Amphiregulin enhances regulatory T cell-suppressive function via the epidermal growth factor receptor

Antibodies to EGF Receptor Family Members Can Upregulate Tumor Immunity

Immunologic mechanisms influence how a cancer patient responds to therapy. Monoclonal antibodies (mAbs) to the epidermal growth factor receptor are clinically approved, and a lung cancer vaccine inducing antibodies to epidermal growth factor (EGF) has some beneficial clinical effects. We tested the hypothesis that mAbs to epidermal growth factor receptor, EGF, and tumor growth factor alpha (TGF-α), in addition to any other effects, can facilitate the generation of a tumor-destructive immunologic response. Data from studies with mouse tumors showed that all 3 of these mAbs stimulated the in vitro generation of a Th1 response with tumor cells killed by spleen cells from mice with SW1 melanoma, B16 melanoma, or ID8 ovarian carcinoma. The mAb to TGF-α was most effective, and tumor lines releasing TGF-α were more sensitive than lines not releasing TGF-α. Stimulated by these findings we then performed pilot experiments in which mice with SW1 melanoma were injected with mAbs intraperitoneally or with a combination of the 2. A combination of anti-TGF-α and anti-PD-1 mAbs could cure mice with established tumor while single anti-TGF-α or anti-PD1 mAbs could not.

Amphiregulin in cellular physiology, health, and disease: Potential use as a biomarker and therapeutic target

Amphiregulin (AREG), which acts as one of the ligands for epidermal receptor growth factor receptor (EGFR), plays a crucial role in tissue repair, inflammation, and immunity. AREG is synthesized as membrane-anchored pre-protein, and is excreted after proteolytic cleavage, and serves as an autocrine or paracrine factor. After engagement with the EGFR, AREG triggers a cascade of signaling events required for many cellular physiological processes including metabolism, cell cycle, and proliferation. Under different inflammatory and pathogenic conditions, AREG is expressed by various activated immune cells that orchestrate both tolerance and host resistance mechanisms. Several factors including xenobiotics, cytokines, and inflammatory lipids have been shown to trigger AREG gene expression and release. In this review, we discuss the structure, function, and regulation of AREG, its role in tissue repair, inflammation, and homeostasis as well as the potential of AREG as a biomarker and therapeutic target.

Identification of a Gene Signature Closely Related to Immunosuppressive Tumour Microenvironment Predicting Prognosis of Patients in EGFR Mutant Lung Adenocarcinoma

Lung adenocarcinomas (LUADs) harbouring epidermal growth factor receptor (EGFR) mutations are generally unable to benefit from immune checkpoint inhibitors (ICIs) due to an immunosuppressive tumour microenvironment (TME) and a lower tumour mutation burden. Currently, no gene signature can comprehensively evaluate the TME and predict the prognosis of patients with EGFR-mutant LUAD. Using the Cancer Genome Atlas database of EGFR-mutant LUAD based on the immune score derived from the ESTIMATE algorithm, we divided 80 patients with EGFR-mutant LUAD samples into high and low immune score groups with different immune microenvironments. Subsequently, we screened 396 differentially expressed immune-related genes with prognostic value. The top Gene Ontology terms were significantly enriched in biological functions related to T cell differentiation, immune response, cell cycle, and cell proliferation, which are closely related to the immune microenvironment of tumours. In addition, the KEGG pathway enrichment analysis mainly focused on cell cycle, cell adhesion molecules, and cytokine-cytokine receptor interaction, which also had a relationship with the immune response. Subsequently, we identified a three-gene signature including BTLA, BUB1B, and CENPE using the LASSO Cox regression model. The three-gene signature could accurately identify patients at risk of EGFR-mutant LUAD in the training and validation sets and high-risk patients from both the sets exhibited significantly shorter overall survival (p=0.0053 and p=0.035, respectively). CIBERSORT was used to evaluate the abundance of immune cell infiltration in the EGFR-mutant LUAD microenvironment. The immune activity of B cells and macrophages was higher in the low-risk group, while the immune activity of natural killer cells and T cells was higher in the high-risk group. Thus, the three-gene signature closely related to immunosuppressive TME could predict the risk and prognosis in patients with EGFR-mutant LUAD.

The Dual Role of Innate Lymphoid and Natural Killer Cells in Cancer. from Phenotype to Single-Cell Transcriptomics, Functions and Clinical Uses

Simple Summary

Innate lymphoid cells (ILCs), a family of innate immune cells including natural killers (NKs), play a multitude of roles in first-line cancer control, in escape from immunity and in cancer progression. In this review, we summarize preclinical and clinical data on ILCs and NK cells concerning their phenotype, function and clinical applications in cellular therapy trials. We also describe how single-cell transcriptome sequencing has been used and forecast how it will be used to better understand ILC and NK involvement in cancer control and progression as well as their therapeutic potential.

Abstract

The role of innate lymphoid cells (ILCs), including natural killer (NK) cells, is pivotal in inflammatory modulation and cancer. Natural killer cell activity and count have been demonstrated to be regulated by the expression of activating and inhibitory receptors together with and as a consequence of different stimuli. The great majority of NK cell populations have an anti-tumor activity due to their cytotoxicity, and for this reason have been used for cellular therapies in cancer patients. On the other hand, the recently classified helper ILCs are fundamentally involved in inflammation and they can be either helpful or harmful in cancer development and progression. Tissue niche seems to play an important role in modulating ILC function and conversion, as observed at the transcriptional level. In the past, these cell populations have been classified by the presence of specific cellular receptor markers; more recently, due to the advent of single-cell RNA sequencing (scRNA-seq), it has been possible to also explore them at the transcriptomic level. In this article we review studies on ILC (and NK cell) classification, function and their involvement in cancer. We also summarize the potential application of NK cells in cancer therapy and give an overview of the most recent studies involving ILCs and NKs at scRNA-seq, focusing on cancer. Finally, we provide a resource for those who wish to start single-cell transcriptomic analysis on the context of these innate lymphoid cell populations.

Senescence and Immunoregulation in the Tumor Microenvironment

Immunotherapies have revolutionized cancer treatment, but despite the many lives that have been extended by these therapies many patients do not respond for reasons that are not well understood. The tumor microenvironment (TME) is comprised of heterogeneous cells that regulate tumor immune responses and likely influence immunotherapy response. Senescent (e.g., aged) stroma within the TME, and its expression of the senescence-associated secretory phenotype induces chronic inflammation that encourages tumor development and disease progression. Senescent environments also regulate the function of immune cells in ways that are decidedly protumorigenic. Here we discuss recent developments in senescence biology and the immunoregulatory functions of senescent stroma. Understanding the multitude of cell types present in the TME, including senescent stroma, will aid in the development of combinatorial therapeutic strategies to increase immunotherapy efficacy.

Harnessing the innate and adaptive immune system for tissue repair and regeneration: Considering more than macrophages

Tissue healing and regeneration is a complex, choreographed, spatiotemporal process involving a plethora of cell types, the activity of which is stringently regulated in order for effective tissue repair to ensue post injury. A number of globally prevalent conditions such as heart disease, organ failure, and severe musculoskeletal disorders require new therapeutic strategies to repair damaged or diseased tissue, particularly given an ageing population in which obesity, diabetes, and consequent tissue defects have reached epidemic proportions. This is further compounded by the lack of intrinsic healing and poor regenerative capacity of certain adult tissues. While vast progress has been made in the last decade regarding tissue regenerative strategies to direct self-healing, for example, through implantation of tissue engineered scaffolds, several challenges have hampered the clinical application of these technologies. Control of the immune response is growing as an attractive approach in regenerative medicine and it is becoming increasingly apparent that an in depth understanding of the interplay between cells of the immune system and tissue specific progenitor cells is of paramount importance. Furthermore, the integration of immunology and bioengineering promises to elevate the efficacy of biomaterial-based tissue repair and regeneration. In this review, we highlight the role played by individual immune cell subsets in tissue repair processes and describe new approaches that are being taken to direct appropriate healing outcomes via biomaterial mediated targeting of immune cell activity. STATEMENT OF SIGNIFICANCE: It is becoming increasingly apparent that controlling the immune response is as an attractive approach in regenerative medicine. Here, we propose that an in-depth understanding of immune system and tissue specific progenitor cell interactions may reveal mechanisms by which tissue healing and regeneration takes place, in addition to identifying novel therapeutic targets that could be used to enhance the tissue repair process. To date, most reviews have focused solely on macrophage subsets. This manuscript details the role of other innate and adaptive immune cells such as innate lymphoid cells (ILCs), natural killer (NK) cells and γδT cells (in addition to macrophages) in tissue healing. We also describe new approaches that are being taken to direct appropriate healing outcomes via biomaterial mediated cytokine and drug delivery.

