IL-2 Receptor Expression Research Articles

Preclinical evidence for preventive and curative effects of resveratrol on xenograft cholangiocarcinogenesis

Cholangiocarcinoma (CCA), the malignant tumor of bile duct epithelial cells, is a relatively rare yet highly lethal cancer. In this work, we tested the ability of Resveratrol (RV) to prevent and cure CCA xenograft in nude mice and investigated molecular mechanisms underpinning such anticancer effect. Human CCA cells were xenografted in mice that were or not treated prior to or after to transplantation with RV. Tumor growth was monitored and analyzed for the markers of cell proliferation, apoptosis, and autophagy. TCGA was interrogated for the molecules possibly targeted by RV. RV could inhibit the growth of human CCA xenograft when administered after implantation and could reduce the growth or even impair the implantation of the tumors when administered prior the transplantation. RV inhibited CCA cell proliferation, induced apoptosis with autophagy, and strongly reduced the presence of CAFs and production of IL-6. Interrogation of CCA dataset in TCGA database revealed that the expression of IL-6 Receptor (IL-6R) inversely correlated with that of MAP-LC3 and BECLIN-1, and that low expression of IL-6R and of MIK67, two pathways downregulated by RV, associated with better survival of CCA patients. Our data demonstrate that RV elicits a strong preventive and curative anticancer effect in CCA by limiting the formation of CAFs and their release of IL-6, and this results in up-regulation of autophagy and apoptosis in the cancer cells. These findings support the clinical use of RV as a primary line of prevention in patients exposed at risk and as an adjuvant therapeutics in CCA patients.

P2Y1 and P2Y2 receptors differ in their role in the regulation of signaling pathways during unloading-induced rat soleus muscle atrophy

The current study aimed to investigate the hypothesis that purinergic receptors P2Y1 and P2Y2 play a regulatory role in gene expression in unloaded muscle. ATP is released from cells through pannexin channels, and it interacts with P2Y1 and P2Y2 receptors, leading to the activation of markers of protein catabolism and a reduction in protein synthesis. To test this hypothesis thirty-two rats were randomly divided into four groups (8 per group): a non-treated control group (C), a group subjected to three days of hindlimb unloading with a placebo (HS), a group subjected to three days of hindlimb unloading treated with a P2Y1 receptor inhibitor, MRS2179 (HSM), and a group subjected to three days of hindlimb unloading treated with a P2Y2 receptor inhibitor, AR-C 118925XX (HSA). This study revealed several key findings following three days of soleus muscle unloading: 1Inhibition of P2Y1 or P2Y2 receptors prevented the accumulation of ATP, the increase in IP3 receptor content, and the decrease in the phosphorylation of GSK-3beta. This inhibition also mitigated the reduction in the rate of protein synthesis. However, it had no significant effect on the markers of mTORC1-dependent signaling. 2Blocking P2Y1 receptors prevented the unloading-induced upregulation of phosphorylated p38MAPK and partially reduced the increase in MuRF1mRNA expression. 3Blocking P2Y2 receptors prevented muscle atrophy during unloading, partially maintained the levels of phosphorylated ERK1/2, reduced the increase in mRNA expression of MAFbx, ubiquitin, and IL-6 receptor, prevented the decrease in phosphorylated AMPK, and attenuated the increase in phosphorylated p70S6K.Taken together, these results suggest that the prevention of muscle atrophy during unloading, as achieved by the P2Y2 receptor inhibitor, is likely mediated through a reduction in catabolic processes and maintenance of energy homeostasis. In contrast, the P2Y1 receptor appears to play a relatively minor role in muscle atrophy during unloading.

IL-6 Receptor Expression on the Surface of T Cells and Serum Soluble IL-6 Receptor Levels in Patients with Microscopic Polyangiitis and Granulomatosis with Polyangiitis.

We investigated the IL-6 receptor (IL-6R) expression on the surface of T cells isolated from peripheral blood mononuclear cells (PBMCs) of microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) patients and measured the serum soluble IL-6R (sIL-6R) levels in these patients. Sera and PBMCs were obtained from 51 patients with MPA (n = 32) and GPA (n = 19), with 25 patients having active disease (defined as a Birmingham Vasculitis Activity Score [BVAS] ≥ 5). The median age of patients was 67.0 years, and 52.9% were women. Serum IL-6 levels were significantly correlated with the BVAS (r = 0.384); however, IL-6R expression on the surface of T cells did not significantly differ based on disease activity. Meanwhile, IL-6R expression on the surface of stimulated CD4+ (median mean fluorescence intensity [MFI] 588.0 vs. 1314.8; p < 0.001), CD4+CD25+ (MFI 853.3 vs. 1527.3; p < 0.001), and CD4+CD45RO+ (MFI 679.5 vs. 1241.5; p < 0.001) T cells was significantly reduced compared with unstimulated conditions. Conversely, patients with active disease exhibited a significantly higher median serum sIL-6R level than those with inactive disease (38.1 ng/mL vs. 34.7 ng/mL; p = 0.029). These results imply that the trans-signalling IL-6 pathway may be more activated than the classical signalling pathway in patients with MPA and GPA, suggesting the therapeutic potential of targeting sIL-6R.

