Interleukin 15: biology and relevance to human disease

Effects of exercise or metformin on myokine concentrations in patients with breast and colorectal cancer: A phase II multi-centre factorial randomized trial

BACKGROUND

Physical activity and metformin pharmacotherapy are associated with improved clinical outcomes in breast and colorectal cancer survivors. Myokines are cytokines secreted from skeletal muscle that may mediate these associations.

METHODS

This hypothesis-generating analysis used biospecimens collected from a multi-centre 2 × 2 factorial randomized design of 116 patients with stage I-III breast and colorectal cancer who were randomized to 12 weeks of (1) aerobic exercise (moderate intensity titrated to 220 min/week); (2) metformin (850 mg daily for 2 weeks and then titrated to 850 mg twice per day); (3) aerobic exercise and metformin; or (4) control. Fourteen myokines were quantified using a multiplex panel. Myokine concentrations were log-transformed, and main effects analyses were conducted using linear mixed-effects regression models. The type I error rate was controlled with the Holm sequential testing procedure.

RESULTS

Randomization to exercise increased leukaemia inhibitory factor (1.26 pg/mL, 95% confidence interval [CI]: 0.69, 1.84; adjusted P = 0.001) and interleukin-15 (2.23 pg/mL, 95% CI: 0.87, 3.60; adjusted P = 0.013) compared with randomization to no exercise. Randomization to metformin decreased apelin (-2.69 pg/mL, 95% CI: -4.31, -1.07; adjusted P = 0.014) and interleukin-15 (-1.74 pg/mL, 95% CI: -2.79, -0.69; adjusted P = 0.013) compared with randomization to no metformin. Metformin decreased myostatin, irisin, oncostatin M, fibroblast growth factor 21 and osteocrin; however, these changes were not statistically significant after correction for multiple comparisons.

CONCLUSIONS

This pilot study demonstrates that randomization to exercise and metformin elicit unique effects on myokine concentrations in cancer patients. This hypothesis-generating observation warrants further basic, translational and clinical investigation and replication.

Bioinformatic Analysis of the Significance of the KIR2DL4 Gene in Recurrent Implantation Failure

Related studies have pointed out that Killer immunoglobulin-like receptor 2DL4 (KIR2DL4) was associated with vascular remodeling in early pregnancy, and it might play an important role in immunity. In this study, recurrent implantation failure (RIF)-related GSE58144 dataset was extracted from the Gene Expression Omnibus (GEO) database. Firstly, the immune micro-environment analyses were conducted to analyze the pathogenesis of KIR2DL4 in RIF. Then, the gene set enrichment analysis (GSEA) was performed to investigate the function of KIR2DL4. Moreover, the TF-mRNA-miRNA and the co-expression networks were constructed to reveal the potential regulation of KIR2DL4. Furthermore, the genes that were associated with KIR2DL4 and differentially expressed in RIF were obtained and defined as key genes, and the functions of these genes were further explored. KIR2DL4 could be used for clinical diagnosis of RIF, and it was correlated with the changes in the immune micro-environment in RIF. From the perspective of function, KIR2DL4 was associated with complement and coagulation cascades, natural killer cell-mediated cytotoxicity, etc. Moreover, the TF-mRNA-miRNA regulatory network was constructed with KIR2DL4, 9 TFs, and 29 miRNAs. Furthermore, KIR2DL4, ACSM1, IL2RB, and PTPN11 were screened as key genes, which were associated with immune-related functions. This study deeply analyzed the function of KIR2DL4 and its role in RIF, and we found that STAT1 might up-regulate KIR2DL4 by INF-γ/JAK2/STAT1 signaling pathway. Besides, over-expressed KIR2DL4 in the mid-luteal endometrium might influence embryo implantation by affecting the embryo implantation microenvironment, which might help deepen the understanding of the molecular mechanism of RIF.

Protective Role of the Podocyte IL-15 / STAT5 Pathway in Focal Segmental Glomerulosclerosis

Introduction

During glomerular diseases, podocyte-specific pathways can modulate the intensity of histological disease and prognosis. The therapeutic targeting of these pathways could thus improve the management and prognosis of kidney diseases. The Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) pathway, classically described in immune cells, has been recently described in detail in intrinsic kidney cells.

Methods

We describe STAT5 expression in human kidney biopsies from patients with focal segmental glomerulosclerosis (FSGS) and studied mice with a podocyte-specific Stat5 deletion in experimental glomerular diseases.

Results

Here, we show, for the first time, that STAT5 is activated in human podocytes in FSGS. In addition, podocyte-specific Stat5 inactivation aggravates the structural and functional alterations in a mouse model of FSGS. This could be due, at least in part, to an inhibition of autophagic flux. Finally, interleukin 15 (IL-15), a classical activator of STAT5 in immune cells, increases STAT5 phosphorylation in human podocytes, and its administration alleviates glomerular injury in vivo by maintaining autophagic flux in podocytes.

Conclusion

Activating podocyte STAT5 with commercially available IL-15 represents a potential new therapeutic avenue for FSGS.

Interleukin-15 in kidney disease and therapeutics

PURPOSE OF REVIEW

Interleukin 15 (IL-15) is a member of the IL-2 family of common gamma chain receptor cytokines with well described anti-inflammatory, pro-survival and pro-proliferative signaling properties. The cytoprotective role of IL-15 in the kidney is now coming into focus with recent reports of its beneficial actions in various forms of kidney disease. This review will summarize what is currently known about IL-15 signaling in the kidney and highlight recent evidence of its beneficial effects on kidney physiology.

RECENT FINDINGS

IL-15 and its heterotrimeric receptor are expressed throughout the kidney. Like all IL-2 family cytokines, IL-15 can activate signaling through the Janus Kinase (JAK)/Signal transducer of activated T-cells (STAT), phosphoinositol-3 kinase (PI-3K)/AKT and mitogen activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathways and recent evidence suggests that STAT5B is an essential transcriptional mediator of prosurvival signaling in glomerular visceral epithelial cells (i.e. podocytes). IL-15 has also been shown to suppress pro-apoptotic signaling in models of acute kidney injury and pro-fibrotic signaling in models of chronic kidney disease.

SUMMARY

The cytoprotective properties of IL-15 suggest that it may have potential as a nonimmunosuppresive therapeutic for kidney disease. A novel class of IL-15 immunotherapies has emerged for the treatment cancer and some have demonstrated efficacy in clinical trials. These well tolerated IL-15 agonists could possibly be repurposed for the treatment of kidney disease and warrant further exploration.

Reprogramming natural killer cells for cancer therapy

The last decade has seen rapid development in the field of cellular immunotherapy, particularly in regard to chimeric antigen receptor (CAR)-modified T cells. However, challenges, such as severe treatment-related toxicities and inconsistent quality of autologous products, have hindered the broader use of CAR-T cell therapy, highlighting the need to explore alternative immune cells for cancer targeting. In this regard, natural killer (NK) cells have been extensively studied in cellular immunotherapy and were found to exert cytotoxic effects without being restricted by human leukocyte antigen and have a lower risk of causing graft-versus-host disease; making them favorable for the development of readily available "off-the-shelf" products. Clinical trials utilizing unedited NK cells or reprogrammed NK cells have shown early signs of their effectiveness against tumors. However, limitations, including limited in vivo persistence and expansion potential, remained. To enhance the antitumor function of NK cells, advanced gene-editing technologies and combination approaches have been explored. In this review, we summarize current clinical trials of antitumor NK cell therapy, provide an overview of innovative strategies for reprogramming NK cells, which include improvements in persistence, cytotoxicity, trafficking and the ability to counteract the immunosuppressive tumor microenvironment, and also discuss some potential combination therapies.

Clearing soluble MIC reverses the impaired function of natural killer cells from patients with multiple myeloma

BACKGROUND

Major histocompatibility complex (MHC) class I chain-related protein (MIC) is a stress-induced ligand released from multiple myeloma (MM) cells during progression, and soluble MIC impairs natural killer group 2D (NKG2D) activating receptor-mediated recognition and function of natural killer (NK) cells. However, whether clearing soluble MIC with a monoclonal antibody (mAb) can restore NK cell activity of MM patients remains undetermined.

METHODS

We analyzed The Cancer Genome Atlas (TCGA) Multiple Myeloma Research Foundation (MMRF) CoMMpass data set to examine the prognostic significance of MIC expression in MM. We examined the level of soluble MIC in paired peripheral blood (PB) and bone marrow (BM) plasma of patients with MM at diagnosis by ELISA. We evaluated the correlation between the level of soluble MIC and immunophenotype of NK cells from MM patients by multicolor flow cytometry. We also generated MIC-overexpressing MM cell line and characterized the cytotoxic function of patient NK cells in the presence of soluble MIC, and examined the impact of clearing soluble MIC with a humanized mAb (huB10G5).