Influenza Vaccines: Successes and Continuing Challenges

Influenza vaccines have been available for over 80 years. They have contributed to significant reductions in influenza morbidity and mortality. However, there have been limitations in their effectiveness, in part due to the continuous antigenic evolution of seasonal influenza viruses, but also due to the predominant use of embryonated chicken eggs for their production. The latter furthermore limits their worldwide production timelines and scale. Therefore today, alternative approaches for their design and production are increasingly pursued, with already licensed quadrivalent seasonal influenza vaccines produced in cell cultures, including based on a baculovirus expression system. Next-generation influenza vaccines aim at inducing broader and longer-lasting immune responses to overcome seasonal influenza virus antigenic drift and to timely address the emergence of a new pandemic influenza virus. Tailored approaches target mechanisms to improve vaccine-induced immune responses in individuals with a weakened immune system, in particular older adults.

EGFR DNA Methylation Correlates With EGFR Expression, Immune Cell Infiltration, and Overall Survival in Lung Adenocarcinoma

Background

The epidermal growth factor receptor (EGFR) is a primary target of molecular targeted therapy for lung adenocarcinoma (LUAD). The mechanisms that lead to epigenetic abnormalities of EGFR in LUAD are still unclear. The purpose of our study was to evaluate the abnormal methylation of EGFR CpG sites as potential biomarkers for LUAD.

Methods

To assess the differentially methylation CpG sites of EGFR in LUAD, we used an integrative study of Illumina HumanMethylation450K and RNA-seq data from The Cancer Genome Atlas (TCGA). We evaluated and compared EGFR multiple-omics data to explore the role of CpG sites located in EGFR promoter regions and gene body regions and the association with transcripts, protein expression levels, mutations, and somatic copy number variation. We calculated the correlation coefficients between CpG sites of EGFR and immune infiltration fraction (by MCPcounter and ESTIMATE) and immune-related pathways in LUAD. Finally, we validated the differential methylation of clinically and prognostically relevant CpG sites using quantitative methylation-specific PCR (qMSP).

Results

We found that the methylation level of many EGFR CpGs in the promoter region was negatively correlated with the transcription level, protein expression, and SCNV, while the methylation at the gene body region was positively correlated with these features. The methylation level of EGFR CpGs in the promoter region was positively correlated with the level of immune infiltration and IFN-γ signature, while the opposite was found for methylation of the gene body region. The qMSP results showed that cg02316066 had a high methylation level, while cg02166842 had a low methylation level in LUAD. There was a high degree of co-methylation between cg02316066 and cg03046247.

Conclusion

Our data indicate that EGFR is an epigenetic regulator in LUAD acting through DNA methylation. Our research provides a theoretical basis for the further detection of EGFR DNA methylation as a predictive biomarker for LUAD survival and immunotherapy.

Lupus susceptibility gene Esrrg modulates regulatory T cells through mitochondrial metabolism

Estrogen-related receptor γ (Esrrg) is a murine lupus susceptibility gene associated with T cell activation. Here, we report that Esrrg controls Tregs through mitochondria homeostasis. Esrrg deficiency impaired the maintenance and function of Tregs, leading to global T cell activation and autoimmunity in aged mice. Further, Esrrg-deficient Tregs presented an impaired differentiation into follicular Tregs that enhanced follicular helper T cells' responses. Mechanistically, Esrrg-deficient Tregs presented with dysregulated mitochondria with decreased oxygen consumption as well as ATP and NAD+ production. In addition, Esrrg-deficient Tregs exhibited decreased phosphatidylinositol and TGF-β signaling pathways and increased mTOR complex 1 activation. We found that the expression of human ESRRG, which is high in Tregs, was lower in CD4+ T cells from patients with lupus than in healthy controls. Finally, knocking down ESRRG in Jurkat T cells decreased their metabolism. Together, our results reveal a critical role of Esrrg in the maintenance and metabolism of Tregs, which may provide a genetic link between lupus pathogenesis and mitochondrial dysfunction in T cells.

Role of Oncogenic Pathways on the Cancer Immunosuppressive Microenvironment and Its Clinical Implications in Hepatocellular Carcinoma

The tumor immune microenvironment, including hepatocellular carcinoma (HCC), is complex, consisting of crosstalk among tumor components such as the cancer cells, stromal cells and immune cells. It is conceivable that phenotypic changes in cancer cells by genetic and epigenetic alterations affect the cancer-stroma interaction and anti-cancer immunity through the expression of immune checkpoint molecules, growth factors, cytokines, chemokines and metabolites that may act on the immune system in tumors. Therefore, predicting the outcome of ICI therapy requires a thorough understanding of the oncogenic signaling pathways in cancer and how they affect tumor immune evasion. In this review, we have detailed how oncogenic signaling pathways can play a role in altering the condition of the cellular components of the tumor immune microenvironment such as tumor-associated macrophages, regulatory T cells and myeloid-derived suppressor cells. The RAS/MAPK, PI3K/Akt, Wnt/β-catenin and JAK/STAT pathways have all been implicated in anti-tumor immunity. We also found that factors that reflect the immune microenvironment of the tumor, including the status of oncogenic pathways such as the volume of tumor-infiltrating T cells, expression of the immune checkpoint protein PD-1 and its ligand PD-L1, and activation of the Wnt/β-catenin signaling pathway, predict a response to ICI therapy in HCC cases.

Role of Oncogenic Pathways on the Cancer Immunosuppressive Microenvironment and Its Clinical Implications in Hepatocellular Carcinoma

The tumor immune microenvironment, including hepatocellular carcinoma (HCC), is complex, consisting of crosstalk among tumor components such as the cancer cells, stromal cells and immune cells. It is conceivable that phenotypic changes in cancer cells by genetic and epigenetic alterations affect the cancer-stroma interaction and anti-cancer immunity through the expression of immune checkpoint molecules, growth factors, cytokines, chemokines and metabolites that may act on the immune system in tumors. Therefore, predicting the outcome of ICI therapy requires a thorough understanding of the oncogenic signaling pathways in cancer and how they affect tumor immune evasion. In this review, we have detailed how oncogenic signaling pathways can play a role in altering the condition of the cellular components of the tumor immune microenvironment such as tumor-associated macrophages, regulatory T cells and myeloid-derived suppressor cells. The RAS/MAPK, PI3K/Akt, Wnt/β-catenin and JAK/STAT pathways have all been implicated in anti-tumor immunity. We also found that factors that reflect the immune microenvironment of the tumor, including the status of oncogenic pathways such as the volume of tumor-infiltrating T cells, expression of the immune checkpoint protein PD-1 and its ligand PD-L1, and activation of the Wnt/β-catenin signaling pathway, predict a response to ICI therapy in HCC cases.

