The Expression and Prognostic Significance of ICOS in NSCLC Integrated Pan-Cancer and Multi-Omics Analyses.

Background: Inducible co-stimulator (ICOS) shows great potential in the regulation of innate and adaptive immunity. However, previous studies of ICOS have often been limited to one or two levels. Methods: Using the data from the online database, the immunohistochemistry, and enzyme-linked immunosorbent assays, we investigated the role of ICOS / PD-L1 on patients with NSCLC at the mRNA, protein, and serum levels. Results: Our data revealed that unlike most solid tumors, the mRNA expression of ICOS was down-regulated in NSCLC. In addition, our data also showed that mRNA expression levels in ICOS are negatively associated with poor clinicopathologic grading but positively associated with better prognostic outcomes and higher Tregs infiltration level. Immunohistochemistry showed that ICOS correlated negatively with the T stage; while PD-L1 levels correlated positively with the N stage and FOXP3 levels. Serological biomarker analysis showed that patients with NSCLC had lower sICOS levels, which increased significantly post-surgery, and combined sICOS and sPD-L1 diagnosis improved efficacy and accuracy of disease diagnosis. Conclusion: Our findings support that ICOS suggests lower pathological staging and better prognosis. ICOS is a potential diagnostic and prognostic biomarker for NSCLC.

Increased co-expression of ICOS and PD-1 predicts poor overall survival in patients with acute myeloid leukemia.

BACKGROUND: Inducible co-stimulatory factor (ICOS) has a dual role: activating cytotoxic T cells against tumors or exacerbating immunosuppression of regulatory T cells (Tregs) to participate in immune evasion. However, the correlation between ICOS and its co-expression with inhibitory immune checkpoints (IICs) and prognosis in acute myeloid leukemia (AML) is little known. METHODS: The prognostic importance of ICOS and IICs in 62 bone marrow (BM) samples of de novo AML patients from our clinical center (GZFPH) was explored and then the RNA sequencing data of 155 AML patients from the Cancer Genome Atlas (TCGA) database was used for validation. RESULTS: In both GZFPH and TCGA cohorts, high expression of ICOS was significantly associated with poor overall survival (OS) in patients with AML (P < 0.05). Importantly, co-expression of ICOS and PD-1, PD-L1, PD-L2, CTLA-4, and LAG-3 predicted poor OS in AML; among them, ICOS/PD-1 was the optimal combination of immune checkpoints (ICs). The co-expression of ICOS and PD-1 was correlated with poor OS in non-acute promyelocytic leukemia (non-APL) patients following chemotherapy. Additionally, ICOS/PD-1 was an independent OS-predicting factor (P < 0.05). Notably, a nomogram model was constructed by combining ICOS/PD-1, age, European Leukemia Net (ELN) risk stratification, and therapy to visually and personalized predict the 1-, 3-, and 5-year OS of patients with non-APL. CONCLUSION: Increased expression of ICOS predicted poor outcomes, and ICOS/PD-1 was the optimal combination of ICs to predict outcomes in patients with AML, which might be a potential immune biomarker for designing novel AML therapy.

ICOS costimulation in combination with CTLA-4 blockade remodels tumor-associated macrophages toward an antitumor phenotype.

We have previously demonstrated synergy between ICOS costimulation (IVAX; ICOSL-transduced B16-F10 cellular vaccine) and CTLA-4 blockade in antitumor therapy. In this study, we employed CyTOF and single-cell RNA sequencing and observed significant remodeling of the lymphoid and myeloid compartments in combination therapy. Compared with anti-CTLA-4 monotherapy, the combination therapy enriched Th1 CD4 T cells, effector CD8 T cells, and M1-like antitumor proinflammatory macrophages. These macrophages were critical to the therapeutic efficacy of anti-CTLA-4 combined with IVAX or anti-PD-1. Macrophage depletion with clodronate reduced the tumor-infiltrating effector CD4 and CD8 T cells, impairing their antitumor functions. Furthermore, the recruitment and polarization of M1-like macrophages required IFN-γ. Therefore, in this study, we show that there is a positive feedback loop between intratumoral effector T cells and tumor-associated macrophages (TAMs), in which the IFN-γ produced by the T cells polarizes the TAMs into M1-like phenotype, and the TAMs, in turn, reshape the tumor microenvironment to facilitate T cell infiltration, immune function, and tumor rejection.