RESULTS

We characterize the importance of MICA in MM by revealing the significantly better overall survival of patients with high MICA expression from TCGA MMRF CoMMpass data set. The level of soluble MICA is more highly elevated in MM than in precursor stages, and the concentration of soluble MICA is higher in BM plasma than in PB. The concentration of soluble MICA in BM was correlated with myeloma burden, while it was negatively correlated with the frequency of NKG2D+ NK cells in diagnostic BM aspirates of MM patients. Soluble MICA downregulated NKG2D expression and decreased cytotoxicity of MM patient NK cells ex vivo, which were reversed by a humanized soluble MIC-clearing mAb (huB10G5) with enhanced degranulation of NK cells.

CONCLUSIONS

Our findings indicate targeting soluble MIC with huB10G5 might be a viable therapeutic approach to promote NKG2D-dependent cellular immunotherapy outcome in MM.

Interleukin-15 alters hippocampal synaptic transmission and impairs episodic memory formation in mice

Cytokines are potent immunomodulators exerting pleiotropic effects in the central nervous system (CNS). They influence neuronal functions and circuit activities with effects on memory processes and behaviors. Here, we unravel a neuromodulatory activity of interleukin-15 (IL-15) in mouse brain. Acute exposure of hippocampal slices to IL-15 enhances gamma-aminobutyricacid (GABA) release and reduces glutamatergic currents, while chronic treatment with IL-15 increases the frequency of hippocampal miniature inhibitory synaptic transmission and impairs memory formation in the novel object recognition (NOR) test. Moreover, we describe that serotonin is involved in mediating the hippocampal effects of IL-15, because a selective 5-HT3A receptor antagonist prevents the effects on inhibitory neurotransmission and ameliorates mice performance in the NOR test. These findings provide new insights into the modulatory activities of cytokines in the CNS, with implications on behavior.

Decreased CD56+CD16-CD94+uNK cells in the mid-luteal phase in women with recurrent implantation failure are associated with IL-15 deficiency

PROBLEM

Whether the abnormal development of uterine natural killer (uNK) cells contributes to women with recurrent implantation failure (RIF) remains unclear.

METHOD OF STUDY

We characterized the development of uNK cells and peripheral blood NK cells (pbNK) in the mid-luteal phase in women with RIF (n = 31) and controls (n = 14) by flow cytometry. Endometrial IL-15 mRNA expression was studied by quantitative reverse transcription-PCR. The GSE58144 dataset was used to validate the correlation results.

RESULTS

We found decreased proportions of stage 4 CD56+CD16-CD94+ uNK cells (median: 9.56% vs. 17.78%, P .014) and increased proportions of stage 6 CD56+CD16+CD57+ uNK cells (median: 1.54% vs. 0.74%, P = .020) in the mid-luteal endometrium of women with RIF compared to fertile women. We also found that there was no quantitative correlation between uNK cells and the corresponding pbNK cell subpopulations (P > .05). In addition, IL-15 mRNA levels in the mid-luteal endometrium were positively correlated with the proportion of CD56+ uNK cells (r = .392, P = .008), especially with stage 4 uNK cell populations (r = .408, P = .005).

CONCLUSIONS

We showed that the proportion of stage 4 uNK cells decreased in the RIF group compared to controls, and the decrease in stage 4 uNK cells correlated positively with low IL-15 mRNA expression. We suggest that the reduced stage 4 uNK cells in women with RIF are associated with IL-15 deficiency.

Celiac disease: mechanisms and emerging therapeutics

Celiac disease (CeD) is a widespread, gluten-induced, autoimmune disorder that lacks any medicinal therapy. Towards the goal of developing non-dietary treatments for CeD, research has focused on elucidating its molecular and cellular etiology. A model of pathogenesis has emerged centered on interactions between three molecular families: specific class II MHC proteins on antigen-presenting cells (APCs), deamidated gluten-derived peptides, and T cell receptors (TCRs) on inflammatory CD4+ T cells. Growing evidence suggests that this pathogenic axis can be pharmacologically targeted to protect patients from some of the adverse effects of dietary gluten. Further studies have revealed the existence of additional host and environmental contributors to disease initiation and tissue damage. This review summarizes our current understanding of CeD pathogenesis and how it is being harnessed for therapeutic design and development.

Single-cell transcriptomic atlas of distinct early immune responses induced by SARS-CoV-2 Proto or its variants in rhesus monkey

Immune responses induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection play a critical role in the pathogenesis and outcome of coronavirus disease 2019 (COVID-19). However, the dynamic profile of immune responses postinfection by SARS-CoV-2 variants of concern (VOC) is not fully understood. In this study, peripheral blood mononuclear cells single-cell sequencing was performed to determine dynamic profiles of immune response to Prototype, Alpha, Beta, and Delta in a rhesus monkey model. Overall, all strains induced dramatic changes in both cellular subpopulations and gene expression levels at 1 day postinfection (dpi), which associated function including adaptive immune response, innate immunity, and IFN response. COVID-19-related genes revealed different gene profiles at 1 dpi among the four SARS-CoV-2 strains, including genes reported in COVID-19 patients with increased risk of autoimmune disease and rheumatic diseases. Delta-infected animal showed inhibition of translation pathway. B cells, T cells, and monocytes showed much commonality rather than specificity among the four strains. Monocytes were the major responders to SARS-CoV-2 infection, and the response lasted longer in Alpha than the other strains. Thus, this study reveals the early immune responses induced by SARS-CoV-2 Proto or its variants in nonhuman primates, which is important information for controlling rapidly evolving viruses.

Phytochemicals as Immunomodulatory Molecules in Cancer Therapeutics

Phytochemicals are natural plant-derived products that provide significant nutrition, essential biomolecules, and flavor as part of our diet. They have long been known to confer protection against several diseases via their anti-inflammatory, immune-regulatory, anti-microbial, and several other properties. Deciphering the role of phytochemicals in the prevention, inhibition, and treatment of cancer-unrestrained cell proliferation due to the loss of tight regulation on cell growth and replication-has been the focus of recent research. Particularly, the immunomodulatory role of phytochemicals, which is pivotal in unchecked cell proliferation and metastasis, has recently been studied extensively. The immune system is a critical component of the tumor microenvironment, and it plays essential roles in both preventing and promoting oncogenesis. Immunomodulation includes stimulation, amplification, or inactivation of some stage(s) of the immune response. Phytochemicals and their products have demonstrated immune regulation, such as macrophage migration, nitric oxide synthase inhibition, lymphocyte, T-cell, and cytokine stimulation, natural killer cell augmentation, and NFκB, TNF, and apoptosis regulation. There is a dearth of extensive accounts of the immunomodulatory effects of phytochemicals in cancer; thus, we have compiled these effects with mechanistic aspects of dietary phytochemicals in cancer, highlighting promising candidates and ongoing clinical trials on immunotherapeutic strategies to mitigate oncogenesis.

Potentiation of natural killer cells to overcome cancer resistance to NK cell-based therapy and to enhance antibody-based immunotherapy

Natural killer (NK) cells are cellular components of the innate immune system that can recognize and suppress the proliferation of cancer cells. NK cells can eliminate cancer cells through direct lysis, by secreting perforin and granzymes, or through antibody-dependent cell-mediated cytotoxicity (ADCC). ADCC involves the binding of the Fc gamma receptor IIIa (CD16), present on NK cells, to the constant region of an antibody already bound to cancer cells. Cancer cells use several mechanisms to evade antitumor activity of NK cells, including the accumulation of inhibitory cytokines, recruitment and expansion of immune suppressor cells such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), modulation of ligands for NK cells receptors. Several strategies have been developed to enhance the antitumor activity of NK cells with the goal of overcoming cancer cells resistance to NK cells. The three main strategies to engineer and boost NK cells cytotoxicity include boosting NK cells with modulatory cytokines, adoptive NK cell therapy, and the employment of engineered NK cells to enhance antibody-based immunotherapy. Although the first two strategies improved the efficacy of NK cell-based therapy, there are still some limitations, including immune-related adverse events, induction of immune-suppressive cells and further cancer resistance to NK cell killing. One strategy to overcome these issues is the combination of monoclonal antibodies (mAbs) that mediate ADCC and engineered NK cells with potentiated anti-cancer activity. The advantage of using mAbs with ADCC activity is that they can activate NK cells, but also favor the accumulation of immune effector cells to the tumor microenvironment (TME). Several clinical trials reported that combining engineered NK cells with mAbs with ADCC activity can result in a superior clinical response compared to mAbs alone. Next generation of clinical trials, employing engineered NK cells with mAbs with higher affinity for CD16 expressed on NK cells, will provide more effective and higher-quality treatments to cancer patients.