IL-4 and IL-13 induce equivalent expression of traditional M2 markers and modulation of reactive oxygen species in human macrophages

In cardiovascular disease, pathological and protective roles are reported for the Th2 cytokines IL-4 and IL-13, respectively. We hypothesised that differential effects on macrophage function are responsible. Type I and II receptor subunit (IL-2Rγ, IL-4Rα and IL-13Rα1) and M2 marker (MRC-1, CCL18, CCL22) expression was assessed via RT-qPCR in IL-4- and IL-13-treated human primary macrophages. Downstream signalling was evaluated via STAT1, STAT3 and STAT6 inhibitors, and IL-4- and IL-13-induced reactive oxygen species (ROS) generation assessed. IL-4 and IL-13 exhibited equivalent potency and efficacy for M2 marker induction, which was attenuated by STAT3 inhibition. Both cytokines enhanced PDBu-stimulated superoxide generation however this effect was 17% greater with IL-4 treatment. Type I IL-4 receptor expression was increased on M1-like macrophages but did not lead to a differing ability of these cytokines to modulate M1-like macrophage superoxide production. Overall, this study did not identify major differences in the ability of IL-4 and IL-13 to modulate macrophage function, suggesting that the opposing roles of these cytokines in cardiovascular disease are likely to be via actions on other cell types. Future studies should directly compare IL-4 and IL-13 in vivo to more thoroughly investigate the therapeutic validity of selective targeting of these cytokines.

Differential effects of heart failure with reduced ejection fraction on locomotor and respiratory muscles

Abstract Background Muscle weakness impairs quality-of-life, exercise capacity, and survival in patients with heart failure and reduced left ventricular ejection fraction (HFrEF). However, the effects on systemic concentrations and local expression of inflammatory cytokines and myokines as well as metabolic markers might differ between locomotor and respiratory muscles. Purpose We prospectively evaluated clinical, functional, and molecular alterations of the diaphragm and the M. vastus lateralis (MVL) from HFrEF patients receiving a left ventricular assist device compared to patients without heart failure undergoing elective coronary bypass grafting (control). Methods Participants (Controls=21, HFrEF=18) underwent cardiopulmonary exercise and respiratory and leg muscle testing. Serum concentrations and local expression of inflammatory cytokines and myokines as well as key enzymes of metabolic pathways were examined in biopsies of the diaphragm and MVL. Results Exercise capacity, respiratory muscle function and endurance force of locomotor muscles were significantly reduced in HFrEF compared with controls (all p&amp;lt;0.05). The serum concentration of Il-6, Il-1beta and TNF-alpha were significantly higher or solely detectable in HFrEF compared with controls. Local mRNA expression of Il-6 was not different in MVL but 2.2-fold higher in the diaphragm of HFrEF compared with controls (p=0.013). In contrast, mRNA expression of Il-6 receptor was significantly reduced by 38% (p=0.004) in MVL of HFrEF compared with controls but comparable in the diaphragm. Serum concentrations of FGF-21 and Musclin were significantly higher in HFrEF compared with controls (all p&amp;lt;0.05). Local mRNA expression of FGF-21 was significantly lower in both MVL and diaphragm of HFrEF compared with controls. FGF-21 receptor 1 mRNA expression was reduced by 18% in the MVL of HFrEF (p=0.02), whereas co-receptor klotho was comparable to controls. In the diaphragm, FGF-21 receptor 1 mRNA expression was comparable between HFrEF and controls, but the co-receptor klotho had a 5-fold higher mRNA expression in HFrEF (p=0.002). We examined the activity of key enzymes of glucose, lipid and ketone metabolism as well as key enzymes of the Krebs cycle. The main differences were found for ß-hydroxyacyl-CoA Dehydrogenase in the diaphragm with a 1.6-fold higher activity in HFrEF compared with controls (p=0.01) and for succinyl-CoA: 3-ketoacid-coenzyme A transferase in the MVL with a 2-fold higher activity in HFrEF compared with controls (p&amp;lt;0.01) indicating a main utilization of lipids in the diaphragm and of ketones in the MVL for energy supply. Conclusions HFrEF induced divergent effects on inflammatory markers, myokine expression and metabolic parameters in locomotor and respiratory muscles in HFrEF patients compared with controls. This indicates that different molecular alterations contribute to locomotor/respiratory muscle dysfunction and reduced whole-body exercise capacity.

