 ng/ml vs 3.12 (2.29, 4.04)×10 5 ng/ml, Z=-2.28, P=0.023; 4.07 (3.19, 5.65)×10 5 ng/ml vs 2.88 (2.24, 3.86)×10 5 ng/ml, Z=-2.42, P=0.016], while there was no significant difference in DAO level between groups. ⑤ The DAO level of RA patients with pulmonary interstitial fibrosis was significantly higher than that in the group without pulmonary interstitial fibrosis [421 (216, 528) ng/ml vs 191 (150, 223) ng/ml, Z=-2.81, P=0.005], while there were no significant differences in DAO and sIgA levels among other groups. Conclusion:In RA patients with inte-stinal mucosal barrier impairment, the DAO level is increased, while the sIgA is decreased, and in addition, elevated peripheral blood Th17 may be involved in the process of intestinal mucosal barrier impairment.

Effects of Notch1 signaling on regulatory T cells and coronary artery lesions in childhood Kawasaki disease / 中华风湿病学杂志

Objective:To explore the effect of Notch1 signaling on regulatory T cells and its roles in vascular damage in patients with Kawasaki disease (KD).Methods:A total of 42 children with KD were enrolled in the present study from March 2019 to June 2020, as 32 age-matched healthy children were recruited as control. The proportions of CD4 +CD25 hiFoxp 3+ regulatory T cells (Treg) and expressions of transcription factor forkhead box protein 3 (Foxp3), cytotoxic T lymphocyte associated antigen-4 (CTLA4), glucocorticoid-induced tumor necrosis factor receptor (GITR), and Notch1 protein were evaluated by flow cytometry. Chromatin immunoprecipitation was conducted to detect acetylation level of histone H4 (H4Ac) associated with the promoter of Foxp3 gene and its binding abilities of Notch1 intracellular domain 1 (NICD1), recombination signal binding protein for immunoglobulin kappa J region (RBP-J) and p300 in CD4 + T cells. Transcription levels of Foxp3, presenilin 1 (PSEN1), mastermind like transcriptional coactivator 1 (MAML1), and RBP-J in CD4 + T cells were determined by real-time polymerase chain reaction (PCR). Concentrations of interleukin (IL)-10 and transforming growth factor-β (TGF-β) in plasma and culture supernatant stimulated with Jagged1 were measured by enzyme linked immunosorbent assay. Independent-sample t-test, Pearson correlation analysis was used as the statistical method in this study. Results:① The frequencies of Treg in acute KD patients decreased significantly [(4.3±1.5)% vs (7.9±2.9)%; t=6.41, P<0.001], as protein levels of Foxp3, CTLA4 and GITR and concentrations of IL-10 and TGF-β in plasma reduced remarkably in acute KD patients ( t=6.87, P<0.001; t=4.26, P<0.001; t=7.88, P<0.001; t=8.42, P<0.001; t=13.01, P<0.001). All parameters afore-mentioned in patients combined with coronary artery lesions (CAL) were lower than those of patients without coronary artery lesions (NCAL) ( t=5.83, P<0.001; t=3.83, P<0.001; t=3.28, P=0.002; t=5.05, P<0.001; t=5.96, P<0.001; t=5.17, P<0.001), and increased after therapy ( t=7.13, P<0.001; t=6.10, P<0.001; t=4.31, P<0.001; t=6.55, P<0.001; t=7.40, P<0.001; t=7.84, P<0.001). ② H4Ac associated with promoter of Foxp3 gene and the binding abilities of NICD1 and p300 in acute KD patients were lower than those of the controls ( t=10.25, P<0.001; t=6.93, P<0.001; t=6.75, P<0.001), and increased remarkably after therapy ( t=7.72, P<0.001; t=4.16, P<0.001; t=5.76, P<0.001). Meanwhile, the three items in CAL group were found to be less than those of NCAL group ( t=6.08, P<0.001; t=2.66, P=0.011; t=6.02, P<0.001). Pearson correlation analysis showed a positive correlation between H4Ac associated with Foxp3 promoter and its mRNA level in acute KD patients ( r=0.47, P<0.001). No statistical significant difference about the binding ability of RBP-J with Foxp3 promoter were found among the groups ( t=0.57, P>0.05; t=0.61, P>0.05; t=1.20, P>0.05). ③ Protein level of Notch1 and the expressions of PSEN1, MAML1 and RBP-J mRNA in CD4 + T cells from acute KD patients were down-regulated remarkably ( t=5.28, P<0.001; t=6.31, P<0.001; t=11.78, P<0.001; t=8.06, P<0.001), and restored after therapy ( t=4.77, P<0.001; t=6.43, P<0.001; t=11.95, P<0.001; t=7.79, P<0.001). In parallel, the four indexes aforementioned of CAL group were lower than those of NCAL group ( t=3.16, P=0.003; t=4.13, P<0.001; t=5.42, P<0.001; t=4.05, P<0.001). Upon rhJagged1 stimulation for 48 hours, H4Ac level of Foxp3 promoter and its binding abilities with NICD1 and p300 in CD4 + T cells in KD patients and control group was significantly higher than those of untreated group [(KD: t=15.36, P<0.001; t=7.25, P<0.001; t=14.29, P<0.001), (Ctrl: t=7.87, P<0.001; t=5.71, P<0.001; t=8.74, P<0.001)], as the binding ability of RBP-J with Foxp3 promoter increased slightly without statistically significant difference (KD: t=1.11, P>0.05; Ctrl: t=1.37, P>0.05). Simultaneously, H4Ac level of Foxp3 promoter and its binding abilities with NICD1 and p300 in KD group were still lower than those of the control group after stimulation ( t=3.86, P<0.001; t=3.42, P=0.001; t=2.85, P=0.006). ④ After incubation of PBMC from heathy children with KD serum, the proportion of Treg cells, protein level of Foxp3 and expressions of Notch1 and RBP-J in CD4 + T cells in the group treated with IVIG increased significantly compared with the untreated group ( t=7.10, P<0.001; t=10.16, P<0.001; t=8.06, P<0.001; t=9.77, P<0.001), as well as H4Ac level of Foxp3 promoter and its binding abilities with NICD1 in the group treat with IVIG were also higher than the latter ( t=7.24, P<0.001; t=8.24, P<0.001). Conclusion:Insufficiency and impaired function of Treg caused by aberrant Notch1 signaling may be the important factor contributing to immune dysfunction and vascular damage in KD.

