Regulation of lymphoid homeostasis by interleukin-15

The Interleukin-15 and Interleukin-8 Axis as a Novel Mechanism for Recurrent Chronic Rhinosinusitis with Nasal Polyps

The prevention of postoperative recurrence after endoscopic sinus surgery (ESS) relies on targeting specific pathological mechanisms according to individuals' immunological profiles. However, essential biomarkers and biological characteristics of difficult-to-treat chronic rhinosinusitis (CRS) patients are not well-defined. The aim of this study was to explore the immunologic profiles of subgroups of CRS patients and determine the specific cytokines responsible for recalcitrant or recurrent CRS with nasal polyposis (rCRSwNP). We used 30 cytokine antibody arrays to determine the key cytokines related to recurrent polypogenesis. Enzyme-linked immunosorbent assay (ELISA) experiments were conducted to assess the levels of these key cytokines in 78 patients. Polymorphonuclear leukocytes (PMNs) isolated from nasal polyps were challenged with specific cytokines to examine the levels of enhanced interleukin (IL)-8 production. Finally, we used immunohistochemistry (IHC) staining to check for the presence and distribution of the biomarkers within nasal polyps. A cytokine antibody array revealed that IL-8, IL-13, IL-15, and IL-20 were significantly higher in the recalcitrant CRSwNP group. Subsequent ELISA screening showed a stepwise increase in tissue IL-8 levels in the CHR, CRSsNP, and CRSwNP groups. PMNs isolated from nine CRSwNP cases all demonstrated enhanced IL-8 production after IL-15 treatment. IHC staining was labeled concurrent IL-8 and IL-15 expression in areas of prominent neutrophil infiltration. Our results suggest that IL-15 within the sinonasal mucosa plays a crucial role in promoting IL-8 secretion by infiltrating PMNs in recalcitrant nasal polyps. In addition, we propose a novel therapeutic strategy targeting the anti-IL-15/IL-8 axis to treat CRS with nasal polyposis.

Cooperative Armoring of CAR and TCR T Cells by T Cell-Restricted IL15 and IL21 Universally Enhances Solid Tumor Efficacy

PURPOSE

Chimeric antigen receptor (CAR) and T-cell receptor (TCR) T-cell therapies are effective in a subset of patients with solid tumors, but new approaches are needed to universally improve patient outcomes. Here, we developed a technology to leverage the cooperative effects of IL15 and IL21, two common cytokine-receptor gamma chain family members with distinct, pleiotropic effects on T cells and other lymphocytes, to enhance the efficacy of adoptive T cells.

EXPERIMENTAL DESIGN

We designed vectors that induce the constitutive expression of either membrane-tethered IL15, IL21, or IL15/IL21. We used clinically relevant preclinical models of transgenic CARs and TCRs against pediatric and adult solid tumors to determine the effect of the membrane-tethered cytokines on engineered T cells for human administration.

RESULTS

We found that self-delivery of these cytokines by CAR or TCR T cells prevents functional exhaustion by repeated stimulation and limits the emergence of dysfunctional natural killer (NK)-like T cells. Across different preclinical murine solid tumor models, we observed enhanced regression with each individual cytokine but the greatest antitumor efficacy when T cells were armored with both.

CONCLUSIONS

The coexpression of membrane-tethered IL15 and IL21 represents a technology to enhance the resilience and function of engineered T cells against solid tumors and could be applicable to multiple therapy platforms and diseases. See related commentary by Ruffin et al., p. 1431.

Precision Enhancement of CAR-NK Cells through Non-Viral Engineering and Highly Multiplexed Base Editing

Natural killer (NK) cells' unique ability to kill transformed cells expressing stress ligands or lacking major histocompatibility complexes (MHC) has prompted their development for immunotherapy. However, NK cells have demonstrated only moderate responses against cancer in clinical trials and likely require advanced genome engineering to reach their full potential as a cancer therapeutic. Multiplex genome editing with CRISPR/Cas9 base editors (BE) has been used to enhance T cell function and has already entered clinical trials but has not been reported in human NK cells. Here, we report the first application of BE in primary NK cells to achieve both loss-of-function and gain-of-function mutations. We observed highly efficient single and multiplex base editing, resulting in significantly enhanced NK cell function. Next, we combined multiplex BE with non-viral TcBuster transposon-based integration to generate IL-15 armored CD19 CAR-NK cells with significantly improved functionality in a highly suppressive model of Burkitt's lymphoma both in vitro and in vivo. The use of concomitant non-viral transposon engineering with multiplex base editing thus represents a highly versatile and efficient platform to generate CAR-NK products for cell-based immunotherapy and affords the flexibility to tailor multiple gene edits to maximize the effectiveness of the therapy for the cancer type being treated.