IL6 suppresses vaccine responses in neonates by enhancing IL2 activity on T follicular helper cells

The inability of neonates to develop CD4+FoxP3-CXCR5hiPD-1hi T follicular helper (TFH) cells contributes to their weak vaccine responses. In previous studies, we measured diminished IgG responses when IL-6 was co-injected with a pneumococcal conjugate vaccine (PCV) in neonatal mice. This is in sharp contrast to adults, where IL-6 improves vaccine responses by downregulating the expression of IL-2Rβ on TFH cells and protecting them from the inhibitory effect of IL-2. In this study, we found that splenic IL-6 levels rapidly increased in both adult and neonatal mice following immunization, but the increase in neonatal mice was significantly more than that of adult mice. Moreover, immunized neonatal TFH cells expressed significantly more IL-2 as well as its receptors, IL-2Rα and IL-2Rβ, than the adult cells. Remarkably, IL-6 co-injection with PCV vaccine further increased the production of IL-2 and the expression of its receptors by neonatal TFH cells, whereas excess IL-6 had totally opposite effect in immunized adult mice. Underscoring the role of IL-6 in activating the IL-2 mediated suppression of vaccine responses, immunization of IL-6 knock-out neonates led to improved antibody responses accompanied by expanded TFH cells as well as lower levels of IL-2 and IL-2 receptors on TFH cells. Moreover, CpG containing PCV improved TFH response in neonates by suppressing the expression of IL-2 receptors on TFH cells and inhibiting IL-2 activity. These findings unveil age-specific differences in IL-6 mediated vaccine responses and highlight the need to consider age-related immunobiological attributes in designing vaccines.

Multiple Myeloma with 1q Gain/Amplification Shows Reduced CD38 Expression Via IL-6R Overexpression

Background: The anti-CD38 monoclonal antibody daratumumab (Dara) significantly improves the outcomes of patients with multiple myeloma (MM). However, chromosome 1q21 gain/amplification (1q+) has been reported to be associated with poor outcomes in patients with relapsed/refractory MM treated with Dara. A recent subgroup analysis of the MAIA study showed that 1q amplification was associated with poor prognosis, even in newly diagnosed patients (Moreau et al. ASH 2022). However, the underlying mechanism of this resistance remains unclear. Aim and Methods: To elucidate the mechanism of Dara resistance in 1q+ MM cells, we focused on CD38 regulation in 1q+ MM. We examined CD38 expression in primary MM cells of 89 patients with newly diagnosed MM. CD38 expression levels were determined as the mean fluorescence intensity (MFI) using flow cytometry (FCM). FCM was performed using the DURAClone RE PC antibody panel on a Navios cytometer, and the data were analyzed using Kaluza analysis software. The CD38 MFI was assessed in the neoplastic plasma cell population (CD38+/CD138+/CD56+ or CD56−/CD19−). The presence of 1q+ was evaluated using interphase fluorescence in situ hybridization (iFISH) in CD138-purified bone marrow plasma cells with a 30% cutoff. Patients with three copies of 1q21 were defined as having a 1q gain, whereas patients with at least four copies were defined as having a 1q amplification. For functional analysis, we employed three human myeloma cell lines (HMCLs) with 1q+ (H929, MOLP8, and MM.1S) and three HMCLs with 1q wild type (WT) (KMS12BM, SKMM2, and NCU-MM1). Results: We found that 1q+ MM cells showed significantly lower CD38 expression than 1q WT MM cells in our primary samples. Furthermore, we found that isolated 1q+ MM without other high-risk cytogenetic abnormalities showed significantly lower CD38 expression than 1q WT MM. We also found that patients with 1q amplification had significantly lower CD38 expression than those with 1q gain. To elucidate the mechanism of CD38 downregulation, we focused on the IL-6 receptor (IL-6R) located on chromosome 1q21 because IL-6-mediated JAK/STAT activation has been shown to regulate CD38 expression. Indeed, as the copy number of 1q increased, the expression of IL-6R also increased in our primary samples. Using published datasets, we also confirmed that 1q21 status is closely associated with IL-6R levels. Furthermore, a significant negative correlation was observed between IL-6R and CD38 expression. Based on these results, we hypothesized that IL-6R overexpression due to 1q gain/amplification contributes to CD38 downregulation in 1q+ MM. To investigate this hypothesis, we first examined the levels of IL-6R in the six HMCLs and verified that 1q+ HMCLs expressed higher levels of IL-6R than 1q WT. We treated these HMCLs with IL-6 and confirmed that only 1q+ HMCLs showed CD38 downregulation. CD38 expression was also downregulated in the primary 1q+ MM samples treated with IL-6 but not in 1q WT samples. Moreover, higher IL-6R expression was observed in 1q+ primary samples than in 1q WT primary samples. IL-6 also led to the robust upregulation of p-STAT3 in HMCLs with 1q+ but not in HMCLs with 1q WT. Particularly, p-STAT3 expression was robustly enhanced in 1q amplification HMCLs that highly expressed IL-6R. Conversely, p-STAT3 expression was minimal in NCU-MM1 cells expressing little or no IL-6R. We also confirmed that IL-6R and STAT3 expressions were significantly and positively correlated in our primary samples and public datasets. Finally, CD38 expression was recovered by treating the 1q+ HMCLs and primary 1q+ MM samples with ruxolitinib (a JAK1/JAK2 inhibitor) or tocilizumab (an anti-IL-6R antibody). Conclusion: Overexpression of IL-6R in 1q+ MM leads to CD38 downregulation through the activation of the JAK/STAT pathway. This may be associated with the reduced efficacy of Dara in patients with 1q+ MM. Ruxolitinib and tocilizumab can potentially restore CD38 expression by suppressing this pathway, thereby enhancing the effects of Dara on 1q+ MM.

