Pro-inflammatory Subset Research Articles

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

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. 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. 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. 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.

Abstract P3074: Alkylating Chemotherapy Reshapes The Immune Landscape Of The Heart

Cancer survivors typically have concomitant cardiac comorbidities and were exposed to various chemotherapeutic agents. Despite extensive investigation, we still have a poor understanding of how chemotherapy agents impact cardiac physiology and disease pathogenesis. Alkylating agents, for instance, carboplatin, are the backbone of many chemotherapy regimens and have been applied in cancer treatment for decades. Cardiac macrophages are the primary component of the cardiac immune landscape and play essential roles in homeostasis and disease. My data implied that alkylating drugs induced cell death of the reparative cardiac macrophages (CCR2-) through activating apoptosis and necroptosis. However, the pro-inflammatory subset (CCR2+) is not decreased. Intriguingly, the reparative macrophages recovered four weeks after the carboplatin treatment through proliferation but showed different gene expression profiles. To investigate the functional influence of these reshaped macrophages in heart diseases, I established a hypertensive heart injury model and an ischemic heart injury model using carboplatin-exposed mice. Interestingly, these mice showed less fibrosis and smaller infarct size. Further, I used CD169-DTR mice that allow selective ablation of CCR2- macrophages. The attenuated remodeling phenotype is abolished without the reshaped CCR2- macrophages. Moreover, the type I interferon signaling in CCR2- macrophage is significantly upregulated in carboplatin-exposed mice upon hypertensive injury. Using neutralizing antibodies to block the IFN-I signaling, I found heart remodeling in carboplatin-treated mice became more advanced. Together, my study revealed that alkylating chemotherapy reshaped the immune landscape of the heart and mitigated adverse heart remodeling by activating the IFN-I signaling pathway in cardiac resident macrophages. These findings highlighted the role of CCR2- macrophages and the IFN-I signaling in the long-term cardiac effects of alkylating chemotherapy.

FADD- and RIPK3-Mediated Cell Death Ensures Clearance of Ly6Chigh Wound Macrophages from Damaged Tissue

Cells of the monocyte/macrophage lineage are an integral component of the body's innate ability to restore tissue function after injury. In parallel to mounting an inflammatory response, clearance of monocytes/macrophages from the wound site is critical to re-establish tissue functionality and integrity during the course of healing. The role of regulated cell death in macrophage clearance from damaged tissue and its implications for the outcome of the healing response is little understood. In this study, we explored the role of macrophage-specific FADD-mediated cell death on Ripk3-/- background in a mechanical skin injury model in mice. We found that combined inhibition of RIPK3-mediated necroptosis and FADD-caspase-8-mediated apoptosis in macrophages profoundly delayed wound healing. Importantly, RIPK3 deficiency alone did not considerably alter the wound healing process and macrophage population dynamics, arguing that inhibition of FADD-caspase-8-dependent death of macrophages is primarily responsible for delayed wound closure. Notably, TNF blockade reversed the accumulation of Ly6Chigh macrophages induced by combined deficiency of FADD and RIPK3, indicating a critical dual role of TNF-mediated prosurvival and cell death signaling, particularly in this highly proinflammatory macrophage subset. Our findings reveal a previously uncharacterized cross-talk of inflammatory and cell death signaling in macrophages in regulating repair processes in the skin.

Supplementation with EPA and DHA omega-3 fatty acids improves peripheral immune cell mitochondrial dysfunction and inflammation in subjects with obesity

