IL-2 Receptor Expression Research Articles

IL-9 and IL-9 receptor expression in lymphocytes from bronchoalveolar lavage fluid of patients with interstitial lung disease

IntroductionIL-9, mainly produced by T helper 9 (Th9) cells, promotes allergic airway inflammation and remodeling through the interaction with its receptor (IL-9R). Th9 cells and IL-9 have also been implicated in tissue fibrosis and autoimmunity pathways. However, the role of IL-9/IL-9R in the pathogenesis of interstitial lung disease (ILD) is unknown. AimTo evaluate IL-9/IL-9R expression in bronchoalveolar lavage fluid (BALF) lymphocytes of patients with various ILDs. MethodsConsecutive patients with ILD, who underwent BAL for diagnostic purposes, were studied. As control group, consecutive patients without evidence of ILD were included. Immunocytochemical staining of BALF lymphocytes for IL-9 and IL-9R was performed and evaluated by two independent readers. Results45 patients, of them 8 had idiopathic pulmonary fibrosis (IPF), 12 nonspecific interstitial pneumonia (NSIP), 10 sarcoidosis, 9 hypersensitivity pneumonitis (HP), 6 cryptogenic organizing pneumonia (COP), and 24 controls were studied. In the ILD group, the highest BALF lymphocyte count was seen in HP followed by NSIP, COP, sarcoidosis, and IPF (p < 0.05 for HP vs IPF). The highest percentages of IL-9 and IL-9R positive lymphocytes were seen in COP. Conversely, NSIP showed the lowest rate of IL-9, and sarcoidosis the lowest rate of IL-9R positive lymphocytes. Only in NSIP, a direct correlation between IL and 9 and IL-9R positive lymphocytes was seen (r = 0.639, p = 0.025). ConclusionBALF lymphocytes IL-9 and IL-9R expression differs between various ILDs and could reflect different pathogenetic mechanisms.

Responses of regulatory and effector T-cells to low-dose interleukin-2 differ depending on the immune environment after allogeneic stem cell transplantation.

CD4+Foxp3+ regulatory T cells (Tregs) play a central role in the maintenance of immune tolerance after allogeneic hematopoietic stem cell transplantation (HSCT). Tregs promptly respond to low concentrations of IL-2 through the constitutive expression of high-affinity IL-2 receptors. It has been reported that low-dose IL-2 therapy increased circulating Tregs and improved clinical symptoms of chronic GVHD. Clinical studies of IL-2 therapy so far have mainly targeted patients in the chronic phase of transplantation when acute immune responses has subsided. However, the biological and clinical effects of exogenous IL-2 in an acute immune environment have not been well investigated. In the current study, we investigated the impact of exogenous IL-2 therapy on the post-transplant homeostasis of T cell subsets which influence the balance between GVHD and GVL in the acute phase, by setting the various immune environments early after HSCT in murine model. We initially found that 5,000 IU of IL-2 was enough to induce the active proliferation of Treg without influencing other conventional T cells (Tcons) when administered to normal mice. However, activated Tcons showed the response to the same dose of IL-2 in recipients after allogeneic HSCT. In a mild inflammatory environment within a threshold, exogenous IL-2 could effectively modulate Treg homeostasis with just limited influence to activated T cells, which resulted in an efficient GVHD suppression. In contrast, in a severely inflammatory environment, exogenous IL-2 enhanced activated T cells rather than Tregs, which resulted in the exacerbation of GVHD. Of interest, in an immune-tolerant state after transplant, exogenous IL-2 triggered effector T-cells to exert an anti-tumor effect with maintaining GVHD suppression. These data suggested that the responses of Tregs and effector T cells to exogenous IL-2 differ depending on the immune environment in the host, and the mutual balance of the response to IL-2 between T-cell subsets modulates GVHD and GVL after HSCT. Our findings may provide useful information in the optimization of IL-2 therapy, which may be personalized for each patient having different immune status.