Immune effector dysfunction signatures predict outcomes in patients with colorectal cancer.

BACKGROUND: Immune effector dysfunction (IED) is mainly manifested as immune exhaustion and senescence, which are the primary obstacles to the success of cancer immunotherapy. In the current study, we characterized the prognostic relevance of IED signatures in patients with colorectal cancer (CRC). METHODS: Immunohistochemistry (IHC) data of CRC tissue samples from 41 newly diagnosed patients in our clinical center (HDPH cohort) were used to investigate the prognostic importance of IED signatures. The results were validated by the RNA sequencing data of 372 CRC patients from the Cancer Genome Atlas (TCGA) database. RESULTS: In the HDPH cohorts, high Natural Killer (NK) and CD8+ tumor-infiltrating lymphocytes (TILs) were associated with poor overall survival (OS) and relapse-free survival (RFS) in CRC patients. Optimal IED signatures, including high expression of CCR9, ISG20, and low expression of ICOS, and CACNA2D2, predicted poor OS and RFS. Moreover, high-risk scores estimated by a weighted combination of these four IED genes were associated with poor OS and RFS. Notably, risk stratification was constructed by combining risk score and tumor node metastasis (TNM) stage better than TNM stage alone in predicting OS and RFS for CRC patients. The above results were confirmed in the TCGA cohort. CONCLUSION: CCR9, ISG20, ICOS, and CACNA2D2 were optimal IED signatures for predicting the outcomes of CRC patients, which might be a potential biomarker for prognostic stratification and designing novel CRC therapy.

Inducing expression of ICOS-L by oncolytic adenovirus to enhance tumor-specific bi-specific antibody efficacy.

BACKGROUND: Intratumoral injection of oncolytic viruses (OVs) shows promise in immunotherapy: ONCOS-102, a genetically engineered OV that encodes Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) demonstrated efficacy in early clinical trials, enhancing T cell infiltration in tumors. This suggests OVs may boost various forms of immunotherapy, including tumor-specific bi-specific antibodies (BsAbs). METHODS: Our study investigated in vitro, how ONCOS-204, a variant of ONCOS-virus expressing the ligand of inducible T-cell co-stimulator (ICOSL), modulates the process of T cell activation induced by a BsAb. ONCOS-102 was used for comparison. Phenotypic and functional changes induced by combination of different OVs, and BsAb in T cell subsets were assessed by flow cytometry, viability, and proliferation assays. RESULTS: Degranulation and IFNγ and TNF production of T cells, especially CD4 + T cells was the most increased upon target cell exposure to ONCOS-204. Unexpectedly, ONCOS-204 profoundly affected CD8 + T cell proliferation and function through ICOS-L/ICOS interaction. The effect solely depended on cell surface expression of ICOS-L as soluble ICOSL did not induce notable T cell activity. CONCLUSIONS: Together, our data suggests that oncolytic adenoviruses encoding ICOSL may enhance functional activity of tumor-specific BsAbs thereby opening a novel avenue for clinical development in immunotherapeutics.

The added value of the HFA/ICOS score in the prediction of chemotherapy-related cardiac dysfunction in breast cancer.