The Janus Face of IL-33 Signaling in Tumor Development and Immune Escape

Simple Summary

Interleukin-33 (IL-33) is often released from damaged cells, acting as a danger signal. IL-33 exerts its function by interacting with its receptor suppression of tumorigenicity 2 (ST2) that is constitutively expressed on most immune cells. Therefore, IL-33/ST2 signaling can modulate immune responses to participate actively in a variety of pathological conditions, such as cancer. Like a two-faced Janus, which faces opposite directions, IL-33/ST2 signaling may play contradictory roles on its impact on cancer progression through both immune and nonimmune cellular components. Accumulating evidence demonstrates both pro- and anti-tumorigenic properties of IL-33, depending on the complex nature of different tumor immune microenvironments. We summarize and discuss the most recent studies on the contradictory effects of IL-33 on cancer progression and treatment, with a goal to better understanding the various ways for IL-33 as a therapeutic target.

Abstract

Interleukin-33 (IL-33), a member of the IL-1 cytokine family, plays a critical role in maintaining tissue homeostasis as well as pathological conditions, such as allergy, infectious disease, and cancer, by promoting type 1 and 2 immune responses. Through its specific receptor ST2, IL-33 exerts multifaceted functions through the activation of diverse intracellular signaling pathways. ST2 is expressed in different types of immune cells, including Th2 cells, Th1 cells, CD8⁺ T cells, regulatory T cells (T_reg), cytotoxic NK cells, group 2 innate lymphoid cells (ILC2s), and myeloid cells. During cancer initiation and progression, the aberrant regulation of the IL-33/ST2 axis in the tumor microenvironment (TME) extrinsically and intrinsically mediates immune editing via modulation of both innate and adaptive immune cell components. The summarized results in this review suggest that IL-33 exerts dual-functioning, pro- as well as anti-tumorigenic effects depending on the tumor type, expression levels, cellular context, and cytokine milieu. A better understanding of the distinct roles of IL-33 in epithelial, stromal, and immune cell compartments will benefit the development of a targeting strategy for this IL-33/ST2 axis for cancer immunotherapy.

The TGF-β Pathway: A Pharmacological Target in Hepatocellular Carcinoma?

Transforming Growth Factor-beta (TGF-β) superfamily members are essential for tissue homeostasis and consequently, dysregulation of their signaling pathways contributes to the development of human diseases. In the liver, TGF-β signaling participates in all the stages of disease progression from initial liver injury to hepatocellular carcinoma (HCC). During liver carcinogenesis, TGF-β plays a dual role on the malignant cell, behaving as a suppressor factor at early stages, but contributing to later tumor progression once cells escape from its cytostatic effects. Moreover, TGF-β can modulate the response of the cells forming the tumor microenvironment that may also contribute to HCC progression, and drive immune evasion of cancer cells. Thus, targeting the TGF-β pathway may constitute an effective therapeutic option for HCC treatment. However, it is crucial to identify biomarkers that allow to predict the response of the tumors and appropriately select the patients that could benefit from TGF-β inhibitory therapies. Here we review the functions of TGF-β on HCC malignant and tumor microenvironment cells, and the current strategies targeting TGF-β signaling for cancer therapy. We also summarize the clinical impact of TGF-β inhibitors in HCC patients and provide a perspective on its future use alone or in combinatorial strategies for HCC treatment.

Application of biomaterials in periodontal tissue repair and reconstruction in the presence of inflammation under periodontitis through the foreign body response: Recent progress and perspectives

Periodontitis would cause dental tissue damage locally. Biomaterials substantially affect the surrounding immune microenvironment through treatment-oriented local inflammatory remodeling in dental periodontitis. This remodeling process is conducive to wound healing and periodontal tissue regeneration. Recent progress in understanding the foreign body response (FBR) and immune regulation, including cell heterogeneity, and cell-cell and cell-material interactions, has provided new insights into the design criteria for biomaterials applied in treatment of periodontitis. This review discusses recent progress and perspectives in the immune regulation effects of biomaterials to augment or reconstruct soft and hard tissue in an inflammatory microenvironment of periodontitis.

The Prognostic Value of Lymph Node Ratio in Locally Advanced Esophageal Cancer Patients Who Received Neoadjuvant Chemotherapy

BACKGROUND

The lymph node (LN) ratio (LNR) has been proposed as a sensitive prognosticator in patients with esophageal squamous cell carcinoma (ESCC), especially when the number of LNs harvested is insufficient. We investigated the association between the LNR and survival in patients with locally advanced ESCC who received neoadjuvant chemotherapy (NAC) and explored whether the LNR is a prognosticator in these patients when stratified by their response to NAC.

METHODS

We retrospectively reviewed 199 locally advanced ESCC patients who received curative resection after NAC between January 2011 and December 2019. The predictive accuracy of the adjusted X-tile cut-off values for LNR of 0 and 0.13 was compared with that in the Union for International Cancer Control pathological N (UICC pN) categories. The association between survival rate and clinicopathological features was examined.

RESULTS

Multivariate analysis identified that the LNR was an independent risk factor for recurrence-free survival [RFS; hazard ratio (HR) 6.917, p < 0.001] and overall survival (OS) (HR 4.998, p < 0.001). Moreover, even when stratified by response to NAC, the LNR was a significant independent risk factor for RFS and OS (p < 0.001). The receiver operating characteristic curves identified that the prognostic accuracy of the LNR tended to be better than that of the UICC pN factor in all cases and responders.

CONCLUSION

The LNR had a significant prognostic value in patients with locally advanced ESCC, including in those who received NAC.

Notch4 signaling limits regulatory T-cell-mediated tissue repair and promotes severe lung inflammation in viral infections

A cardinal feature of COVID-19 is lung inflammation and respiratory failure. In a prospective multi-country cohort of COVID-19 patients, we found that increased Notch4 expression on circulating regulatory T (Treg) cells was associated with disease severity, predicted mortality, and declined upon recovery. Deletion of Notch4 in Treg cells or therapy with anti-Notch4 antibodies in conventional and humanized mice normalized the dysregulated innate immunity and rescued disease morbidity and mortality induced by a synthetic analog of viral RNA or by influenza H1N1 virus. Mechanistically, Notch4 suppressed the induction by interleukin-18 of amphiregulin, a cytokine necessary for tissue repair. Protection by Notch4 inhibition was recapitulated by therapy with Amphiregulin and, reciprocally, abrogated by its antagonism. Amphiregulin declined in COVID-19 subjects as a function of disease severity and Notch4 expression. Thus, Notch4 expression on Treg cells dynamically restrains amphiregulin-dependent tissue repair to promote severe lung inflammation, with therapeutic implications for COVID-19 and related infections.

The role of T cells in age-related diseases

Age-related T cell dysfunction can lead to failure of immune tolerance mechanisms, resulting in aberrant T cell-driven cytokine and cytotoxic responses that ultimately cause tissue damage. In this Review, we discuss the role of T cells in the onset and progression of age-associated conditions, focusing on cardiovascular disorders, metabolic dysfunction, neuroinflammation and defective tissue repair and regeneration. We present different mechanisms by which T cells contribute to inflammageing and might act as modulators of age-associated diseases, including through enhanced pro-inflammatory and cytotoxic activity, defective clearance of senescent cells or regulation of the gut microbiota. Finally, we propose that 'resetting' immune system tolerance or targeting pathogenic T cells could open up new therapeutic opportunities to boost resilience to age-related diseases.

EGFR-HIF1α signaling positively regulates the differentiation of IL-9 producing T helper cells

Interleukin 9 (IL-9)-producing helper T (Th9) cells are essential for inducing anti-tumor immunity and inflammation in allergic and autoimmune diseases. Although transcription factors that are essential for Th9 cell differentiation have been identified, other signaling pathways that are required for their generation and functions are yet to be explored. Here, we identify that Epidermal Growth Factor Receptor (EGFR) is essential for IL-9 induction in helper T (Th) cells. Moreover, amphiregulin (Areg), an EGFR ligand, is critical for the amplification of Th9 cells induced by TGF-β1 and IL-4. Furthermore, our data show that Areg-EGFR signaling induces HIF1α, which binds and transactivates IL-9 and NOS2 promoters in Th9 cells. Loss of EGFR or HIF1α abrogates Th9 cell differentiation and suppresses their anti-tumor functions. Moreover, in line with its reliance on HIF1α expression, metabolomics profiling of Th9 cells revealed that Succinate, a TCA cycle metabolite, promotes Th9 cell differentiation and Th9 cell-mediated tumor regression.