IL-21R blockade reduces atherosclerosis development in LDLR-/- mice

Background and Aims : Many pro-inflammatory cytokines increase during atherosclerosis and contribute to disease progression. Elevated IL-21 serum levels have been found in CAD patients, but its exact role in atherosclerosis remains unknown. IL-21 is primarily secreted by T-cells and binds to the IL-21 receptor (IL-21R), which is expressed on most lymphoid and myeloid cells. Consequently, IL-21/IL-21R signaling has pleiotropic effects and can cause activation of immune cells but can also inhibit anti-inflammatory Tregs. In this study, we aim to provide further insight into the role of IL-21 in atherosclerosis by blocking the IL-21/IL-21R axis.Methods: First, we confirmed IL-21R expression on many immune cells within the atherosclerotic plaque of Ldlr-/- mice and carotid endarterectomy patients using flow cytometry and scRNAseq. Next, Ldlr-/- mice were fed a Western-type diet for five weeks, during which mice were treated with an IL-21R blocking antibody or an isotype control.Results: IL-21R blockade significantly reduced atherosclerosis development by 38%. This coincided with increased atheroprotective Foxp3 expression within aortic CD4+ T-cells and elevated percentages of CD4+Foxp3+ cells in lymphoid organs (spleen: αIL-21R: 14.02±0.48% vs. ctr: 12.18±0.32%, P <0.01, HLN: αIL-21R: 21.97±1.05% vs. ctr: 18.77±1.06%, P<0.05). Similarly, significantly increased anti-inflammatory IL-10 was observed in serum (αIL-21R: 617.63±156.93 vs ctr: 36.01±29.93 pg/mL, P <0.001) and culture supernatant from splenocytes (αIL-21R: 64.86±10.24 vs ctr: 38.48±5.41 pg/mL, P <0.05) of αIL-21R-treated mice.Conclusions: Collectively, we show that IL-21R blockade reduces atherosclerosis by promoting atheroprotective regulatory T-cell immunity and elevating anti-inflammatory IL-10 production, representing a promising novel therapeutic strategy to extend health span and to combat CVD. Background and Aims : Many pro-inflammatory cytokines increase during atherosclerosis and contribute to disease progression. Elevated IL-21 serum levels have been found in CAD patients, but its exact role in atherosclerosis remains unknown. IL-21 is primarily secreted by T-cells and binds to the IL-21 receptor (IL-21R), which is expressed on most lymphoid and myeloid cells. Consequently, IL-21/IL-21R signaling has pleiotropic effects and can cause activation of immune cells but can also inhibit anti-inflammatory Tregs. In this study, we aim to provide further insight into the role of IL-21 in atherosclerosis by blocking the IL-21/IL-21R axis. Methods: First, we confirmed IL-21R expression on many immune cells within the atherosclerotic plaque of Ldlr-/- mice and carotid endarterectomy patients using flow cytometry and scRNAseq. Next, Ldlr-/- mice were fed a Western-type diet for five weeks, during which mice were treated with an IL-21R blocking antibody or an isotype control. Results: IL-21R blockade significantly reduced atherosclerosis development by 38%. This coincided with increased atheroprotective Foxp3 expression within aortic CD4+ T-cells and elevated percentages of CD4+Foxp3+ cells in lymphoid organs (spleen: αIL-21R: 14.02±0.48% vs. ctr: 12.18±0.32%, P <0.01, HLN: αIL-21R: 21.97±1.05% vs. ctr: 18.77±1.06%, P<0.05). Similarly, significantly increased anti-inflammatory IL-10 was observed in serum (αIL-21R: 617.63±156.93 vs ctr: 36.01±29.93 pg/mL, P <0.001) and culture supernatant from splenocytes (αIL-21R: 64.86±10.24 vs ctr: 38.48±5.41 pg/mL, P <0.05) of αIL-21R-treated mice. Conclusions: Collectively, we show that IL-21R blockade reduces atherosclerosis by promoting atheroprotective regulatory T-cell immunity and elevating anti-inflammatory IL-10 production, representing a promising novel therapeutic strategy to extend health span and to combat CVD.

Artemisia annua L. Aqueous Extract Promotes Intestine Immunity and Antioxidant Function in Broilers.

This study was conducted to investigate the effects of Artemisia annua L. aqueous extract (AAE) on intestinal immune and antioxidative function of broilers. A total of 200 one-day-old Arbor Acre broilers were randomly allotted into five dietary treatment groups, with five replicates per treatment and eight broilers per replicate. The five treatment diets were formulated by adding, respectively, 0 (control group), 0.5, 1.0, 1.5, and 2.0 g/kg AAE in the basal diet. The results showed that dietary inclusion of AAE quadratically decreased interleukin (IL)-1β content, linearly decreased IL-6 content in the small intestine through regulating the nuclear factor-kappa B signal pathway, and quadratically increased immunoglobulin (Ig)M and sIgA content in ileum and jejunum. Besides, there was a quadratic decrease in the gene expression of IL-1β, IL-6, and toll like receptor 4 (TLR4) in ileum on day 21, and the gene expression of IL-6 and TLR4 in duodenum on day 42, thereby improving small intestinal immune function in broilers. Additionally, dietary inclusion of AAE improves antioxidative function through the nuclear factor-erythroid 2-related factor 2 (Nrf2) signal pathway in the small intestinal mucosa of broilers, especially, quadratically increased catalase (CAT) and superoxidase dismutase activity in ileum, and total antioxidant capacity and glutathione peroxidase activity in duodenum, and quadratically decreased malondialdehyde concentration in ileum, besides, linearly increased heme oxygenase-1 and Nrf2 gene expression in jejunum and ileum on day 42, quadratically increased CAT gene expression in the small intestine. Furthermore, regression analyses of the above parameters showed that the optimal dose range of AAE in the diet of broilers was 1.12–1.38 g/kg.