Omega-3 fatty acids (w-3 FA) have anti-inflammatory effects and improve mitochondrial function. Nonetheless, little is known about their effect on mitochondrial bioenergetics of peripheral blood mononuclear cells (PBMCs) in individuals with obesity. Thus, this study aimed to determine the mitochondrial bioenergetics status and cell subset composition of PBMCs during obesity, before and after 1 month supplementation with w-3 FA. We performed a case-control study with twelve women with normal BMI (lean group) and 19 with grade 2 obesity (obese group), followed by a before-after prospective study where twelve subjects with obesity received a 1 month intervention with 5.25 g of w-3 FA (3.5 g eicosapentaenoic (EPA) and 1.75 g docosahexaenoic (DHA) acids), and obtained PBMCs from all participants. Mitochondrial bioenergetic markers, including basal and ATP-production associated respiration, proton leak, and nonmitochondrial respiration, were higher in PBMCs from the obese group vs. the lean group. The bioenergetic health index (BHI), a marker of mitochondrial function, was lower in the obese vs. the lean group. In addition, Th1, Th2, Th17, CD4+ Tregs, CD8+ Tregs, and Bregs, M1 monocytes and pDCreg cells were higher in PBMCs from the obese group vs. the lean group. The w-3 FA intervention improved mitochondrial function, mainly by decreasing nonmitochondrial respiration and increasing the reserve respiratory capacity and BHI. The intervention also reduced circulating pro-inflammatory and anti-inflammatory lymphocyte and monocytes subsets in individuals with obesity. The mitochondrial dysfunction of PBMCs and the higher proportion of peripheral pro-inflammatory and anti-inflammatory immune cells in subjects with obesity, improved with 1 month supplementation with EPA and DHA.

Macrophage recognition of non-self MHCI triggers signaling pathways directing differentiation and initiating tissue repair.

Abstract Injury resolution requires a coordinated immune-mediated response executed by macrophages (MΦs). Yet, how MΦs convert local stimuli into effective repair is poorly understood. Furthermore, organ transplants (Tx) will fail over time due to fibrosis, despite immunosuppressants targeting adaptive immune cells. We hypothesizethis is due to dysregulated MΦ-mediated tissue repair of grafts. Donor MHCI can be recognized by monocytes and MΦs via paired-immunoglobulin-like receptor-A (PIR-A), but if non-self MHCI recognition disrupts repair is an unanswered question. To test this, Wildtype (WT), Rag2 −/−γc −/−, and Pira −/−C57BL/6 (H-2 b) MΦ differentiation was assessed after exposure to allogeneic (BALB/c; H-2 d; allo) or syngeneic (syn) materials using flow cytometry or phosphoflow. The function of syn- and allo-exposed MΦs were compared with live-cell imaging of wound healing assays. Allo materials generated Ly6c hiCD86 hiMΦs in both WT and Rag2 −/−γc −/−recipients in vivo. Recombinant H2-D dalone behaved similarly in vitro. Interestingly, Ly6c hiCD86 hiMΦ differentiation in response to non-self MHCI was not PIR-A mediated, but by Ly49d-triggered PLCγ2 activation of NF-κB and mTOR coupled with increased glycolysis. Moreover, MΦ allo exposure profoundly amplified MΦ repair in comparison to other well characterized MΦ subsets (i.e. LPS/IFNγ or IL-4 stimulated). We identify an unappreciated relationship between innate allorecognition and MΦ repair. Specifically, MΦs recognize non-self MHCI via Ly49d, and triggering this novel pathway mediates MΦ differentiation in phenotypically pro-inflammatory subsets with amplified repair functions. Such a mechanism would contribute to Tx graft fibrosis and related pathology over time. Supported by grants from NIH (5T32AI074490-14, R01HL122489)

Shouhui Tongbian Capsules induce regression of inflammation to improve intestinal barrier in mice with constipation by targeted binding to Prkaa1: With no obvious toxicity

Constipation arising from the poor bowel movement is a rife enteric health problem. Shouhui Tongbian Capsule (SHTB) is a traditional Chinese medicine (TCM) which effectively improve the symptoms of constipation. However, the mechanism has not been fully evaluated. The purpose of this study was to evaluate the effect of SHTB on the symptoms and intestinal barrier of mice with constipation. Our data showed that SHTB effectively improved the constipation induced by diphenoxylate, which was confirmed by shorter first defecation time, higher internal propulsion rate and fecal water content. Additionally, SHTB improved the intestinal barrier function, which was manifested by inhibiting the leakage of Evans blue in intestinal tissues and increasing the expression of occludin and ZO-1. SHTB inhibited NLRP3 inflammasome signaling pathway and TLR4/NF-κB signaling pathway, reduced the number of proinflammatory cell subsets and increased the number of immunosuppressive cell subsets to relieve inflammation. The photochemically induced reaction coupling system combined with cellular thermal shift assay and central carbon metabolomics technology confirmed that SHTB activated AMPKα through targeted binding to Prkaa1 to regulate Glycolysis/Gluconeogenesis and Pentose Phosphate Pathway, and finally inhibited intestinal inflammation. Finally, no obvious toxicity related to SHTB was found in a repeated drug administration toxicity test for consecutive 13 weeks. Collectively, we reported SHTB as a TCM targeting Prkaa1 for anti-inflammation to improve intestinal barrier in mice with constipation. These findings broaden our knowledge of Prkaa1 as a druggable target protein for inflammation inhibition, and open a new avenue to novel therapy strategy for constipation injury.

