The role of IL-21 in immunity and cancer

Site-Specific Radiolabeling of a Human PD-L1 Nanobody via Maleimide-Cysteine Chemistry

Immune checkpoint inhibitors targeting the programmed cell death-1 (PD-1) and its ligand PD-L1 have proven to be efficient cancer therapies in a subset of patients. From all the patients with various cancer types, only 20% have a positive response. Being able to distinguish patients that do express PD-1/PD-L1 from patients that do not allows patients to benefit from a more personalized and efficient treatment of tumor lesion(s). Expression of PD-1 and PD-L1 is typically assessed via immunohistochemical detection in a tumor biopsy. However, this method does not take in account the expression heterogeneity within the lesion, nor the possible metastasis. To visualize whole-body PD-L1 expression by PET imaging, we developed a nanobody-based radio-immunotracer targeting PD-L1 site-specifically labeled with gallium-68. The cysteine-tagged nanobody was site-specifically conjugated with a maleimide (mal)-NOTA chelator and radiolabeling was tested at different nanobody concentrations and temperatures. Affinity and specificity of the tracer, referred to as [⁶⁸Ga]Ga-NOTA-mal-hPD-L1 Nb, were assayed by surface plasmon resonance and on PD-L1^POS or PD-L1^NEG 624-MEL cells. Xenografted athymic nude mice bearing 624-MEL PD-L1^POS or PD-L1^NEG tumors were injected with the tracer and ex vivo biodistribution was performed 1 h 20 min post-injection. Ideal ⁶⁸Ga-labeling conditions were found at 50 °C for 15 min. [⁶⁸Ga]Ga-NOTA-mal-hPD-L1 Nb was obtained in 80 ± 5% DC-RCY with a RCP > 99%, and was stable in injection buffer and human serum up to 3 h (>99% RCP). The in vitro characterization showed that the NOTA-functionalized Nb retained its affinity and specificity. Ex vivo biodistribution revealed a tracer uptake of 1.86 ± 0.67% IA/g in the positive tumors compared with 0.42 ± 0.04% IA/g in the negative tumors. Low background uptake was measured in the other organs and tissues, except for the kidneys and bladder, due to the expected excretion route of Nbs. The data obtained show that the site-specific ⁶⁸Ga-labeled NOTA-mal-hPD-L1 Nb is a promising PET radio-immunotracer due to its ease of production, stability and specificity for PD-L1.

The role of various interleukins in acute myeloid leukemia

Interleukins are signaling molecules involved in the immune system, and they play a variety of roles in different diseases and cancers. Acute myeloid leukemia (AML) is the most common type of leukemia in adults, and survival rate after diagnosis is very low. Investigating the role interleukins play in AML can help understand the progression of the disease. There exists a need for more effective treatment of AML. Interleukins can be used to guide immunotherapy for AML. This review article will examine how specific interleukins play a role in AML disease progression and how they can be utilized as a future treatment option.

The role of interleukins and the widely studied TNF-α in non-Hodgkin's lymphoma

Non-Hodgkin's lymphoma is a relatively common cancer with malignant tendencies. Although there is no current cure for the disease, research has been successful in figuring out the mechanisms of how the disease progresses, however, there is still a lot of unknowns, and more research must be done to find the ultimate cause of the disease. Interleukins and various cytokines play unique roles in the development of cancer. This review article summarizes the pathophysiology between certain interleukins and non-Hodgkin's lymphoma. Although TNF-α is not an interleukin, the article examines TNF-α due to its high correspondence with cancer. The article also describes a promising immunotherapy for the disease, while looking at immunotherapies that have been successful in other types of cancer and disease.

Oncolytic adenovirus: A tool for reversing the tumor microenvironment and promoting cancer treatment (Review)

Immunogene therapy can enhance the antitumor immune effect by introducing genes encoding co‑stimulation molecules, cytokines, chemokines and tumor‑associated antigens into treatment cells or human cells through genetic engineering techniques. Oncolytic viruses can specifically target tumor cells and replicate indefinitely until they kill tumor cells. If combined with immunogene therapy, oncolytic viruses can play a more powerful antitumor role. The high pressure, hypoxia and acidity in the tumor microenvironment (TME) provide suitable conditions for tumor cells to survive. To maximize the potency of oncolytic viruses, various methods are being developed to promote the reversal of the TME, thereby maximizing transmission of replication and immunogenicity. The aim of the present review was to discuss the basic mechanisms underlying the effects of oncolytic adenoviruses on the TME, and suggest how to combine the modification of the adenovirus with the TME to further combat malignant tumors.

Characterization of γδT cells in lung of Plasmodium yoelii-infected C57BL/6 mice

Background

Malaria has high morbidity and mortality rates in some parts of tropical and subtropical countries. Besides respiratory and metabolic function, lung plays a role in immune system. γδT cells have multiple functions in producing cytokines and chemokines, regulating the immune response by interacting with other cells. It remains unclear about the role of γδT cells in the lung of mice infected by malaria parasites.

Methods

Flow cytometry (FCM) was used to evaluate the frequency of γδT cells and the effects of γδT cells on the phenotype and function of B and T cells in Plasmodium yoelii-infected wild-type (WT) or γδTCR knockout (γδT KO) mice. Haematoxylin-eosin (HE) staining was used to observe the pathological changes in the lungs.

Results

The percentage and absolute number of γδT cells in the lung increased after Plasmodium infection (p < 0.01). More γδT cells were expressing CD80, CD11b, or PD-1 post-infection (p < 0.05), while less γδT cells were expressing CD34, CD62L, and CD127 post-infection (p < 0.05). The percentages of IL-4⁺, IL-5⁺, IL-6⁺, IL-21⁺, IL-1α⁺, and IL-17⁺ γδT cells were increased (p < 0.05), but the percentage of IFN-γ-expressing γδT cells decreased (p < 0.05) post-infection. The pathological changes in the lungs of the infected γδT KO mice were not obvious compared with the infected WT mice. The proportion of CD3⁺ cells and absolute numbers of CD3⁺ cells, CD3⁺ CD4⁺ cells, CD3⁺ CD8⁺ cells decreased in γδT KO infected mice (p < 0.05). γδT KO infected mice exhibited no significant difference in the surface molecular expression of T cells compared with the WT infected mice (p > 0.05). While, the percentage of IFN-γ-expressing CD3⁺ and CD3⁺ CD8⁺ cells increased in γδT KO infected mice (p < 0.05). There was no significant difference in the absolute numbers of the total, CD69⁺, ICOS⁺, and CD80⁺ B cells between the WT infected and γδT KO infected mice (p > 0.05).

Conclusions

The content, phenotype, and function of γδT cells in the lung of C57BL/6 mice were changed after Plasmodium infection. γδT cells contribute to T cell immune response in the progress of Plasmodium infection.

Leflunomide ameliorates experimental autoimmune myasthenia gravis by regulating humoral and cellular immune responses

Leflunomide, an immunosuppressive disease-modifying anti-rheumatic drug (DMARD), is widely used in the treatment of rheumatoid arthritis (RA), psoriatic arthritis (PA) as well as multiple sclerosis. However, its role in myasthenia gravis (MG) has not yet been clearly explored. Here, we investigated the effect of leflunomide on experimental autoimmune myasthenia gravis (EAMG) in vivo and in vitro. The results demonstrated that leflunomide alleviated the severity of EAMG associated with reduced serum total anti-acetylcholine receptor (AChR) IgG levels. During the development of EAMG, the increase of follicular helper T cells (Tfh) 1, Tfh 17 cells and decrease of follicular regulatory T cells (Tfr) were reversely altered after leflunomide administration. Our work further found that leflunomide might inhibit Tfh cells through the IL-21/STAT3 pathway to reduce the secretion of antibodies by B cells. In addition, leflunomide rebuilt the balance of Th1/Th2/Th17/Treg subsets. These results suggested that leflunomide ameliorated EAMG severity by regulating humoral immune responses and Th cell profiles thereby providing a novel effective treatment strategy for MG.

Increased expression of interleukin-21-inducible genes in minor salivary glands are associated with primary Sjögren’s syndrome disease characteristics

Objective

To determine the upregulation of IL-21-inducible genes in minor salivary glands (MSGs) in 28 primary SS (pSS) patients and 12 non-pSS subjects and correlate it with disease characteristics.

Methods

RNA sequencing was utilized to compare IL-21-inducible genes expression in the MSGs between pSS and non-pSS subjects. The subgroups were characterized according to the IL-21 score calculated by seven IL-21-inducible genes. Furthermore, the disease characteristics and transcripts implicated in hypoxia and interferon signalling were assessed in two pSS subgroups.