BACKGROUND: The 2022 ESC Guidelines on Cardio-Oncology recommend baseline cardiovascular risk stratification before starting anticancer drugs, using the new risk assessment tools proposed by the Heart Failure Association (HFA) and the International Cardio-Oncology Society (ICOS).Our study aimed to assess the clinical application of HFA/ICOS risk score in breast cancer patients undergoing chemotherapy and its usefulness in predicting the development of chemotherapy-related cardiac dysfunction (CTRCD). METHODS: A prospective multicentric study enrolled 109 breast cancer patients treated with anthracyclines with or without trastuzumab. A cardiological evaluation, including ECG and echocardiogram at baseline (T0), 3 (T1), 6 (T2), and 12 months (T3) after starting treatment was performed. HFA/ICOS score was assessed in all patients. The population was divided into low, medium, high, and very-high risk.During follow-up, CTRCD and other cardiovascular events have been evaluated. RESULTS: 61 patients were low risk, 37 medium, 9 high, 2 very-high risk criteria. We found a significantly higher incidence of overall cardiotoxicity (CTRCD and other cardiovascular events) in the very-high risk group (100%) compared with the medium (29%) and low risk groups (13%). CTRCD incidence was also significantly higher in the high risk group (55%). CTRCD resulted as being associated with baseline arterial hypertension and baseline HFA/ICOS risk score of high ( p  = 0.006) or very-high ( p  < 0.0001). CONCLUSION: Our study confirms the HFA/ICOS score's ability to predict cardiovascular toxicity in breast cancer women and the need for close monitoring especially in high and very-high risk patients.

The response of CD27+CD38+ plasmablasts, CD24hiCD38hi transitional B cells, CXCR5-ICOS+PD-1+ Tph, Tph2 and Tfh2 subtypes to allergens in children with allergic asthma.

BACKGROUND: Allergic asthma is a type I allergic reaction mediated by serum Immunoglobulin E (IgE). B cell-mediated humoral immune response to allergens in the pathophysiology of allergic asthma have not been thoroughly elucidated. Peripheral helper T cells (Tph) and follicular helper T cells (Tfh) promote B cell differentiation and antibody production in inflamed tissues. OBJECTIVE: To investigate the roles of B cell subsets, Tph cell subsets and Tfh cell subsets in allergic immune responses. METHODS: Circulating B cell subsets, Tph cell subsets and Tfh cell subsets in 33 children with allergic asthma and 17 healthy children were analyzed using multicolor flow cytometry. The level of serum total IgE was also assessed. RESULTS: Our study found that CD27+CD38+ plasmablasts and CD24hiCD38hi transitional B cells increased and were correlated with serum total IgE level, CD27- naive B cells and CD24hiCD27+ B cells decreased in children with allergic asthma. CXCR5- Tph, CXCR5-ICOS+ Tph, CXCR5-ICOS+PD-1+ Tph, CXCR5+ICOS+ Tfh and CXCR5+ICOS+PD-1+ Tfh increased in children with allergic asthma. Further analysis showed increased Tph2, Tph17, Tfh2 and Tfh17 subtypes while decreased Tph1 and Tfh1 subtypes in children with allergic asthma. Most interestingly, Tph2 or Tfh2 subtypes had a positive correlation with serum total IgE level. CONCLUSION: Overall, these results provide insight into the allergens elicited B, Tph or Tfh cell response and identify heretofore unappreciated CD24hiCD38hi transitional B cells, CD24hiCD27+ B cells, CXCR5- Tph, CXCR5-ICOS+PD-1+ Tph, Tph2 subtypes and Tfh2 subtypes response to allergens.

Design of cyclic peptides as novel inhibitors of ICOS/ICOSL interaction.

Compared to small molecules and antibodies, cyclic peptides exhibit unique biochemical and therapeutic attributes in the realm of pharmaceutical applications. The interaction between the inducible costimulator (ICOS) and its ligand (ICOSL) plays a key role in T-cell differentiation and activation. ICOS/ICOSL inhibition results in a reduction in the promotion of immunosuppressive regulatory T cells (Tregs) in both hematologic malignancies and solid tumors. Herein, we implement the computational cPEPmatch approach to design the first examples of cyclic peptides that inhibit ICOS/ICOSL interaction. The top cyclic peptide from our approach possessed an IC50 value of 1.87 ± 0.15 µM as an ICOS/ICOSL inhibitor and exhibited excellent in vitro pharmacokinetic properties as a drug candidate. Our work will lay the groundwork for future endeavors in cancer drug discovery, with the goal of developing cyclic peptides that target the ICOS/ICOSL interaction.

Tumor-infiltrating mast cells stimulate ICOS+ regulatory T cells through an IL-33 and IL-2 axis to promote gastric cancer progression.