Impact of IL-21-associated peripheral and brain crosstalk on the Alzheimer’s disease neuropathology

Alzheimer’s disease (AD) is associated with dysregulated immune and inflammatory responses. Emerging evidence indicates that peripheral immune activation is linked to neuroinflammation and AD pathogenesis. The present study focuses on determining the role of IL-21 in the pathogenesis of AD using human samples and the 5xFAD mice model. We find that the levels of IL-21 are increased in the periphery of both humans and mice in AD. In addition, the proportions of IL-21 target cells, Tfh and B plasma cells as well as activation of monocytes is increased in PBMCs from AD and mild cognitively impaired (MCI) subjects as compared to age-matched controls, indicating immune activation. In contrast, the percentage of B1 cells that control inflammation is decreased. These changes are due to IL-21 as the expression of IL-21 receptor (IL-21R) is higher on all these cells in AD. Furthermore, treatment with recombinant IL-21 in AD mice also leads to similar alterations in Tfh, B, B1, and macrophages. The effect of IL-21 is not confined to the periphery since increased expression of IL-21R is also observed in both humans and mice hippocampus derived from the AD brains. In addition, mice injected with IL-21 display increased deposition of amyloid beta (Aβ) plaques in the brain which is reduced following anti-IL-21R antibody that blocks the IL-21 signaling. Moreover, activation of microglia was enhanced in IL-21-injected mice. In keeping with enhanced microglial activation, we also observed increased production of pro-inflammatory cytokines, IL-18 and IL-6 in IL-21-injected mice. The microglial activation and cytokines were both inhibited following IL-21R blockage. Altogether, IL-21 escalates AD pathology by enhancing peripheral and brain immune and inflammatory responses leading to increased Aβ plaque deposition.Graphical abstractIL-21 impacts AD neuropathology by enhancing peripheral and neuronal immuneactivation, inflammation, and Aβ plaque deposition. Increased levels of IL-21 in the circulationof AD and MCI subjects enhances the proportions of Tfh and B plasma cells indicative ofperipheral immune activation. On the other hand, the proportions of B1 cells that help reduceinflammation and clear Aβ are reduced. In addition to the periphery, IL-21 also acts on the brainvia IL-21 receptor, IL-21R that displays increased expression in the hippocampi of AD and MCIsubjects. IL-21 enhances the activation of microglia, induces the secretion of pro-inflammatorycytokines and deposition of Aβ plaques in the brain in AD.

Tissue-based IL-10 signalling in helminth infection limits IFNγ expression and promotes the intestinal Th2 response

Type 2 immunity is activated in response to both allergens and helminth infection. It can be detrimental or beneficial, and there is a pressing need to better understand its regulation. The immunosuppressive cytokine IL-10 is known as a T helper 2 (Th2) effector molecule, but it is currently unclear whether IL-10 dampens or promotes Th2 differentiation during infection. Here we show that helminth infection in mice elicits IL-10 expression in both the intestinal lamina propria and the draining mesenteric lymph node, with higher expression in the infected tissue. In vitro, exogenous IL-10 enhanced Th2 differentiation in isolated CD4+ T cells, increasing expression of GATA3 and production of IL-5 and IL-13. The ability of IL-10 to amplify the Th2 response coincided with its suppression of IFNγ expression and in vivo we found that, in intestinal helminth infection, IL-10 receptor expression was higher on Th1 cells in the small intestine than on Th2 cells in the same tissue, or on any Th cell in the draining lymph node. In vivo blockade of IL-10 signalling during helminth infection resulted in an expansion of IFNγ+ and Tbet+ Th1 cells in the small intestine and a coincident decrease in IL-13, IL-5 and GATA3 expression by intestinal T cells. These changes in Th2 cytokines correlated with reduced expression of type 2 effector molecules, such as RELMα, and increased parasite egg production. Together our data indicate that IL-10 signalling promotes Th2 differentiation during helminth infection at least in part by regulating competing Th1 cells in the infected tissue.