Regulatory T cells contribute to the immunosuppressive phenotype of neutrophils in a mouse model of chronic lymphocytic leukemia

BackgroundImpaired neutrophil activity is an important issue in chronic lymphocytic leukemia (CLL), as it contributes to a dysfunctional immune response leading to life-threatening infections in patients. Some features typical of CLL neutrophils, e.g., the B-cell-supportive secretion profile, have already been described. However, most of these studies were performed on cells isolated from peripheral blood. It is still unclear which molecular factors and cell types are involved in shaping neutrophil function and phenotype in the CLL microenvironment. Since regulatory T cells (Treg) play an important role in CLL progression and influence the activity of neutrophils, we investigated the crosstalk between Treg and neutrophils in the spleen using a murine model of CLL.MethodsIn this work, we used an Eµ-TCL1 mouse model of human CLL. For our in vivo and ex vivo experiments, we inoculated wild-type mice with TCL1 leukemic cells isolated from Eµ-TCL1 transgenic mice and then monitored disease progression by detecting leukemic cells in peripheral blood. We analyzed both the phenotype and activity of neutrophils isolated from the spleens of TCL1 leukemia-bearing mice. To investigate the interrelation between Treg and neutrophils in the leukemia microenvironment, we performed experiments using TCL1-injected DEREG mice with Treg depletion or RAG2KO mice with adoptively transferred TCL1 cells alone or together with Treg.ResultsThe obtained results underline the plasticity of the neutrophil phenotype, observed under the influence of leukemic cells alone and depending on the presence of Treg. In particular, Treg affect the expression of CD62L and IL-4 receptor in neutrophils, both of which are crucial for the function of these cells. Additionally, we show that Treg depletion and IL-10 neutralization induce changes in the leukemia microenvironment, partially restoring the “healthy” phenotype of neutrophils.ConclusionsAltogether, the results indicate that the crosstalk between Treg and neutrophils in CLL may play an important role in CLL progression by interfering with the immune response.

Overcoming lung cancer immunotherapy resistance by combining nontoxic variants of IL-12 and IL-2.

Engineered cytokine-based approaches for immunotherapy of cancer are poised to enter the clinic, with IL-12 being at the forefront. However, little is known about potential mechanisms of resistance to cytokine therapies. We found that orthotopic murine lung tumors were resistant to systemically delivered IL-12 fused to murine serum albumin (MSA, IL12-MSA) because of low IL-12 receptor (IL-12R) expression on tumor-reactive CD8+ T cells. IL2-MSA increased binding of IL12-MSA by tumor-reactive CD8+ T cells, and combined administration of IL12-MSA and IL2-MSA led to enhanced tumor-reactive CD8+ T cell effector differentiation, decreased numbers of tumor-infiltrating CD4+ regulatory T cells, and increased survival of lung tumor-bearing mice. Predictably, the combination of IL-2 and IL-12 at therapeutic doses led to significant dose-limiting toxicity. Administering IL-12 and IL-2 analogs with preferential binding to cells expressing Il12rb1 and CD25, respectively, led to a significant extension of survival in mice with lung tumors while abrogating dose-limiting toxicity. These findings suggest that IL-12 and IL-2 represent a rational approach to combination cytokine therapy whose dose-limiting toxicity can be overcome with engineered cytokine variants.