Efficacy of using oral methotrexate with phototherapy in the treatment of vitiligo in comparison with single phototherapy treatment: A double-blinded randomized controlled trial

BACKGROUND

Vitiligo is an acquired skin disease with a worldwide prevalence of 0.5%-2% and a tendency to involve both genders. Although the exact pathologic mechanism is unknown, there is some evidence for the role of autoimmunity in this disease. Based on this theory, various immunosuppressive agents, such as topical or systemic corticosteroids and phototherapy (including narrowband ultraviolet B), are used. Methotrexate is another immunosuppressant that has recently become popular as a single treatment for vitiligo; however, the synergistic effect and its superiority over other treatments are two crucial factors that are still obscure. This study aimed to compare the efficacy of methotrexate+ NB-UVB versus placebo+ NB-UVB in vitiligo patients.

METHODS

In this double-blinded, randomized controlled trial, 42 patients were randomly allocated into two groups: the first group received three times weekly NB-UVB plus placebo, and the second group was treated with three times weekly NB-UVB in combination with a weekly dose of 12.5 mg MTX. The total duration of treatment was 6 months, patients were followed up every 2 months, and the assessment tools were VASI (repigmentation indicator) and VIDA (disease activity indicator) scores.

RESULTS

Both treatment groups showed improvement in VASI and VIDA scores during 6-month follow-up, but no statistical significance was found between the two treatment methods.

CONCLUSION

This study demonstrated that both treatment modalities were equally effective, and further studies are required to evaluate the efficacy of MTX with other medications with longer follow-up and a larger sample size.

Severe hematotoxicity after CD19 CAR-T therapy is associated with suppressive immune dysregulation and limited CAR-T expansion

Prolonged cytopenias after chimeric antigen receptor (CAR) T cell therapy are a significant clinical problem and the underlying pathophysiology remains poorly understood. Here, we investigated how (CAR) T cell expansion dynamics and serum proteomics affect neutrophil recovery phenotypes after CD19-directed CAR T cell therapy. Survival favored patients with "intermittent" neutrophil recovery (e.g., recurrent neutrophil dips) compared to either "quick" or "aplastic" recovery. While intermittent patients displayed increased CAR T cell expansion, aplastic patients exhibited an unfavorable relationship between expansion and tumor burden. Proteomics of patient serum collected at baseline and in the first month after CAR-T therapy revealed higher markers of endothelial dysfunction, inflammatory cytokines, macrophage activation, and T cell suppression in the aplastic phenotype group. Prolonged neutrophil aplasia thus occurs in patients with systemic immune dysregulation at baseline with subsequently impaired CAR-T expansion and myeloid-related inflammatory changes. The association between neutrophil recovery and survival outcomes highlights critical interactions between host hematopoiesis and the immune state stimulated by CAR-T infusion.

Widespread and dynamic expression of granzyme C by skin-resident antiviral T cells

After recognition of cognate antigen (Ag), effector CD8+ T cells secrete serine proteases called granzymes in conjunction with perforin, allowing granzymes to enter and kill target cells. While the roles for some granzymes during antiviral immune responses are well characterized, the function of others, such as granzyme C and its human ortholog granzyme H, is still unclear. Granzyme C is constitutively expressed by mature, cytolytic innate lymphoid 1 cells (ILC1s). Whether other antiviral effector cells also produce granzyme C and whether it is continually expressed or responsive to the environment is unknown. To explore this, we analyzed granzyme C expression in different murine skin-resident antiviral lymphocytes. At steady-state, dendritic epidermal T cells (DETCs) expressed granzyme C while dermal γδ T cells did not. CD8+ tissue-resident memory T cells (TRM) generated in response to cutaneous viral infection with the poxvirus vaccinia virus (VACV) also expressed granzyme C. Both DETCs and virus-specific CD8+ TRM upregulated granzyme C upon local VACV infection. Continual Ag exposure was not required for maintained TRM expression of granzyme C, although re-encounter with cognate Ag boosted expression. Additionally, IL-15 treatment increased granzyme C expression in both DETCs and TRM. Together, our data demonstrate that granzyme C is widely expressed by antiviral T cells in the skin and that expression is responsive to both environmental stimuli and TCR engagement. These data suggest that granzyme C may have functions other than killing in tissue-resident lymphocytes.

Interaction of S100A6 Protein with the Four-Helical Cytokines

S100 is a family of over 20 structurally homologous, but functionally diverse regulatory (calcium/zinc)-binding proteins of vertebrates. The involvement of S100 proteins in numerous vital (patho)physiological processes is mediated by their interaction with various (intra/extra)cellular protein partners, including cell surface receptors. Furthermore, recent studies have revealed the ability of specific S100 proteins to modulate cell signaling via direct interaction with cytokines. Previously, we revealed the binding of ca. 71% of the four-helical cytokines via the S100P protein, due to the presence in its molecule of a cytokine-binding site overlapping with the binding site for the S100P receptor. Here, we show that another S100 protein, S100A6 (that has a pairwise sequence identity with S100P of 35%), specifically binds numerous four-helical cytokines. We have studied the affinity of the recombinant forms of 35 human four-helical cytokines from all structural families of this fold to Ca2+-loaded recombinant human S100A6, using surface plasmon resonance spectroscopy. S100A6 recognizes 26 of the cytokines from all families of this fold, with equilibrium dissociation constants from 0.3 nM to 12 µM. Overall, S100A6 interacts with ca. 73% of the four-helical cytokines studied to date, with a selectivity equivalent to that for the S100P protein, with the differences limited to the binding of interleukin-2 and oncostatin M. The molecular docking study evidences the presence in the S100A6 molecule of a cytokine-binding site, analogous to that found in S100P. The findings argue the presence in some of the promiscuous members of the S100 family of a site specific to a wide range of four-helical cytokines. This unique feature of the S100 proteins potentially allows them to modulate the activity of the numerous four-helical cytokines in the disorders accompanied by an excessive release of the cytokines.

Exploiting an Interleukin-15 Heterodimeric Agonist (N803) for Effective Immunotherapy of Solid Malignancies

Identifying effective immunotherapies for solid tumors remains challenging despite the significant clinical responses observed in subsets of patients treated with immune checkpoint inhibitors. Interleukin-15 (IL-15) is a promising cytokine for the treatment of cancer as it stimulates NK and CD8⁺ lymphocytes. However, unfavorable pharmacokinetics and safety concerns render recombinant IL-15 (rIL-15) a less attractive modality. These shortcomings were addressed by the clinical development of heterodimeric IL-15 agonists, including N803. In preclinical tumor models, N803 elicited significant Th1 immune activation and tumor suppressive effects, primarily mediated by NK and CD8⁺ T lymphocytes. In addition, multiple clinical studies have demonstrated N803 to be safe for the treatment of cancer patients. The combination of N803 with the immune checkpoint inhibitor nivolumab demonstrated encouraging clinical responses in nivolumab-naïve and nivolumab-refractory patients with non-small cell lung cancer. In a recent Phase II/III clinical study, most Bacillus Calmette-Guerin (BCG)-refractory bladder cancer patients treated with N803 plus BCG experienced durable complete responses. Currently, N803 is being evaluated preclinically and clinically in combination with various agents, including chemotherapeutics, immune checkpoint inhibitors, vaccines, and other immuno-oncology agents. This report will review the mechanism(s) of action of N803 and how it relates to the preclinical and clinical studies of N803.

Predicting the Progress of Tuberculosis by Inflammatory Response-Related Genes Based on Multiple Machine Learning Comprehensive Analysis

Background

Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis, affects approximately one-quarter of the global population and is considered one of the most lethal infectious diseases worldwide. The prevention of latent tuberculosis infection (LTBI) from progressing into active tuberculosis (ATB) is crucial for controlling and eradicating TB. Unfortunately, currently available biomarkers have limited effectiveness in identifying subpopulations that are at risk of developing ATB. Hence, it is imperative to develop advanced molecular tools for TB risk stratification.

Methods

The TB datasets were downloaded from the GEO database. Three machine learning models, namely LASSO, RF, and SVM-RFE, were used to identify the key characteristic genes related to inflammation during the progression of LTBI to ATB. The expression and diagnostic accuracy of these characteristic genes were subsequently verified. These genes were then used to develop diagnostic nomograms. In addition, single-cell expression clustering analysis, immune cell expression clustering analysis, GSVA analysis, immune cell correlation, and immune checkpoint correlation of characteristic genes were conducted. Furthermore, the upstream shared miRNA was predicted, and a miRNA-genes network was constructed. Candidate drugs were also analyzed and predicted.