INTRODUCTION: In solid tumors, regulatory T cell (Treg) and mast cell perform different roles depending on the microenvironment. Nevertheless, mast cell and Treg-mediated interactions in gastric cancer (GC) are unclear, as are their regulation, function, and clinical significance. OBJECTIVE: The present study demonstrated the mechanism of tumor-infiltrating mast cells stimulating ICOS+ regulatory T cells via the IL-33/IL-2 axis to promote the growth of gastric cancer. METHODS: Analyses of 98 patients with GC were conducted to examine mast cell counts, ICOS+ Tregs, and the levels of IL-33 or IL-2. Isolated ICOS+ Treg and CD8+ T cell were stimulated, cultured and tested for their functional abilities in vitro and in vivo. RESULTS: GC patients exhibited a significantly more production of IL-33 in tumors. Mast cell stimulated by tumor-derived IL-33 exhibited a prolonged lifespan through IL-33 mediated inhibition of apoptosis. Moreover, mast cells stimulated by tumor-derived IL-33 secreted IL-2, which induced Treg expansion. These inducible Tregs displayed an activated immunosuppressive phenotype with positive expression for the inducible T cell co-stimulator (ICOS). In vitro, IL-2 from IL to 33-stimulated mast cells induced increased numbers of ICOS+ Tregs with increased immunosuppressive activity against proliferation and effector function of CD8+ T cell. In vivo, ICOS+ Tregs were treated with anti-IL-2 neutralizing antibody followed by co-injection with CD8+ T cells in GC mouse model, which showed an increased CD8+ T cell infiltration and effector molecules production, meanwhile tumor growth and progression were inhibited. Besides, reduction in GC patient survival was associated with tumor-derived ICOS+ Tregs. CONCLUSION: Our results highlight a crosstalk between GC-infiltrating mast cells and ICOS+ Tregs and provide a novel mechanism describing ICOS+ Treg expansion and induction by an IL-33/mast cell/IL-2 signaling axis in GC, and also provide functional evidence that the modulation of this immunosuppressive pathway can attenuate GC-mediated immune tolerance.

Molecular and clinical characterization of ICOS expression in breast cancer through large-scale transcriptome data.

ICOS (Inducible T Cell Costimulator), one of the co-stimulatory B7 superfamily members, was characterized as a co-stimulatory receptor for T-cell enhancement. However, the role of ICOS in breast cancer remains largely unknown. The present study systematically investigated the expression pattern and its relation to clinical characteristics and immunotherapy by integrating multiple clinical cohorts and large-scale gene expression data. This study included 2994 breast tumor samples with transcriptome data and matched clinical data. To make our findings more reliable, we set the TCGA cohort as the discovery set and the METABRIC cohort as the validation set. The expression of ICOS in breast cancer is strongly associated with major clinical and molecular characteristics. There is an association between higher ICOS expression and malignant subtypes and grades of tumors. In addition, gene ontology analysis based on genes significantly correlated with ICOS expression indicated that the expression of ICOS is mainly associated with immune responses and inflammation. We also observed strong correlations between ICOS and other promising immune-checkpoint molecules, including PD1, PDL1, CTLA4, and IDO1. Furthermore, we found that ICOS expression is associated with the response to anti-PDL1 immunotherapy and may serve as a biomarker for immunotherapy prediction. Our results indicated higher ICOS expression is significantly associated with favorable survival in triple-negative breast cancer (TNBC) patients, but not for all subtypes of breast cancer patients. In summary, ICOS correlates with higher malignant breast cancers, and it contributes to the regulation of the immune microenvironment of breast tumors, making it a potential biomarker and immunotherapy target.

Discovery of ICOS-Targeted Small Molecules Using Pharmacophore-Based Screening.