Human-derived Treg and MSC combination therapy may augment immunosuppressive potency in vitro, but did not improve blood brain barrier integrity in an experimental rat traumatic brain injury model

Traumatic brain injury (TBI) causes both physical disruption of the blood brain barrier (BBB) and altered immune responses that can lead to significant secondary brain injury and chronic inflammation within the central nervous system (CNS). Cell therapies, including mesenchymal stromal cells (MSC), have been shown to restore BBB integrity and augment endogenous splenic regulatory T cells (Treg), a subset of CD4+ T cells that function to regulate immune responses and prevent autoimmunity. We have recently shown that infusion of human cord blood-derived Treg decreased neuroinflammation after TBI in vivo and in vitro. However, while both cells have demonstrated anti-inflammatory and regenerative potential, they likely utilize differing, although potentially overlapping, mechanisms. Furthermore, studies investigating these two cell types together, as a combination therapy, are lacking. In this study, we compared the ability of Treg+MSC combination therapy, as well as MSC and Treg monotherapies, to improve BBB permeability in vivo and suppress inflammation in vitro. While Treg+MSC combination did not significantly augment potency in vivo, our in vitro data demonstrates that combination therapy may augment therapeutic potency and immunosuppressive potential compared to Treg or MSC monotherapy.

Immunotherapy in Treating EGFR-Mutant Lung Cancer: Current Challenges and New Strategies

Lung cancer is the leading cause of cancer-related deaths worldwide. Immune checkpoint inhibitors, including monoclonal antibodies against programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1), have dramatically improved the survival and quality of life of a subset of non-small cell lung cancer (NSCLC) patients. Multiple predictive biomarkers have been proposed to select the patients who may benefit from the immune checkpoint inhibitors. EGFR-mutant NSCLC is the most prevalent molecular subtype in Asian lung cancer patients. However, patients with EGFR-mutant NSCLC show poor response to anti-PD-1/PD-L1 treatment. While small-molecule EGFR tyrosine kinase inhibitors (TKIs) are the preferred initial treatment for EGFR-mutant NSCLC, acquired drug resistance is severely limiting the long-term efficacy. However, there is currently no further effective treatment option for TKIs-refractory EGFR-mutant NSCLC patients. The reasons mediating the poor response of EGFR-mutated NSCLC patients to immunotherapy are not clear. Initial investigations revealed that EGFR-mutated NSCLC has lower PD-L1 expression and a low tumor mutational burden, thus leading to weak immunogenicity. Moreover, the use of PD-1/PD-L1 blockade prior to or concurrent with osimertinib has been reported to increase the risk of pulmonary toxicity. Furthermore, emerging evidence shows that PD-1/PD-L1 blockade in NSCLC patients can lead to hyperprogressive disease associated with dismal prognosis. However, it is difficult to predict the treatment toxicity. New biomarkers are urgently needed to predict response and toxicity associated with the use of PD-1/PD-L1 immunotherapy in EGFR-mutated NSCLC. Recently, promising data have emerged to suggest the potentiation of PD-1/PD-L1 blockade therapy by anti-angiogenic agents and a few other novel therapeutic agents. This article reviews the current investigations about the poor response of EGFR-mutated NSCLC to anti-PD-1/PD-L1 therapy, and discusses the new strategies that may be adopted in the future.

Facilitating resolution of life-threatening acute GVHD with human chorionic gonadotropin and epidermal growth factor

Acute graft-versus-host disease (aGVHD) is a potentially fatal complication of allogeneic hematopoietic cell transplantation that fails to improve with intense immunosuppression in some patients. We hypothesized that urinary-derived human chorionic gonadotropin (uhCG) could help facilitate resolution of life-threatening aGVHD when added as supportive care via 2 potential mechanisms: immunomodulation (akin to its role in pregnancy) and supplementation of epidermal growth factor (EGF; to aid in epithelial repair). In a phase 1 study, 26 participants received subcutaneous injections of uhCG in addition to standard immunosuppression (13 receiving initial therapy for high-risk aGVHD [according to the Minnesota criteria] and 13 receiving second-line therapy). Participants underwent serial blood testing for biomarkers of hormone response, immune modulation, and aGVHD activity on study. uhCG was well tolerated, with no dose-limiting toxicities. Sixty-two percent of patients in the high-risk cohort and 54% of patients in the second-line cohort had a complete response at study day 28. Plasma EGF was elevated sixfold (from 4 to 24 pg/mL; P = .02) at 6 hours postdose in the high-risk cohort, in contrast to no peak in plasma EGF in the more severe second-line cohort. After 1 week of uhCG, patients reported a twofold increase in the regulatory T cell to conventional T-cell ratio, suggesting immune modulation despite high-dose steroids. Responding patients reported significantly lower plasma amphiregulin and higher plasma butyrate levels at study completion, suggesting improvement in mucosal damage over time. uhCG is a novel, safe, supportive therapy, proceeding to phase 2 testing at 2000 units/m2 in high-risk aGVHD. This study was registered at www.clinicaltrials.gov as #NCT02525029.

Tissue mast cell counts may be associated with decreased severity of gastrointestinal acute GVHD and nonrelapse mortality

The functions of mast cells in human graft-versus-host disease (GVHD) are unknown. We studied 56 patients who had an allogeneic hematopoietic cell transplantation (alloHCT) with a biopsy for diagnosis of gastrointestinal tract (GIT) GVHD before any treatment (including steroids): 35 with GIT GVHD, 21 HCT recipients whose biopsies did not confirm GVHD, and 9 with a new diagnosis of inflammatory bowel disease (IBD) as a comparison. The median number of mast cells (mean of CD117+ cells, counted in 3 selected spots under 40× magnification) was similar between patients with GVHD (59 cells) and those without GVHD (60 cells). However, the median number of mast cells was significantly associated with maximum clinical stage of GIT GVHD; the lowest counts of mast cells were observed in the highest clinical stage of GIT GVHD (stage 1, 80; stage 2, 69; stage 3, 54; stage 4, 26; P = .01). Moreover, every decrease by 10 mast cells was associated with increased nonrelapse mortality through 1 year (hazard ratio, 0.77; 95% confidence interval, 0.59-1.00; P = .05). AlloHCT recipients all had significantly fewer mast cells, even those without GVHD compared with those with IBD (median, 59 vs 119; P < .01). The median number of GIT mast cells was also significantly lower in patients who received myeloablative conditioning (61.5 cells) than in those who received reduced intensity conditioning (78 cells) in the entire study population (P = .02). We conclude that GIT mast cells are depleted in all alloHCT patients, more prominently in those receiving myeloablative conditioning and those with severe GIT GVHD. Our novel findings warrant further investigation into the biological effects of mast cells in GIT GVHD.

Kidney GATA3+ regulatory T cells play roles in the convalescence stage after antibody-mediated renal injury

FoxP3+ regulatory T cells (Tregs) play crucial roles in peripheral immune tolerance. In addition, Tregs that reside or accumulate in nonlymphoid tissues, called tissue Tregs, exhibit tissue-specific functions and contribute to the maintenance of tissue homeostasis and repair. In an experimental mouse model of crescentic glomerulonephritis induced by an anti-glomerular basement membrane antibody, Tregs started to accumulate in the kidney on day 10 of disease onset and remained at high levels (~30-35% of CD4+ T cells) during the late stage (days 21-90), which correlated with stable disease control. Treg depletion on day 21 resulted in the relapse of renal dysfunction and an increase in Th1 cells, suggesting that Tregs are essential for disease control during the convalescence stage. The Tregs that accumulated in the kidney showed tissue Treg phenotypes, including high expression of GATA3, ST2 (the IL33 receptor subunit), amphiregulin (Areg), and PPARγ. Although T-bet+ Tregs and RORγt+ Tregs were observed in the kidney, GATA3+ Tregs were predominant during the convalescence stage, and a PPARγ agonist enhanced the accumulation of GATA3+ Tregs in the kidney. To understand the function of specific genes in kidney Tregs, we developed a novel T cell transfer system to T cell-deficient mice. This experiment demonstrates that ST2, Areg, and CCR4 in Tregs play important roles in the accumulation of GATA3+ Tregs in the kidney and in the amelioration of renal injury. Our data suggest that GATA3 is important for the recruitment of Tregs into the kidney, which is necessary for convalescence after renal tissue destruction.