ERBIN and phosphoglucomutase 3 deficiency.

ERBIN and phosphoglucomutase 3 (PGM3) mutations both lead to rare primary atopic disorders characterized by allergic disease and connective tissue abnormalities, though each disorder has its own rather unique pattern of multisystem presentations. Pathway studies show how ERBIN mutations allow for enhanced TGFb signaling, and prevent STAT3 from negative-regulating TGFb signaling. This likely explains many elements of clinical overlap between disorders of STAT3 and TGFb signaling. The excessive TGFb signaling leading to increased IL-4 receptor expression also provides the rationale for precision-based therapy blocking the IL-4 receptor to treat the atopic disease. The mechanism by which PGM3 deficiency leads to atopic phenotypes is not well understood, nor is the broad variability in disease penetrance and expressivity, though preliminary studies suggest an overlap with IL-6 receptor signaling defects.

Expression of IL-7 receptor on Th1, Th17 lymphocytes in patients with psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic immune-mediated inflammatory disease of the joints, spine, and entheses that can occur in patients with psoriasis. The prevalence of psoriatic arthritis is high in Russia, in recent years there has been an increase in its incidence rates. The pathogenesis of PsA is based on the activation of Th1, Th17 cells. Pro-inflammatory cytokines produced by the cells are involved in the cascade of reactions leading to the joint deformity and bone destruction. For some autoimmune diseases associated with the Th1/Th17 response, IL-7 has been found to be involved in pathogenetic mechanisms. At the same time, IL-7 is assumed to support autoreactive T lymphocytes. Effect of the cytokine on cells is provided by the binding to a specific receptor thus causing a signal transmission into the cell and inducing the processes of differentiation, proliferation, and production of cytokines. In animal models of autoimmune diseases, usage of blocking antibodies to α-chain of the IL-7 receptor (IL-7R) was shown to cause reduced inflammation in target tissues and decreased number of infiltrating T lymphocytes. Therefore, the aim of this work was to investigate the in vitro effects of IL-7 and blockade of the α-chain of the IL-7 receptor on the contents of Th1, Th17 lymphocytes and expression of IL-7 receptor subunits on these cells in normal subjects and in psoriatic arthritis. The study included nine patients with PsA in the stage of exacerbation of the underlying disease (mean age 44±6.5 years) and 6 healthy individuals (mean age 45±2.7 years). The in vitro effects of IL-7 and specific blocking monoclonal antibodies (aCD127) was evaluated in cultures of mononuclear cells from peripheral blood. Flow cytometry was used to determine the expression of IL-7 receptor subunits (CD127, CD132) and to assess cell phenotypes in peripheral blood and cultured cells. We have shown for the first time that patients with PsA have an increased number of CD127+CD132- and CD127+CD132+ cells among Th17 lymphocytes, as well as CD127+CD132-, CD127+CD132+ and CD127-CD132+ cells among Th1 lymphocytes, which suggests participation of IL-7 in maintaining these cell populations. Upon the in vitro supplement of IL-7, an increase in the Th1 cell contents and a decreased number of Th17 cells were observed, both in donors and PsA patients, and the opposite effect was observed under the conditions of IL-7R of blockade. Under the influence of IL-7, as well as with blocking antibodies, there was a significant decrease in CD127 expression on Th1, Th17 lymphocytes. However, a decrease in the number of CD127-132+ among Th1, Th17 lymphocytes occurred only following blockade with antibodies. That is, despite redistribution of Th1 and Th17 lymphocytes in culture, the cells of these populations were not activated under the IL-7 receptor blockade. The obtained data may serve as a basis for choosing the IL-7 receptor as a target in the development of targeted drugs for the treatment of PsA.