There are currently no small molecules clinically approved as immune checkpoint modulators. Besides possessing oral bioavailability, cell-penetrating capabilities and enhanced tumor penetration compared to monoclonal antibodies (mAbs), small molecules are amenable to pharmacokinetic optimization, which allows adopting flexible dosage regimens that may avoid immune-related adverse events associated with mAbs. The interaction of inducible co-stimulator (ICOS) with its ligand (ICOS-L) plays key roles in T-cell differentiation and activation of T-cell to B-cell functions. This study represents the development and validation of a virtual screening strategy to identify small molecules that bind a novel druggable binding pocket in human ICOS. We used a lipophilic canyon in the apo-structure of ICOS and the ICOS/ICOS-L interface individually as templates for molecular dynamics simulation to generate 3D pharmacophores subsequently used for virtual screening campaigns. Our strategy was successful finding a first-in-class small molecule ICOS binder (5P, KD value=108.08±26.76 µM) and validating biophysical screening platforms for ICOS-targeted small molecules. We anticipate that future structural optimization of 5P will result in the discovery of high affinity chemical ligands for ICOS.

Expression and prognosis of inducible T-cell co-stimulator and its ligand in Chinese stage I-III lung adenocarcinoma patients.

BACKGROUND: Immunotherapy has become the fastest-adopting treatment paradigm for lung cancer with improved survival. By binding with its ligand (inducible T-cell co-stimulator and its ligand [ICOSL]), an inducible T-cell co-stimulator (ICOS) could contribute to reversing immunosuppression and improving immune response and thus be a potential target for cancer immunotherapy. METHODS: We selected 54 formalin-fixed, paraffin-embedded tumor tissues from cases with stage I-III lung adenocarcinoma cancer. Immunohistochemical expression of ICOS and ICOSL was evaluated. The correlation with clinical parameters in Chinese patients was also compared with TCGA results. RESULTS: The positive rates of ICOS and ICOSL were 68% and 81.5%, respectively, in lung tumor tissues. Of these, 9 cases had a low expression of ICOS, and 22 cases had a high expression of ICOS; ICOSL expression was low in 20 cases and high in 24 cases. According to the International Association for the Study of Lung Cancer (8th edition), phase I lesions were detected in 21 cases, phase II lesions in 15 cases, and phase III lesions in 18 cases. The median survival time of all patients was 44.5 months, and the median disease-free survival was 32 months. Univariate analysis showed that the factors significantly associated with overall survival were tumor size, regional lymph node involvement, stage, and expression level of ICOS/ICOSL. Survival analysis using log-rank test indicated that the lower ICOS+ cell infiltration may predict poor prognosis, whereas lower ICOSL protein expression may be associated with better prognosis, but ICOSL data need further validation in larger samples due to inconsistency in TCGA mRNA prediction. CONCLUSION: ICOS/ICOSL might be associated with prognosis of lung cancer, and ICOS and its ligand may be potential therapeutic targets in non-small cell lung cancer.

CCR9/CXCR5 Co-Expressing CD4 T Cells Are Increased in Primary Sjögren's Syndrome and Are Enriched in PD-1/ICOS-Expressing Effector T Cells.

Primary Sjögren's syndrome (pSS) is an autoimmune disease characterised by B cell hyperactivity. CXCR5+ follicular helper T cells (Tfh), CXCR5-PD-1hi peripheral helper T cells (Tph) and CCR9+ Tfh-like cells have been implicated in driving B cell hyperactivity in pSS; however, their potential overlap has not been evaluated. Our aim was to study the overlap between the two CXCR5- cell subsets and to study their PD-1/ICOS expression compared to "true" CXCR5/PD-1/ICOS-expressing Tfh cells. CXCR5- Tph and CCR9+ Tfh-like cell populations from peripheral blood mononuclear cells of pSS patients and healthy controls (HC) were compared using flow cytometry. PD-1/ICOS expression from these cell subsets was compared to each other and to CXCR5+ Tfh cells, taking into account their differentiation status. CXCR5- Tph cells and CCR9+ Tfh-like cells, both in pSS patients and HC, showed limited overlap. PD-1/ICOS expression was higher in memory cells expressing CXCR5 or CCR9. However, the highest expression was found in CXCR5/CCR9 co-expressing T cells, which are enriched in the circulation of pSS patients. CXCR5- Tph and CCR9+ Tfh-like cells are two distinct cell populations that both are enriched in pSS patients and can drive B cell hyperactivity in pSS. The known upregulated expression of CCL25 and CXCL13, ligands of CCR9 and CXCR5, at pSS inflammatory sites suggests concerted action to facilitate the migration of CXCR5+CCR9+ T cells, which are characterised by the highest frequencies of PD-1/ICOS-positive cells. Hence, these co-expressing effector T cells may significantly contribute to the ongoing immune responses in pSS.