Results

We observed that the expression of the IL-21-inducible genes (IL-21, IL-21R, JAK3, STAT1, HLA-B, CCR7 and CXCL10), the so-called IL-21 signature genes, was significantly increased in pSS patients. The upregulation of JAK3 expression may be induced by hypomethylation of the JAK3 promoter in pSS patients and putatively associated with POU2F2. The patients with increased IL-21 signature gene expression showed an increased EULAR Sjögren’s Syndrome Disease Activity Index score and increased enrichment of B cells, memory B cells, CD4+ T cells and CD8+ T cells. Furthermore, the IL-21 scores in the anti-SSA+, SSB+, ANA+ and high IgG samples were higher than those in the respective antibody-negative samples and normal IgG. In addition, we found both hypoxia and IFN-relevant genes showed strong correlation with IL-21 signature gene expression, indicating their interaction in pSS.

Conclusion

IL-21 signature gene was associated with typical disease characteristics in pSS, which provides insight into the contribution of the IL-21 signalling pathway to the pathogenesis of the disease and might provide a novel treatment strategy for this subtype of pSS.

Functional Inhibition of Natural Killer Cells in a BALB/c Mouse Model of Liver Fibrosis Induced by Schistosoma japonicum Infection

Background and Aims

Schistosomiasis japonica is a widespread human zoonotic disease, and in China, there are many patients with schistosomiasis suffering from liver fibrosis. Many studies have shown that natural killer (NK) cells could reduce the progression of hepatic fibrosis by directly killing hepatic stellate cells (HSCs). However, NK cells could not inhibit the progress of liver fibrosis induced by Schistosoma japonicum infection. We aimed to investigate the function of NK cells in schistosomiasis.

Methods

BALB/c mice were infected with S. japonicum cercariae. The receptors and their proportions expressed on NK cells in the liver and spleen from infected mice were detected using flow cytometry. Levels of IFN-γ, perforin, and granzyme of NK cells, and collagen I, III, and α-SMA of hepatic tissue, were detected using quantitative real-time PCR. Changes in cytokine levels in sera were detected using a cytometric bead array. Liver fibrosis was evaluated using hematoxylin and eosin and Masson staining. NK function in the schistosomiasis model was analyzed.

Results

From 2 to 4 weeks post-infection, NK cells were activated, with significantly increased levels of effector molecules (IFN-γ, perforin, and granzyme) that peaked at 4 weeks after infection. The proportion of NK cells increased in the liver and spleen from 6 to 10 weeks post-infection. However, the function of NK cells was inhibited from 6 to 10 weeks post-infection with significantly decreased levels of activated receptors (AR), inhibitory receptors (IR), and effector molecules. The levels of IFN-γ, IL-12, and IL-6 in mouse serum peaked at 6 weeks post-infection, and IL-10 and IL-21 levels peaked at 8 weeks post-infection. Hepatic fibrosis markers increased significantly at 6 weeks after infection.

Conclusion

Our study suggested that NK cells were activated from 2 to 4 weeks post-infection and participated in inflammation in the mouse model. After the S. japonicum laid their eggs, NK cells became inhibited, with decreased levels of both activating and inhibitory NK cell receptors, as well as cytotoxic molecules. In addition, liver fibrosis formed. In mice infected with S. japonicum, the process of liver fibrosis might be alleviated by removing the functional inhibition of NK cells.

Germline mutations and blood malignancy (Review)

Germline mutations are congenital genetic mutations in germ cells that originate from sperm or ovum and are generally incorporated into every cell of the offspring's body. Somatic mutations are acquired genetic mutations that form under the influence of environmental factors during embryo formation and epigenetic development. Generally, only a portion of the cells in the human body have the same somatic mutations. Clinical detection of germline mutations is intended to determine inherited malignancies and identify high‑risk families, and detection of somatic mutation is proposed to find targeted drugs, monitor tumor loading for guided therapy, and evaluate prognosis. Large‑scale population cohort studies have shown that germline mutations are closely related to the occurrence, development, and prognosis of diseases. Patients with cancer‑predisposition germline mutations can be used as sentinels in high‑risk families. Traditional histopathology is no longer enough to identify types of cancers. Even within a particular type of tumor, there is great heterogeneity between internal molecules. The Pan‑Cancer Research Program as well as other projects seek to use large quantities of data from different types of tumor research databases to carry out integrated analysis in order to establish potential non‑tumor‑specific tumor markers and targets by increasing the sample size to identify more molecular mechanisms. This review intends to summarize some of the relevant mechanisms underlying germline mutations in blood disorders.

Modulation of Immune Infiltration of Ovarian Cancer Tumor Microenvironment by Specific Subpopulations of Fibroblasts

Tumor immune infiltration plays a key role in the progression of solid tumors, including ovarian cancer, and immunotherapies are rapidly emerging as effective treatment modalities. However, the role of cancer-associated fibroblasts (CAFs), a predominant stromal constituent, in determining the tumor-immune microenvironment and modulating efficacy of immunotherapies remains poorly understood. We have conducted an extensive bioinformatic analysis of our and other publicly available ovarian cancer datasets (GSE137237, GSE132289 and GSE71340), to determine the correlation of fibroblast subtypes within the tumor microenvironment (TME) with the characteristics of tumor-immune infiltration. We identified (1) four functional modules of CAFs in ovarian cancer that are associated with the TME and metastasis of ovarian cancer, (2) immune-suppressive function of the collagen 1,3,5-expressing CAFs in primary ovarian cancer and omental metastases, and (3) consistent positive correlations between the functional modules of CAFs with anti-immune response genes and negative correlation with pro-immune response genes. Our study identifies a specific fibroblast subtype, fibroblast functional module (FFM)2, in the ovarian cancer tumor microenvironment that can potentially modulate a tumor-promoting immune microenvironment, which may be detrimental toward the effectiveness of ovarian cancer immunotherapies.

Identification of Novel Therapeutic Molecular Targets in Inflammatory Bowel Disease by Using Genetic Databases

Purpose

Utilization of genetic databases to identify genes involved in ulcerative colitis (UC), Crohn’s disease (CD), and their extra-intestinal manifestations.

Methods

Protein coding genes involved in ulcerative colitis (3783 genes), Crohn’s disease (3980 genes), uveitis (1043 genes), arthritis (5583 genes), primary sclerosing cholangitis (PSC) (1313 genes), and pyoderma gangrenosum (119 genes) were categorized using four genetic databases. These include Genecards: The Human Gene Database (www.genecards.org), DisGeNET (https://www.disgenet.org/), The Comparative Toxicogenomics Database (http://ctdbase.org/) and the Universal Protein Resource (https://www.uniprot.org/). NDex, Network Data Exchange (http://www.ndexbio.org/), was then utilized for mapping a unique signal pathway from the identified shared genes involved in the above disease processes.

Results

We have detected a unique array of 20 genes with the highest probability of overlay in UC, CD, uveitis, arthritis, pyoderma gangrenosum, and PSC. Figure 1 represents the interactome of these 20 protein coding genes. Of note, unique immune modulators in different disease processes are also noted. Interleukin-25 (IL-25) and monensin-resistant homolog 2 (MON-2) are only noted in UC, CD, pyoderma gangrenosum, and arthritis. Arachidonate 5-lipoxygenase (ALOX5) is involved in UC, CD, and arthritis. SLCO1B3 is exclusively involved with pyoderma gangrenosum, UC, and CD. As expected, TNF involvement is noted in CD, UC, PSC, and arthritis. Table 1 depicts the detailed result.

Conclusion

Our work has identified a distinctive set of genes involved in IBD and its associated extra-intestinal disease processes. These genes play crucial roles in mechanisms of immune response, inflammation, and apoptosis and further our understanding of this complex disease process. We postulate that these genes play a critical role at intersecting pathways involved in inflammatory bowel disease, and these novel molecules, their upstream and downstream effectors, are potential targets for future therapeutic agents.

Adenovirus-mediated overexpression of interleukin-21 regulates the development of oral squamous cell carcinoma in vitro

Interleukin-21 (IL-21) is an important cytokine that is currently being investigated for its potential use in tumor immunotherapy in the future. In tumor cells, IL-21 stimulates the immune response by increasing the cytotoxic activity of natural killer cells, B cells and CD8⁺ T cells, which in turn induces the apoptosis of tumor cells. The therapeutic effects of IL-21 have been investigated in several types of disease and numerous clinical trials are in progress. The aim of the present study was to determine the role of IL-21 in oral squamous cell carcinoma (OSCC) in vitro. IL-21 expression was detected in OSCC tissues via RT-qPCR, western blotting and immunohistochemistry analyses. The results demonstrated that IL-21 protein expression decreased in OSCC tissues. IL-21 was overexpressed using adenovirus in CAL-27 cells. The Cell Counting Kit-8 assay demonstrated that overexpression of IL-21 inhibited cell proliferation. Furthermore, overexpression of IL-21 inhibited cell migration, detected by the wound healing assay, and promoted cell apoptosis, detected by TUNEL staining and flow cytometry analysis. The results demonstrated that overexpression of IL-21 inhibited activation of the JNK signaling pathway. In conclusion, the findings of the present study suggest that IL-21 may function as a potent antitumor agent in OSCC.

