Accumulation of T-helper 22 cells, interleukin-22 and myeloid-derived suppressor cells promotes gastric cancer progression in elderly patients

Everolimus alleviates CD4+ T cell inflammation by regulating autophagy and cellular redox homeostasis

Aging is associated with the onset and progression of multiple diseases, which limit health span. Chronic low-grade inflammation in the absence of overt infection is considered the simmering source that triggers age-associated diseases. Failure of many cellular processes during aging is mechanistically linked to inflammation; however, the overall decline in the cellular homeostasis mechanism of autophagy has emerged as one of the top and significant inducers of inflammation during aging, frequently known as inflammaging. Thus, physiological or pharmacological interventions aimed at improving autophagy are considered geroprotective. Rapamycin analogs (rapalogs) are known for their ability to inhibit mTOR and thus regulate autophagy. This study assessed the efficacy of everolimus, a rapalog, in regulating inflammatory cytokine production in T cells from older adults. CD4+ T cells from older adults were treated with a physiological dose of everolimus (0.01 µM), and indices of autophagy and inflammation were assessed to gain a mechanistic understanding of the effect of everolimus on inflammation. Everolimus (Ever) upregulated autophagy and broadly alleviated inflammatory cytokines produced by multiple T cell subsets. Everolimus's ability to alleviate the cytokines produced by Th17 subsets of T cells, such as IL-17A and IL-17F, was dependent on autophagy and antioxidant signaling pathways. Repurposing the antineoplastic drug everolimus for curbing inflammaging is promising, given the drug's ability to restore multiple cellular homeostasis mechanisms.

Current status and future perspective of natural killer cell therapy for cancer

Natural killer (NK) cells possess innate abilities to effectively eliminate cancer cells. However, because of difficulties of proliferation and easy to be induced dysfunction in the setting of cancer post NK cell therapy, the curative effect of NK cell infusion has been constrained and not been widely applicable in clinical practice. The rapid development of biotechnology has promoted the development of NK cell therapy for cancer treatment. In this review, we will provide a comprehensive analysis of the current status and future prospects of NK cell therapy for cancer, focusing on the biological characteristics of NK cells, as well as strategies to enhance their targeting capabilities and overcome tumor immune suppression within the microenvironment.

Thymus-derived hormonal and cellular control of cancer

The thymus gland is a central lymphoid organ in which developing T cell precursors, known as thymocytes, undergo differentiation into distinct type of mature T cells, ultimately migrating to the periphery where they exert specialized effector functions and orchestrate the immune responses against tumor cells, pathogens and self-antigens. The mechanisms supporting intrathymic T cell differentiation are pleiotropically regulated by thymic peptide hormones and cytokines produced by stromal cells in the thymic microenvironment and developing thymocytes. Interestingly, in the same way as T cells, thymic hormones (herein exemplified by thymosin, thymulin and thymopoietin), can circulate to impact immune cells and other cellular components in the periphery. Evidence on how thymic function influences tumor cell biology and response of patients with cancer to therapies remains unsatisfactory, although there has been some improvement in the knowledge provided by recent studies. Herein, we summarize research progression in the field of thymus-mediated immunoendocrine control of cancer, providing insights into how manipulation of the thymic microenvironment can influence treatment outcomes, including clinical responses and adverse effects of therapies. We review data obtained from clinical and preclinical cancer research to evidence the complexity of immunoendocrine interactions underpinning anti-tumor immunity.

Decreased frequency of Th22 cells and IL-22 cytokine in kidney transplant patients with active cytomegalovirus infection

BACKGROUND

The immunity of CD4⁺ T cell subsets against human cytomegalovirus (HCMV) is considerable due to their essential role in controlling the infection in transplant individuals. Previously explained CD4⁺ subsets such as T helper (Th) 1 have been proven to have a protective role against HCMV infection, while the role of the recently identified Th22 subset has not been described yet. Here, the frequency changes of Th22 cells and the IL-22 cytokine production were investigated in kidney transplant recipients with and without HCMV infection.