Effect of interleukin-23R overexpression on Th17/Treg balance in experimental autoimmune uveitis mice / 中华眼底病杂志

Objective:To investigate the effect of interleukin (IL)-23 receptor (IL-23R) overexpression on the balance of T helper 17 (Th17 cells)/regulatory T cells (Treg cells) in experimental autoimmune uveitis (EAU) mice.Methods:Twelve 8-week-old female C57BL/6J mice were randomly divided into LV-Ctrl group and LV-IL-23R group, with 6 mice in each group. Two groups of mice were injected with LV-Ctrl and LV-IL-23R lentiviruses through the tail vein, respectively; 7 days after injection, the EAU mouse model was established by active immunization with vitamin A-binding protein 1-20 between photoreceptors. Starting from 13 days after immunization, the fundus of the mice was observed by indirect ophthalmoscopy every 2 days and clinical scores were performed; 30 days after immunization, hematoxylin-eosin staining was used to observe the histopathological changes of mouse retina. The levels of IL-17 in serum of the two groups of mice were detected by enzyme-linked immunosorbent assay; the proportion of Th17 cells and Treg cells was detected by flow cytometry. The relative mRNA expression of IL-23R, IL-17, retinoic acid-related orphan receptor γt (RORγt), IL-10 and forkhead transcripyion factor p3 (Foxp3) were detected by real-time quantitative polymerase chain reaction. Comparisons between groups were performed using repeated measures analysis of variance, independent samples Mann-Whitney U test, and independent samples t test. Results:Compared with the LV-Ctrl group, the retinal inflammatory reaction of the LV-IL-23R group was more severe. At 13 days after immunization, there was no significant difference in fundus inflammation scores between LV-IL-23R group and LV-Ctrl group ( t=-2.001, P=0.058); 15-29 days after immunization. The fundus inflammation scores of LV-IL-23R group were higher than those of LV-Ctrl group, and the difference was statistically significant ( t=-4.429,-6.578, -7.768, -10.183, -6.325, -7.304, -4.841, -6.872; P<0.001). Histopathological examination showed that the infiltration of inflammatory cells in the fundus increased, the retinal structure was damaged more seriously, and the histopathological score was significantly increased, and the difference was statistically significant ( t=-4.339, P=0.001). Compared with the LV-Ctrl group, the relative expression of IL-23R mRNA in the spleen of the LV-IL-23R group was significantly increased, and the difference was statistically significant ( Z=2.087, P=0.037). The relative expression of IL-17 and RORγt mRNA increased, while the relative expression of IL-10 and Foxp3 mRNA decreased, and the differences were statistically significant ( t=-6.313,-5.922, 4.844, 7.572; P=0.003, 0.004, 0.008, 0.002). Compared with the LV-Ctrl group, the level of IL-17 in the serum of the mice in the LV-IL-23R group was significantly increased, and the difference was statistically significant ( t=-5.423, P=0.002); the proportion of Th17 cells in the spleen and lymph nodes was significantly increased, whereas, the proportion of Treg cells was significantly reduced, and the difference was statistically significant ( t=-4.290, 3.700; P=0.002, 0.006). Conclusion:IL-23R overexpression can promote Th17/Treg imbalance in EAU mice, and aggravate the clinical and pathological manifestations of EAU.