Cancer metastasis as a non-healing wound

Most cancer deaths are caused by metastasis: recurrence of disease by disseminated tumour cells at sites distant from the primary tumour. Large numbers of disseminated tumour cells are released from the primary tumour, even during the early stages of tumour growth. However, only a minority survive as potential seeds for future metastatic outgrowths. These cells must adapt to a relatively inhospitable microenvironment, evade immune surveillance and progress from the micro- to macro-metastatic stage to generate a secondary tumour. A pervasive driver of this transition is chronic inflammatory signalling emanating from tumour cells themselves. These signals can promote migration and engagement of stem and progenitor cell function, events that are also central to a wound healing response. In this review, we revisit the concept of cancer as a non-healing wound, first introduced by Virchow in the 19th century, with a new tumour cell-intrinsic perspective on inflammation and focus on metastasis. Cellular responses to inflammation in both wound healing and metastasis are tightly regulated by crosstalk with the surrounding microenvironment. Targeting or restoring canonical responses to inflammation could represent a novel strategy to prevent the lethal spread of cancer.

Immune Checkpoint Inhibitors in EGFR-Mutated NSCLC: Dusk or Dawn?

Although immune checkpoint inhibitors (ICIs) that target programmed cell death protein-1/programmed cell death ligand-1 axis have significantly shifted the treatment paradigm in advanced NSCLC, clinical benefits of these agents are limited in patients with EGFR-mutated NSCLC. Several predictive biomarkers (e.g., programmed cell death ligand-1 expression, tumor mutation burden), which have been validated in EGFR-wild type NSCLC, however, are not efficacious in EGFR-mutated tumors, suggesting the unique characteristics of tumor microenvironment of EGFR-mutated NSCLC. Here, we first summarized the clinical evidence on the efficacy of ICIs in patients with EGFR-mutated NSCLC. Then, the cancer immunogram features of EGFR-mutated NSCLC was depicted to visualize the state of cancer-immune system interactions, including tumor foreignness, tumor sensitivity to immune effectors, metabolism, general immune status, immune cell infiltration, cytokines, and soluble molecules. We further discussed the potential subpopulations with EGFR mutations that could benefit from ICI treatment. Lastly, we put forward future strategies to adequately maximize the efficacy of ICI treatment in patients with EGFR-mutated NSCLC in the upcoming era of combination immunotherapies.

Butyrate modulates adipose-derived stem cells isolated from polygenic obese and diabetic mice to drive enhanced immunosuppression

BACKGROUND AIMS

Adipose-derived stem cells (ASCs) offer promising therapeutic possibilities for immunomodulation. Butyrate (BA) exerts potent anti-inflammatory effects and exhibits multiple regulatory functionalities in adipose tissue (AT). The authors aimed to explore whether BA modulates ASCs to augment their immunosuppressive capabilities.

METHODS

The authors examined the potency of BA and ASCs for controlling anti-CD3 plus CD28-stimulated splenocyte proliferation in vitro, both in combination and with pre-treatment. Further, the authors investigated genes specifically upregulated by BA-treated ASCs, which were harvested from ASC-splenocyte co-culture after the removal of floating splenocytes. In addition, the authors investigated the influence of oral BA supplementation on the ex vivo immunosuppressive potency of ASCs from BALB/c and Tsumura, Suzuki, obese, diabetes (TSOD) mice.

RESULTS

BA enhanced the immunosuppressive potency of ASCs when directly added to ASC-splenocyte co-cultures or via pre-conditioning treatment. The percentages of ASC-induced Foxp3⁺ regulatory T cells increased, whereas the numbers of ASC-suppressed T helper 17 cells further decreased after BA exposure. The messenger RNA expression levels of inducible nitric oxide (NO) synthase (iNOS), chemokines, IL-10 and amphiregulin in ASCs co-cultured with activated splenocytes were upregulated after incubation with BA. This was accompanied by an amplification of iNOS-inducing cytokines, interferon gamma and tumor necrosis factor alpha in the ASC-splenocyte co-culture, triggering ASCs to produce high NO levels under the influence of BA. Mechanistically, the authors detected BA-mediated acetylated histone H3 in ASCs. BA treatment consistently improved the immunosuppressive potency of ASCs derived from both BALB/c and TSOD mice.

CONCLUSIONS

The use of BA to counteract metaflammation by restoring the defective immunomodulation of ASCs from dysregulated AT in obese donors is recommended.

Hyperprogressive Disease: Main Features and Key Controversies

Along with the positioning of immunotherapy as a preferential treatment for a wide variety of neoplasms, a new pattern of response consisting in a sudden acceleration of tumor growth has been described. This phenomenon has received the name of "hyperprogressive disease", and several definitions have been proposed for its identification, most of them relying on radiological criteria. However, due to the fact that the cellular and molecular mechanisms have not been elucidated yet, there is still some debate regarding whether this fast progression is induced by immunotherapy or only reflects the natural course of some highly aggressive neoplasms. Moreover, contradictory results of trials including patients with different cancer types suggest that both the incidence, the associated factors and the implications regarding prognosis might differ depending on tumor histology. This article intends to review the main publications regarding this matter and critically approach the most controversial aspects.

Afatinib Exerts Immunomodulatory Effects by Targeting the Pyrimidine Biosynthesis Enzyme CAD

Current clinical trials of combined EGFR-tyrosine kinase inhibitors (TKI) and immune checkpoint blockade (ICB) therapies show no additional effect. This raises questions regarding whether EGFR-TKIs attenuate ICB-enhanced CD8⁺ T lymphocyte function. Here we show that the EGFR-TKI afatinib suppresses CD8⁺ T lymphocyte proliferation, and we identify CAD, a key enzyme of de novo pyrimidine biosynthesis, to be a novel afatinib target. Afatinib reduced tumor-infiltrating lymphocyte numbers in Lewis lung carcinoma (LLC)-bearing mice. Early afatinib treatment inhibited CD8⁺ T lymphocyte proliferation in patients with non-small cell lung cancer, but their proliferation unexpectedly rebounded following long-term treatment. This suggests a transient immunomodulatory effect of afatinib on CD8⁺ T lymphocytes. Sequential treatment of afatinib with anti-PD1 immunotherapy substantially enhanced therapeutic efficacy in MC38 and LLC-bearing mice, while simultaneous combination therapy showed only marginal improvement over each single treatment. These results suggest that afatinib can suppress CD8⁺ T lymphocyte proliferation by targeting CAD, proposing a timing window for combined therapy that may prevent the dampening of ICB efficacy by EGFR-TKIs. SIGNIFICANCE: This study elucidates a mechanism of afatinib-mediated immunosuppression and provides new insights into treatment timing for combined targeted therapy and immunotherapy. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/12/3270/F1.large.jpg.

Mesenchymal Stem and Stromal Cells Harness Macrophage-Derived Amphiregulin to Maintain Tissue Homeostasis

The cross-talk between mesenchymal stem and stromal cells (MSCs) and macrophages is critical for the restoration of tissue homeostasis after injury. Here, we demonstrate a pathway through which MSCs instruct macrophages to resolve inflammation and preserve tissue-specific stem cells, leading to homeostasis in mice with autoimmune uveoretinitis and sterile-injury-induced corneal epithelial stem cell deficiency. Distinct from their conventional role in macrophage reprogramming to anti-inflammatory phenotype by a PGE2-dependent mechanism, MSCs enhance the phagocytic activity of macrophages, which partly depends on the uptake of MSC mitochondria-containing extracellular vesicles. The MSC-primed macrophages increase the secretion of amphiregulin (AREG) in a phagocytosis-dependent manner. AREG is essential for MSC-primed macrophages to suppress immune responses through regulatory T (Treg) cells and to protect corneal epithelial stem cells via apoptosis inhibition and proliferation promotion. Hence, the data reveal that MSCs harness macrophage-derived AREG to maintain tissue homeostasis after injury and provide a therapeutic target in immune-mediated disease and regenerative medicine.