P096 Characterization of suppressive immune cell subsets in mouse models of colitis-associated colorectal cancer

Abstract Background Chronic colonic inflammation in inflammatory bowel disease (IBD) patients increases the risk of colitis-associated cancer (CAC). Cancer development in CAC is different from that observed in sporadic colorectal cancer (CRC). Most studies have focused on the role of pro-inflammatory immune cell subsets in CAC, yet it is becoming increasingly clear that immunosuppression may also drive cancer progression. We hypothesize that emergence of immunosuppressive cell subsets as a result of chronic intestinal inflammation, dampens anti-tumor immune responses and accelerates the development of CAC. Methods To simulate cancer formation in the background of chronic inflammation, mice were treated with azoxymethane (AOM) followed by three cycles of dextran sodium sulphate (DSS). Apc Min/+ mice treated with AOM were used to model sporadic CRC. After 10 weeks, immune cells from the proximal and distal colonic lamina propria, mesenteric lymph nodes (MLNs) and tumors were obtained for microscopy analyses and processed to obtain single cell suspensions for flow cytometry. Immune cell populations were studied by conventional flow cytometry and immunofluorescence. Results We observed a significant increase in absolute numbers of PD1+CTLA4+TIM3+ ‘exhausted’ CD4+ T cells in the lamina propria from proximal colons in CAC mice as compared to sporadic CRC mice. Interestingly, these numbers showed a positive correlation with the inflammation score in AOM/DSS, demonstrating that chronic inflammation is associated with the emergence of ‘exhausted’ T cells. In addition, we observed a trend to higher numbers of M2-like (MHCII-CD206+) suppressive macrophages and CD4+FoxP3+ regulatory T cells (Tregs) in tumors from CAC mice compared to sporadic CRC. When analysing T cell immune responses in the MLNs, we found a significant decrease in the ratio IFNγ/IL10-producing CD8+ T cells in CAC mice as compared to CRC mice, suggesting a shift towards an anti-inflammatory T cell response in CAC. Conclusion In summary, suppressive immune cell subsets were increased in colonic mucosa and tumors from CAC mice as a result of chronic inflammation, which may be associated with the development of dysplasia. Further functional studies are necessary to prove the role of suppressive immune subsets in IBD-associated dysplasia- and carcinoma progression.

Inflammation induced by excessive expression of CD4 T-cell lymphocytes & proinflammatory cytokines results in bacterial dissemination in Mycobacterium tuberculosis-infected guinea pig model.

As CD4+ and CD8+ T lymphocyte numbers decline, the conventional, localized forms of tuberculosis shift to the atypical, disseminated forms. Variations in lymphocyte and immune cell expression levels affect how tuberculosis manifests in disseminated forms. Understanding the relationship between lymphocyte counts (CD4+ and CD8+) and pro-inflammatory cytokines such as tumour necrosis factor-alpha, interleukin-12 and interferon, we may therefore be able to shed light on how infections spread and suggest potential biomarkers for these immune factors. In this study, 15 guinea pigs were infected with Mycobacterium tuberculosis (M.tb) H37Rv strain and grouped into three groups of five each for further investigation. Serum samples and bronchoalveolar lavage (BAL) fluid were examined for the expression of pro-inflammatory cytokines and T-cell subsets in guinea pigs infected with pulmonary tuberculosis and disseminated tuberculosis. We found that M.tb escapes macrophages due to pro-inflammatory cytokine dysregulation. Despite the protective immunity created by T-cells and cytokines, M.tb bacilli may spread to other organs due to inflammation induced by these immune components. A high number of T-cells and stimulated cytokine production are involved in triggering inflammation after necrotic tissue develops and tuberculosis spreads. Our findings imply that increased bacilli in the spleen at the eighth week of infection may be caused by the overexpression of CD4+ T-cell lymphocyte subsets and cytokines that generated inflammation during the fourth week of infection. This is a pilot study with a small sample size and less assertive inference. Larger studies would be helpful to validate the results of the present investigation.