EOSINOPHILIC AND NEUTROPHILIC CYTOKINES AND RECEPTOR EXPRESSION IN PATIENTS WITH ASTHMA AND FIXED AIRFLOW LIMITATION

TYPE: Late Breaking Abstract TOPIC: Allergy and Airway PURPOSE: To compare the differential T2 and non-T2 cytokines receptor expression in asthmatic patients with FAL (FEV1 <70%) and without FAL METHODS: The descriptive study was conducted from 2020 to 2022. Eosinophils, neutrophils, ILC2, Th2, Th17 were counted by flow cytometry. Receptor expression on inflammatory cells (IL-4R, IL-5R, CXCR1, IL-17R) was measured. RESULTS: A total of 87 asthmatic patients with FAL (n =36) and without FAL (n = 44) were enrolled, and healthy subjects (n=7). The post-BD FEV1 % predicted in asthma with FAL and without FAL were 57.9% and 86% (P < 0.01). Asthma with FAL has a higher median blood eosinophil counts than those without FAL and healthy subjects. The IL-5 receptors and IL4R expression on eosinophils in asthma with and without FAL were not different. The increased IL17 receptor expression on neutrophils were noted in asthmatic regardless of FAL compared to healthy subjects (78 % [75-95] vs 76 % [66-95] vs 44 % [5-77], p=0.018). CXCR1 expression on neutrophils was not different between asthma groups. CONCLUSIONS: T2 inflammatory cells and T2 cytokine receptor expression were not different among asthma regarding FAL. The expression of the IL-17 receptor on neutrophils is the underlying pathobiology of asthma with FAL. CLINICAL IMPLICATIONS: Identification of the endotype and the potential target therapy of asthma with FAL. DISCLOSURE: No significant relationships. KEYWORD: Asthma

A Notch/IL-21 signaling axis primes bone marrow T cell progenitor expansion.

Long-term impairment in T cell–mediated adaptive immunity is a major clinical obstacle following treatment of blood disorders with hematopoietic stem cell transplantation. Although T cell development in the thymus has been extensively characterized, there are significant gaps in our understanding of prethymic processes that influence early T cell potential. We have uncovered a Notch/IL-21 signaling axis in bone marrow common lymphoid progenitor (CLP) cells. IL-21 receptor expression was driven by Notch activation in CLPs, and in vivo treatment with IL-21 induced Notch-dependent CLP proliferation. Taking advantage of this potentially novel signaling axis, we generated T cell progenitors ex vivo, which improved repopulation of the thymus and peripheral lymphoid organs of mice in an allogeneic transplant model. Importantly, Notch and IL-21 activation were equally effective in the priming and expansion of human cord blood cells toward the T cell fate, confirming the translational potential of the combined treatment.

Role of Grail in intestinal inflammation

Abstract Intestinal homeostasis depends on interaction between the microbiota and host immune system, and disruption of this balance results in predominance of inflammatory responses leading to inflammatory bowel disease. However, to date, precise cell-intrinsic regulatory mechanisms that controls intestinal inflammation are poorly understood. Here we show that expression of the E3 ubiquitin ligase Grail is diminished in colon tissues of mice with colitis and Grail deficiency leads to increased susceptibility to colitis. Importantly, Grail deficiency disrupted pro-/anti-inflammatory balance towards inflammatory immune responses at the steady state and during colitis. Mechanistically, loss of Grail intrinsically diminished the expression of IL-10 and IL-10 receptor (IL-10R) by adaptive and innate immune cells in colonic mucosa. Besides the intestinal immunity, Grail deficiency leads to a decrease in microbial diversity and an enrichment of pro-inflammatory microbiota. Thus, Grail plays a protective role during intestinal inflammation by supporting regulatory immune responses and shaping the microbiota.