Granulocyte-Macrophage Colony-Stimulating Factor Influence on Soluble and Membrane-Bound ICOS in Combination with Immune Checkpoint Blockade.

With the successful development of immune checkpoint blockade, there remains the continued need to improve efficacy and decrease toxicities. The addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) to ipilimumab has previously demonstrated both an improvement in efficacy and decrease in the incidence of high-grade adverse events. ICOS+CD4+ or ICOS+CD8+ peripheral blood T cells are significantly greater in the patients treated with ipilimumab plus GM-CSF than in the patients treated with ipilimumab alone. To better understand the effects of GM-CSF on inducible T-cell costimulator (ICOS) and clinical outcomes, the relative roles of identified soluble ICOS and membrane-bound ICOS were evaluated. The ICOS splice variant was secreted and found to have immunologic suppressive effects. Changes in soluble ICOS splice variant levels in treated patients correlated with clinical outcomes. GM-CSF enhanced membrane-bound ICOS in an IL12-dependent manner but did not increase soluble ICOS levels. Whereas soluble ICOS plays a role in immune suppression, GM-CSF efficacy involves increasing membrane-bound ICOS and induction of dendritic cell development. Thus, soluble ICOS splice variants may be used as a biomarker for GM-CSF and immune checkpoint blockade-based therapies.

Optimal dosing regimen of CD73 blockade improves tumor response to radiotherapy through iCOS downregulation.

BACKGROUND: Irradiation (IR) and immune checkpoint inhibitor (ICI) combination is a promising treatment modality. However, local and distance treatment failure and resistance can occur. To counteract this resistance, several studies propose CD73, an ectoenzyme, as a potential target to improve the antitumor efficiency of IR and ICI. Although CD73 targeting in combination with IR and ICI has shown attractive antitumor effects in preclinical models, the rationale for CD73 targeting based on CD73 tumor expression level deserves further investigations. METHODS: Here we evaluated for the first time the efficacy of two administration regimens of CD73 neutralizing antibody (one dose vs four doses) in combination with IR according to the expression level of CD73 in two subcutaneous tumor models expressing different levels of CD73. RESULTS: We showed that CD73 is weakly expressed by MC38 tumors even after IR, when compared with the TS/A model that highly expressed CD73. Treatment with four doses of anti-CD73 improved the TS/A tumor response to IR, while it was ineffective against the CD73 low-expressing MC38 tumors. Surprisingly, a single dose of anti-CD73 exerted a significant antitumor activity against MC38 tumors. On CD73 overexpression in MC38 cells, four doses of anti-CD73 were required to improve the efficacy of IR. Mechanistically, a correlation between a downregulation of iCOS expression in CD4+ T cells and an improved response to IR after anti-CD73 treatment was observed and iCOS targeting could restore an impaired benefit from anti-CD73 treatment. CONCLUSIONS: These data emphasize the importance of the dosing regimen for anti-CD73 treatment to improve tumor response to IR and identify iCOS as part of the underlying molecular mechanisms. Our data suggest that the selection of appropriate dosing regimen is required to optimize the therapeutic efficacy of immunotherapy-radiotherapy combinations.

Thymoma patients with or without myasthenia gravis have increased Th17 cells, IL-17 production and ICOS expression.