CD98 defines a metabolically flexible, proinflammatory subset of low-density neutrophils in systemic lupus erythematosus.

Low-density neutrophils (LDN) are a distinct subset of neutrophils rarely detected in healthy people but appear in the blood of patients with autoimmune diseases, including systemic lupus erythematosus (SLE), and are mobilised in response to granulocyte colony-stimulating factor (G-CSF). The aim of this study was to identify novel mechanisms responsible for the pathogenic capacity of LDN in SLE. Neutrophils were isolated from donors treated with G-CSF, and whole-cell proteomic analysis was performed on LDN and normal-density neutrophils. CD98 is significantly upregulated in LDN from G-CSF donors and defines a subset of LDN within the blood of SLE patients. CD98 is a transmembrane protein that dimerises with L-type amino acid transporters. We show that CD98 is responsible for the increased bioenergetic capacity of LDN. CD98 on LDN mediates the uptake of essential amino acids that are used by mitochondria to produce adenosine triphosphate, especially in the absence of glucose. Inhibition of CD98 reduces the metabolic flexibility of this population, which may limit their pathogenic capacity. CD98+ LDN produce more proinflammatory cytokines and chemokines than their normal density counterparts and are resistant to apoptosis, which may also contribute to tissue inflammation and end organ damage in SLE. CD98 provides a phenotypic marker for LDN that facilitates identification of this population without density-gradient separation and represents a novel therapeutic target to limit its pathogenic capacity.

Cytotoxic CD8+ T Cells Are Involved in the Thrombo-Inflammatory Response during First-Diagnosed Atrial Fibrillation.

Atrial myopathy and atrial fibrillation (AF) accompany thrombo-inflammation. This facilitates disease progression and promotes major adverse cardiovascular events (MACEs). Thrombin receptor (protease-activated receptor 1, PAR1) signalling is central in mediating thrombo-inflammation. We hypothesised that PAR1 signalling links coagulation and inflammation through cytotoxic CD8+ T lymphocytes in patients presenting with first-diagnosed AF (FDAF). A total of 210 patients were studied. We included data and blood samples from patients presenting with FDAF (n = 160), cardiac tissue from patients with paroxysmal AF (n = 32) and 20 controls. During early AF, a pro-inflammatory and cytotoxic subset of T lymphocytes (CD8+) circulated more frequently when compared to patients with chronic cardiovascular disease but without AF, accompanied by elevated plasma levels of CD8+ effector molecules, which corresponded to biomarkers of adverse cardiac remodelling and atrial dysfunction. Activation of tissue factor (TF) and PAR1 was associated with pro-inflammatory and cytotoxic effector functions. PAR1-related CD8+ cell activation was more frequent in FDAF patients that experienced a MACE. In patients with FDAF, the TF-factor Xa-factor IIa-axis contributes to thrombo-inflammation via PAR1 in CD8+ T cells. Intervening in this cascade might be a promising synergistic approach to reducing disease progression and the vascular complications of AF.

The eighth International Forum on Stem Cells: virtual meeting, October 20-21, 2022.

The eighth International Forum on Stem Cells: virtual meeting, October 20-21, 2022.

Global Characteristics and Dynamics of Single Immune Cells After Myocardial Infarction.