Exacerbated Vascular Inflammation Following Traumatic Hemorrhage in Obese Rats

IntroductionObesity increases the risk for morbidity and mortality in trauma patients. These complications are associated with prolonged tissue hypoperfusion, hypercoagulability, and edema that reflect profound vascular damage. Traumatic hemorrhage acutely attenuates vascular responsiveness, but the degree of this dysfunction during the obese state is not known. Traumatic hemorrhage also increases circulating inflammatory cytokines; however, the local inflammatory response in vascular cells is unknown. We hypothesized that obesity potentiates trauma‐induced vascular inflammation and dysfunction.MethodsMale Sprague‐Dawley rats (~250g) fed either normal chow (NC; 13.5% kcal fat, n=20), moderate‐fat (MF; 33% kcal fat, n=20), or high‐fat (HF; 60% kcal fat, n=20) diet for 6‐8 weeks were assigned to a traumatic hemorrhage protocol or sham control. Under anesthesia, hemorrhage was induced by the laceration of a mesenteric artery and a Grade V splenic injury. Hypotension (mean arterial pressure = 30–40 mm Hg) was maintained for 30 minutes. Vasoconstrictor and vasodilator properties were assessed ex vivo in isolated mesenteric arteries pre‐ and post‐ hemorrhage. Carotid arteries collected after hemorrhage or sham control were flushed with trizol to collect endothelial cells (ECs). Gene expression was assessed in ECs and the remaining carotid artery (media + adventitia) cells for pro‐inflammatory interleukin (IL)‐1β, and IL‐6, pro‐oxidant NADPH oxidase 2 (NOX2), and α‐adrenergic receptor.ResultsIn NC rats, hemorrhage attenuated norepinephrine‐induced vasoconstriction and endothelium‐dependent dilation. This was accompanied by elevated IL‐1β expression in carotid artery ECs and elevated IL‐1β, IL‐6, NOX2, and α‐adrenergic receptor expression in the carotid artery media + adventitia post‐hemorrhage versus sham control. In MF and HF rats, norepinephrine‐induced vasoconstriction and endothelium‐dependent dilation did not change pre‐ to post‐hemorrhage. In sham animals, endothelial cell IL‐1β and NOX2 expression were higher in HF compared with NC rats. Similar to NC rats, the MF and HF rats had higher IL‐1β expression in carotid artery ECs, and IL‐1β, IL‐6, NOX2, and α‐adrenergic receptor expression in the carotid artery media + adventitia post‐hemorrhage compared with sham. The hemorrhage‐induced elevation of IL‐1β in carotid artery ECs and media + adventitia was greater in HF rats compared with NC and MF rats.ConclusionOur clinically‐relevant model of traumatic hemorrhage attenuates vascular responsiveness and induces vascular inflammation. The attenuated vascular responsiveness following hemorrhage is absent in MF and HF rats, while the elevated vascular inflammation persists. HF rats have an amplified arterial inflammatory response to hemorrhage, both in ECs and in cells of the media + adventitia. The augmented vascular inflammatory response to hemorrhage in HF rats may explain the worse outcomes in obese trauma patients.

Early heterogeneity of IL2R□ expression influences the programming of exhausted CD8T cells during chronic infection

Abstract IL-2 signaling at the time of CD8 T cell activation is a critical factor dictating effector and memory CD8 T cell differentiation. However, how IL-2 signaling impacts exhausted CD8 T cell fate outcomes remains poorly defined. Here, we address the role of IL-2 signaling in regulating the differentiation of the stem-like and terminally exhausted CD8 T cells. Prolonged expression of the high affinity IL-2 receptor (IL-2Ra, CD25), and resultant increase in IL-2 signaling drives terminal differentiation of effector cells during acute infection. We hypothesized that curtailing this signal would prevent terminal differentiation and promote the formation of less exhausted stem-cell like TCF-1+CD8T cells in chronic antigenic setting. Our studies show that blocking IL-2 signals at the early phase of chronic infection significantly increased the proportions of TCF-1+CD8T cells. Similarly, knocking down Il2ra augmented the development of TCF-1+CD8T cells. The therapeutic success of PD-1/PD-L1 checkpoint blockade immunotherapy (CBI) relies primarily on stem-cell like cells for vigorous expansion and effector responses. Thus, we next investigated how FACS-purified CD25Hi and CD25Lo cells adoptively transferred into infection-matched chronically infected recipients respond to PD-1 CBI. In contrast to CD25Hi cells, CD25Lo cells underwent vigorous proliferation after PD-1 CBI and produced high amount of effector molecules (GzmB, TNF-α and IFN-γ). Collectively, these data highlight the role of IL-2 signaling in the regulation of CD8 T cell exhaustion, which may be therapeutically exploited to optimize treatments of chronic infections and cancers with immune checkpoint inhibitors. Supported by NIH R21AI154363 NIH R01AI32819

IL-10 Signaling in T Cells is Essential for Transplant Tolerance Induction

Abstract Costimulation blockade (CoB)-based immunotherapy is a promising approach for transplant recipients yet to be realized. Elucidating which factors impact the efficacy of CoB is a necessary step to enable clinical applicability. In this regard, pro- and anti-inflammatory cytokines are being recognized as having an impact on T cell activation beyond effector differentiation. We then aimed at elucidating the role that direct IL-10 signaling in T cells has on the outcome of CoB. We employed a mouse skin transplt model were Balb/c skin was transplanted to wt C57BL/6 (B6) mice or to B6 with T cell-restricted expression of a dominant negative IL-10 receptor (10R-DN). Recipients received peri-transplant donor specific infusion and three weekly anti-CD154 mAb doses. Unmanipulated 10R-DN recipients rejected their transplant with dynamics identical to wt B6. However, differently from wt B6, graft survival in 10R-DN could not be promoted by CoB (MST 105d vs 30d in the latter) revealing a novel and important effect of IL-10 on T cells. This accelerated rejection correlated with increased production of TNF-α, IFN-γ and IL-17 by T cells in draining lymphoid tissues. MLR experiments indicated that despite IL-10 signaling is not involved in the ability of anti-CD154 to modulate alloreactive T cell proliferation, absence of this pathway increased the differentiation of TH1 effector cells. Moreover, the same experiments indicated that lack of IL-10 signaling in T cells impaired induction of Tregs. Overall, our results reveal previously unappreciated roles of IL-10 signaling in T cells that represent potential “Achille’s Heels” in the successful implementation of CoB and suggest complementary interventions for the actuation of robust immunoregulation. Supported by a grant from JDRF (2-SRA-2016-304-S-B)