Thymoma associated myasthenia gravis (TAMG) is a small disease subgroup with autoantibodies against the acetylcholine receptor. The aim of this study was to assess the role of T helper (Th) cells in TAMG compared to thymoma patients without MG (TOMA) and healthy controls (HC). Peripheral blood cells were used for intracellular cytokine measurements and phenotyping of CD4+ Th cells. IL-21 and IL-4 productions and peripheral Th cells were higher in TAMG compared to TOMA patients and HC. Increases of ICOS and Th17 population were detected both in TAMG and TOMA groups. Higher IL-10 and Th1 population have been observed related to thymectomy. ICOS expression and Th17 induced by thymoma may contribute to the development of TAMG.

Involvement of CD40-CD40L and ICOS-ICOSL in the development of chronic rhinosinusitis by targeting eosinophils.

Background: Chronic rhinosinusitis (CRS), whose prevalence and pathogenesis are age-related, is characterized by nasal tissue eosinophil infiltration. CD40-CD40 ligand (CD40L) pathway involves in the eosinophil-mediated inflammation, and inducible co-stimulator (ICOS)-ICOS ligand (ICOSL) signal can strengthen CD40-CD40L interaction. Whether CD40-CD40L and ICOS-ICOSL have a role in the development of CRS remains unknown. Objectives: The aim of this study is to investigate the association of CD40-CD40L and ICOS-ICOSL expression with CRS and underlying mechanisms. Methods: Immunohistology detected the expression of CD40, CD40L, ICOS, and ICOSL. Immunofluorescence was performed to evaluate the co-localizations of CD40 or ICOSL with eosinophils. Correlations between CD40-CD40L and ICOS-ICOSL as well as clinical parameters were analyzed. Flow cytometry was used to explore the activation of eosinophils by CD69 expression and the CD40 and ICOSL expression on eosinophils. Results: Compared with the non-eCRS subset, ECRS (eosinophilic CRS) subset showed significantly increased CD40, ICOS, and ICOSL expression. The CD40, CD40L, ICOS, and ICOSL expressions were all positively correlated with eosinophil infiltration in nasal tissues. CD40 and ICOSL were mainly expressed on eosinophils. ICOS expression was significantly correlated with the expression of CD40-CD40L, whereas ICOSL expression was correlated with CD40 expression. ICOS-ICOSL expression positively correlated with blood eosinophils count and disease severity. rhCD40L and rhICOS significantly enhanced the activation of eosinophils from patients with ECRS. Tumor necrosis factor-α (TNF-α) and interleukin-5 (IL-5) obviously upregulated CD40 expression on eosinophils, which was significantly inhibited by the p38 mitogen-activated protein kinase (MAPK) inhibitor. Conclusions: Increased CD40-CD40L and ICOS-ICOSL expressions in nasal tissues are linked to eosinophils infiltration and disease severity of CRS. CD40-CD40L and ICOS-ICOSL signals enhance eosinophils activation of ECRS. TNF-α and IL-5 regulate eosinophils function by increasing CD40 expression partly via p38 MAPK activation in patients with CRS.

Augmenting TCR signal strength and ICOS costimulation results in metabolically fit and therapeutically potent human CAR Th17 cells.

IL-17-producing antigen-specific human T cells elicit potent antitumor activity in mice. Yet, refinement of this approach is needed to position it for clinical use. While activation signal strength regulates IL-17 production by CD4+ T cells, the degree to which T cell antigen receptor (TCR) and costimulation signal strength influences Th17 immunity remains unknown. We discovered that decreasing TCR/costimulation signal strength by incremental reduction of αCD3/costimulation beads progressively altered Th17 phenotype. Moreover, Th17 cells stimulated with αCD3/inducible costimulator (ICOS) beads produced more IL-17A, IFNγ, IL-2, and IL-22 than those stimulated with αCD3/CD28 beads. Compared with Th17 cells stimulated with the standard, strong signal strength (three beads per T cell), Th17 cells propagated with 30-fold fewer αCD3/ICOS beads were less reliant on glucose and favored the central carbon pathway for bioenergetics, marked by abundant intracellular phosphoenolpyruvate (PEP). Importantly, Th17 cells stimulated with weak αCD3/ICOS beads and redirected with a chimeric antigen receptor that recognizes mesothelin were more effective at clearing human mesothelioma. Less effective CAR Th17 cells generated with high αCD3/ICOS beads were rescued by overexpressing phosphoenolpyruvate carboxykinase 1 (PCK1), a PEP regulator. Thus, Th17 therapy can be improved by using fewer activation beads during manufacturing, a finding that is cost effective and directly translatable to patients.