Results

In comparison to LTBI, a total of 96 upregulated and 26 downregulated genes related to the inflammatory response were identified in ATB. These characteristic genes have demonstrated excellent diagnostic performance and significant correlation with many immune cells and immune sites. The results of the miRNA-genes network analysis suggested a potential role of hsa-miR-3163 in the molecular mechanism of LTBI progressing into ATB. Moreover, retinoic acid may offer a potential avenue for the prevention of LTBI progression to ATB and for the treatment of ATB.

Conclusion

Our research has identified key inflammatory response-related genes that are characteristic of LTBI progression to ATB and hsa-miR-3163 as a significant node in the molecular mechanism of this progression. Our analyses have demonstrated the excellent diagnostic performance of these characteristic genes and their significant correlation with many immune cells and immune checkpoints. The CD274 immune checkpoint presents a promising target for the prevention and treatment of ATB. Furthermore, our findings suggest that retinoic acid may have a role in preventing LTBI from progressing to ATB and in treating ATB. This study provides a new perspective for differential diagnosis of LTBI and ATB and may uncover potential inflammatory immune mechanisms, biomarkers, therapeutic targets, and effective drugs in the progression of LTBI into ATB.

The effects of progesterone on immune cellular function at the maternal-fetal interface and in maternal circulation

Progesterone is a sex steroid hormone that plays a critical role in the establishment and maintenance of pregnancy. This hormone drives numerous maternal physiological adaptations to ensure the continuation of pregnancy and to facilitate fetal growth, including broad and potent modulation of the maternal immune system to promote maternal-fetal tolerance. In this brief review, we provide an overview of the immunomodulatory functions of progesterone in the decidua, placenta, myometrium, and maternal circulation during pregnancy. Specifically, we summarize current evidence of the regulated functions of innate and adaptive immune cells induced by progesterone and its downstream effector molecules in these compartments, including observations in human pregnancy and in animal models. Our review highlights the gaps in knowledge of interactions between progesterone and maternal cellular immunity that may direct future research.

Assessment of Interleukin-15 (IL-15) Concentration in Children with Idiopathic Nephrotic Syndrome

Idiopathic nephrotic syndrome (INS) is a chronic glomerular disease in children, characterized by severe proteinuria, hypoalbuminemia, and/or presence of edema and hyperlipidemia. The pathogenesis, however, has not been yet established. The clinical course of the disease is characterized by frequent relapses. Interleukin-15 (IL-15) is a pro-inflammatory cytokine, that apart from its involvement in the immune system, was found to be playing a vital role in various cells' functioning, including renal tissue. It is desirable to look for new predictors of INS. Our study aimed to evaluate IL-15 as a potential marker in the early diagnosis of the disease. The cohort participating in the study consisted of patients hospitalized in Clinical Hospital No. 1 in Zabrze, from December 2019 to December 2021, including study group with INS (n = 30) and control group (n = 44). Results: The concentration of IL-15 in both serum and urine was significantly elevated in patients with INS, compared to healthy controls. The cytokine might serve as a marker of the disease, however, further research on larger study groups is needed.

Interleukin-2 family cytokines: An overview of genes, expression, signaling and functional roles in teleost

The interleukin-2 (IL-2) family cytokines include IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21, which share γ chain (γc) subunit in receptors. The IL-2 family cytokines have unique biological effects that regulate differentiation, survival and activation of multiple lymphocyte lineages. Deficiency of IL-2 family signaling pathway in mammals prevents CD4⁺ T cells from developing effector functions and CD8⁺ T cells from developing immunological memory. In the present review, we addressed available information from teleost IL-2 family cytokines and discussed implications in teleost immunity. Also, we described and discussed their expression profiles, receptors, signaling transductions and functions. In teleost, IL-2 family has 5 members (IL-2, IL-4/13, IL-7, IL-15, IL-21) without IL-9, and their receptors share a common γc subunit and include other 6 subunits (IL-2Rβ1/2, IL-4Rα1/2, IL-13Rα1/2, IL-7Rα, IL-15Rα, and IL-21Rα1/2). Some paralogues have changes in domain structure and show differential expression, modulation, functions. IL-2 family cytokines constitutively express in many immune associated tissues and are largely induced after pathogenic microbial stimulation. In general, there are relatively conserved functions in the IL-2 family throughout vertebrates, and many of the key IL-2 family members are important in lymphocyte proliferation and differentiation, development, inflammation from fishes to mammals. This review will give an update on the effective information of teleost IL-2 family cytokines. Thus, it will provide a source of reference for other researchers/readers and inspire further interest.

Immunomodulatory Function of Interleukin-15 and Its Role in Exercise, Immunotherapy, and Cancer Outcomes

Exercise has been shown to improve physical and psychosocial outcomes for people across the cancer care continuum. A proposed mechanism underpinning the relationship between exercise and cancer outcomes is exercise-induced immunomodulation via secretion of anti-inflammatory myokines from skeletal muscle tissue. Myokines have the potential to impair cancer growth through modulation of natural killer (NK) cells and CD8+ T cells while improving the effectiveness of cancer therapies. Interleukin-15 (IL-15), one of the most abundant myokines found in skeletal muscle, has a key immunoregulatory role in supporting the proliferation and maturation of T cells and NK cells, which have a key role in the host's immune response to cancer. Furthermore, IL-15 is being explored clinically as an immunotherapy agent with doses similar to the IL-15 concentrations released by skeletal muscle during exercise. Here we review the role of IL-15 within the immune system, examine how IL-15 is produced as a myokine during exercise, and how it may improve outcomes for people with cancer, specifically as an adjuvant or neoadjuvant to immunotherapy. We summarize the available evidence showing changes in IL-15 in response to both acute exercise and training, and the results are inconsistent; higher quality research is needed to advance the understanding of how exercise-mediated increases in IL-15 potentially benefit those who are being treated for, or who have had, cancer.

Allogeneic natural killer cell therapy

Interest in adoptive cell therapy for treating cancer is exploding owing to early clinical successes of autologous chimeric antigen receptor (CAR) T lymphocyte therapy. However, limitations using T cells and autologous cell products are apparent as they (1) take weeks to generate, (2) utilize a 1:1 donor-to-patient model, (3) are expensive, and (4) are prone to heterogeneity and manufacturing failures. CAR T cells are also associated with significant toxicities, including cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, and prolonged cytopenias. To overcome these issues, natural killer (NK) cells are being explored as an alternative cell source for allogeneic cell therapies. NK cells have an inherent ability to recognize cancers, mediate immune functions of killing and communication, and do not induce graft-versus-host disease, cytokine release syndrome, or immune effector cell-associated neurotoxicity syndrome. NK cells can be obtained from blood or cord blood or be derived from hematopoietic stem and progenitor cells or induced pluripotent stem cells, and can be expanded and cryopreserved for off-the-shelf availability. The first wave of point-of-care NK cell therapies led to the current allogeneic NK cell products being investigated in clinical trials with promising preliminary results. Basic advances in NK cell biology and cellular engineering have led to new translational strategies to block inhibition, enhance and broaden target cell recognition, optimize functional persistence, and provide stealth from patients' immunity. This review details NK cell biology, as well as NK cell product manufacturing, engineering, and combination therapies explored in the clinic leading to the next generation of potent, off-the-shelf cellular therapies for blood cancers.

IL-15 Prevents the Development of T-ALL from Aberrant Thymocytes with Impaired DNA Repair Functions and Increased NOTCH1 Activation

We previously reported that NOD.Scid mice lacking interleukin-15 (IL-15), or IL-15 receptor alpha-chain, develop T-acute lymphoblastic leukemia (T-ALL). To understand the mechanisms by which IL-15 signaling controls T-ALL development, we studied the thymocyte developmental events in IL-15-deficient Scid mice from NOD and C57BL/6 genetic backgrounds. Both kinds of mice develop T-ALL characterized by circulating TCR-negative cells expressing CD4, CD8 or both. Analyses of thymocytes in NOD.Scid.Il15^-/- mice prior to T-ALL development revealed discernible changes within the CD4^-CD8^- double-negative (DN) thymocyte developmental stages and increased frequencies of CD4⁺CD8⁺ double-positive cells with a high proportion of TCR-negative CD4⁺ and CD8⁺ cells. The DN cells also showed elevated expressions of CXCR4 and CD117, molecules implicated in the expansion of DN thymocytes. T-ALL cell lines and primary leukemic cells from IL-15-deficient NOD.Scid and C57BL/6.Scid mice displayed increased NOTCH1 activation that was inhibited by NOTCH1 inhibitors and blockers of the PI3K/AKT pathway. Primary leukemic cells from NOD.Scid.Il15^-/- mice survived and expanded when cultured with MS5 thymic stromal cells expressing Delta-like ligand 4 and supplemented with IL-7 and FLT3 ligand. These findings suggest that IL-15 signaling in the thymus controls T-ALL development from aberrant thymocytes with an impaired DNA repair capacity and increased NOTCH1 activation.