B Cells Specific CpG Induces High IL-10 and IL-6 Expression In Vitro in Neuro-Behçet's Disease.

Remitting-RelapsingMultiple Sclerosis (RRMS) and Neuro-Behçet Disease (NBD) are two chronic neuroinflammatory disorders leading to neurological damage. Herein, we investigated in these patients the IL-10-producing cells during the early stages of these disorders. Cellular and molecular investigations were carried out on treatment naive patients suffering from RRMS and NBD recruited at the first episode of clinical relapse. Our findings demonstrate that CSF-B cells from NBD patients, but not RRMS, are the major source of intrathecal IL-10 as compared to T-CD4 cells. Moreover, we showed a lower expression of TGF-β and IL35, in the CSF cells of NBD patients as compared to the control group. Specific in vitro CpG stimulation of peripheral blood B cells from NBD patients resulted in a concomitant early mRNA expression of IL6 and IL10 but was limited to IL10 for RRMS patients. Furthermore, mRNA expression of IL-6 and IL-10 receptors was assessed and intriguingly IL6ST receptor subunit was significantly lower in NBD CSF, but not RRMS while IL10RB was increased in both. Deciphering the role of increased IL-10-producing B cells and IL10RB despite relapsing disease as well as the discordant expression of IL6 and IL6ST may pave the way for a better understanding of the pathophysiology of these neuro-inflammatory disorders.

Th17 Cells Participate in Thy1.1 Glomerulonephritis Which Is Ameliorated by Tacrolimus

Introduction: Thy1.1 glomerulonephritis (Thy1.1 GN) in rats is widely used as an experimental model of mesangial proliferative glomerulonephritis (GN). We previously reported that T-helper (Th) cells were accumulated in glomeruli from the early phase of this model and that not Th2 cells but Th1 cells play an important role in the development of glomerular alterations. Although Th17 is reported to be involved in the pathogenesis of several autoimmune diseases, the role of Th17 cells in the pathogenesis of mesangial alterations in Thy1.1 GN remains unclear. Methods: The kinetics of the infiltration of subsets of Th cells and the expression of IL-17 in Thy1.1 GN were analyzed. Next, the localization and the cell types of IL-17 receptor (IL-17R)-positive cells and IL-6-positive cells were analyzed. Then, the effect of tacrolimus on the expressions of Th17-related cytokines in Thy1.1 GN was analyzed. Results: Not only Th1 cells but also Th17 cells were recruited into glomeruli from the early phase of the disease. mRNA expression of IL-17 in glomeruli was elevated. The increased positive expression of IL-17R was detected in the mesangial area, and some of IL-17R-positive cells were co-stained with IL-6. Tacrolimus treatment ameliorated mesangial alterations by suppressing the expressions of Th17-related cytokines such as IL-17 and IL-6. Conclusion: Th17 cells participate in the development of Thy1.1 GN, a mimic of mesangial proliferative GN, and Th17 cells and their related cytokines are pertinent therapeutic targets.

Association between IL-7 and primary Sjögren's syndrome: A single-center study and a systematic scoping review