Interleukin (IL)-21 Promotes the Differentiation of IgA-Producing Plasma Cells in Porcine Peyer's Patches via the JAK-STAT Signaling Pathway

Secretory IgA is critical to prevent the invasion of pathogens via mucosa. However, the key factors and the mechanisms of IgA generation in the porcine gut are not well-understood. In this study, a panel of factors, including BAFF, APRIL, CD40L, TGF-β1, IL-6, IL-10, IL-17A, and IL-21, were employed to stimulate IgM⁺ B lymphocytes from porcine ileum Peyer's patches. The results showed that IL-21 significantly upregulated IgA production of B cells and facilitated cell proliferation and differentiation of antibody-secreting cells. In addition, three transcripts in porcine IgA class switch recombination (CSR), germ-line transcript α, post-switch transcript α, and circle transcript α, were first amplified by (nest-)PCR and sequenced. All these key indicators of IgA CSR were upregulated by IL-21 treatment. Furthermore, we found that IL-21 predominantly activated JAK1, STAT1, and STAT3 proteins and confirmed that the JAK-STAT signaling pathway was involved in porcine IgA CSR. Thus, IL-21 plays an important role in the proliferation and differentiation of IgA-secreting cells in porcine Peyer's patches through the JAK-STAT signaling pathway. These findings provide insights into the mucosal vaccine design by regulation of IL-21 for the prevention and control of enteric pathogens in the pig industry.

Suppressing miR-21 activity in tumor-associated macrophages promotes an antitumor immune response

microRNA-21 (miR-21) is the most commonly upregulated miRNA in solid tumors. This cancer-associated microRNA (oncomiR) regulates various downstream effectors associated with tumor pathogenesis during all stages of carcinogenesis. In this study, we analyzed the function of miR-21 in noncancer cells of the tumor microenvironment to further evaluate its contribution to tumor progression. We report that the expression of miR-21 in cells of the tumor immune infiltrate, and in particular in macrophages, was responsible for promoting tumor growth. Absence of miR-21 expression in tumor- associated macrophages (TAMs), caused a global rewiring of their transcriptional regulatory network that was skewed toward a proinflammatory angiostatic phenotype. This promoted an antitumoral immune response characterized by a macrophage-mediated improvement of cytotoxic T-cell responses through the induction of cytokines and chemokines, including IL-12 and C-X-C motif chemokine 10. These effects translated to a reduction in tumor neovascularization and an induction of tumor cell death that led to decreased tumor growth. Additionally, using the carrier peptide pH (low) insertion peptide, we were able to target miR-21 in TAMs, which decreased tumor growth even under conditions where miR-21 expression was deficient in cancer cells. Consequently, miR-21 inhibition in TAMs induced an angiostatic and immunostimulatory activation with potential therapeutic implications.

T follicular helper cell-mediated IL-21 production suppresses FOXP3 expression of T follicular regulatory-like cells in diffuse large B cell lymphoma patients

Based on CD25 expression, T follicular helper cells (Tfh) could be divided into T follicular regulatory (Tfr)-like subset (CD25⁺CD4⁺CXCR5⁺) and CD25^- Tfh subset (CD25^-CD4⁺CXCR5⁺). Patients with diffuse large B cell lymphoma (DLBCL) display high level of Tfr-like cells in blood and tumor. This Tfr-like subset could suppress CD8 T cell response while promote tumor cell proliferation. In this study, we investigated the transcription factors and regulatory elements associated with Tfr-like cells in DLBCL patients. Both circulating and tumor-infiltrating Tfr-like cells presented slightly higher Blimp-1 expression and significantly higher Foxp3 expression than the CD25^- Tfh subset. As the IL-2 receptor, CD25 could be moderately upregulated in stimulated CD25^- Tfh cells. However, stimulated CD25^- Tfh cells could not upregulate Foxp3, indicating that the distinction between Foxp3-low CD25^-CXCR5⁺CD4⁺ T cells and Foxp3-high CD25⁺CXCR5⁺CD4⁺ T cells was not due to differences in stimulation status. Regarding cytokine production, while both Tfr-like and CD25^- Tfh cells upregulated IL-21 and IL-10 during stimulation, the CD25^- Tfh cells presented significantly higher IL-21 and lower IL-10 expression than the Tfr-like cells, and the TGF-β expression was only increased in Tfr-like cells. Interestingly, IL-21 secreted from CD25^- Tfh cells negatively regulated the expression of Foxp3 and IL-10 of autologous Tfr-like cells. Together, these results demonstrated that the Tfr-like and CD25^- Tfh subsets of circulating Tfh cells presented different functions and should be investigated separately.

Transforming growth factor-β promotes the function of HIV-specific CXCR5+ CD8 T cells

HIV replication can be inhibited by CXCR5⁺ CD8 T cells (follicular cytotoxic T cell [TFC]) which transfer into B-cell follicles where latent HIV infection persists. However, how cytokines affect TFC remain unclear. Understanding which cytokines show the ability to affect TFC could be a key strategy toward curing HIV. Similar mechanisms could be used for the growth and transfer of TFCs and follicular helper T (TFH) cells; as a result, we hypothesized that cytokines IL-6, IL-21, and transforming growth factor-β (TGF-β), which are necessary for the differentiation of TFH cells, could also dictate the development of TFCs. In this work, lymph node mononuclear cells and peripheral blood mononuclear cells from HIV-infected individuals were cocultured with IL-6, IL-21, and TGF-β. We then carried out T-cell receptor (TCR) repertoire analysis to compare the differences between CXCR5^- and CXCR5⁺ CD8 T cells. Our results showed that the percentage and function of TFC can be enhanced by stimulation with TGF-β. Besides, TGF-β stimulation enhanced the diversity of TCR and complementarity-determining region 3 sequences. HIV DNA showed a negative correlation with TFC. The use of TGF-β to promote the expression of CXCR5⁺ CD8 T cells could become a new treatment approach for curing HIV.

Glypican-3-Specific CAR T Cells Coexpressing IL15 and IL21 Have Superior Expansion and Antitumor Activity against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth most common cause of cancer-related death in the world, and curative systemic therapies are lacking. Chimeric antigen receptor (CAR)-expressing T cells induce robust antitumor responses in patients with hematologic malignancies but have limited efficacy in patients with solid tumors, including HCC. IL15 and IL21 promote T-cell expansion, survival, and function and can improve the antitumor properties of T cells. We explored whether transgenic expression of IL15 and/or IL21 enhanced glypican-3-CAR (GPC3-CAR) T cells' antitumor properties against HCC. We previously optimized the costimulation in GPC3-CARs and selected a second-generation GPC3-CAR incorporating a 4-1BB costimulatory endodomain (GBBz) for development. Here, we generated constructs encoding IL15, IL21, or both with GBBz (15.GBBz, 21.GBBz, and 21.15.GBBz, respectively) and examined the ability of transduced T cells to kill, produce effector cytokines, and expand in an antigen-dependent manner. We performed gene-expression and phenotypic analyses of GPC3-CAR T cells and CRISPR-Cas9 knockout of the TCF7 gene. Finally, we measured GPC3-CAR T-cell antitumor activity in murine xenograft models of GPC3+ tumors. The increased proliferation of 21.15.GBBz T cells was at least in part dependent on the upregulation and maintenance of TCF-1 (encoded by TCF7) and associated with a higher percentage of stem cell memory and central memory populations after manufacturing. T cells expressing 21.15.GBBz had superior in vitro and in vivo expansion and persistence, and the most robust antitumor activity in vivo These results provided preclinical evidence to support the clinical evaluation of 21.15.GPC3-CAR T cells in patients with HCC.

Human Plasmacytoid Dendritic Cells and Cutaneous Melanoma

The prognosis of metastatic melanoma (MM) patients has remained poor for a long time. However, the recent introduction of effective target therapies (BRAF and MEK inhibitors for BRAFV600-mutated MM) and immunotherapies (anti-CTLA-4 and anti-PD-1) has significantly improved the survival of MM patients. Notably, all these responses are highly dependent on the fitness of the host immune system, including the innate compartment. Among immune cells involved in cancer immunity, properly activated plasmacytoid dendritic cells (pDCs) exert an important role, bridging the innate and adaptive immune responses and directly eliminating cancer cells. A distinctive feature of pDCs is the production of high amount of type I Interferon (I-IFN), through the Toll-like receptor (TLR) 7 and 9 signaling pathway activation. However, published data indicate that melanoma-associated escape mechanisms are in place to hijack pDC functions. We have recently reported that pDC recruitment is recurrent in the early phases of melanoma, but the entire pDC compartment collapses over melanoma progression. Here, we summarize recent advances on pDC biology and function within the context of melanoma immunity.