IL-7 producing immunotherapy improves ex vivo T cell functions of immunosenescent patients, especially post hip fracture

ABSTRACT Following acute stress such as trauma or sepsis, most of critically ill elderly patients become immunosuppressed and susceptible to secondary infections and enhanced mortality. We have developed a virus-based immunotherapy encoding human interleukin-7 (hIL-7) aiming at restoring both innate an adaptative immune homeostasis in these patients. We assessed the impact of this encoded hIL-7 on the ex vivo immune functions of T cells from PBMC of immunosenescent patients with or without hip fracture. T-cell ex vivo phenotyping was characterized in terms of senescence (CD57), IL-7 receptor (CD127) expression, and T cell differentiation profile. Then, post stimulation, activation status, and functionality (STAT5/STAT1 phosphorylation and T cell proliferation assays) were evaluated by flow cytometry. Our data show that T cells from both groups display immunosenescence features, express CD127 and are activated after stimulation by virotherapy-produced hIL-7-Fc. Interestingly, hip fracture patients exhibit a unique functional ability: An important T cell proliferation occurred compared to controls following stimulation with hIL-7-Fc. In addition, stimulation led to an increased naïve T cell as well as a decreased effector memory T cell proportions compared to controls. This preliminary study indicates that the produced hIL-7-Fc is well recognized by T cells and initiates IL-7 signaling through STAT5 and STAT1 phosphorylation. This signaling efficiently leads to T cell proliferation and activation and enables a T cell “rejuvenation.” These results are in favor of the clinical development of the hIL-7-Fc expressing virotherapy to restore or induce immune T cell responses in immunosenescent hip fracture patients.

Comparative analysis of the expression of the soluble IL-7 receptor in patients with arthropathy

Arthropathy is one of the most prevalent diseases, which are based on the destruction and remodeling of cartilage and bone tissue. The inflammation that precedes destruction can be caused by mechanical stress on the joints, or by autoimmune reactions. Recently, IL-7 is considered as one of the key cytokines that promote the production of matrix metalloproteinases, catabolic enzymes, T cell-mediated activation of monocytes, and maturation of osteoclasts. The soluble form of the IL-7 receptor can help prolong the lifespan of IL-7 and thereby it ensures the bioavailability of the cytokine and mediates effect of IL-7 on cells. The aim of this study was to determine the soluble form of the IL-7 receptor (sIL-7R) in the blood plasma of patients with rheumatoid arthritis (RA), osteoarthritis (OA), psoriatic arthritis (PsA) and psoriasis vulgaris (PS), as well as healthy individuals. The RA patients included in the study had moderate to high disease activity according to the DAS28 index. Patients with PsA predominantly had moderate and low disease activity (DAS28) and were characterized by mild to moderate disease severity (PASI). In accordance with the PASI index, patients with PS with mild and severe severity of the disease were included in the study. All patients with OA had a metabolic phenotype that is accompanied by an elevated body mass index.sIL-7R was determined in blood plasma by enzyme-linked immunosorbent assay. It was found that in patients with arthropathy, the level of soluble form of IL-7 was increased relative to healthy individuals, with the exception of the group of patients with PsA. Also, a high concentration of sIL-7R was observed in patients with PS. Analyzing the clinical characteristics of the patients, we found that sIL-7R levels were elevated in RA and PsA patients with high disease activity by DAS28. In addition, positive correlations were found between the concentration of sIL-7R and DAS28 in RA and PsA. In patients with PsA with moderate severity of the disease (PASI), the concentration of sIL-7R was also increased relative to donor's values. On the contrary, in patients with PS, a high level of sIL-7R was noted regardless of the severity of the disease. In patients with OA, no relationship was found between sIL-7R levels and clinical parameters.Thus, an elevated level of sIL-7R in patients with arthropathy may indicate the involvement of IL-7 and its receptor system in the pathogenesis of joint diseases. The IL-7 receptor may become a promising target both in the treatment of joint diseases and other autoimmune diseases, including psoriasis.

Neutrophil-Derived IL-6 Potentially Drives Ferroptosis Resistance in B Cells in Lupus Kidney.

Ferroptosis resistance is vital for B cell development, especially in inflammatory diseases, yet the underlying mechanism is still unclear. In this study, based on the scRNA-seq technique and flow cytometry, we discovered a proportion of neutrophils exhibited upregulated expression of the IL-6 and correlated with the expression of IL-6 receptor and SLC7A11 from B cells in lupus kidney. Moreover, we identified that in lupus kidney, neutrophils could provide IL-6 to facilitate ferroptosis resistance in B cells via SLC7A11, and inhibition of SLC7A11 could significantly enhance ferroptosis in B cells and could decrease B cell proliferation. This study helps understand the crosstalk between neutrophils and B cells in the kidney in the development of lupus.