METHODS

Twenty kidney transplant patients and ten healthy controls were enrolled in this study. Patients were categorized into HCMV + and HCMV- groups based on the HCMV DNA real-time PCR results. After isolating CD4⁺ T cells from PBMCs, the phenotype (CCR6⁺CCR4⁺CCR10⁺) and cytokine profile (IFN-γ^-IL-17^-IL-22⁺) of Th22 cells were analyzed by flow cytometry. The gene expression of Aryl Hydrocarbon Receptor (AHR) transcription factor was analyzed by real-time PCR.

RESULTS

The phenotype frequency of these cells was lower in recipients with infection than in those without infection and healthy controls (1.88 ± 0.51 vs. 4.31 ± 1.05; P = 0.03 and 4.22 ± 0.72; P = 0.01, respectively). A lower Th22 cytokine profile was observed in patients with infection than in the two other groups (0.18 ± 0.03 vs. 0.20 ± 0.03; P = 0.96 and 0.33 ± 0.05; P = 0.04, respectively). AHR expression was also lower in patients with active infection.

CONCLUSIONS

Overall, this study for the first time suggests that the reduced levels of Th22 subset and IL-22 cytokine in patients with active HCMV infection might indicate the protective role of these cells against HCMV.

Therapeutic strategies for gastric cancer targeting immune cells: Future directions

Gastric cancer (GC) is a malignancy with a high incidence and mortality, and the emergence of immunotherapy has brought survival benefits to GC patients. Compared with traditional therapy, immunotherapy has the advantages of durable response, long-term survival benefits, and lower toxicity. Therefore, targeted immune cells are the most promising therapeutic strategy in the field of oncology. In this review, we introduce the role and significance of each immune cell in the tumor microenvironment of GC and summarize the current landscape of immunotherapy in GC, which includes immune checkpoint inhibitors, adoptive cell therapy (ACT), dendritic cell (DC) vaccines, reduction of M2 tumor-associated macrophages (M2 TAMs), N2 tumor-associated neutrophils (N2 TANs), myeloid-derived suppressor cells (MDSCs), effector regulatory T cells (eT_regs), and regulatory B cells (B_regs) in the tumor microenvironment and reprogram TAMs and TANs into tumor killer cells. The most widely used immunotherapy strategies are the immune checkpoint inhibitor programmed cell death 1/programmed death-ligand 1 (PD-1/PD-L1) antibody, cytotoxic T lymphocyte–associated protein 4 (CTLA-4) antibody, and chimeric antigen receptor T (CAR-T) in ACT, and these therapeutic strategies have significant anti-tumor efficacy in solid tumors and hematological tumors. Targeting other immune cells provides a new direction for the immunotherapy of GC despite the relatively weak clinical data, which have been confirmed to restore or enhance anti-tumor immune function in preclinical studies and some treatment strategies have entered the clinical trial stage, and it is expected that more and more effective immune cell–based therapeutic methods will be developed and applied.

Impact of Immunotherapy on CD4 T Cell Phenotypes and Function in Cancer

Immunotherapy has become a standard treatment in many cancers and it is based on three main therapeutic axes: immune checkpoint blockade (ICB), vaccination and adoptive cell transfer (ACT). If originally these therapies mainly focused on exploiting CD8 T cells given their role in the direct elimination of tumor cells, increasing evidence highlights the crucial role CD4 T cells play in the antitumor immune response. Indeed, these cells can profoundly modulate the tumor microenvironment (TME) by secreting different types of cytokine or by directly eliminating cancer cells. In this review, we describe how different CD4 T cell subsets can contribute to tumor immune responses during immunotherapy and the novel high-throughput immune monitoring tools that are expected to facilitate the study of CD4 T cells, at antigen-specific and single cell level, thus accelerating bench-to-bed translational research in cancer.