Gene expression profiling informs HPV cervical histopathology but not recurrence/relapse after LEEP in ART-suppressed HIV+HPV+ women

Identification of factors associated with human papillomavirus (HPV) cervical histopathology or recurrence/relapse following loop electrosurgical excision procedure (LEEP) would allow for better management of the disease. We investigated whether gene signatures could (i) associate with HPV cervical histopathology and (ii) identify women with post-LEEP disease recurrence/relapse. Gene array analysis was performed on paraffin-embedded cervical tissue-isolated RNA from two cross-sectional cohorts of antiretroviral therapy (ART)-suppressed HIV+HPV+ coinfected women: (i) 55 women in South Africa recruited into three groups: high risk (HR) (-) (n = 16) and HR (+) (n = 15) HPV without cervical histopathology and HR (+) HPV with cervical intraepithelial neoplasia (CIN) grade 1/2/3 (n = 24), (ii) 28 women in Botswana with CIN2/3 treated with LEEP 12-month prior to recruitment and presenting with (n = 13) and without (n = 15) lesion recurrence/relapse (tissue was analyzed at first LEEP). Three distinct gene expression signatures identified were able to segregate: (i) HR+ HPV and CIN1/2/3, (ii) HR HPV-free and cervical histopathology-free and (iii) HR+ HPV and cervical histopathology-free. Immune activation and neoplasia-associated genes (n = 272 genes; e.g. IL-1A, IL-8, TCAM1, POU4F1, MCM2, SMC1B, CXCL6, MMP12) were a feature of cancer precursor dysplasia within HR HPV infection. No difference in LEEP tissue gene expression was detected between women with or without recurrence/relapse. In conclusion, distinctive gene signatures were associated with presence of cervical histopathology in tissues from ART-suppressed HIV+/HPV+ coinfected women. Lack of detection of LEEP tissue gene signature able to segregate subsequent post-LEEP disease recurrence/relapse indicates additional factors independent of local gene expression as determinants of recurrence/relapse.

Genomic, proteomic, and immunologic associations with a durable complete remission of measurable metastatic melanoma induced by a patient-specific dendritic cell vaccine

This report describes efforts to understand the immune mechanism of action that led to a complete response in a patient with progressive, refractory, metastatic melanoma after treatment with a therapeutic vaccine consisting of autologous dendritic cells (DC) loaded with autologous tumor antigens (ATA) derived from cells that were self-renewing in cell culture. Her histocompatibility type proved to be HLA B27 with extensive mutations in the HLA-A locus. Exomic analysis of proliferating tumor cells revealed more than 2800 non-synonymous mutations compared to her leukocytes. Histology of resected tumor lesions showed no evidence of an existing or suppressed immune response. In in vitro mixed cell cultures, DC loaded with ATA induced increased IL-22 expression, and a four-fold increase in CD8 + T lymphocytes. Cryopreserved blood samples obtained at week-0, 1 week before the first of three-weekly vaccine injections, and at week-4, 1 week after the third dose, were analyzed by protein array and compared for 110 different serum markers. At baseline, she had marked elevations of amyloid A, IL-12p40, IL21, IL-22, IL-10, IL-16, GROa, TNF-alpha, IL-3, and IL-2, and a lesser elevation of IL-15. One week after 3 weekly vaccinations she had a further 80% increase in amyloid A, a further 66% increase in IL-22, a 92% decrease in IL12p40, a 45% decrease in TGF-β and 26% decrease in IL-10. The data suggested that by 3 weeks after the first DCV injection, vaccine-induced changes in this particular patient were most consistent with enhanced innate and Th1 immune responses rather than Th2 or Th17.

Interleukin 21 Receptor/Ligand Interaction Is Linked to Disease Progression in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) displays a marked fibro-inflammatory microenvironment in which infiltrated immune cells fail to eliminate the tumor cells and often—rather paradoxically—promote tumor progression. Of special interest are tumor-promoting T cells that assume a Th17-like phenotype because their presence in PDAC tissue is associated with a poor prognosis. In that context, the role of IL-21, a major cytokine released by Th17-like cells, was assessed. In all tissue samples (n = 264) IL-21⁺ immune cells were detected by immunohistochemistry and high density of those cells was associated with poor prognosis. In the majority of patients (221/264), tumor cells expressed the receptor for IL-21 (IL-21R) and also a downstream target of IL-21, Blimp-1 (199/264). Blimp-1 expression closely correlated with IL-21R expression and multivariate analysis revealed that expression of both IL-21R and Blimp-1 was associated with shorter survival time of the patients. In vitro data using pancreatic tumor cells lines provided a possible explanation: IL-21 activated ERK and STAT3 pathways and upregulated Blimp-1. Moreover, IL-21 increased invasion of tumor cell lines in a Blimp-1-dependent manner. As an in vivo correlate, an avian xenograft model was used. Here again Blimp-1 expression was significantly upregulated in IL-21 stimulated tumor cells. In summary, our data showed an association of IL-21⁺ immune cell infiltration and IL-21 receptor expression in PDAC with poor survival, most likely due to an IL-21-mediated promotion of tumor cell invasion and enhanced colony formation, supporting the notion of the tumor-promoting abilities of the tumor microenvironment.

Cytokines (IL-15, IL-21, and IFN-γ) in rheumatoid arthritis: association with positivity to autoantibodies (RF, anti-CCP, anti-MCV, and anti-PADI4) and clinical activity

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial membrane damage and autoantibody production. RA is a heterogeneous disease, where cytokines such as IL-15, IL-21, and IFN-γ have been associated. However, their association with the autoantibodies has not been clearly described. The aim of this study was to evaluate the relationship between the cytokines IL-15, IL-21, and IFN-γ with the autoantibodies (RF, anti-CCP, anti-MCV, and anti-PADI4) in RA and disease activity.

METHODOLOGY

This study included 153 RA patients and 80 control subjects (CS). The levels of IL-15, IL-21, IFN-γ, anti-CCP, anti-MCV, and anti-PADI4 were quantified by ELISA, whereas RF was quantified by turbidimetry. The disease activity was evaluated by the indices disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR), clinical disease activity index (CDAI), and simple disease activity index (SDAI).

RESULTS

The serum levels of IL-15, IL-21, and IFN-γ, and autoantibodies were increased in RA patients, compared with CS (p < 0.05). A correlation was found between IL-21 and anti-CCP and anti-MCV (p < 0.05). According to RA evolution, RF, anti-CCP, and anti-MCV had higher levels in early RA. In addition, increased levels of IL-21 were observed in RA seropositive patients (RF/anti-CCP/anti-MCV). The higher levels of both cytokines and autoantibodies were observed in moderate activity, evaluated by the three indices.

CONCLUSIONS

Our results suggest that the increased soluble levels of IL-15, IL-21, and IFN-γ are involved in the inflammatory network in RA. However, IL-21 serum levels are associated with higher titers of autoantibodies (RF, anti-CCP, and anti-MCV) and IL-15 with moderate activity. Key Points • IL-15, IL-21, and IFN-y are associated with the immunopathology of RA, but not significantly with the evolution of the disease. • RF, anti-CCP, and anti-MCV had higher levels in early than established RA. • IL-21 has an association with RF, anti-CCP, and anti-MCVand, for this reason, could be proposed as a disease biomarker. • Patients with activity moderate of disease showed higher levels of RF, anti-CCP, anti-MCV, and IL-15.

Restoring thymic function: Then and now

Thymic vulnerability, a leading cause of defective immunity, was discovered decades ago. To date, several strategies have been investigated to unveil any immunorestorative capacities they might confer. Studies exploiting castration, transplantation, adoptive cell therapies, hormones/growth factors, and cytokines have demonstrated enhanced in vitro and in vivo thymopoiesis, albeit with clinical restrictions. In this review, we will dissect the thymus on a physiological and pathological level and discuss the pros and cons of several strategies esteemed thymotrophic from a pre-clinical perspective. Finally, we will shed light on interleukin (IL)-21, a pharmacologically-promising cytokine with a significant thymotrophic nature, and elaborate on its potential clinical efficacy and safety in immune-deficient subjects.

Development of Automated Separation, Expansion, and Quality Control Protocols for Clinical-Scale Manufacturing of Primary Human NK Cells and Alpharetroviral Chimeric Antigen Receptor Engineering