The Role of Innate and Adaptive Immune Cells in Skeletal Muscle Regeneration

Skeletal muscle regeneration is highly dependent on the inflammatory response. A wide variety of innate and adaptive immune cells orchestrate the complex process of muscle repair. This review provides information about the various types of immune cells and biomolecules that have been shown to mediate muscle regeneration following injury and degenerative diseases. Recently developed cell and drug-based immunomodulatory strategies are highlighted. An improved understanding of the immune response to injured and diseased skeletal muscle will be essential for the development of therapeutic strategies.

Specialized regulatory T cells control venous blood clot resolution through SPARC

The cells and mechanisms involved in blood clot resorption are only partially known. We show that regulatory T cells (Tregs) accumulate in venous blood clots and regulate thrombolysis by controlling the recruitment, differentiation and matrix metalloproteinase (MMP) activity of monocytes. We describe a clot Treg population that forms the matricellular acid- and cysteine-rich protein SPARC (secreted protein acidic and rich in cysteine) and show that SPARC enhances monocyte MMP activity and that SPARC+ Tregs are crucial for blood clot resorption. By comparing different treatment times, we define a therapeutic window of Treg expansion that accelerates clot resorption.

Innate Lymphoid Cells and Adaptive Immune Cells Cross-Talk: A Secret Talk Revealed in Immune Homeostasis and Different Inflammatory Conditions

The inflammatory immune response has evolved to protect the host from different pathogens, allergens, and endogenous death or damage-associated molecular patterns. Both innate and adaptive immune components are crucial in inducing an inflammatory immune response depending on the stimulus type and its duration of exposure or the activation of the primary innate immune response. As the source of inflammation is removed, the aggravated immune response comes to its homeostatic level. However, the failure of the inflammatory immune response to subside to its normal level generates chronic inflammatory conditions, including autoimmune diseases and cancer. Innate lymphoid cells (ILCs) are newly discovered innate immune cells, which are present in abundance at mucosal surfaces, including lungs, gastrointestinal tract, and reproductive tract. Also, they are present in peripheral blood circulation, skin, and lymph nodes. They play a crucial role in generating the pro-inflammatory immune response during diverse conditions. On the other hand, adaptive immune cells, including different types of T and B cells are major players in the pathogenesis of autoimmune diseases (type 1 diabetes mellitus, rheumatoid arthritis, psoriasis, and systemic lupus erythematosus, etc.) and cancers. Thus the article is designed to discuss the immunological role of different ILCs and their interaction with adaptive immune cells in maintaining the immune homeostasis, and during inflammatory autoimmune diseases along with other inflammatory conditions (excluding pathogen-induced inflammation), including cancer, graft-versus-host diseases, and human pregnancy.

The Binary Classification of Protein Kinases

In an earlier publication a binary model for chronic diseases classification has been proposed. According to the model, chronic diseases were classified as “high Treg” or “low Treg” diseases, depending on whether the immune response is anti- or pro-inflammatory and assuming that regulatory T cells are major determinants of the response. It turned out that most cancers are “high Treg” diseases, while autoimmune diseases are “low Treg”. This paper proposes a molecular cause for this binary response. The mechanism proposed depends on the effect of protein kinases on the immune system. Thus, protein kinases are classified as anti- or pro-inflammatory kinases depending on whether they drive “high Treg” or “low Treg” diseases. Observations reported in the earlier publication can be described in terms of anti-inflammatory kinase (AIK) or pro-inflammatory kinase (PIK) activity. Analysis of literature data reveals that the two classes of kinases display distinctive properties relating to their interactions with pathogens and environmental factors. Pathogens that promote Treg activity (“high Treg” pathogens) activate AIKs, while pathogens that suppress Treg activity (“low Treg” pathogens) activate PIKs. Diseases driven by AIKs are associated with “high Treg” pathogens while those diseases driven by PIKs are associated with “low Treg” pathogens. By promoting the activity of AIKs, alcohol consumption increases the risk of “high Treg” cancers but decreases the risk of some “low Treg” autoimmune diseases. JAK1 gain-of-function mutations are observed at high frequencies in autoimmune diseases while JAK1 loss-of-function mutations are observed at high frequencies in cancers with high tumor-infiltrating Tregs. It should also be noted that the corresponding two classes of protein kinase inhibitors are mutually exclusive in terms of their approved therapeutic indications. There is no protein kinase inhibitor that is approved for the treatment of both autoimmune diseases and “high Treg” cancers. Although there are exceptions to the conclusions presented above, these conclusions are supported by the great bulk of published data. It therefore seems that the binary division of protein kinases is a useful tool for elucidating (at the molecular level) many distinctive properties of cancers and autoimmune diseases.

The Unique Biology behind the Early Onset of Breast Cancer

Breast cancer commonly affects women of older age; however, in developing countries, up to 20% of breast cancer cases present in young women (younger than 40 years as defined by oncology literature). Breast cancer in young women is often defined to be aggressive in nature, usually of high histological grade at the time of diagnosis and negative for endocrine receptors with poor overall survival rate. Several researchers have attributed this aggressive nature to a hidden unique biology. However, findings in this aspect remain controversial. Thus, in this article, we aimed to review published work addressing somatic mutations, chromosome copy number variants, single nucleotide polymorphisms, differential gene expression, microRNAs and gene methylation profile of early-onset breast cancer, as well as its altered pathways resulting from those aberrations. Distinct biology behind early-onset of breast cancer was clear among estrogen receptor-positive and sporadic cases. However, further research is needed to determine and validate specific novel markers, which may help in customizing therapy for this group of patients.

T reg-specific insulin receptor deletion prevents diet-induced and age-associated metabolic syndrome

Adipose tissue (AT) regulatory T cells (T regs) control inflammation and metabolism. Diet-induced obesity causes hyperinsulinemia and diminishes visceral AT (VAT) T reg number and function, but whether these two phenomena were mechanistically linked was unknown. Using a T reg–specific insulin receptor (Insr) deletion model, we found that diet-induced T reg dysfunction is driven by T reg–intrinsic insulin signaling. Compared with Foxp3^cre mice, after 13 wk of high-fat diet, Foxp3^creInsr^fl/fl mice exhibited improved glucose tolerance and insulin sensitivity, effects associated with lower AT inflammation and increased numbers of ST2⁺ T regs in brown AT, but not VAT. Similarly, Foxp3^creInsr^fl/fl mice were protected from the metabolic effects of aging, but surprisingly had reduced VAT T regs and increased VAT inflammation compared with Foxp3^cre mice. Thus, in both diet- and aging-associated hyperinsulinemia, excessive Insr signaling in T regs leads to undesirable metabolic outcomes. Ablation of Insr signaling in T regs represents a novel approach to mitigate the detrimental effects of hyperinsulinemia on immunoregulation of metabolic syndrome.