IL-6 suppresses vaccine responses in neonatal mice by enhancing IL-2 activity on T follicular helper cells

Abstract The inability of neonates to develop CD4+CXCR5+PD-1+ T follicular helper (TFH) cells contributes to their weak vaccine responses. In previous studies, we measured diminished IgG responses when IL-6 was co-injected with a pneumococcal conjugate vaccine (PCV) in neonatal mice. This is in sharp contrast to adults, where IL-6 improves vaccine responses by downregulating the expression of IL-2Rβ on TFH cells and protecting them from the inhibitory effect of IL-2. In this study, we found that splenic IL-6 levels rapidly increased in both adult and neonatal mice following immunization, but the increase in neonatal mice was significantly more than that of adult mice. Moreover, immunized neonatal TFH cells expressed significantly more IL-2 as well as its receptors, IL-2Rα and IL-2Rβ, than the adult cells. Remarkably, IL-6 co-injection with PCV vaccine further increased the production of IL-2 and the expression of its receptors by neonatal TFH cells, whereas excess IL-6 had totally opposite effect in immunized adult mice. Underscoring the role of IL-6 in activating the IL-2 mediated suppression of vaccine responses, immunization of IL-6 knock-out neonates led to improved antibody responses accompanied by expanded TFH cells as well as lower levels of IL-2 and IL-2 receptors on TFH cells. Moreover, CpG containing PCV improved TFH response in neonates by suppressing the expression of IL-2 receptors on TFH cells and inhibiting IL-2 activity. These findings unveil age-specific differences in IL-6 mediated vaccine responses and highlight the need to consider age-related immunobiological attributes in designing vaccines. This study was funded by US FDA, Perinatal Health Center of Excellence (PHCE) grant to Mustafa Akkoyunlu as well as intramural grants from US FDA.

Tri-modal single cell (TEA-seq) profiling reveals a novel, epigenetically distinct T cell subset in children and global molecular reprogramming across age

Abstract Most single cell analyses of human T cell heterogeneity use a single modality (i.e., RNA or ATAC or protein), with limited ability to deconvolute complex cellular and molecular alterations that can occur during human aging and disease. Here, we use a new trimodal single cell technology (TEA-seq) to elucidate the interplay between the surface proteome, transcriptome, and epigenome in more than 300,000 T cells from healthy children (11–13 yrs) and older adults (55–65 yrs). We uncover that age universally drives molecular reprogramming across all T cell subsets towards a more activated basal state. Naive CD4 T cells, considered relatively resistant to aging, exhibited far more pronounced transcriptional reprogramming than naive CD8 T cells, in which alterations are preferentially driven by compositional shifts in naive-like memory subsets. We further discover a novel naïve-like CD8aa T cell subset lost with age that displays an innate-like transcriptome, a KLF/SP-rich epigenome and high IL-21 receptor expression. These data reveal the complex molecular landscape of the human T cell compartment that may contribute to differential immune responses across age. Supported by grants from NIH (K01 AG068373 to CEG) and the Allen Institute

IL-17 cytokines preferentially act on naïve CD4+ T cells with the IL-17AF heterodimer inducing the greatest functional changes.

CD4+ T-helper 17 (Th17) T cells are a key population in protective immunity during infection and in self-tolerance/autoimmunity. Through the secretion of IL-17, Th17 cells act in promotion of inflammation and are thus a major potential therapeutic target in autoimmune disorders. Recent reports have brought to light that the IL-17 family cytokines, IL-17A, IL-17F and IL-17AF, can directly act on CD4+ T-cells, both in murine and human systems, inducing functional changes in these cells. Here we show that this action is preferentially targeted toward naïve, but not memory, CD4+ T-cells. Naïve cells showed transcriptome changes as early as 48 hours post-IL-17 exposure, whereas memory cells remained unaffected as late as 7 days. These functional differences occurred despite similar IL-17 receptor expression on these subsets and were maintained in co-culture/transwell systems, with each subset maintaining its functional response to IL-17. Importantly, there were differences in downstream transcriptional signaling by the three IL-17 cytokines, with the IL-17AF heterodimer conferring both the greatest transcriptional change and most altered functional consequences. Detailed transcriptome analysis provides important insights into the genes and pathways that are modulated as a result of IL-17-mediated signaling and may serve as targets of future therapies.