In cellular immunotherapies, natural killer (NK) cells often demonstrate potent antitumor effects in high-risk cancer patients. But Good Manufacturing Practice (GMP)-compliant manufacturing of clinical-grade NK cells in high numbers for patient treatment is still a challenge. Therefore, new protocols for isolation and expansion of NK cells are required. In order to attack resistant tumor entities, NK cell killing can be improved by genetic engineering using alpharetroviral vectors that encode for chimeric antigen receptors (CARs). The aim of this work was to demonstrate GMP-grade manufacturing of NK cells using the CliniMACS^® Prodigy device (Prodigy) with implemented applicable quality controls. Additionally, the study aimed to define the best time point to transduce expanding NK cells with alpharetroviral CAR vectors. Manufacturing and clinical-scale expansion of primary human NK cells were performed with the Prodigy starting with 8-15.0 × 10⁹ leukocytes (including 1.1–2.3 × 10⁹ NK cells) collected by small-scale lymphapheresis (n = 3). Positive fraction after immunoselection, in-process controls (IPCs), and end product were quantified by flow cytometric no-wash, single-platform assessment, and gating strategy using positive (CD56/CD16/CD45), negative (CD14/CD19/CD3), and dead cell (7-aminoactinomycine [7-AAD]) discriminators. The three runs on the fully integrated manufacturing platform included immunomagnetic separation (CD3 depletion/CD56 enrichment) followed by NK cell expansion over 14 days. This process led to high NK cell purities (median 99.1%) and adequate NK cell viabilities (median 86.9%) and achieved a median CD3+ cell depletion of log −3.6 after CD3 depletion and log −3.7 after immunomagnetic CD3 depletion and consecutive CD56 selection. Subsequent cultivation of separated NK cells in the CentriCult^® chamber of Prodigy resulted in approximately 4.2–8.5-fold NK cell expansion rates by adding of NK MACS^® basal medium containing NK MACS^® supplement, interleukin (IL)-2/IL-15 and initial IL-21. NK cells expanded for 14 days revealed higher expression of natural cytotoxicity receptors (NKp30, NKp44, NKp46, and NKG2D) and degranulation/apoptotic markers and stronger cytolytic properties against K562 compared to non-activated NK cells before automated cultivation. Moreover, expanded NK cells had robust growth and killing activities even after cryopreservation. As a crucial result, it was possible to determine the appropriate time period for optimal CAR transduction of cultivated NK cells between days 8 and 14, with the highest anti-CD123 CAR expression levels on day 14. The anti-CD123 CAR NK cells showed retargeted killing and degranulation properties against CD123-expressing KG1a target cells, while basal cytotoxicity of non-transduced NK cells was determined using the CD123-negative cell line K562. Time-lapse imaging to monitor redirected effector-to-target contacts between anti-CD123 CAR NK and KG1a showed long-term effector–target interaction. In conclusion, the integration of the clinical-scale expansion procedure in the automated and closed Prodigy system, including IPC samples and quality controls and optimal time frames for NK cell transduction with CAR vectors, was established on 48-well plates and resulted in a standardized GMP-compliant overall process.

Mechanisms by Which the Gut Microbiota Influences Cytokine Production and Modulates Host Inflammatory Responses

The gastrointestinal tract encounters a wide variety of microorganisms, including beneficial symbionts, pathobionts, and pathogens. Recent evidence has shown that the gut microbiota, directly or indirectly through its components, such as metabolites, actively participates in the host inflammatory response by cytokine-microbiota or microbiota-cytokine modulation interactions, both in the gut and systemically. Therefore, further elucidation of host cytokine molecular pathways and microbiota components will provide a novel and promising therapeutic approach to control or prevent inflammatory disease and to maintain host homeostasis. The purpose of this review is to summarize well-established scientific findings and provide an updated overview regarding the direct and indirect mechanisms by which the gut microbiota can influence the inflammatory response by modulating the host's cytokine pathways that are mostly involved, but not exclusively so, with gut homeostasis. In addition, we will highlight recent results from our group, which suggest that the microbiota promotes cytokine release from inflammatory cells though activation of microbial metabolite sensor receptors that are more highly expressed on inflammatory and intestinal epithelial cells.

Epigenetic Changes in Alveolar Type II Lung Cells of A/J Mice Following Intranasal Treatment with Lipopolysaccharide

Lipopolysaccharide (LPS) is a bacterial endotoxin present in cigarette smoke. LPS is known to induce inflammation and to increase the size and the multiplicity of lung tumors induced by tobacco-specific nitrosamines. However, the means by which LPS contributes to pulmonary carcinogenesis are not known. One possible mechanism includes LPS-mediated epigenetic deregulation, which leads to aberrant expression of genes involved in DNA repair, tumor suppression, cell cycle progression, and cell growth. In the present work, epigenetic effects of LPS were examined in alveolar type II lung cells of A/J mice. Type II cells were selected because they serve as progenitors of lung adenocarcinomas in smoking induced lung cancer. A/J mice were intranasally treated with LPS, followed by isolation of alveolar type II cells from the lung using cell panning. Global levels of DNA methylation and histone acetylation were quantified by mass spectrometry, while genome-wide transcriptomic changes were characterized by RNA-Seq. LPS treatment was associated with epigenetic changes including decreased cytosine formylation and reduced histone H3K14 and H3K23 acetylation, as well as altered expression levels of genes involved in cell adhesion, inflammation, immune response, and epigenetic regulation. These results suggest that exposure to inflammatory agents in cigarette smoke leads to early epigenetic changes in the lung, which may collaborate with genetic changes to drive the development of lung cancer.

Effect of Th9/IL-9 on the growth of gastric cancer in nude mice

Objective

By neutralizing IL-9 in a nude mouse model, the study aimed to investigate the role of Th9/IL-9 on the growth of gastric cancer in mice.

Materials and methods

Male BALB/c nude mice were randomly divided into three groups: a normal control group (Control), an SGC-7901 xenografted nude mice model group (Model), and a rIL-9 treatment group (Treat). The weight of the tumors was recorded to calculate the tumor inhibition rate. Flow cytometry was used to detect the cell frequency of Th9, Th17, and Treg in peripheral blood. The IL-4, IL-9, IL-10, IL-25, VEGF, and TGF-β levels in serum were determined by ELISA. The cellular migration and invasion were investigated by transwell assay. Immunohistochemical and Western blot were used to detect the expression of IL-9, CD34, PU.1, p53, and p21 proteins in gastric cancer tissue. The mRNA expression levels of IL-9, IL-21, and PU.1 in gastric cancer tissue were determined by qRT-PCR.

Result

rIL-9 can significantly inhibit the growth of gastric cancer. The frequency of Th9, Th17, and Treg in peripheral blood was decreased upon treatment. The levels of IL-4, IL-9, IL-10, IL-25, VEGF, and TGF-β in serum were significantly reduced in the Treat group compared with the Model group (P<0.05). rIL-9 can inhibit cellular migration and invasion and reduce the mRNA level of IL-9, IL-21, and PU.1. Meanwhile, in the Treat group, the expression of IL-9, CD34, and PU.1 was significantly reduced, whereas the expression of p53 and p21 was significantly increased compared with the Model group (P<0.05).

Conclusion

This study suggested that Th9/IL-9 has a deleterious role in gastric cancer.

Clinical significance and immunobiology of IL-21 in autoimmunity

Interleukin-21 (IL-21), an autocrine cytokine predominantly produced by follicular helper T (Tfh) and T helper 17 (Th17) cells, has been proven to play an important role in the immune system, for example, by promoting proliferation and the development of Tfh and Th17 cells, balancing helper T cell subsets, inducing B cell generation and differentiation into plasma cells, and enhancing the production of immunoglobulin. These effects are mainly mediated by activation of the JAK/STAT, MAPK and PI3K pathways. Some IL-21 target genes, such as B lymphocyte induced maturation protein-1 (Blimp-1), suppressor of cytokine signaling (SOCS), CXCR5 and Bcl-6, play important roles in the immune response. Therefore, IL-21 has been linked to autoimmune diseases. Indeed, IL-21 levels are increased in the peripheral blood and tissues of patients with systematic lupus erythematosus (SLE), rheumatoid arthritis (RA), type 1 diabetes (T1D), immune thrombocytopenia (ITP), primary Sjogren's syndrome (pSS), autoimmune thyroid disease (AITD) and psoriasis. This increased IL-21 even positively associates with Tfh cells, plasma cells, autoantibodies and disease activity in SLE and RA. Additionally, IL-21 has been utilized as a therapeutic target in SLE, RA, T1D and psoriatic mouse models. Profoundly, clinical trials have shown safety and improvement in RA patients. However, tolerance and long-term pharmacodynamics effects with low bioavailability have been found in SLE patients. Therefore, this review aims to summarize the latest progress on IL-21 function and its signaling pathway and discuss the role of IL-21 in the pathogenesis of and therapy for autoimmune diseases, with the hope of providing potential therapeutic and diagnostic strategies for clinical use.

IL-21-mediated expansion of Vγ9Vδ2 T cells is limited by the Tim-3 pathway

Vγ9Vδ2 T cells are the main γδ T subset in the peripheral blood and lymphoid organs. Previous studies have shown that Vγ9Vδ2 T cells could expand in the presence of phosphoantigens and IL-2 and exert antitumor functions. However, their potency was limited because sustained proliferation could not be achieved, possibly due to exhaustion caused by prolonged antigenic stimulation. In this study, we examined the proliferative response of Vγ9Vδ2 T cells to IL-21, a cytokine previously shown to promote NK cell and CD8 T cell cytotoxicity. We found that IL-21 could significantly improve the proliferation of phosphoantigen-stimulated Vγ9Vδ2 T cells in a dose-dependent manner. However, in acute myeloid leukemia (AML) patients, the efficacy of IL-21 was significantly reduced. Vγ9Vδ2 T cells from AML patients exhibited lower expression of IL-21R, and required higher levels of IL-21 for expansion. IL-21-treated Vγ9Vδ2 T cells from AML patients presented lower increase in STAT1 phosphorylation than Vγ9Vδ2 T cells from healthy volunteers. Interestingly, AML Vγ9Vδ2 T cells presented significantly higher Tim-3 expression than healthy Vγ9Vδ2 T cells. IL-21 treatment further induced Tim-3 upregulation. Blocking Tim-3 increased the proliferation and the STAT phosphorylation in Vγ9Vδ2 T cells in response to IL-21. Together, these results demonstrated that IL-21 could significantly expand the Vγ9Vδ2 T cells, but its efficacy was limited since it also increased the expression of checkpoint molecule Tim-3.