Manipulating NK cellular therapy from cancer to invasive fungal infection: promises and challenges

The ideal strategy to fight an infection involves both (i) weakening the invading pathogen through conventional antimicrobial therapy, and (ii) strengthening defense through the augmentation of host immunity. This is even more pertinent in the context of invasive fungal infections whereby the majority of patients have altered immunity and are unable to mount an appropriate host response against the pathogen. Natural killer (NK) cells fit the requirement of an efficient, innate executioner of both tumour cells and pathogens – their unique, targeted cell killing mechanism, combined with other arms of the immune system, make them potent effectors. These characteristics, together with their ready availability (given the various sources of extrinsic NK cells available for harvesting), make NK cells an attractive choice as adoptive cellular therapy against fungi in invasive infections. Improved techniques in ex vivo NK cell activation with expansion, and more importantly, recent advances in genetic engineering including state-of-the-art chimeric antigen receptor platform development, have presented an opportune moment to harness this novel therapeutic as a key component of a multipronged strategy against invasive fungal infections.

Contribution of natural killer cells in innate immunity against colorectal cancer

Natural killer cells are members of the innate immune system and promote cytotoxic activity against tumor or infected cells independently from MHC recognition. NK cells are modulated by the expression of activator/inhibitory receptors. The ratio of this activator/inhibitory receptors is responsible for the cytotoxic activity of NK cells toward the target cells. Owing to the potent anti-tumor properties of NK cells, they are considered as interesting approach in tumor treatment. Colorectal cancer (CRC) is the second most common cause of death in the world and the incidence is about 2 million new cases per year. Metastatic CRC is accompanied by a poor prognosis with less than three years of overall survival. Chemotherapy and surgery are the most adopted treatments. Besides, targeted therapy and immune checkpoint blockade are novel approach to CRC treatment. In these patients, circulating NK cells are a prognostic marker. The main target of CRC immune cell therapy is to improve the tumor cell's recognition and elimination by immune cells. Adaptive NK cell therapy is the milestone to achieve the purpose. Allogeneic NK cell therapy has been widely investigated within clinical trials. In this review, we focus on the NK related approaches including CAR NK cells, cell-based vaccines, monoclonal antibodies and immunomodulatory drugs against CRC tumoral cells.

The role of interleukin-15 in the development and treatment of hematological malignancies

Cytokines are a vital component of the immune system that controls the activation and growth of blood cells. However, chronic overexpression of cytokines can trigger cellular events leading to malignant transformation. The cytokine interleukin-15 (IL-15) is of particular interest, which has been shown to contribute to the development and progression of various hematological malignancies. This review will provide an overview of the impact of the immunopathogenic function of IL-15 by studying its role in cell survival, proliferation, inflammation, and treatment resistance. We will also review therapeutic approaches for inhibiting IL-15 in blood cancers.

Soluble factors from TLR4- or TCR-activated cells contribute to stability of the resting phenotype and increase the expression of CXCR4 of human memory CD4 T cells

It has been proposed that cytokines can induce activation of resting T cells in an antigen-independent manner. However, experimental conditions have included the use of fetal serum and nanogram concentrations of added cytokines. To evaluate the effect of cytokines and chemokines generated by activated immune cells on the phenotypic profile of human memory CD4 T cells, the cells were cultured in FBS-free conditions in the presence of IL-15 and 5% of hAB serum and incubated with conditioned medium (CM) obtained from PBMC activated through the TCR using anti-CD3/CD28/CD2 antibodies (TCR-CM) or through TLR4 using bacterial LPS (TLR4-CM). Cytokines and chemokines present in the CMs were evaluated by ProcartaPlex immunoassay. Cell viability, proliferation, and surface markers were determined by flow cytometry on day 2, 5, and 8 of culture. Cell viability was maintained by TLR4-CM plus IL-15 for 8 days but decreased in the presence of the TCR-CM plus IL-15. In combination with IL-15, the TLR4-CM, but not the TCR-CM, maintained the expression of CD3 and CD4 stable. Both conditions stabilized the expression of CD45RO and CCR5. Thus, the TLR4-CM better supported the viability and stability of the memory phenotype. None of the CMs induced proliferation or expression of activation markers; however, they induced an increased expression of CXCR4. This study indicates that resting memory CD4 T cells are not activated by, but may be sensitive to soluble factors produced by antigen or PAMP-stimulated cells, which may contribute to their homeostasis and favor the CXCR4 expression.

Implication of IL-7 receptor alpha chain expression by CD8+ T cells and its signature in defining biomarkers in aging

CD8⁺ T cells play an important role in host defense against infections and malignancies as well as contribute to the development of inflammatory disorders. Alterations in the frequency of naïve and memory CD8⁺ T cells are one of the most significant changes in the immune system with age. As the world population rapidly ages, a better understanding of aging immune function or immunosenescence could become a basis for discovering treatments of illnesses that commonly occur in older adults. In particular, biomarkers for immune aging could be utilized to identify individuals at high risk of developing age-associated conditions and help monitor the efficacy of therapeutic interventions targeting such conditions. This review details the possible role of CD8⁺ T cell subsets expressing different levels of the cytokine receptor IL-7 receptor alpha chain (IL-7Rα) and the gene signature associated with IL-7Rα as potential biomarkers for immune aging given the association of CD8⁺ T cells in host defense, inflammation, and immunosenescence.

Anti‐thymocyte globulin‐mediated immunosenescent alterations of T cells in kidney transplant patients

Objectives

Kidney transplant (KT) is the most effective treatment for end‐stage renal disease. The immunosuppressant anti‐thymocyte globulin (ATG) has been applied for induction therapy to reduce the risk of acute transplant rejection for patients at high immunological risk. Despite its putative role in replicative stress during immune reconstitution, the effects of ATG on T‐cell immunosenescent changes remain to be understood.

Methods

Phenotypic and functional features of senescent T cells were examined by flow cytometry in 116 healthy controls (HC) and 95 KT patients for comparative analysis according to ATG treatment and CMV reactivation. The TCR repertoire was analysed in peripheral blood mononuclear cells (PBMCs) of KT patients.

Results

T cells of KT patients treated with ATG (ATG⁺) show typical immunosenescent features, accumulation of CD28⁻, CD85j⁺ or CD57⁺ T cells, and imbalance of functional T‐cell subsets, compared with untreated KT patients (ATG⁻). Plasma IL‐15 and CMV‐IgG levels were higher in KT patients than in HCs, and the IL‐15 level positively correlated with the frequency of CD28⁻ T cells in KT patients. ATG⁺ patients had a higher prevalence of CMV reactivation, which is associated with an increased frequency of CD28⁻ T cells. As a result, ATG⁺ patients had expanded CMV‐specific T cells and decreased TCR diversity. However, proliferation, cytokine‐producing capacity and polyfunctionality of T cells were preserved in ATG⁺ patients.

Conclusion

Our findings suggest that ATG treatment contributes to the accumulation of senescent T cells, which may have lifelong clinical implications in KT patients. Thus, these patients require long‐term and comprehensive immune monitoring.

A peptoid interleukin‐15 receptor antagonist suppresses inflammation and arthritis in mice

Objective

To discover a novel peptoid antagonist that targets the interleukin‐15 (IL‐15) receptor and to evaluate its therapeutic efficacy in the treatment of inflammation and arthritis.

Methods

A new compound (IFRA3, interleukin‐15 receptor antagonist 3) was discovered using a unique on‐bead two‐colour combinatorial cell screening of a peptoid library. The interaction of IFRA3 with IL‐15 receptor was assessed by in vitro pull‐down and thermal shift assays. The efficacy of IFRA3 in treating inflammation and arthritis was evaluated in mouse models.

Results

IFRA3Q1 (a tetrameric derivative of IFRA3) inhibited the activity of IL‐15 and suppressed CTLL‐2 cell proliferation (which depends on IL‐15 activity). IFRA3Q1 exhibited strong in vivo anti‐inflammatory activity in carrageenan‐induced inflammation in mice. Furthermore, IFRA3Q1 inhibited collagen‐induced arthritis in DBA/1J mice.

Conclusion

By binding to and inhibiting the function of IL‐15 receptor, IFRA3Q1 exhibited significant anti‐arthritis activity. Our findings suggest that IFRA3Q1 represents a new paradigm for arthritis therapy by targeting IL‐15 signalling.