Immunomodulatory mechanism of interleukin-7 receptor α antibody attenuating renal injury in MRL/lpr lupus mice / 中华肾脏病杂志

Objective:To investigate the effect of interleukin (IL)-7 receptor α (IL-7Rα) antibody on the immune inflammation and renal injury in MRL/lpr lupus mice.Methods:Fifteen 3-4-week-old female MRL/lpr lupus mice (specific pathogen free) weighing 15-16 g were bred to 14-week-old and randomly divided into three groups: IL-7Rα antibody intervention group, isotype antibody (positive control) group and normal saline (negative control) group. The mice in the threc groups were intraperitoneally injected with IL-7Rα antibody, isotype antibody and normal saline respectively, with 100 μg three times a week for 4 weeks. At the age of 18-week old, the mice were sacrificed. Twenty-four-hour urinary protein was detected by Coomassie brilliant blue method, serum creatinine was detected by peroxidase method, and the expression of autoantibody (anti-double strand DNA antibody) and inflammatory factors such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and IL-21 was detected by enzyme-linked immunosorbent assay method. Renal pathology was detected by PAS and Sirius red staining, and CD3 and F4/80 in renal tissues were detected by immunohistochemistry method. Regulatory T cells, follicullar helper T cells (Tfh) and follicular regulatory T cells (Tfr) were detected by flow cytometry.Results:The 24-hour urinary protein, serum creatinine, serum anti-double strand DNA antibody and serum IFN-γ and IL-21 in the IL-7Rα antibody intervention group were significantly lower than those in the control groups (all P<0.01). However, there was no significant difference in serum TNF-α among the three groups ( F=0.39, P>0.05). The positive infiltrating cells of CD3 and F4/F80, and the ratio of type Ⅰ/Ⅲ collagen fibers ( F=41.11, P<0.01) of renal tissues in the IL-7Rα antibody intervention group were lower than those in the other two groups. Compared with the control groups, the ratio of regulatory T cells (CD4 +CD25 +Foxp3 +)/effector T cells (CD4 +CD25 +) in blood of IL-7Rα antibody intervention group increased ( F=21.64, P<0.01), while the ratio of Tfr (CD4 +CXCR5 +Foxp3 +)/Tfh (CD4 +CXCR5 +) in peripheral blood and spleen increased ( F=38.95, P<0.01; F=12.90, P<0.01). Conclusion:IL-7Rα antibody can reduce the production of autoantibodies such as anti-double strand DNA antibody and inflammatory factors by increasing the ratio of regulatory T cells and Tfr/Tfh, thus alleviating immune inflammation and renal damage in MRL/lpr lupus mice.