IL-17, IL-21, and IL-22 Cytokines of T Helper 17 Cells in Cancer

CD4+ T helper (Th) cells are important regulators of cellular immune response. Newly discovered interleukin (IL)-17-producing CD4+ T cells are known as T helper 17 cells (Th17). They are distinct subset from the T helper type 1 (Th1) and 2 (Th2) lineages. The differentiation of Th17 cells has been intensively studied; however, the role of Th17 cells in different diseases including cancer is still under investigation. Besides IL-17 family cytokines, Th17 cells produce IL-22, IL-21, and IL-26. The dysregulated function of Th17 cells and their cytokines could contribute to pathology of diseases, including cancer. The role of cytokines of Th17 cells such as IL-17, IL-21, and IL-22 in cancer will be discussed in this review.

Upregulated Interleukin 21 Receptor Enhances Proliferation and Epithelial-Mesenchymal Transition Process in Benign Prostatic Hyperplasia

Background: Interleukins (ILs) and related chronic inflammation have been found to contribute to the development of benign prostatic hyperplasia (BPH) in recent decades. As a late member of the ILs family, IL-21 receptor (IL-21R) can modulate cell proliferation, however, IL-21R activity in the prostate has not been examined. The current study aimed to elucidate a potential role of IL-21R in the development of BPH. Material and Methods: Human prostate tissues, cell lines and rats were used. QRT-PCR, Western blot, and immunohistochemistry, along with hematoxylin and eosin, Masson's trichrome, and immunofluorescent staining were performed. BPH-1 cells with IL-21R silenced were cultured or co-cultured with macrophages (active THP-1, AcTHP-1). Apoptosis and cell cycle phases were determined via flow cytometry. Epithelial-mesenchymal transition (EMT) processes were also examined. In vivo, rat prostatitis was induced with intraprostatic injected lipopolysaccharide (LPS). Results: IL-21R was highly expressed in human as well as rat prostate, mainly in the epithelial compartment. BPH concomitant with prostatitis significantly upregulated the expression of IL-21R. Knockdown of IL-21R induced cell apoptosis and cycle arrest at G0/G1 phase, and blocked the EMT process in BPH-1 cells. When IL-21R silenced BPH-1 cells were co-cultured with AcTHP-1 cells, these aforementioned processes and IL-21R change were completely reversed. Prostatic hyperplasia was observed with IL-21R upregulated in LPS induced prostatitis rats. More specifically, the expression of apoptosis, cyclin, and EMT proteins in this rat model are altered in a manner consistent with that seen in the cell line model. Conclusions: Our novel data demonstrates the expression and functional activities of IL-21R in the mechanism for development of BPH. IL-21R mainly localized in prostate epithelium and it was upregulated in hyperplastic prostate tissues. IL-21R enhanced proliferation of BPH-1 cells, via inhibiting cell apoptosis, and modulating cell cycles, as well as the EMT process, in response to inflammatory stimuli.

A Subset of CXCR5+CD8+ T Cells in the Germinal Centers From Human Tonsils and Lymph Nodes Help B Cells Produce Immunoglobulins

Recent studies indicated that CXCR5⁺CD8⁺ T cells in lymph nodes could eradicate virus-infected target cells. However, in the current study we found that a subset of CXCR5⁺CD8⁺ T cells in the germinal centers from human tonsils or lymph nodes are predominately memory cells that express CD45RO and CD27. The involvement of CXCR5⁺CD8⁺ T cells in humoral immune responses is suggested by their localization in B cell follicles and by the concomitant expression of costimulatory molecules, including CD40L and ICOS after activation. In addition, CXCR5⁺CD8⁺ memory T cells produced significantly higher levels of IL-21, IFN-γ, and IL-4 at mRNA and protein levels compared to CXCR5⁻CD8⁺ memory T cells, but IL-21-expressing CXCR5⁺CD8⁺ T cells did not express Granzyme B and perforin. When cocultured with sorted B cells, sorted CXCR5⁺CD8⁺ T cells promoted the production of antibodies compared to sorted CXCR5⁻CD8⁺ T cells. However, fixed CD8⁺ T cells failed to help B cells and the neutralyzing antibodies against IL-21 or CD40L inhibited the promoting effects of sorted CXCR5⁺CD8⁺ T cells on B cells for the production of antibodies. Finally, we found that in the germinal centers of lymph nodes from HIV-infected patients contained more CXCR5⁺CD8⁺ T cells compared to normal lymph nodes. Due to their versatile functional capacities, CXCR5⁺CD8⁺ T cells are promising candidate cells for immune therapies, particularly when CD4⁺ T cell help are limited.

[Expression of interleukin-9 in colon cancer tissues and its clinical significance]

OBJECTIVE

To investigate the expression of interleukin-9 (IL-9) in colon cancer tissues and its clinical significance.

METHODS

Immunohistochenmistry and qRT-PCR were used to detect the expressions of IL-9 protein and mRNA in 92 colon cancer tissues and paired adjacent normal tissues. The correlation of IL-9 expressions with the clinicopathological features and prognosis of the patients was analyzed.

RESULTS

IL-9 protein and mRNA expressions were significantly higher in adjacent normal tissues than in the colon cancer tissues (P < 0.001). In colon cancer patients, IL-9 expression was significantly correlated with TNM stage (P=0.013), Ducks stage (P=0.025) and lymph node metastasis (P=0.004) but not with gender, age, tumor size, differentiation or hepatic metastasis (P > 0.05). The survival time of colon cancer patients with positive IL-9 expression was significantly longer than that of patients negative for IL-9 expression (P=0.015).

CONCLUSIONS

IL-9 expression is lowered in colon cancer tissues compoved with in the adjacent normal tissues. IL-9 expression is negatively correlated with TNM staging, Ducks staging and lymph node metastasis but positively with good prognosis, suggesting its important role in the tumor microenvironment of colon cancer.

Distribution of circulating follicular helper T cells and expression of interleukin-21 and chemokine C-X-C ligand 13 in gastric cancer

Circulating follicular helper T (cTfh) cells are a novel subset of cluster of differentiation (CD)4+ helper T cells. Interleukin (IL)-21 and C-X-C motif chemokine ligand (CXCL)13 are the principal effectors and chemotactic regulatory factors of Tfh. However, the roles of IL-21 and CXCL13 in gastric cancer have not yet been completely elucidated. The aim of the present study was to investigate the distribution of cTfh cells, and the expression of IL-21 and CXCL13 in patients with gastric cancer was evaluated in order to ascertain the significance and potential mechanisms of these effectors in gastric cancer. A total of 50 patients with gastric cancer were enrolled as the study subjects, with 30 healthy individuals selected as controls. The percentage of cTfh cells (cTfh%) in the peripheral blood was calculated using flow cytometry. They are identified in the present study as CD4+ chemokine C-X-C receptor (CXCR)5+ inducible T cell co-stimulator (ICOS)+ cells. The serum levels of IL-21 and CXCL13 were determined by ELISA. The cTfh% in the peripheral blood and the concentration of IL-21 and CXCL13 in the serum were significantly higher in patients with gastric cancer compared with the control group. cTfh% was significantly higher in patients with lymph node metastasis, Tumor-Node-Metastasis (TNM) stage III-IV and low differentiation. The concentrations of IL-21 and CXCL13 in patients with lymph node metastasis and/or TNM III-IV were significantly higher than in those without lymph node metastasis or with TNM I-II. There was a positive correlation between cTfh%/CXCL13 and IL-21/CXCL13, while there was no correlation between cTfh%/IL-21. cTfh cells and associated factors (IL-21/CXCL13) may be involved in the development and progression of gastric cancer. There may be mutual regulation among cTfh cells, IL-21 and CXCL13.

The role of the common gamma-chain family cytokines in γδ T cell-based anti-cancer immunotherapy

Cytokines of the common gamma-chain receptor family, comprising interleukin (IL)-2, IL-4, IL-7, IL-9, IL-15 and IL-21, are vital with respect to organizing and sustaining healthy immune cell functions. Supporting the anti-cancer immune response, these cytokines inspire great interest for their use as vaccine adjuvants and cancer immunotherapies. It is against this background that gamma delta (γδ) T cells, as special-force soldiers and natural contributors of the tumor immunosurveillance, also received a lot of attention the last decade. As γδ T cell-based cancer trials are coming of age, this present review focusses on the effects of the different cytokines of the common gamma-chain receptor family on γδ T cells with respect to boosting γδ T cells as a therapeutic target in cancer immunotherapy. This review also gathers data that IL-15 in particular exhibits key features for augmenting the anti-tumor activity of effector killer γδ T cells whilst overcoming the myriad of immune escape mechanisms used by cancer cells.