Low-Dose rIL-15 Protects from Nephrotoxic Serum Nephritis via CD8+ T Cells

Rapid progressive glomerulonephritis (GN) often leads to end-stage kidney disease, driving the need for renal replacement therapy and posing a global health burden. Low-dose cytokine-based immunotherapies provide a new strategy to treat GN. IL-15 is a strong candidate for the therapy of immune-mediated kidney disease since it has proven to be tubular-protective before. Therefore, we set out to test the potential of low-dose rIL-15 treatment in a mouse model of nephrotoxic serum nephritis (NTS), mimicking immune complex-driven GN in humans. A single low-dose treatment with rIL-15 ameliorated NTS, reflected by reduced albuminuria, less tissue scarring, fewer myeloid cells in the kidney, and improved tubular epithelial cell survival. In addition, CD8⁺ T cells, a primary target of IL-15, showed altered gene expression and function corresponding with less cytotoxicity mediated by rIL-15. With the use of transgenic knock-out mice, antibody depletion, and adoptive cell transfer studies, we here show that the beneficial effects of rIL-15 treatment in NTS depended on CD8⁺ T cells, suggesting a pivotal role for them in the underlying mechanism. Our findings add to existing evidence of the association of IL-15 with kidney health and imply a potential for low-dose rIL-15 immunotherapies in GN.

Molecular pathogenesis of Cutaneous T cell Lymphoma: Role of chemokines, cytokines, and dysregulated signaling pathways

Cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of lymphoproliferative neoplasms that exhibit a wide spectrum of immune-phenotypical, clinical, and histopathological features. The biology of CTCL is complex and remains elusive. In recent years, the application of next-generation sequencing (NGS) has evolved our understanding of the pathogenetic mechanisms, including genetic aberrations and epigenetic abnormalities that shape the mutational landscape of CTCL and represent one of the important pro-tumorigenic principles in CTCL initiation and progression. Still, identification of the major pathophysiological pathways including genetic and epigenetic components that mediate malignant clonal T cell expansion has not been achieved. This is of prime importance given the role of malignant T cell clones in fostering T helper 2 (Th2)-bias tumor microenvironment and fueling progressive immune dysregulation and tumor cell growth in CTCL patients, manifested by the secretion of Th2-associated cytokines and chemokines. Alterations in malignant cytokine and chemokine expression patterns orchestrate the inflammatory milieu and influence the migration dynamics of malignant clonal T cells. Here, we highlight recent insights about the molecular mechanisms of CTCL pathogenesis, emphasizing the role of cytokines, chemokines, and associated downstream signaling networks in driving immune defects, malignant transformation, and disease progression. In-depth characterization of the CTCL immunophenotype and tumoral microenvironment offers a facile opportunity to expand the therapeutic armamentarium of CTCL, an intractable malignant skin disease with poor prognosis and in dire need of curative treatment approaches.

The implications of IL-15 trans-presentation on the immune response

Interleukin-15 is a pleiotropic cytokine type I four alpha-helical bundle cytokine that along with IL-2, IL-4, IL-7, IL-9, and IL-21 shares the common cytokine receptor γ chain, γ_c. IL-15 is vital for the development, survival, and expansion of natural killer cells and for the development of CD8⁺ memory T cells. Whereas other family γ_c cytokines signal by directly binding to their target cells, IL-15 is distinctive in that it binds to IL-15Rα, a sushi domain containing binding protein that is expressed on a number of cell types, including monocytes and dendritic cells as well as T cells, and then is trans-presented to responding cells that express IL-2Rβ and γ_c. This distinctive mechanism for IL-15 relates to its role in signaling in the context of cell-cell interactions and signaling synapses. The actions of IL-15 and ways of manipulating its actions to potential therapeutic benefit are discussed.

Control of Simian Immunodeficiency Virus Infection in Prophylactically Vaccinated, Antiretroviral Treatment-Naive Macaques Is Required for the Most Efficacious CD8 T Cell Response during Treatment with the Interleukin-15 Superagonist N-803

The IL-15 superagonist N-803 has been shown to enhance the function of CD8 T cells and NK cells. We previously found that in a subset of vaccinated, ART-naive, SIV⁺ rhesus macaques, N-803 treatment led to a rapid but transient decline in plasma viremia that positively correlated with an increase in the frequency of CD8 T cells. Here, we tested the hypothesis that prophylactic vaccination was required for the N-803 mediated suppression of SIV plasma viremia. We either vaccinated rhesus macaques with a DNA prime/Ad5 boost regimen using vectors expressing SIVmac239 gag with or without a plasmid expressing IL-12 or left them unvaccinated. The animals were then intravenously infected with SIVmac239M. 6 months after infection, the animals were treated with N-803. We found no differences in the control of plasma viremia during N-803 treatment between vaccinated and unvaccinated macaques. Interestingly, when we divided the SIV⁺ animals based on their plasma viral load set-points prior to the N-803 treatment, N-803 increased the frequency of SIV-specific T cells expressing ki-67⁺ and granzyme B⁺ in animals with low plasma viremia (<10⁴ copies/mL; SIV controllers) compared to animals with high plasma viremia (>10⁴ copies/mL; SIV noncontrollers). In addition, Gag-specific CD8 T cells from the SIV⁺ controllers had a greater increase in CD8⁺CD107a⁺ T cells in ex vivo functional assays than did the SIV⁺ noncontrollers. Overall, our results indicate that N-803 is most effective in SIV⁺ animals with a preexisting immunological ability to control SIV replication. IMPORTANCE N-803 is a drug that boosts the immune cells involved in combating HIV/SIV infection. Here, we found that in SIV⁺ rhesus macaques that were not on antiretroviral therapy, N-803 increased the proliferation and potential capacity for killing of the SIV-specific immune cells to a greater degree in animals that spontaneously controlled SIV than in animals that did not control SIV. Understanding the mechanism of how N-803 might function differently in individuals that control HIV/SIV (for example, individuals on antiretroviral therapy or spontaneous controllers) compared to settings where HIV/SIV are not controlled, could impact the efficacy of N-803 utilization in the field of HIV cure.

Molecular characterization and expression analysis of interleukin-15 (IL-15) genes in orange-spotted grouper (Epinephelus coioides) in response to Vibrio harveyi challenge

As a member of the γc family, interleukin 15 plays an important function in the immune response. In this study, we cloned an IL15 from Epinephelus coioides (named Ec-IL15). The open reading frame of Ec-IL15 is 528 bp, encoding 175 amino acids. Sequence alignment analysis showed that EcIL-15 has a conserved Pfam: IL15 domain and four cysteine residues. Subcellular localization studies have shown that Ec-IL15 is distributed in whole cells. In healthy groupers, Ec-IL15 was expressed in all 11 tissues tested and the highest in liver. After ConA, PHA, LPS and poly I:C stimulation, Ec-IL15 expression of HKLs was significantly upregulated. After V. harveyi infection, the expression of Ec-IL15 in 9 tissues was significantly upregulated and peaked within 48 h. In addition, recombinant Ec-IL15 protein can not only stimulate HKLs proliferation and cytokine expression, but also has the potential as an immune enhancer.

Effect of cellular aging on memory T-cell homeostasis

The fact that T-cell numbers remain relatively stable throughout life, and that T-cell proliferation rates increase during lymphopenia, has led to the consensus that T-cell numbers are regulated in a density-dependent manner. Competition for resources among memory T cells has been proposed to underlie this ‘homeostatic’ regulation. We first review how two classic models of resource competition affect the T-cell receptor (TCR) diversity of the memory T-cell pool. First, ‘global’ competition for cytokines leads to a skewed repertoire that tends to be dominated by the very first immune response. Second, additional ‘cognate’ competition for specific antigens results in a very diverse and stable memory T-cell pool, allowing every antigen to be remembered, which we therefore define as the ‘gold-standard’. Because there is limited evidence that memory T cells of the same specificity compete more strongly with each other than with memory T cells of different specificities, i.e., for ‘cognate’ competition, we investigate whether cellular aging could account for a similar level of TCR diversity. We define cellular aging as a declining cellular fitness due to reduced proliferation. We find that the gradual erosion of previous T-cell memories due to cellular aging allows for better establishment of novel memories and for a much higher level of TCR diversity compared to global competition. A small continual source (either from stem-cell-like memory T-cells or from naive T-cells due to repeated antigen exposure) improves the diversity of the memory T-cell pool, but remarkably, only in the cellular aging model. We further show that the presence of a source keeps the inflation of chronic memory responses in check by maintaining the immune memories to non-chronic antigens. We conclude that cellular aging along with a small source provides a novel and immunologically realistic mechanism to achieve and maintain the ‘gold-standard’ level of TCR diversity in the memory T-cell pool.