IL-7 receptor expression is frequent in T-cell acute lymphoblastic leukemia and predicts sensitivity to JAK inhibition

AbstractT-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with a dismal prognosis related to refractory/relapsing diseases, raising the need for new targeted therapies. Activating mutations of interleukin-7–receptor pathway genes (IL-7Rp) play a proven leukemia-supportive role in T-ALL. JAK inhibitors, such as ruxolitinib, have recently demonstrated preclinical efficacy. However, prediction markers for sensitivity to JAK inhibitors are still lacking. Herein, we show that IL-7R (CD127) expression is more frequent (∼70%) than IL-7Rp mutations in T-ALL (∼30%). We compared the so-called nonexpressers (no IL-7R expression/IL-7Rp mutation), expressers (IL7R expression without IL-7Rp mutation), and mutants (IL-7Rp mutations). Integrative multiomics analysis outlined IL-7R deregulation in virtually all T-ALL subtypes, at the epigenetic level in nonexpressers, genetic level in mutants, and posttranscriptional level in expressers. Ex vivo data using primary-derived xenografts support that IL-7Rp is functional whenever the IL-7R is expressed, regardless of the IL-7Rp mutational status. Consequently, ruxolitinib impaired T-ALL survival in both expressers and mutants. Interestingly, we show that expressers displayed ectopic IL-7R expression and IL-7Rp addiction conferring a deeper sensitivity to ruxolitinib. Conversely, mutants were more sensitive to venetoclax than expressers. Overall, the combination of ruxolitinib and venetoclax resulted in synergistic effects in both groups. We illustrate the clinical relevance of this association by reporting the achievement of complete remission in 2 patients with refractory/relapsed T-ALL. This provides proof of concept for translation of this strategy into clinics as a bridge-to-transplantation therapy. IL7R expression can be used as a biomarker for sensitivity to JAK inhibition, thereby expanding the fraction of patients with T-ALL eligible for ruxolitinib up to nearly ∼70% of T-ALL cases.

Abstract 1850: A first-in-class PD1-IL18 immunocytokine (BPT567) targets PD-1+ IL18R+ CD8+ T effector cells enriched in the tumor microenvironment and exhibits potent antitumor efficacy with excellent tolerability

Abstract Immunocytokines (IC) leverage orthogonal mechanisms of action in one molecule to induce potent antitumor immune responses. PD-1-targeting ICs are of particular interest since they harbor the multifunctional ability to selectively target antigen-experienced PD-1+ CD8+ T cells enriched in the tumor microenvironment (TME), release them from PD-(L)1 pathway inhibition, be retained within the TME, and simultaneously deliver potent cytokine receptor stimulation to the same T cell in cis (cis-signaling). Interleukin (IL-18) is a proinflammatory cytokine that stimulates both innate and adaptive immunity and generates potent antitumor activity mediated by both T effector and NK cells. Recent evidence indicates that a subset of tumor-infiltrated PD-1+ CD8+ T effector cells hallmarked by high expression of IL-18 receptor exhibits a superior cytotoxic and proliferative phenotype. Hence, we developed a PD1-IL18 IC to specifically target and activate intratumoral IL-18R-expressing PD-1+ CD8+ T cells. We engineered a conjugatable variant of human IL-18 with enhanced potency and significant resistance to IL-18 binding protein (IL-18BP) and utilized this enhanced IL-18 payload to create a PD1-IL18 IC (BPT567) via site-specific chemical conjugation to a defined lysine residue within the heavy chain of an anti-human PD-1 antibody (Ab). Conjugation did not affect the basic properties of the Ab as neither binding to PD-1 nor the interaction with the neonatal Fc receptor (FcRn) or Fcγ receptors were significantly impacted. Of note, the conjugation handle in our enhanced IL-18 variant was inserted at a site distinct from its N- or C-terminus to preserve the full potency and selectivity of the IL-18 payload. As a result, BPT567 exhibits increased potency and marked resistance to IL-18BP inhibition compared to wild-type IL-18. In vivo, BPT567 shows striking antitumor efficacy in multiple syngeneic mouse tumor models that is superior to responses induced by an anti-PD-1 Ab alone, a non-targeted IL-18 IC or the combination of both agents. Our evidence suggests that the strong in vivo efficacy observed is attributed to a preferential activation of PD-1+ tumor-infiltrated immune cells. The excellent tolerability and large therapeutic window observed in mice may be driven by less potent immune cell activation in the periphery. Citation Format: Jean-Philippe Carralot, Kea Martin, Rubén Alvarez Sanchez, Roy Meoded, Caoimhe Herr, Philipp Moosman, Arnaud Goepfert, Andrew Chi, Vijaya J. Pattabiraman, Bertolt Kreft. A first-in-class PD1-IL18 immunocytokine (BPT567) targets PD-1+ IL18R+ CD8+ T effector cells enriched in the tumor microenvironment and exhibits potent antitumor efficacy with excellent tolerability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1850.

IL-23 Receptor Expression on T Helper 17 Cells and its Implication in Multiple Sclerosis Relapse

IL-23 Receptor Expression on T Helper 17 Cells and its Implication in Multiple Sclerosis Relapse