Certain BCG-reactive responses are associated with bladder cancer prognosis

A subset of bladder patients does not respond to BCG treatment effectively and the underlying reason behind this observation is currently unclear. CD4+ T cells are composed of various subsets that each expresses a distinctive set of cytokines and can potently shift the immune response toward various directions. In this study, we examined the CD4+ T-cell cytokine response in bladder cancer patients toward BCG stimulation. We found that bladder cancer patients presented a variety of responses toward BCG, with no uniform characteristics. Those patients with high IFN-γ and IL-21 expression in CD4+ T cells presented significantly better prognosis than patients with low cytokine secretion in CD4+ T cells. Tumor-infiltrating CD4+ T cells were significantly less potent in expressing IFN-γ, IL-4, and IL-17, and more potent in expressing IL-10 than circulating CD4+ T cells. In addition, we found no difference in CD80, CD86, or MHC II expression by macrophages from patients with different IFN-γ and IL-21 levels. However, the secretion of IL-12, a Th1-skewing cytokine, was released at significantly higher level by macrophages from patients with high IFN-γ or high IL-21 secretion. We also identified that modulating monocytes/macrophages by GM-CSF-mediated polarization resulted in significantly elevated expression of IFN-γ and IL-21 from CD4+ T cells. Overall, these results suggested that the specific types of responses mounted by CD4+ T cells were critical to the final outcome of bladder cancer patients and can be influenced by monocyte/macrophage polarization.

Trial Watch: Immunostimulation with recombinant cytokines for cancer therapy

Cytokines regulate virtually aspects of innate and adaptive immunity, including the initiation, execution and extinction of tumor-targeting immune responses. Over the past three decades, the possibility of using recombinant cytokines as a means to elicit or boost clinically relevant anticancer immune responses has attracted considerable attention. However, only three cytokines have been approved so far by the US Food and Drug Administration and the European Medicines Agency for use in cancer patients, namely, recombinant interleukin (IL)-2 and two variants of recombinant interferon alpha 2 (IFN-α2a and IFN-α2b). Moreover, the use of these cytokines in the clinics is steadily decreasing, mostly as a consequence of: (1) the elevated pleiotropism of IL-2, IFN-α2a and IFN-α2b, resulting in multiple unwarranted effects; and (2) the development of highly effective immunostimulatory therapeutics, such as immune checkpoint blockers. Despite this and other obstacles, research in the field continues as alternative cytokines with restricted effects on specific cell populations are being evaluated. Here, we summarize research preclinical and clinical developments on the use of recombinant cytokines for immunostimulation in cancer patients.

IL-21 modulates memory and exhaustion phenotype of T-cells in a fatty acid oxidation-dependent manner

T-cell-based therapies represent a promising strategy for cancer treatment. In this context, cytokines are discussed as a bona fide instrument for fine-tuning T- cell biology. One promising candidate is the pleiotropic interleukin-21 (IL-21) with only little being known regarding its direct effects on human T-cells. Thus, we sought out to characterize the impact of IL-21 on T-cell metabolism, fitness, and differentiation. Culturing T-cells in presence of IL-21 elicited a metabolic skewing away from aerobic glycolysis towards fatty acid oxidation (FAO). These changes of the metabolic framework were paralleled by increased mitochondrial fitness and biogenesis. However, oxidative stress levels were not increased but rather decreased. Furthermore, elevated FAO and mitochondrial biomass together with enhanced antioxidative properties are linked to formation of longer lasting memory responses and less PD-1 expression. We similarly observed an IL-21-triggered induction of central memory-like T-cells and reduced levels of PD-1 on the cell surface. Taken together, IL-21 shifts T-cells towards an immunometabolic phenotype that has been associated with increased survivability and enhanced anti-tumor efficacy. In addition, our data reveals a novel interconnection between fatty acid metabolism and immune function regulated by IL 21.

A prospective study of immune and inflammation markers and risk of lung cancer among female never smokers in Shanghai

There is a paucity of data on risk factors for lung cancer among never smokers. Here, we have carried out the first large study of circulating inflammation markers and lung cancer risk among female never smokers in Shanghai. A study of 248 lung cancer cases in female never smokers and 263 controls was nested within the Shanghai Women's Health Study (n = 75221), matched by dates of birth and blood collection (mean follow-up time = 7.5 years). Prediagnostic plasma levels of 65 inflammation markers were measured using a Luminex bead-based assay. Odds ratios (ORs) were estimated with multivariable logistic regression. Nine of 61 evaluable markers were statistically significantly associated with lung cancer risk among never smoking Chinese women (P-trend across categories <0.05). Soluble interleukin-6 receptor [sIL-6R; highest versus lowest category OR = 2.37; 95% confidence interval (CI) 1.40-4.02) and chemokine (C-C motif) ligand 2/monocyte chemotactic protein 1; (OR = 1.62; 95% CI 0.94-2.80) were associated with an increased risk of lung cancer, whereas interleukin (IL)-21 (OR = 0.53; 95%CI 0.31-0.93), chemokine (C-X3-C motif) ligand 1/fractalkine (OR = 0.54; 95% CI 0.30-0.96), soluble vascular endothelial growth factor receptor 2 (sVEGFR2, OR = 0.45; 95% CI 0.26-0.76), sVEGFR3 (OR = 0.53; 95% CI 0.32-0.90), soluble tumor necrosis factor receptor I (OR = 0.49; 95% CI 0.29-0.83), IL-10 (OR = 0.60; 95% CI 0.34-1.05) and C-reactive protein (OR = 0.63; 95% CI 0.37-1.06) were associated with a decreased risk. sIL-6R remained significantly associated with lung cancer risk >7.5 years prior to diagnosis. Markers involved in various aspects of the immune response were associated with subsequent lung cancer risk, implicating inflammation in the etiology of lung cancer among female never smokers.

Precocious Interleukin 21 Expression in Naive Mice Identifies a Natural Helper Cell Population in Autoimmune Disease

Interleukin 21 (IL-21) plays key roles in humoral immunity and autoimmune diseases. It is known to function in mature CD4+ T follicular B cell helper (TFH) cells, but its potential involvement in early T cell ontogeny is unclear. Here, we find that a significant population of newly activated thymic and peripheral CD4+ T cells functionally expresses IL-21 soon after birth. This naturally occurring population, termed natural (n)TH21 cells, exhibits considerable similarity to mature TFH cells. nTH21 cells originating and activated in the thymus are strictly dependent on autoimmune regulator (AIRE) and express high levels of NUR77, consistent with a bias toward self-reactivity. Their activation/expansion in the periphery requires gut microbiota and is held in check by FoxP3+ TREG cells. nTH21 cells are the major thymic and peripheral populations of IL-21+ cells to expand in an IL-21-dependent humoral autoimmune disease. These studies link IL-21 to T cell ontogeny, self-reactivity, and humoral autoimmunity.

Role of interleukin (IL)-17 and T-helper (Th)17 cells in cancer

Interleukin-17 (IL-17), a pleiotropic proinflammatory cytokine, is reported to be significantly generated by a distinct subset of CD4⁺ T-cells, upgrading cancer-elicited inflammation and preventing cancer cells from immune surveillance. T-helper (Th)17 cells produced from naive CD4⁺ T cells have recently been renowned and generally accepted, gaining eminence in cancer studies and playing the effective role in context of cancer. Th17 cells are the main source of IL-17-secreting cells, It was found that other cell types produced this cytokine as well, including Group 3 innate lymphoid cells (ILC3), δγT cells, invariant natural killer T (iNKT) cells, lymphoid-tissue inducer (LTi)-like cells and Natural killer (NK) cells. Th17-associated cytokines give impetus to tumor progression, or inducing angiogenesis and metastasis. This review demonstrates an understanding on how the pro- or antitumor function of Th17 cells and IL-17 may change cancer progression, leading to the appearance of complex and pivotal biologic activities in tumor.