IL-15/IL-15Rα in SJS/TEN: Relevant Expression of IL15 and IL15RA in Affected Skin

Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a life-threatening hypersensitivity reaction to medications characterized by keratinocyte apoptosis and skin detachment. IL-15 serum levels have been associated with severity and prognosis of SJS/TEN. We have measured IL-15 concentrations in serum and blister fluid (BF) from patients with SJS/TEN by ELISA and used quantitative RT-PCR to analyze the expression of IL15 and IL15RA (encoding for IL-15 Receptor-α chain) genes in peripheral blood and BF cells, including isolated monocytes, and in affected skin. A positive correlation was found between IL-15 serum levels and a percent of detached skin. BF concentrations were higher, but no correlation was found. Higher IL15 and IL15RA gene expression levels were found in skin-infiltrating blister fluid cells compared to peripheral mononuclear cells. Moreover, IL15RA transcripts were barely detected in healthy skin, being the highest expression levels found in samples from two SJS/TEN patients who did not survive. The cutaneous expression of IL-15Rα in SJS/TEN may provide an explanation to the tissue-specific immune cytotoxic response in this clinical entity, and the results suggest that the effects of IL-15 in SJS/TEN patients may be dependent on the expression of its private receptor IL-15Rα in affected skin.

IL-2/IL-2R signaling and IL-2Rα-targeted therapy in anaplastic large cell lymphoma

Anaplastic large cell lymphoma (ALCL) is a CD30-positive non-Hodgkin's T‑cell lymphoma. Despite the implementation of CD30 antibody-drug conjugate-targeted therapy into front-line treatment regimens, the prognosis of some subtypes of the disease remains unsatisfactory. In the relapsed/refractory setting, effective second-line treatment options are still lacking. However, it has been reported that blockade of direct downstream targets of activator protein‑1 (AP-1) transcription factors, which are highly dysregulated in ALCL, results in complete and sustained remission in late-stage relapsed/refractory anaplastic lymphoma kinase (ALK)-positive ALCL patients. Moreover, it has been identified that involvement of the BATF3/AP‑1 module promotes lymphomagenesis via oncogenic BATF3/IL-2/IL-2R signaling through hyperphosphorylation of ERK1/2, STAT1, and STAT5 in ALCL cells regardless of their ALK status. Therefore, targeting BATF3/IL-2/IL-2R signaling may represent a novel therapeutic alternative for ALCL patients.

Identification of Malignant Cell Populations Associated with Poor Prognosis in High-Grade Serous Ovarian Cancer Using Single-Cell RNA Sequencing

Simple Summary

Ovarian cancer has a high recurrence rate (~75%), and tumor heterogeneity is associated with such tumor recurrence. However, it is still poorly understood in ovarian cancer. To reveal tumor heterogeneity, we performed single-cell RNA sequencing (RNA-seq) of serous ovarian cancer cells from four different patients: two with primary carcinoma, one with recurrent carcinoma, and one with carcinoma treated with interval debulking surgery. As a result, we found two malignant tumor cell subtypes associated with poor prognosis. One malignant population included the earliest cancer cells and cancer stem-like cells. SLC3A1 and PEG10 were identified as the marker genes of cancer-initiating cells. The other malignant population expressing CA125 (MUC16), the most common biomarker for ovarian cancer, is associated with a decrease in the number of tumor-infiltrating cytotoxic T lymphocytes (CTLs). Our findings will offer new markers for diagnosis and choosing treatments targeting the malignant populations in ovarian cancer.

Abstract

To reveal tumor heterogeneity in ovarian cancer, we performed single-cell RNA sequencing (RNA-seq). We obtained The Cancer Genome Atlas (TCGA) survival data and TCGA gene expression data for a Kaplan–Meier plot showing the association of each tumor population with poor prognosis. As a result, we found two malignant tumor cell subtypes associated with poor prognosis. Next, we performed trajectory analysis using scVelo and Monocle3 and cell–cell interaction analysis using CellphoneDB. We found that one malignant population included the earliest cancer cells and cancer stem-like cells. Furthermore, we identified SLC3A1 and PEG10 as the marker genes of cancer-initiating cells. The other malignant population expressing CA125 (MUC16) is associated with a decrease in the number of tumor-infiltrating cytotoxic T lymphocytes (CTLs). Moreover, cell–cell interaction analysis implied that interactions mediated by LGALS9 and GAS6, expressed by this malignant population, caused the CTL suppression. The results of this study suggest that two tumor cell populations, including a cancer-initiating cell population and a population expressing CA125, survive the initial treatment and suppress antitumor immunity, respectively, and are associated with poor prognosis. Our findings offer a new understanding of ovarian cancer heterogeneity and will aid in the development of diagnostic tools and treatments.

Development and Characterization of an Anti-Cancer Monoclonal Antibody for Treatment of Human Carcinomas

NEO-201 is an IgG1 humanized monoclonal antibody (mAb) that binds to tumor-associated variants of carcinoembryonic antigen-related cell adhesion molecule (CEACAM)-5 and CEACAM-6. NEO-201 reacts to colon, ovarian, pancreatic, non-small cell lung, head and neck, cervical, uterine and breast cancers, but is not reactive against most normal tissues. NEO-201 can kill tumor cells via antibody-dependent cell-mediated cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC) to directly kill tumor cells expressing its target. We explored indirect mechanisms of its action that may enhance immune tumor killing. NEO-201 can block the interaction between CEACAM-5 expressed on tumor cells and CEACAM-1 expressed on natural killer (NK) cells to reverse CEACAM-1-dependent inhibition of NK cytotoxicity. Previous studies have demonstrated safety/tolerability in non-human primates, and in a first in human phase 1 clinical trial at the National Cancer Institute (NCI). In addition, preclinical studies have demonstrated that NEO-201 can bind to human regulatory T (Treg) cells. The specificity of NEO-201 in recognizing suppressive Treg cells provides the basis for combination cancer immunotherapy with checkpoint inhibitors targeting the PD-1/PD-L1 pathway.

Natural killer cells: Innate immune system as a part of adaptive immunotherapy in hematological malignancies

Natural killer (NK) cells are part of a phylogenetically old defense system, which is characterized by its strong cytolytic function against physiologically stressed cells such as tumor cells and virus-infected cells. Their use in the treatment of hematological malignancies may be more advantageous in several ways when compared with the already established T lymphocyte-based immunotherapy. Given the different mechanisms of action, allogeneic NK cell products can be produced in a non-personal based manner without the risk of the formidable graft-versus-host disease. Advanced manufacturing processes are capable of producing NK cells relatively easily in large and clinically sufficient numbers, useable without subsequent manipulations or after genetic modifications, which can solve the lack of specificity and improve clinical efficacy of NK cell products. This review summarizes the basic characteristics of NK cells and provides a quick overview of their sources. Results of clinical trials in hematological malignancies are presented, and strategies on how to improve the clinical outcome of NK cell therapy are discussed.

Inhibition of tumor necrosis factor improves conventional steroid therapy for Stevens-Johnson syndrome/toxic epidermal necrolysis in a cohort of patients

BACKGROUND

Systemic steroid therapies for Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) have been challenged because of their limited benefits. Whether additional tumor necrosis factor (TNF) α inhibition provides an optimized approach remains unexplored.

OBJECTIVE

To investigate the efficacy of TNF-α inhibition combined with a steroid to treat SJS/TEN and to identify potential biomarkers.

METHODS

Twenty-five patients with SJS/TEN were recruited and divided into 2 groups: 10 patients received methylprednisolone and 15 patients received etanercept plus methylprednisolone. Serum levels of granzyme B, perforin, interferon-γ, interleukin (IL) 6, IL-15, IL-18, macrophage inflammatory protein 1α, macrophage inflammatory protein 1β, and TNF-α were measured by multiplex cytokine analysis kits during the acute and resolution phases.

RESULTS

Compared with the steroid monotherapy, the combination therapy significantly shortened the course of the initial steroid treatment and the duration of the acute stage, hospitalization stay, and skin re-epithelialization. Although both therapies significantly reduced IL-15 levels; the combination therapy also decreased IL-6 and IL-18 levels. While the level of IL-15 was positively correlated with skin re-epithelialization time in both groups, the level of IL-6 served as an additional marker for the course of the disease in the combination therapy group.

LIMITATIONS

The cohort size is relatively small.

CONCLUSION

Additional TNF-α inhibition to steroid treatment appeared to improve outcomes for SJS/TEN.