Background Myocardial infarction (MI) is characterized by the emergence of dead or dying cardiomyocytes and excessive immune cell infiltration after coronary vessel occlusion. However, the complex transcriptional profile, pathways, cellular interactome, and transcriptional regulators of immune subpopulations after MI remain elusive. Methods and Results Here, male C57BL/6 mice were subjected to MI surgery and monitored for 1 day and 7 days, or sham surgery for 7 days, then cardiac CD45-positive immune cells were collected for single-cell RNA sequencing to determine immune heterogeneity. A total of 30 135 CD45+ immune cells were partitioned into macrophages, monocytes, neutrophils, dendritic cells, and T or B cells for further analysis. We showed that macrophages enriched for Olr1 and differentially expressed Gpnmb represented 2 crucial ischemia-associated macrophages with distinct proinflammatory and prophagocytic capabilities. In contrast to the proinflammatory subset of macrophages enriched for Olr1, Gpnmb-positive macrophages exhibited higher phagocytosis and fatty acid oxidation preference, which could be abolished by etomoxir treatment. In addition to macrophages, MI triggered prompt recruitment of neutrophils into murine hearts, which constituted the sequential cell-fate from naïve S100a4-positive, to activated Sell-high, to aging Icam1-high neutrophils. In silico tools predicted that the excessively expanded neutrophils at 1 day were attributed to chemokine C-C motif ligand/chemokine C-X-C motif ligand pathways, whereas CD80/inducible T-cell costimulator (ICOS) signaling was responsible for the immunosuppressive response at day 7 after MI. Finally, the Fos/AP-1 (activator protein 1) regulon was identified as the critical regulator of proinflammatory responses, which was significantly activated in patients with dilated cardiomyopathy and ischemic cardiomyopathy. We showed the enriched Fos/AP-1 target gene loci in genome-wide association study signals for coronary artery diseases and MI. Targeting Fos/AP-1 with the selective inhibitor T5224 blunted leukocyte infiltration and alleviated cardiac dysfunction in the preclinical murine MI model. Conclusions Taken together, this single-cell RNA sequencing data lay the groundwork for the understanding of immune cell heterogeneity and dynamics in murine ischemic hearts. Moreover, Fos/AP-1 inhibition mitigates inflammatory responses and cardiac dysfunction, which might provide potential therapeutic benefits for heart failure intervention after MI.

Immune-modulation by 7, 8-diacetoxy-4-methylthiocoumarin in total body-irradiated mice: Implications for the mitigation of radiation-induced hematopoietic injury

AimsDevelopment of novel medical countermeasures (MCMs) against acute radiation syndrome (ARS) and the associated lethality involves protection from and/or mitigation of radiation-induced hematopoietic injury, a critical clinical component of ARS. We earlier identified the molecule 7,8-diacetoxy-4-methylthiocoumarin (DAMTC) as a potent mitigator of hematopoietic injury and mortality in C57BL/6 mice when administered 24 h following total body irradiation (TBI). In the present study, we investigated mechanisms and functional relevance of immune modulation by DAMTC during the mitigation of hematopoietic injury. Main methodsC57BL/6 mice were subjected to TBI doses of 3 and 7.6Gy; administered DAMTC intra-peritoneally 24 h post TBI. Isolation, characterization, intra-cellular cytokine analysis of myeloid cells from bone marrow and spleen accompanied by flow cytometric determination and characterization of B-lymphocytes, serum isolation from peripheral blood and cytokine analysis. Key findingsResults showed that DAMTC induced stimulation of pro-inflammatory myeloid subsets in the bone marrow and spleen of TBI mice. Further, it promoted a favorable transition from Th2 to Th1 immunity, triggered humoral immunity, and activated an intricately balanced inflammatory response that appear to contribute to immune-modulation. SignificanceThus, the present study shows that immune-modulation maybe one of the contributing factors for the mitigation of hematopoietic injury by DAMTC and underscores its efficacy as a potent mitigator of hematopoietic injury that merits to be developed further as a novel MCM to combat H-ARS.

Association of Interleukin-17F Polymorphism and Mortality Predictors with the Risk of COVID-19.