Optimization of Human NK Cell Manufacturing: Fully Automated Separation, Improved Ex Vivo Expansion Using IL-21 with Autologous Feeder Cells, and Generation of Anti-CD123-CAR-Expressing Effector Cells

The administration of ex vivo expanded natural killer (NK) cells as potential antitumor effector cells appears to be suitable for effector cell-based immunotherapies in high-risk cancer patients. However, good manufacturing practice (GMP)-compliant manufacturing of clinical-grade NK cells at sufficiently high numbers represents a great challenge. Therefore, previous expansion protocols for those effector cells were improved and optimized by using newly developed culture medium, interleukin (IL)-21, and autologous feeder cells (FCs). Separation of primary human NK cells (CD56⁺CD3^-) was carried out with the CliniMACS Prodigy^® in a single process, starting with approximately 1.2 × 10⁹ leukocytes collected by small-scale lymphapheresis or from buffy coats. Enriched NK cells were adjusted to starting cell concentrations within approximately 1 × 10⁶ effector cells/mL and cultured in comparative expansion experiments for 14 days with IL-2 (1,000 IU/mL) in different GMP-compliant media (X-VIVO^™10, CellGro^®, TexMACS^™, and NK MACS^®). After medium optimization, beneficial effects for functionality and phenotype were investigated at the beginning of cell expansion with irradiated (25 Gy) autologous FCs at a ratio of 20:1 (feeder: NK) in the presence or absence of IL-21 (100 ng/mL). Additionally, expanded NK cells were gene modified to express chimeric antigen receptors (CARs) against CD123, a common marker for acute myeloid leukemia (AML). Cytotoxicity, degranulation, and cytokine release of transduced NK cells were determined against KG1a cells in flow cytometric analysis and fluorescent imaging. The Prodigy manufacturing process revealed high target cell viabilities (median 95.4%), adequate NK cell recovery (median 60.4%), and purity of 95.4% in regard to CD56⁺CD3^- target cells. The process in its early phase of development led to a median T-cell depletion of log 3.5 after CD3 depletion and log 3.6 after the whole process, including CD3 depletion and CD56 enrichment steps. Manually performed experiments to test different culture media demonstrated significantly higher NK cell expansion rates and an approximately equal distribution of CD56^dimCD16^pos and CD56^brightCD16^dim&neg NK subsets on day 14 with cells cultivated in NK MACS^® media. Moreover, effector cell expansion in manually performed experiments with NK MACS^® containing IL-2 and irradiated autologous FCs and IL-21, both added at the initiation of the culture, induced an 85-fold NK cell expansion. Compared to freshly isolated NK cells, expanded NK cells expressed significantly higher levels of NKp30, NKp44, NKG2D, TRAIL, FasL, CD69, and CD137, and showed comparable cell viabilities and killing/degranulation activities against tumor and leukemic cell lines in vitro. NK cells used for CAR transduction showed the highest anti-CD123 CAR expression on day 3 after gene modification. These anti-CD123 CAR-engineered NK cells demonstrated improved cytotoxicity against the CD123^pos AML cell line KG1a and primary AML blasts. In addition, CAR NK cells showed higher degranulation and enhanced secretion of tumor necrosis factor alpha, interferon gamma, and granzyme A and B. In fluorescence imaging, specific interactions that initiated apoptotic processes in the AML target cells were detected between CAR NK cells and KG1a. After the fully automated NK cell separation process on Prodigy, a new NK cell expansion protocol was generated that resulted in high numbers of NK cells with potent antitumor activity, which could be modified efficiently by novel third-generation, alpha-retroviral SIN vector constructs. Next steps are the integration of the manual expansion procedure in the fully integrated platform for a standardized GMP-compliant overall process in this closed system that also may include gene modification of NK cells to optimize target-specific antitumor activity.

Identification of the novel 3' UTR sequences of human IL-21 mRNA as potential targets of miRNAs

Hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma worldwide. However, the strategy of HBV to escape from the host immune system remains largely unknown. In this study, we examined extracellular vesicles (EVs) secreted from human hepatocytes infected with HBV. EVs includeing exosomes are nano-size vesicles with proteins, mRNAs, and microRNAs (miRNAs), which can be transmitted to different cells. We found that 104 EV associated miRNAs were increased in hepatocytes more than 2-fold by HBV infection. We then selected those that were potentially implicated in immune regulation. Among them, five HBV-induced miRNAs were found to potentially target multiple sequences in the 3'UTR of IL-21, a cytokine that induces anti-viral immunity. Moreover, expression of a reporter gene with the 3' UTR of human IL-21 mRNA was suppressed by the five miRNAs individually. Finally, IL-21 expression in cloned human T cells was down-regulated by the five miRNAs. Collectively, this study identified the novel 3' UTR sequences of human IL-21 mRNA and potential binding sites of HBV-induced EV-miRNAs.

Shaping of Natural Killer Cell Antitumor Activity by Ex Vivo Cultivation

Natural killer (NK) cells are a promising tool for the use in adoptive immunotherapy, since they efficiently recognize and kill tumor cells. In this context, ex vivo cultivation is an attractive option to increase NK cells in numbers and to improve their antitumor potential prior to clinical applications. Consequently, various strategies to generate NK cells for adoptive immunotherapy have been developed. Here, we give an overview of different NK cell cultivation approaches and their impact on shaping the NK cell antitumor activity. So far, the cytokines interleukin (IL)-2, IL-12, IL-15, IL-18, and IL-21 are used to culture and expand NK cells. The selection of the respective cytokine combination is an important factor that directly affects NK cell maturation, proliferation, survival, distribution of NK cell subpopulations, activation, and function in terms of cytokine production and cytotoxic potential. Importantly, cytokines can upregulate the expression of certain activating receptors on NK cells, thereby increasing their responsiveness against tumor cells that express the corresponding ligands. Apart from using cytokines, cocultivation with autologous accessory non-NK cells or addition of growth-inactivated feeder cells are approaches for NK cell cultivation with pronounced effects on NK cell activation and expansion. Furthermore, ex vivo cultivation was reported to prime NK cells for the killing of tumor cells that were previously resistant to NK cell attack. In general, NK cells become frequently dysfunctional in cancer patients, for instance, by downregulation of NK cell activating receptors, disabling them in their antitumor response. In such scenario, ex vivo cultivation can be helpful to arm NK cells with enhanced antitumor properties to overcome immunosuppression. In this review, we summarize the current knowledge on NK cell modulation by different ex vivo cultivation strategies focused on increasing NK cytotoxicity for clinical application in malignant diseases. Moreover, we critically discuss the technical and regulatory aspects and challenges underlying NK cell based therapeutic approaches in the clinics.

Chitosan nanoparticle-based delivery of fused NKG2D-IL-21 gene suppresses colon cancer growth in mice

Nanoparticles can be loaded with exogenous DNA for the potential expression of cytokines with immune-stimulatory function. NKG2D identifies major histocompatibility complex class I chain-related protein in human and retinoic acid early induced transcript-1 in mouse, which acts as tumor-associated antigens. Biologic agents based on interleukin 21 (IL-21) have displayed antitumor activities through lymphocyte activation. The NKG2D-IL-21 fusion protein theoretically identifies tumor cells through NKG2D moiety and activates T cells through IL-21 moiety. In this study, double-gene fragments that encode the extracellular domains of NKG2D and IL-21 genes were connected and then inserted into the pcDNA3.1(-) plasmid. PcDNA3.1-dsNKG2D-IL-21 plasmid nanoparticles based on chitosan were generated. Tumor cells pretransfected with dsNKG2D-IL-21 gene nanoparticles can activate natural killer (NK) and CD8⁺ T cells in vitro. Serum IL-21 levels were enhanced in mice intramuscularly injected with the gene nanoparticles. DsNKG2D-IL-21 gene nanoparticles accumulated in tumor tissues after being intravenously injected for ~4-24 h. Treatment of dsNKG2D-IL-21 gene nanoparticles also retarded tumor growth and elongated the life span of tumor-bearing mice by activating NK and T cells in vivo. Thus, the dsNKG2D-IL-21 gene nanoparticles exerted efficient antitumor activities and would be potentially used for tumor therapy.

Unveil the mysterious mask of cytokine-based immunotherapy for melanoma

Melanoma is the leading cause of death among all skin cancers and its incidence continues to rise rapidly worldwide in the past decades. The available treatment options for melanoma remain limited despite extensive clinical research. Melanoma is an immunogenic tumor and great advances in immunology in recent decades allow for the development of immunotherapeutic agents against melanoma. In recent years, immunotherapy utilizing cytokines has been particularly successful in certain cancers and holds promise for patients with advanced melanoma. In this review, an overview of the current status and emerging perspectives on cytokine immunotherapy for melanoma are discussed in details. Such a study will be helpful to unveil the mysterious mask of cytokine-based immunotherapy for melanoma.

Tertiary lymphoid structures, drivers of the anti-tumor responses in human cancers

The characterization of the microenvironment of human tumors led to the description of tertiary lymphoid structures (TLS) characterized by mature dendritic cells in a T-cell zone adjacent to B-cell follicle including a germinal center. TLS represent sites of lymphoid neogenesis that develop in most solid cancers. Analysis of the current literature shows that the TLS presence is associated with a favorable clinical outcome for cancer patients, regardless of the approach used to quantify TLS and the stage of the disease. Using several approaches that combine immunohistochemistry, gene expression assays, and flow cytometry on large series of lung tumors, our work demonstrated that TLS are important sites for the initiation and/or maintenance of the local and systemic T- and B-cell responses against tumors. Surrounded by high endothelial venules, they represent a privileged area for the recruitment of lymphocytes into tumors and generation of central-memory T and B cells that circulate and limit cancer progression. TLS can be considered as a novel biomarker to stratify the overall survival risk of untreated cancer patients and as a marker of efficient immunotherapies. The induction and manipulation of cancer-associated TLS using drug agonists and/or biotherapies should open new avenues to treat cancer patients.