Antitumour immunity regulated by aberrant ERBB family signalling

Aberrant signalling of ERBB family members plays an important role in tumorigenesis and in the escape from antitumour immunity in multiple malignancies. Molecular-targeted agents against these signalling pathways exhibit robust clinical efficacy, but patients inevitably experience acquired resistance to these molecular-targeted therapies. Although cancer immunotherapies, including immune checkpoint inhibitors (ICIs), have shown durable antitumour response in a subset of the treated patients in multiple cancer types, clinical efficacy is limited in cancers harbouring activating gene alterations of ERBB family members. In particular, ICI treatment of patients with non-small cell lung cancers with epidermal growth factor receptor (EGFR) alterations and breast cancers with HER2 alterations failed to show clinical benefits, suggesting that EGFR and HER2 signalling may have an essential role in inhibiting antitumour immune responses. Here, we discuss the mechanisms by which the signalling of ERBB family members affects not only autonomous cancer hallmarks, such as uncontrolled cell proliferation, but also antitumour immune responses in the tumour microenvironment and the potential application of immune-genome precision medicine into immunotherapy and molecular-targeted therapy focusing on the signalling of ERBB family members.

Resident Innate Immune Cells in the Cornea

The cornea is a special interface between the internal ocular tissue and the external environment that provides a powerful chemical, physical, and biological barrier against the invasion of harmful substances and pathogenic microbes. This protective effect is determined by the unique anatomical structure and cellular composition of the cornea, especially its locally resident innate immune cells, such as Langerhans cells (LCs), mast cells (MCs), macrophages, γδ T lymphocytes, and innate lymphoid cells. Recent studies have demonstrated the importance of these immune cells in terms of producing different cytokines and other growth factors in corneal homeostasis and its pathologic conditions. This review paper briefly describes the latest information on these resident immune cells by specifically analyzing research from our laboratory.

Immune regulation in renal inflammation

Renal inflammation, induced by autoantigen recognition or toxic drugs, leads to renal tissue injury and decline in kidney function. Recent studies have demonstrated the crucial role for regulatory T cells in suppressing pathogenic adaptive but also innate immune responses in the inflamed kidney. However, there is also evidence for other immune cell populations with immunosuppressive function in renal inflammation. This review summarizes mechanisms of immune cell regulation in immune-mediated glomerulonephritis and acute and chronic nephrotoxicity.

In vivo silencing of amphiregulin by a novel effective Self-Assembled-Micelle inhibitory RNA ameliorates renal fibrosis via inhibition of EGFR signals

Amphiregulin (AREG) is a transmembrane glycoprotein recently implicated in kidney fibrosis. Previously, we reported that the AREG-targeting Self-Assembled-Micelle inhibitory RNA (SAMiRNA-AREG) alleviated fibrosis by stably silencing the AREG gene, and reduced the side effects of conventional siRNA treatment of pulmonary fibrosis. However, the therapeutic effect of SAMiRNA-AREG in renal fibrosis has not been studied until now. We used two animal models of renal fibrosis generated by a unilateral ureteral obstruction (UUO) and an adenine diet (AD) to investigate whether SAMiRNA-AREG inhibited renal fibrosis. To investigate the delivery of SAMiRNA-AREG to the kidney, Cy5-labeled SAMiRNA-AREG was injected into UUO- and AD-induced renal fibrosis models. In both kidney disease models, SAMiRNA-AREG was delivered primarily to the damaged kidney. We also confirmed the protective effect of SAMiRNA-AREG in renal fibrosis models. SAMiRNA-AREG markedly decreased the UUO- and AD-induced AREG mRNA expression. Furthermore, the mRNA expression of fibrosis markers, including α-smooth muscle actin, fibronectin, α1(I) collagen, and α1(III) collagen in the UUO and AD-induced kidneys, was diminished in the SAMiRNA-AREG-treated mice. The transcription of inflammatory markers (tumor necrosis factor-α and monocyte chemoattractant protein-1) and adhesion markers (vascular cell adhesion molecule 1 and intercellular adhesion molecule 1) was attenuated. The hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining results showed that SAMiRNA-AREG decreased renal fibrosis, AREG expression, and epidermal growth factor receptor (EGFR) phosphorylation in the UUO- and AD-induced models. Moreover, we studied the effects of SAMiRNA-AREG in response to TGF-β1 in mouse and human proximal tubule cells, and mouse fibroblasts. TGF-β1-induced extracellular matrix production and myofibroblast differentiation were attenuated by SAMiRNA-AREG. Finally, we confirmed that upregulated AREG in the UUO or AD models was mainly localized in the distal tubules. In conclusion, SAMiRNA-AREG represents a novel siRNA therapeutic for renal fibrosis by suppressing EGFR signals.

Pretreatment neutrophil-to-lymphocyte ratio predicts treatment efficacy and prognosis of cytotoxic anticancer drugs, molecular targeted drugs, and immune checkpoint inhibitors in patients with advanced non-small cell lung cancer

Background

Neutrophil-to-lymphocyte ratio (NLR) has recently attracted attention as a prognostic predictor in patients with non-small cell lung cancer (NSCLC) who receive immune checkpoint inhibitors (ICIs). However, the utility of NLR in relation to cytotoxic anticancer drugs or molecular targeted drugs remains unclear. We determined if NLR could predict the treatment efficacy and prognosis in NSCLC patients who receive cytotoxic anticancer drugs or molecular targeted drugs, as well as ICIs, in a cross-sectional manner.

Methods

Of 658 patients with advanced NSCLC who received first-line systemic treatment in our hospital between 2008 and 2019, 312 who met the analytical criteria were included in the study. We retrospectively analyzed the ability of NLR with a cut-off value of 5 to predict time to treatment failure (TTF) and overall survival (OS) in patients who received the following treatments: first-line treatment with molecular targeted drugs (mt group, n=100); first-line treatment with cytotoxic anticancer drugs (wt group, n=212); and first-line treatment with cytotoxic anticancer drugs followed by ICIs (ICI group, n=58).

Results

In the high- and low-NLR mt subgroups, median TTFs were 6.7 and 14.9 months (P<0.01), respectively, and median survival times (MSTs) were 17.8 and 39.1 months (P<0.01), respectively. In the high- and low-NLR wt subgroups, median TTFs were 1.5 and 5.8 months (P<0.01), and MSTs were 6.3 and 20.7 months (P<0.01), respectively. In the high- and low-NLR ICI subgroups, median TTFs were 1.3 and 6.8 months (P<0.01), and MSTs were 9.2 and 25.8 months (P<0.01), respectively. Multivariate analysis identified NLR as a significant independent predictor of TTF [hazard ratio (HR) 1.89, P=0.01; HR 2.51, P<0.01; and HR 5.06, P<0.01 in the mt, wt, and ICI groups, respectively) and OS (HR 3.81, P<0.01; HR 2.59, P<0.01; and HR 2.48, P<0.01, respectively).

Conclusions

This study showed that NLR might be a predictor of treatment efficacy and prognosis in advanced NSCLC patients who receive various systemic treatments. This finding of consistent applicability of NLR to a wide variety of systemic treatments is of great significance.

A Potential Role of Group 2 Innate Lymphoid Cells in Eosinophilic Chronic Rhinosinusitis With Nasal Polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP), a type 2-based upper airway disease, is mainly characterized by high asthma comorbidity and recurrence after surgery. It has been shown that type 2 cytokines, including interleukin (IL)-4, IL-5, and IL-13 released from T helper 2 (Th2) cells as well as group 2 innate lymphoid cells (ILC2s), contribute to chronic inflammation of CRSwNP. This review summarizes recent progresses made in our understanding of ILC2 activity, particularly ILC2 accumulation at airway inflammation sites, cooperation with Th2 cells in aggravating the CRSwNP inflammatory process and interactions with regulatory T cells (Tregs) in resisting Tregs-mediated suppressive function in allergic inflammation. A better understanding of the biology of ILC2s should lay a good foundation in elucidating the pathogenesis of CRSwNP, and subsequently may lead to the development of new therapeutic strategies for the management of CRSwNP.