Th-17 cells, a proinflammatory subset of CD4 T lymphocytes, have been suggested as a possible cause of coronavirus disease-19 (COVID-19)-related immunological injuries. The aim of this study was to investigate the relationship between IL-17F (rs763780) polymorphism and the susceptibility to and outcomes of COVID-19 infection and to determine the clinical and laboratory predictors of COVID-19 death. This case-control study included 132 COVID-19 patients and 135 healthy age- and sex-matched controls. The participants were tested for IL-17F rs763780 polymorphism via TaqMan-based genotyping and for the expression of IL-17 by enzyme-linked immunosorbent assay. This study also investigated the predictors for COVID-19 mortality. A non-statistically significant association was observed between IL-17F alleles and genotypes with COVID-19 (P=0.309, P=0.138, respectively). Moreover, no significant difference in the IL-17F genotypes was observed between non-survivors and survivors (P=0.482). In the multivariate analysis, the participants with the following characteristics had 17.7-, 11.2-, 8-, and 17.9-fold higher odds of exhibiting in-hospital mortality, respectively: (1) hypertension, (2) age of >57 years, (3) WBC count of >12.6 × 103/mm3, and (4) D-dimer of >0.9 ng/ml. The ROC curve analysis showed that IL-17 at a cutoff point of >46 pg/ml was a perfect discriminator of COVID-19 patients from control subjects (AUC = 1.0). The findings indicate that the IL-17F H161R variant does not influence the risk of COVID-19. However, the IL-17 level is a perfect discriminator of COVID-19 infection. Hypertension, age of >57 years, white blood cell count of >12.6 × 103/mm3, and D-dimer of >0.9 ng/ml are the independent predictors for death among COVID-19 patients.

B cells from old mice induce the generation of inflammatory T cells through metabolic pathways

We have measured the capacity of B cells from young and old mice to induce the differentiation of naïve CD4 + T cells from young mice into pro-inflammatory subsets. We found that only B cells from old mice are inflammatory and induce in vitro secretion of the pro-inflammatory cytokines IL-17A and IFN-γ by T cells. In co-culture experiments, B cells from old mice showed a strong helper function on T cells from young mice, making them pro-inflammatory, and this effect is regulated by metabolic pathways, mainly anaerobic glycolysis, leading to increased RNA expression of the enzyme lactate dehydrogenase (LDHA) and increased secretion of lactate. These results have indicated that lactate is a crucial player of the B cell-induced polarization of T cells. When we measured the effects of lactate on isolated CD4 + T cells from young mice, we found that lactate increases RNA expression of LDHA, secretion of pro-inflammatory cytokines and NF-kB activation. Moreover, lactate effects in culture can be abrogated in the presence of the specific inhibitor of LDHA, FX11. These results altogether may have relevant clinical implications and suggest novel targets for therapeutic interventions in patients with inflammatory conditions and diseases.

Neutrophil N1 and N2 Subsets and Their Possible Association with Periodontitis: A Scoping Review.

Periodontitis is a chronic non-communicable disease caused by dysbiotic changes that affect the subgingival microbiota. During periodontitis, neutrophils play a central role in the initial recognition of bacteria, and their number increases with the appearance of the first signs of periodontal inflammation. Recent evidence has led to the proposition that neutrophils can also functionally polarize, determining selective activity patterns related to different diseases. Two well-defined neutrophil phenotypes have been described, the pro-inflammatory N1 subset and the suppressor N2 subset. To date, it has not been established whether these different neutrophil subtypes play a role in the pathogenesis of periodontitis. Thus, this scoping review aimed to determine whether there was evidence to suggest that the neutrophils present in periodontal tissues can be associated with certain phenotypes. The research question, population, concept, and context sought to identify original articles, in humans, that detected the presence of neutrophils in the periodontal tissues of people affected by periodontitis. Based on the search strategy, we found 3658 studies. After removing the papers with abstracts not related to the outcome measures and eligibility criteria, 16 articles were included for qualitative analysis. Several studies identified the presence of different neutrophil subsets, specifically, the naive, pro- and para-inflammatory, hyper-reactive and hyper-active, and high- and low-responder phenotypes. The existing evidence demonstrates the presence of pro-inflammatory, hyper-reactive and high-responder neutrophils in periodontal tissues affected with periodontitis. There is no evidence demonstrating the presence of the N1 or N2 phenotypes in periodontal tissues during periodontitis. However, the existence of pro-inflammatory phenotypes, which increase NETosis and degranulation, and increase the production of pro-inflammatory cytokines, could be suggestive of the N1 phenotypes.