BackgroundThere is a lack of single marker reflecting systemic activity of primary Sjögren's syndrome (pSS). Our aim is to determine the association between interleukin(IL)-7 and pSS by combining a single-center study and a systematic scoping review. MethodsThere were 58 patients with pSS and 30 healthy controls (HCs) included in the single-center study. The multiplex immunoassay was used for detecting concentrations of IL-7, IL-4, IL-9, IL-10, IL-17, interferon(IFN) -γ, INF-α and INF-β in sera. pSS patients were evaluated for systemic activity in accordance with the European League against Rheumatism SS Disease Activity Index (ESSDAI). In the systematic scoping review, all studies regarding association of IL-7 with pSS were included. ResultspSS patients showed higher serum IL-7 levels (P = 0.028 vs HCs) which were associated with neutrophil, neutrophil-to-lymphocyte ratio(NLR), platelet-to-lymphacyte ratio(PLR), red blood cell distribution width(RDW), erythrocyte sedimentation rate(ESR), immunoglobulin(Ig)G, C-reactive protein (CRP), fever, lymphadenopathy and ESSDAI. Serum IL-7 correlated with Th cell related cytokines. Findings of the systematic scoping review on 15 articles were as follows. Firstly, IL-7 expression in salivary glands (SGs), serum and saliva increased in pSS, while IL-7 receptor(IL-7R) expression increased in SGs but decreased in peripheral blood. Secondly, increased IL-7 was mainly from SGs of pSS patients, but whether IL-7 was mainly produced by SG epithelial cells remained to be validated. Thirdly, IL-7 could exert a key role in pSS immunopathology. Although IL-7 had no direct effect on SGECs, it could activate B and T cells and stimulate secretion of IL-17, IL-4 and IFNs. ConclusionNot only are IL-7 and soluble IL-7R potential biomarkers for monitoring pSS activity, but also targeting IL-7/IL-7R pathway may be a promising therapeutic strategy.

Dexmedetomidine Activates Akt, STAT6 and IRF4 Modulating Cytoprotection and Macrophage Anti-Inflammatory Phenotype Against Acute Lung Injury in vivo and in vitro.

PurposeThis study aims to investigate the cytoprotective and anti-inflammatory effects of an α2-adrenoreceptor (α2-AR) agonist, dexmedetomidine (Dex), on lipopolysaccharides (LPS)-induced acute lung injury and underlying mechanisms with focus on alveolar macrophage polarization modulation.MethodsC57BL/6 mice were intraperitoneally injected LPS (10 mg/kg) with or without Dex (25 µg/kg) and/or α2-AR antagonist atipamezole (Atip, 500 µg/kg). Lung tissues were then analysed to determine injuries. In vitro, human pulmonary epithelial cells (A549) and mice alveolar macrophages (MH-S) were exposed to LPS (10 ng/mL) with or without different concentrations of Dex (0.1–100 nM). Alveolar macrophage polarization, NLRP3 inflammasome activation and inflammatory responses were determined. PTEN/Akt signaling and its downstream transcriptional factors as targets for macrophage polarization were assessed.ResultsDex treatment significantly reduced pro-inflammatory M1 macrophage polarization and NLRP3 inflammasome activation in the lungs relative to the mice treated with LPS. The similar pattern reduction of NLRP3 inflammasome activation by Dex was also found in A549 cells. Atip partly reversed the anti-inflammatory effects of Dex. In cultured alveolar macrophages, Dex reduced LPS-mediated expression of IL-1, −6 and TNF-α receptors while promoting alveolar macrophages differentiation towards a M2 anti-inflammatory phenotype. Additionally, LPS increased Akt signaling activation in a time-dependent manner, which was further activated by Dex via inhibiting phosphatase and tensin homolog (PTEN). The action of Dex on Akt signaling shifted alveolar macrophages from M1 to M2 phenotype through increasing STAT6 and IRF4 transcriptional factors.ConclusionDex protected against LPS-induced lung injury and suppressed LPS-induced pulmonary inflammatory responses by attenuating the NLRP3 inflammasome activation and promoting anti-inflammatory M2 macrophage polarization.

Cytokine-induced transient monocyte IL-7Ra expression and the serum milieu in tuberculosis.

Bacterial components and cytokines induce IL-7 receptor (IL-7Rα) expression in monocytes. Aberrant low IL-7Rα expression of monocytes has been identified as a feature of tuberculosis immunopathology. Here, we investigated the mechanisms underlying IL-7Rα regulation of monocytes and tuberculosis serum effects on IL-7Rα expression. Serum samples from tuberculosis patients and healthy controls, cytokine candidates, and mycobacterial components were analyzed for in vitro effects on IL-7Rα expression of primary monocytes, monocyte-derived macrophages (MDM), and monocyte cell lines. IL-7Rα regulation during culture and the role of FoxO1 were characterized. In vitro activation-induced IL-7Rα expression in human monocytes and serum samples from tuberculosis patients boosted IL-7Rα expression. Although pathognomonic tuberculosis cytokines were not associated with serum effects, we identified cytokines (i.e., GM-CSF, IL-1β, TNF-α, IFN-γ) that induced IL-7Rα expression in monocytes and/or MDM comparable to mycobacterial components. Blocking of cytokine subsets (i.e., IL-1β/TNF-α in monocytes, GM-CSF in MDM) largely diminished IL-7Rα expression induced by mycobacterial components. Finally, we showed that in vitro-induced IL-7Rα expression was transient and dependent on constitutive FoxO1 expression in primary monocytes and monocyte cell lines. This study demonstrated the crucial roles of cytokines and constitutive FoxO1 expression for transient IL-7Rα expression in monocytes.