Non-Redundant Roles of T Cell Costimulation Pathways in Inflammatory Arthritis Revealed by Dual Blockade of ICOS and CD28 with Acazicolcept (ALPN-101).

OBJECTIVE: CD28 and inducible T cell costimulator (ICOS) appear to have nonredundant roles in T cell activation and adaptive immunity. We undertook this study to characterize in vitro and in vivo the therapeutic potential of acazicolcept (ALPN-101), an Fc fusion protein of a human variant ICOS ligand (ICOSL) domain designed to inhibit both CD28 and ICOS costimulation, in inflammatory arthritis. METHODS: Acazicolcept was compared in vitro with inhibitors of either the CD28 or ICOS pathways (abatacept and belatacept [CTLA-4Ig], prezalumab [anti-ICOSL monoclonal antibody]) in receptor binding and signaling assays, and in a collagen-induced arthritis (CIA) model. Acazicolcept was also compared in cytokine and gene expression assays of peripheral blood mononuclear cells (PBMCs) from healthy donors or rheumatoid arthritis (RA) or psoriatic arthritis (PsA) patients stimulated with artificial antigen-presenting cells (APCs) expressing CD28 and ICOS ligands*. RESULTS: Acazicolcept bound CD28 and ICOS, prevented ligand binding, and inhibited human T cell functional interactions, matching or exceeding the activity of CD28 or ICOS costimulatory single-pathway inhibitors tested individually or in combination. Acazicolcept administration significantly reduced disease in the CIA model and more potently than abatacept. Acazicolcept also inhibited proinflammatory cytokine production from stimulated PBMCs in cocultures with artificial APCs and demonstrated unique effects on gene expression distinct from those induced by abatacept, prezalumab, or a combination of both. CONCLUSION: Both CD28 and ICOS signaling play critical roles in inflammatory arthritis. Therapeutic agents such as acazicolcept that coinhibit both ICOS and CD28 signaling may mitigate inflammation and/or disease progression in RA and PsA more effectively than inhibitors of either pathway alone.

Comprehensive analysis of the role of ICOS ( CD278 ) in pan-cancer prognosis and immunotherapy.

BACKGROUND: The immunological checkpoint known as Inducible T Cell Costimulatory Factor (ICOS, Cluster of Differentiation, CD278) is activated and expressed on T cells. Both somatic cells and antigen-presenting cells expressed its ligand, ICOSL (including tumor cells in the tumor microenvironment).It is important for immunosuppression. Uncertainty surrounds the function of ICOS in tumor immunity. METHODS: Several bioinformatics techniques were employed by us to thoroughly examine the expression and prognostic value of ICOS in 33 cancers based on data collected from TCGA and GTEx. In addition, ICOS was explored with pathological stage, tumor-infiltrating cells, immune checkpoint genes, mismatch repair (MMR) genes, DNA methyltransferases (DNMTs), microsatellite instability (MSI),and tumor mutation burden (TMB).In addition,To ascertain the level of ICOS expression in various cells, qRT-PCR was employed. RESULTS: The findings revealed that ICOS expression was up regulation in most cancer types. The high expression of ICOS in tumor samples was related to the poor prognosis of UVM and LGG; The positive prognosis was boosted by the strong expression of ICOS in OV, SARC, SKCM, THYM, UCEC, and HNSC. The result is that the expression of malignancy was revealed by the immune cells' invasion.profile of ICOS in different types of cancer. Different ways that ICOS expression is connected to immune cell infiltration account for variations in patient survival. Additionally, the TMB, MSI, MMR, and DNMT genes as well as ICOS expression are linked in many cancer types.The results of PCR showed that it is highly expressed in gastric, breast, liver and renal cell carcinoma cell lines compared with normal cells. CONCLUSION: This study suggests that ICOS may be a potential tumor immunotherapy target and prognostic marker.