Activation of mitochondrial telomerase reverses relative lymphopenia post myocardial infarction: results from the randomised, double-blinded TACTIC phase IIa pilot trial

Abstract Background Immune ageing is a phenomenon which includes lymphopenia, expansion of pro-inflammatory T-lymphocyte subsets and telomere shortening. While lymphopenia predicts mortality after myocardial infarction (MI), MI itself leads to both an increase in terminally differentiated memory CD8+ T-lymphocytes (CD8+ TEMRAs) and a decrease in telomere length. Activation of telomerase has been shown to ameliorate lymphopenia, and improve heart function after MI in mouse models. TA-65 is an oral telomerase activator, which may ameliorate immune ageing and improve outcome after MI. Methods This double-blinded, randomized placebo-controlled pilot study evaluated the use of TA-65 in 90 MI patients over 65 years, the average onset age for immune ageing. Patients were randomised to either TA-65 (16 mg daily, n=45) or placebo (n=45) for 12 months. The majority of patients underwent percutaneous coronary intervention (87%) or coronary artery bypass surgery (2%) as treatment for their index MI. The pre-defined primary endpoint was the proportion of CD8+ TEMRA T-lymphocytes at 12 months, a marker of immune ageing. A linear mixed effects model was used for the analysis. Results The proportion of CD8+ TEMRAs after 12 months did not differ between the 2 treatment groups, although only increased significantly in the placebo group (+2.2%, 95% CI: 0.14–4.24). TA-65 was well tolerated, with total adverse events lower in the treatment group (TA-65 vs. placebo group: n=130 vs. n=185). We observed at 12 months a 62% reduction in mean high-sensitivity CRP (hsCRP: TA-65 vs. placebo group: 1.1±0.9 vs. 2.9±6.4 mg/L) and a 15%-increase in mean peripheral blood lymphocytes in TA-65 after 12 months. In the whole sample, among those who were treated with TA-65 compared to Placebo, after 12 months peripheral blood lymphocytes increased (+285 cells /μl, 95% CI: 117–452). The latter was due to significant increases in the TA-65 group from baseline to 12 months across all major lymphocyte populations: CD3+ (+15%), CD4+ (+14%),CD8+ T-lymphocytes (+19%), B-lymphocytes (+17%) and natural killer cells (+12%), while no changes occurred in major lymphocyte populations in the placebo group over the course of the study. Conclusion In this randomised clinical trial, we found that while CD8+ TEMRAs were not significantly altered after 12 months, the telomerase activator TA-65 significantly increased all major lymphocyte subsets and substantially reduced hsCRP at 12 months in patients with MI. These findings suggest TA-65 holds great promise in potentially reducing inflammation while improving an age-related decline in major lymphocyte populations, thereby enhancing immunity. A larger, multicentre, powered phase IIb efficacy trial to examine the potential effect of TA-65 in prognosis and heart function after MI is therefore warranted. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): TA-Science, New York, USA

Early administration of lenalidomide after allogeneic hematopoietic stem cell transplantation suppresses graft-versus-host disease by inhibiting T-cell migration to the gastrointestinal tract.

IntroductionAllogeneic hematopoietic stem cell transplantation (aHSCT) is a curative treatment for hematopoietic malignancies. Graft‐versus‐host disease (GVHD) is a major complication of aHSCT. After transplantation, the balance of immune conditions, such as proinflammatory cytokine level and T‐cell subset count, influences GVHD magnitude. Lenalidomide (LEN) is an immunomodulatory drug used for treating several hematological malignancies such as multiple myeloma, adult T‐cell lymphoma/leukemia, and follicular lymphoma. However, the impact of LEN on immune responses after aHSCT has not been elucidated.MethodsWe analyzed the lymphocyte composition in naïve mice treated with LEN. Subsequently, we treated host mice with LEN, soon after aHSCT, and analyzed GVHD severity as well as the composition and characteristics of lymphocytes associated with GVHD.ResultsUsing a mouse model, we demonstrated the beneficial effects of LEN for treating acute GVHD. Although natural killer cells were slightly increased by LEN, it did not significantly change T‐cell proliferation and the balance of the T‐cell subset in naïve mice. LEN did not modulate the suppressive function of regulatory T cells (Tregs). Unexpectedly, LEN prevented severe GVHD in a mouse acute GVHD model. Donor‐derived lymphocytes were more numerous in host mice treated with LEN than in host mice treated with vehicle. Lymphocyte infiltration of the gastrointestinal tract in host mice treated with LEN was less severe compared to that in host mice treated with vehicle. The percentage of LPAM‐1 (α4β7‐integrin)‐expressing Foxp3−CD4+ T cells was significantly lower in host mice treated with LEN than in host mice treated with vehicle, whereas that of LPAM‐1‐expressing Tregs was comparable.ConclusionsLEN may be useful as a prophylactic agent for acute GVHD‐induced mortality through the inhibition of lymphocyte migration to the gastrointestinal tract. Our data show the effect of LEN on immune responses early after aHSCT and suggest that cereblon, a molecular target of LEN, may be a therapeutic target for preventing acute GVHD‐induced mortality.