Lenabasum Reduces Porphyromonas gingivalis-Driven Inflammation.

The aim of this study was to evaluate the potential anti-inflammatory and anti-resorptive effects of lenabasum in the context of Porphyromonas gingivalis (Pg)-induced inflammation. Lenabasum or ajulemic acid (1',1'-dimethylheptyl-THC-11-oic-acid), a synthetic analog of THC-11-oic acid, has already demonstrated anti-inflammatory properties for the treatment of several inflammatory diseases. In vitro, the cytocompatibility of lenabasum was evaluated in human oral epithelial cells (EC), oral fibroblasts and osteoblasts by metabolic activity assay. The effect of lenabasum (5µM) treatment of Pg-LPS- and P. gingivalis-infected EC on the pro- and anti-inflammatory markers was studied through RTqPCR. In vivo, lenabasum was injected subcutaneously in a P. gingivalis-induced calvarial abscess mouse model to assess its pro-healing effect. Concentrations of lenabasum up to 5µM were cytocompatible in all cell types. Treatment of Pg-LPS and Pg-infected EC with lenabasum (5µM; 6h) reduced the gene expression of TNF-α, COX-2, NF-κB, and RANKL, whereas it increased the expression of IL-10 and resolvin E1 receptor respectively (p < 0.05). In vivo, the Pg-elicited inflammatory lesions' clinical size was significantly reduced by lenabasum injection (30µM) vs untreated controls (45%) (p < 0.05). Histomorphometric analysis exhibited improved quantity and quality of bone (with reduced lacunae) and significantly reduced calvarial soft tissue inflammatory score in mice treated with lenabasum (p < 0.05). Tartrate-resistant acid phosphatase activity assay (TRAP) also demonstrated decreased osteoclastic activity in the treatment group compared to that in the controls. Lenabasum showed promising anti-inflammatory and pro-resolutive properties in the management of Pg-elicited inflammation, and thus, its potential as adjuvant periodontal treatment should be further investigated.

Cure of syngeneic carcinomas with targeted IL-12 through obligate reprogramming of lymphoid and myeloid immunity.

Therapeutic IL-12 has demonstrated the ability to reduce local immune suppression in preclinical models, but clinical development has been limited by severe inflammation-related adverse events with systemic administration. Here, we show that potent immunologic tumor control of established syngeneic carcinomas can be achieved by i.t. administration of a tumor-targeted IL-12 antibody fusion protein (NHS–rmIL-12) using sufficiently low doses to avoid systemic toxicity. Single-cell transcriptomic analysis and ex vivo functional assays of NHS–rmIL-12–treated tumors revealed reinvigoration and enhanced proliferation of exhausted CD8+ T lymphocytes, induction of Th1 immunity, and a decrease in Treg number and suppressive capacity. Similarly, myeloid cells transitioned toward inflammatory phenotypes and displayed reduced suppressive capacity. Cell type–specific IL-12 receptor–KO BM chimera studies revealed that therapeutic modulation of both lymphoid and myeloid cells is required for maximum treatment effect and tumor cure. Study of single-cell data sets from human head and neck carcinomas revealed IL-12 receptor expression patterns similar to those observed in murine tumors. These results describing the diverse mechanisms underlying tumor-directed IL-12–induced antitumor immunity provide the preclinical rationale for the clinical study of i.t. NHS–IL-12.

IL-3 Expands Pre-Basophil and Mast Cell Progenitors by Upregulating the IL-3 Receptor Expression

Basophils and mast cells play a critical role in allergic inflammation and provide protective immunity against certain types of parasitic infections. Expansion of basophils and mast cells to the critical numbers is believed to be an essential step in enabling basophils and mast cells to carry out their protective functions. However, factors that drive basophil and mast cell expansion are still incompletely understood. We tested the roles of cytokines and growth factors IL-3, TSLP, GM-CSF, IL-5, SCF, IL-7, IL-25, and IL-33 in promoting the differentiation of pre-basophil and mast cell progenitors (pre-BMPs)in vitro.We found that while GM-CSF only expanded basophils, IL-3 promoted the differentiation of pre-BMPs into both basophils and mast cells. We found that IL-3 expanded the number of pre-BMPsin vivo. We showed that IL-3 upregulatedIl3ramRNA and protein expression on pre-BMPs, supporting that IL-3 expands pre-BMPs in part by upregulating the IL-3 receptor expression. Although Gata2 mRNA expression was upregulated by IL-3 treatment in pre-BMPs, it is dispensable for IL-3-mediated upregulation of IL-3 receptor expression. Our study reveals a novel mechanism through which IL-3 expands basophil and mast cells.