2022 update on the scientific premise and clinical trials for IL-15 agonists as cancer immunotherapy

Diverse cytokines and their receptors on immune cells constitute a highly complex network in the immune system. Some therapeutic cytokines and their derivatives have been approved for cancer treatment. IL-15 is an immune-regulating cytokine with multiple functions, among which the function of activating the immunity of cancer patients has great potential in cancer immunotherapy. In this review, we introduce the functions of IL-15 and discuss its role in regulating the immune system in different immune cells. Meanwhile, we will address the applications of IL-15 agonists in cancer immunotherapy and provide prospects for the next generation of therapeutic designs. Although many challenges remain, IL-15 agonists offer a new therapeutic option in the future direction of cancer immunotherapy.

Crosstalk between IL-15Rα+ tumor-associated macrophages and breast cancer cells reduces CD8+ T cell recruitment

Background

Interleukin‐15 (IL‐15) is a promising immunotherapeutic agent owing to its powerful immune‐activating effects. However, the clinical benefits of these treatments are limited. Crosstalk between tumor cells and immune cells plays an important role in immune escape and immunotherapy drug resistance. Herein, this study aimed to obtain in‐depth understanding of crosstalk in the tumor microenvironment for providing potential therapeutic strategies to prevent tumor progression.

Methods

T‐cell killing assays and co‐culture models were developed to determine the role of crosstalk between macrophages and tumor cells in breast cancer resistant to IL‐15. Western blotting, histological analysis, CRISPR‐Cas9 knockout, multi‐parameter flow cytometry, and tumor cell‐macrophage co‐injection mouse models were developed to examine the mechanism by which IL‐15Rα⁺ tumor‐associated macrophages (TAMs) regulate breast cancer cell resistance to IL‐15.

Results

We found that macrophages contributed to the resistance of tumor cells to IL‐15, and tumor cells induced macrophages to express high levels of the α subunit of the IL‐15 receptor (IL‐15Rα). Further investigation showed that IL‐15Rα⁺ TAMs reduced the protein levels of chemokine CX3C chemokine ligand 1 (CX3CL1) in tumor cells to inhibit the recruitment of CD8⁺ T cells by releasing the IL‐15/IL‐15Rα complex (IL‐15Rc). Administration of an IL‐15Rc blocking peptide markedly suppressed breast tumor growth and overcame the resistance of cancer cells to anti‐ programmed cell death protein 1 (PD‐1) antibody immunotherapy. Interestingly, Granulocyte‐macrophage colony‐stimulating factor (GMCSF) induced γ chain (γc) expression to promote tumor cell‐macrophage crosstalk, which facilitated tumor resistance to IL‐15. Additionally, we observed that the non‐transcriptional regulatory function of hypoxia inducible factor‐1alpha (HIF‐1α) was essential for IL‐15Rc to regulate CX3CL1 expression in tumor cells.

Conclusions

The IL‐15Rc‐HIF‐1α‐CX3CL1 signaling pathway serves as a crosstalk between macrophages and tumor cells in the tumor microenvironment of breast cancer. Targeting this pathway may provide a potential therapeutic strategy for enhancing the efficacy of cancer immunotherapy.

Recombinant BCG to Enhance Its Immunomodulatory Activities

The bacillus Calmette-Guérin (BCG) is an attenuated Mycobacterium bovis derivative that has been widely used as a live vaccine against tuberculosis for a century. In addition to its use as a tuberculosis vaccine, BCG has also been found to have utility in the prevention or treatment of unrelated diseases, including cancer. However, the protective and therapeutic efficacy of BCG against tuberculosis and other diseases is not perfect. For three decades, it has been possible to genetically modify BCG in an attempt to improve its efficacy. Various immune-modulatory molecules have been produced in recombinant BCG strains and tested for protection against tuberculosis or treatment of several cancers or inflammatory diseases. These molecules include cytokines, bacterial toxins or toxin fragments, as well as other protein and non-protein immune-modulatory molecules. The deletion of genes responsible for the immune-suppressive properties of BCG has also been explored for their effect on BCG-induced innate and adaptive immune responses. Most studies limited their investigations to the description of T cell immune responses that were modified by the genetic modifications of BCG. Some studies also reported improved protection by recombinant BCG against tuberculosis or enhanced therapeutic efficacy against various cancer forms or allergies. However, so far, these investigations have been limited to mouse models, and the prophylactic or therapeutic potential of recombinant BCG strains has not yet been illustrated in other species, including humans, with the exception of a genetically modified BCG strain that is now in late-stage clinical development as a vaccine against tuberculosis. In this review, we provide an overview of the different molecular engineering strategies adopted over the last three decades in order to enhance the immune-modulatory potential of BCG.

IL15 and Anti-PD-1 Augment the Efficacy of Agonistic Intratumoral Anti-CD40 in a Mouse Model with Multiple TRAMP-C2 Tumors

PURPOSE

IL15 promotes activation and maintenance of natural killer (NK) and CD8+ T effector memory cells making it a potential immunotherapeutic agent for the treatment of cancer. However, monotherapy with IL15 was ineffective in patients with cancer, indicating that it would have to be used in combination with other anticancer agents. The administration of high doses of common gamma chain cytokines, such as IL15, is associated with the generation of "helpless" antigen-nonspecific CD8 T cells. The generation of the tumor-specific cytotoxic T cells can be mediated by CD40 signaling via agonistic anti-CD40 antibodies. Nevertheless, parenteral administration of anti-CD40 antibodies is associated with unacceptable side effects, such as thrombocytopenia and hepatic toxicity, which can be avoided by intratumoral administration.

EXPERIMENTAL DESIGN

We investigated the combination of IL15 with an intratumoral anti-CD40 monoclonal antibody (mAb) in a dual tumor TRAMP-C2 murine prostate cancer model and expanded the regimen to include an anti-PD-1 mAb.

RESULTS

Here we demonstrated that anti-CD40 given intratumorally not only showed significant antitumor activity in treated tumors, but also noninjected contralateral tumors, indicative of abscopal efficacy. The combination of IL15 with intratumoral anti-CD40 showed an additive immune response with an increase in the number of tumor-specific tetramer-positive CD8 T cells. Furthermore, the addition of anti-PD-1 further improved efficacy mediated by the anti-CD40/IL15 combination.

CONCLUSIONS

These studies support the initiation of a clinical trial in patients with cancer using IL15 in association with the checkpoint inhibitor, anti-PD-1, and intratumoral optimized anti-CD40.

Networks of CD8+ T Cell Response Activation in Melanoma and Vitiligo

Melanoma is an aggressive skin cancer derived from melanocyte, which shows high response rate to cancer immunotherapy, such as immune checkpoint inhibitors (ICIs). Vitiligo is an autoimmune skin disease resulting from the destruction of melanocytes by autoreactive CD8+ T cells. Vitiligo induced by cancer immunotherapy is a favorable prognostic factor in patients with melanoma, and growing evidence supports the fact that melanocyte/melanoma-shared antigen (MSA)-specific CD8+ T cells infiltrated in the tumor (melanoma) and skin (vitiligo) microenvironment play pivotal roles in the prognosis of both diseases. Thus, cellular communications that promote MSA-specific CD8+ T cells recruitment, proliferation, and effector functions are now seen as key targets to enhance the efficacy of current therapies for both diseases. Here, we discussed recent advancements in illustrating immune signaling pathways and immune cell types that regulate migration, proliferation, and function of MSA-specific CD8+ T cells in melanoma and vitiligo; and future immunotherapeutic approaches that may enhance clinical outcomes of both diseases.

A novel fusion protein scaffold 18/12/TxM activates the IL-12, IL-15, and IL-18 receptors to induce human memory-like natural killer cells

Natural killer (NK) cells are cytotoxic innate lymphoid cells that are emerging as a cellular immunotherapy for various malignancies. NK cells are particularly dependent on interleukin (IL)-15 for their survival, proliferation, and cytotoxic function. NK cells differentiate into memory-like cells with enhanced effector function after a brief activation with IL-12, IL-15, and IL-18. N-803 is an IL-15 superagonist composed of an IL-15 mutant (IL-15N72D) bound to the sushi domain of IL-15Rα fused to the Fc region of IgG1, which results in physiological trans-presentation of IL-15. Here, we describe the creation of a novel triple-cytokine fusion molecule, 18/12/TxM, using the N-803 scaffold fused to IL-18 via the IL-15N72D domain and linked to a heteromeric single-chain IL-12 p70 by the sushi domain of the IL-15Rα. This molecule displays trispecific cytokine activity through its binding and signaling through the individual cytokine receptors. Compared with activation with the individual cytokines, 18/12/TxM induces similar short-term activation and memory-like differentiation of NK cells on both the transcriptional and protein level and identical in vitro and in vivo anti-tumor activity. Thus, N-803 can be modified as a functional scaffold for the creation of cytokine immunotherapies with multiple receptor specificities to activate NK cells for adoptive cellular therapy.