Treg cell therapy: How cell heterogeneity can make the difference

CD4⁺ CD25^high CD127^low/- FOXP3⁺ T regulatory cells are responsible for maintaining immune tolerance and controlling excessive immune responses. Treg cell use in pre-clinical animal models showed the huge therapeutic potential of these cells in immune-mediated diseases and laid the foundations for their applications in therapy in humans. Currently, there are several clinical trials utilizing the adoptive transfer of Treg cells to reduce the morbidity in autoimmune disorders, allogeneic HSC transplantation, and solid organ transplantation. However, a large part of them utilizes total Treg cells without distinction of their biological variability. Many studies on the heterogeneity of Treg cell population revealed distinct subsets with different functions in the control of the immune response and induction of peripheral tolerance. Some of these subsets also showed a role in controlling the general homeostasis of non-lymphoid tissues. All these Treg cell subsets and their peculiar properties can be therefore exploited to develop novel therapeutic approaches. This review describes these functionally distinct subsets, their phenotype, homing properties and functions in lymphoid and non-lymphoid tissues. In addition, we also discuss the limitations in using Treg cells as a cellular therapy and the strategies to enhance their efficacy.

Combinations using checkpoint blockade to overcome resistance

The advent of immunotherapy for cancer represented a paradigm shift in the treatment approach of neoplasia. Immune-checkpoint inhibitors (ICIs) were demonstrated to significantly improve outcomes, including overall survival across several cancer types, with yearly-durable responses. Nevertheless, many patients derive minor or no benefit with immune checkpoint (IC)-blockade, including patients with cancer types traditionally considered immunogenic. Combination strategies of ICIs with chemotherapy, radiotherapy, targeted therapies or other immunotherapy compounds have been conceived in order to boost the immune-responses and potentially overcome resistance to ICIs. This review focuses on mechanisms underlying resistance to IC-blockade and provides an overview of potential advantages and limitations of combination strategies currently under investigation.

Clinical outcomes of immune checkpoint blockades and the underlying immune escape mechanisms in squamous and adenocarcinoma NSCLC

Immune checkpoint blockades (ICBs) have changed the standard of care of squamous and adenocarcinoma non‐small cell lung cancer (NSCLC). Whereas detailed researches regarding ICBs in the two major histological subtypes are rare. In order to uncover the clinical efficacy differences between squamous and adenocarcinoma NSCLC and better understand the underlying immune‐regulatory mechanisms, we compared the survival benefits of ICBs between the two subtypes by revealing phase 3 randomized trials and attempted to uncover the immune‐regulatory discrepancy. Generally, compared with nonsquamous NSCLC, squamous NSCLC benefited more from ICBs in Keynote 024, CheckMate 026, CheckMate 227 and CheckMate 017 and similar in OAK, but less in Keynote 010 and PACIFIC. We revealed that the tumor mutation burden (TMB) level, the programmed cell death ligand 1 (PD‐L1) expression, tumor infiltrating lymphocytes (TILs) in the tumor microenvironment (TME), chemokines, and oncogenic driver alterations within the two subtypes may contributed to the clinical outcomes of ICBs. We prospected that the combinations of ICBs with chemotherapy, radiation therapy, and antiangiogenic therapy could be promising strategies to re‐immunize the less immunogenic tumors and further enhance the efficacy of ICBs.

Group 2 Innate Lymphoid Cells: A Double-Edged Sword in Cancer?

Group 2 Innate Lymphoid Cells (ILC2s) belong to the family of helper ILCs which provide host defense against infectious agents, participate in inflammatory responses and mediate lymphoid organogenesis and tissue repair, mainly at the skin and mucosal level. Based on their transcriptional, phenotypic and functional profile, ILC2s mirror the features of the adaptive CD4+ Th2 cell subset, both contributing to the so-called type 2 immune response. Similar to other ILCs, ILC2s are rapidly activated by signals deriving from tissue and/or other tissue-resident immune cells. The biologic activity of ILCs needs to be tightly regulated in order to prevent them from contributing to severe inflammation and damage in several organs. Indeed, ILC2s display both enhancing and regulatory roles in several pathophysiological conditions, including tumors. In this review, we summarize the actual knowledge about ILC2s ability to induce or impair a protective immune response, their pro- or antitumor activity in murine models, human (children and adults) pathologies and the potential strategies to improve cancer immunotherapy by exploiting the features of ILC2s.

Regulatory T cell heterogeneity and therapy in autoimmune diseases

Regulatory T (Treg) cells are a group of CD4⁺ T cell with high expression of CD25 and cell linage specific transcription factor forkhead box P3 (Foxp3) and play a vital role in maintaining immune homeostasis. In the last two decades, researchers have shown that Treg cells involved in the occurrence, development and prognosis of many diseases, especially in autoimmune diseases. Treg targeted therapies, such as low-dose interleukin-2 (IL-2) treatment and Treg infusion therapy, which are aimed at restoring the number or function of Treg cells, have become a hot topic in clinical trials of these diseases. It is believed that Treg cells are heterogeneous. Different subsets of Treg cells have various functions and play different parts in immunomodulatory. Gaining insights into Treg heterogeneity will help us further understand the function of Treg cells and provide news ideas for the selective therapeutic manipulation of Treg cells. In this review, we mainly summarize the heterogeneity of Treg cells and their potential therapeutic value in autoimmune diseases.

Hypothesis generative head-to-head study comparing efficacy of afatinib and osimertinib based on immunological biomarkers in Japanese NSCLC patients with EGFR mutations (Heat on Beat study)

Background:

In the FLAURA trial, superiority of osimertinib over the standard of care (SOC) was not demonstrated in Asian patients; SOC seemed favorable among Japanese patients (hazard ratio 1.39, 95% confidence interval 0.82–2.33). Three reasons are suggested: since rechallenge with epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) is covered by health insurance in Japan, EGFR-TKI rechallenge rate was higher in SOC than in the osimertinib group, which resulted in a long-term sequential administration of EGFR-TKIs; treatment discontinuation rate was high in the osimertinib group due to adverse events such as interstitial pneumonia among Japanese patients. EGFR-TKIs enhance tumor antigen-specific cytotoxicity of T cells, especially first- and second-generation EGFR-TKIs, which are more active against various cells with wild-type EGFR, including regulatory T cells. Consequently, subsequent immune checkpoint inhibitor therapy seemed more promising in the SOC group. Therefore, optimal first-line EGFR-TKI for EGFR-mutant advanced lung cancer may not have been identified in Japanese patients.

Methods:

The Heat on Beat study is a randomized, open-label, multicenter, phase II study to compare OS between initial treatment with afatinib and osimertinib in treatment-naïve patients with advanced or recurrent EGFR-mutant NSCLC. Exploration of immunomonitoring through peripheral blood mononuclear cells will also be performed, before, during, and after treatment. Treatment-naïve EGFR mutation-positive non-small cell lung cancer (NSCLC) patients (N = 100) will be randomized to two groups in a 1:1 ratio. The co-primary endpoints are 3-year survival rate and characterization of immune environment associated with response to afatinib, osimertinib, or immune checkpoint inhibitors. Enrollment will start in May 2020 at 28 sites in Japan and continue for 1 year, with 3-year follow-up.

Discussion:

Because there is no clinical trial comparing second- with third-generation EGFR-TKI for advanced EGFR-mutant NSCLC, our study would provide a major impact on clinical practice.

Trial registration

Japan Registry of Clinical Trials, jRCTs031190221, registered date: 25 February 2020, https://jrct.niph.go.jp/en-latest-detail/jRCTs031190221

Neural Regulation of Interactions Between Group 2 Innate Lymphoid Cells and Pulmonary Immune Cells

Emerging evidence supports the involvement of nervous system in the regulation of immune responses. Group 2 innate lymphoid cells (ILC2), which function as a crucial bridge between innate and adaptive immunity, are present in large numbers in barrier tissues. Neuropeptides and neurotransmitters have been found to participate in the regulation of ILC2, adding a new dimension to neuroimmunity. However, a comprehensive and detailed overview of the mechanisms of neural regulation of ILC2, associated with previous findings and prospects for future research, is still lacking. In this review, we compile existing information that supports neurons as yet poorly understood regulators of ILC2 in the field of lung innate and adaptive immunity, focusing on neural regulation of the interaction between ILC2 and pulmonary immune cells.