IL-22 Signaling in the Tumor Microenvironment

Interleukin (IL)-22 belongs to the IL-10 cytokine family which performs biological functions by binding to heterodimer receptors comprising a type 1 receptor chain (R1) and a type 2 receptor chain (R2). IL-22 is mainly derived from CD4+ helper T cells, CD8+ cytotoxic T cells, innate lymphocytes, and natural killer T cells. It can activate downstream signaling pathways such as signal transducer and activator of transcription (STAT)1/3/5, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of rapamycin (mTOR) through these heterodimer receptors. Although IL-22 is produced by immune cells, its specific receptor IL-22R1 is selectively expressed in nonimmune cells, such as hepatocytes, colonic epithelial cells, and pancreatic epithelial cells (Jiang et al. Hepatology 54(3):900-9, 2011; Jiang et al. BMC Cancer 13:59, 2013; Curd et al. Clin Exp Immunol 168(2):192-9, 2012). Immune cells do not respond to IL-22 stimulation directly within tumors, reports from different groups have revealed that IL-22 can indirectly regulate the tumor microenvironment (TME). In the present chapter, we discuss the roles of IL-22 in malignant cells and immunocytes within the TME, meanwhile, the potential roles of IL-22 as a target for drug discovery will be discussed.

A Double Edged Sword Role of Interleukin-22 in Wound Healing and Tissue Regeneration

Wound healing and tissue regeneration is an intricate biological process that involves repair of cellular damage and maintenance of tissue integrity. Cascades involved in wound healing and tissue regeneration highly overlap with cancer causing pathways. Usually, subsequent tissue damage events include release of a number of cytokines to accomplish post-trauma restoration. IL-22 is one of the cytokines that are immediately produced to initiate immune response against several tissue impairments. IL-22 is a fundamental mediator in inflammation, mucous production, protective role against pathogens, wound healing, and tissue regeneration. However, accumulating evidence suggests pivotal role of IL-22 in instigation of various cancers due to its pro-inflammatory and tissue repairing activity. In this review, we summarize how healing effects of IL-22, when executed in an uncontrollable fashion can lead to carcinogenesis.

Clinical significance of peripheral blood CD11b+/CD33+/HLA-DR- myeloid cells in infants and children with infectious diseases and increased CRP

Background: At early ages, recurrent or persistent infections are associated with increased serum C-reactive protein (CRP). Inflammatory mediators release inhibitory cells named myeloid-derived suppressor cell (MDSC) into circulating and tumor tissues. In the present study, we assayed the percentage and count of whole blood CD11b+/CD33+/HLA-DR- MDSCs or myeloid cells at early ages with infectious diseases and increased CRP. Methods: In this study, the clinical significance of CD11b+/CD33+/HLA-DR- MDSCs or myeloid cells was evaluated in whole blood samples from 40 patients with infectious disease and 20 healthy controls by flow cytometry analysis. Subsequently, the Pearson correlation between the percentage and absolute count of MDSCs with clinical parameters were obtained by SPSS analysis. A p value of < 0.05 was considered statistically significant. Results: We found a significantly higher level of MDSCs in infants and children with infectious diseases and increased CRP as compared to healthy controls (P=0.003). However, the results of analysis showed no correlation between MDSC percentage and count with grouped age and sex in patient groups. Conclusion: Our findings showed a significant correlation between the high level of serum CRP and peripheral blood CD11b+/CD33+/HLA-DR- MDSCs at early ages. This study could be a roadmap for future studies to use increased CRP as a potential prognostic biomarker to target MDSCs in children with recurrent or persistent infections.

TH9, TH17, and TH22 Cell Subsets and Their Main Cytokine Products in the Pathogenesis of Colorectal Cancer

In recent years, several newly identified T helper (T_H) cell subsets, such as T_H9, T_H17, and T_H22 cells, and their respective cytokine products, IL-9, IL-17, and IL-22, have been reported to play critical roles in the development of chronic inflammation in the colorectum. Since chronic inflammation is a potent driving force for the development of human colorectal cancer (CRC), the contributions of T_H9/IL-9, T_H17/IL-17, and T_H22/IL-22 in the pathogenesis of CRC have recently become an increasingly popular area of scientific investigation. Extensive laboratory and clinical evidence suggests a positive relationship between these new T_H subsets and the growth and formation of CRC, whereas, administration of IL-9, IL-17, and IL-22 signaling inhibitors can significantly alter the formation of colorectal chronic inflammation or CRC lesions in animal models, suggesting that blocking these cytokine signals might represent promising immunotherapeutic strategies. This review summarizes recent findings and currently available data for understanding the vital role and therapeutic significance of T_H9/IL-9, T_H17/IL-17, and T_H22/IL-22 in the development of colorectal tumorigenesis.