Insights into the role of neutrophils in neuropsychiatric systemic lupus erythematosus: Current understanding and future directions.

Central nervous system (CNS) involvement of systemic lupus erythematosus (SLE), termed neuropsychiatric SLE (NPSLE), is a major and debilitating manifestation of the disease. While patients with SLE mostly complain of common neuropsychological symptoms such headache and mild mood disorders that may not even be technically attributed to SLE, many SLE patients present with life-threatening NPSLE syndromes such as cerebrovascular disease, seizures and psychosis that are equally challenging in terms of early diagnosis and therapy. While we are just beginning to unravel some mysteries behind the immunologic basis of NPSLE, advancements in the mechanistic understanding of the complex pathogenic processes of NPSLE have been emerging through recent murine and human studies. The pathogenic pathways implicated in NPSLE are multifarious and various immune effectors such as cell-mediated inflammation, autoantibodies and cytokines including type I interferons have been found to act in concert with the disruption of the blood-brain barrier (BBB) and other neurovascular interfaces. Beyond antimicrobial functions, neutrophils are emerging as decision-shapers during innate and adaptive immune responses. Activated neutrophils have been recognized to be involved in ischemic and infective processes in the CNS by releasing neutrophil extracellular traps (NETs), matrix metalloproteinase-9 and proinflammatory cytokines. In the context of NPSLE, these mechanisms contribute to BBB disruption, neuroinflammation and externalization of modified proteins on NETs that serve as autoantigens. Neutrophils that sediment within the peripheral blood mononuclear cell fraction after density centrifugation of blood are generally defined as low-density neutrophils (LDNs) or low-density granulocytes. LDNs are a proinflammatory subset of neutrophils that are increased with SLE disease activity and are primed to undergo NETosis and release cytokines such as interferon-α and tumor necrosis factor. This review discusses the immunopathogenesis of NPSLE with a focus on neutrophils as a core mediator of the disease and potential target for translational research in NPSLE.

LNA-anti-miR-150 alleviates renal interstitial fibrosis by reducing pro-inflammatory M1/M2 macrophage polarization.

Renal interstitial fibrosis (RIF) is a common pathological feature contributing to chronic injury and maladaptive repair following acute kidney injury. Currently, there is no effective therapy for RIF. We have reported that locked nuclear acid (LNA)-anti-miR-150 antagonizes pro-fibrotic pathways in human renal tubular cells by regulating the suppressor of cytokine signal 1 (SOCS1)/Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. In the present study, we aimed to clarify whether LNA-anti-miR-150 attenuates folic acid-induced RIF mice by regulating this pathway and by reducing pro-inflammatory M1/M2 macrophage polarization. We found that renal miR-150 was upregulated in folic acid-induced RIF mice at day 30 after injection. LNA-anti-miR-150 alleviated the degree of RIF, as shown by periodic acid–Schiff and Masson staining and by the expression of pro-fibrotic proteins, including alpha-smooth muscle actin and fibronectin. In RIF mice, SOCS1 was downregulated, and p-JAK1 and p-STAT1 were upregulated. LNA-anti-miR-150 reversed the changes in renal SOCS1, p-JAK1, and p-STAT1 expression. In addition, renal infiltration of total macrophages, pro-inflammatory M1 and M2 macrophages as well as their secreted cytokines were increased in RIF mice compared to control mice. Importantly, in folic acid-induced RIF mice, LNA-anti-miR-150 attenuated the renal infiltration of total macrophages and pro-inflammatory subsets, including M1 macrophages expressing CD11c and M2 macrophages expressing CD206. We conclude that the anti-renal fibrotic role of LNA-anti-miR-150 in folic acid-induced RIF mice may be mediated by reducing pro-inflammatory M1 and M2 macrophage polarization via the SOCS1/JAK1/STAT1 pathway.