Interplay between Microbiota and γδ T Cells: Insights into Immune Homeostasis and Neuro-Immune Interactions

The gastrointestinal (GI) tract of multicellular organisms, especially mammals, harbors a symbiotic commensal microbiota with diverse microorganisms including bacteria, fungi, viruses, and other microbial and eukaryotic species. This microbiota exerts an important role on intestinal function and contributes to host health. The microbiota, while benefiting from a nourishing environment, is involved in the development, metabolism and immunity of the host, contributing to the maintenance of homeostasis in the GI tract. The immune system orchestrates the maintenance of key features of host-microbe symbiosis via a unique immunological network that populates the intestinal wall with different immune cell populations. Intestinal epithelium contains lymphocytes in the intraepithelial (IEL) space between the tight junctions and the basal membrane of the gut epithelium. IELs are mostly CD8+ T cells, with the great majority of them expressing the CD8αα homodimer, and the γδ T cell receptor (TCR) instead of the αβ TCR expressed on conventional T cells. γδ T cells play a significant role in immune surveillance and tissue maintenance. This review provides an overview of how the microbiota regulates γδ T cells and the influence of microbiota-derived metabolites on γδ T cell responses, highlighting their impact on immune homeostasis. It also discusses intestinal neuro-immune regulation and how γδ T cells possess the ability to interact with both the microbiota and brain.

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.

Engineering NK-CAR.19 cells with the IL-15/IL-15Rα complex improved proliferation and anti-tumor effect in vivo

Introduction

Natural killer 92 (NK-92) cells are an attractive therapeutic approach as alternative chimeric antigen receptor (CAR) carriers, different from T cells, once they can be used in the allogeneic setting. The modest in vivo outcomes observed with NK-92 cells continue to present hurdles in successfully translating NK-92 cell therapies into clinical applications. Adoptive transfer of CAR-NK-92 cells holds out the promise of therapeutic benefit at a lower rate of adverse events due to the absence of GvHD and cytokine release syndrome. However, it has not achieved breakthrough clinical results yet, and further improvement of CAR-NK-92 cells is necessary.

Methods

In this study, we conducted a comparative analysis between CD19-targeted CAR (CAR.19) co-expressing IL-15 (CAR.19-IL15) with IL-15/IL-15Rα (CAR.19-IL15/IL15Rα) to promote NK cell proliferation, activation, and cytotoxic activity against B-cell leukemia. CAR constructs were cloned into lentiviral vector and transduced into NK-92 cell line. Potency of CAR-NK cells were assessed against CD19-expressing cell lines NALM-6 or Raji in vitro and in vivo in a murine model. Tumor burden was measured by bioluminescence.

Results

We demonstrated that a fourth- generation CD19-targeted CAR (CAR.19) co-expressing IL-15 linked to its receptor IL-15/IL-15Rα (CAR.19-IL-15/IL-15Rα) significantly enhanced NK-92 cell proliferation, proinflammatory cytokine secretion, and cytotoxic activity against B-cell cancer cell lines in vitro and in a xenograft mouse model.

Conclusion

Together with the results of the systematic analysis of the transcriptome of activated NK-92 CAR variants, this supports the notion that IL-15/IL-15Rα comprising fourth-generation CARs may overcome the limitations of NK-92 cell-based targeted tumor therapies in vivo by providing the necessary growth and activation signals.

IL-15 and N-803 for HIV Cure Approaches

In spite of the advances in antiretroviral therapy to treat HIV infection, the presence of a latent reservoir of HIV-infected cells represents the largest barrier towards finding a cure. Among the different strategies being pursued to eliminate or reduce this latent reservoir, the γc-cytokine IL-15 or its superagonist N-803 are currently under clinical investigation, either alone or with other interventions. They have been shown to reactivate latent HIV and enhance immune effector function, both of which are potentially required for effective reduction of latent reservoirs. In here, we present a comprehensive literature review of the different in vitro, ex vivo, and in vivo studies conducted to date that are aimed at targeting HIV reservoirs using IL-15 and N-803.

The intestinal γδ T cells: functions in the gut and in the distant organs

Located in the frontline against the largest population of microbiota, the intestinal mucosa of mammals has evolved to become an effective immune system. γδ T cells, a unique T cell subpopulation, are rare in circulation blood and lymphoid tissues, but rich in the intestinal mucosa, particularly in the epithelium. Via rapid production of cytokines and growth factors, intestinal γδ T cells are key contributors to epithelial homeostasis and immune surveillance of infection. Intriguingly, recent studies have revealed that the intestinal γδ T cells may play novel exciting functions ranging from epithelial plasticity and remodeling in response to carbohydrate diets to the recovery of ischemic stroke. In this review article, we update regulatory molecules newly defined in lymphopoiesis of the intestinal γδ T cells and their novel functions locally in the intestinal mucosa, such as epithelial remodeling, and distantly in pathological setting, e.g., ischemic brain injury repair, psychosocial stress responses, and fracture repair. The challenges and potential revenues in intestinal γδ T cell studies are discussed.

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.

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.

Harnessing IL-15 signaling to potentiate NK cell-mediated cancer immunotherapy

Natural killer (NK) cells, a crucial component of the innate immune system, have long been of clinical interest for their antitumor properties. Almost every aspect of NK cell immunity is regulated by interleukin-15 (IL-15), a cytokine in the common γ-chain family. Several current clinical trials are using IL-15 or its analogs to treat various cancers. Moreover, NK cells are being genetically modified to produce membrane-bound or secretory IL-15. Here, we discuss the key role of IL-15 signaling in NK cell immunity and provide an up-to-date overview of IL-15 in NK cell therapy.

Co-expression IL-15 receptor alpha with IL-15 reduces toxicity via limiting IL-15 systemic exposure during CAR-T immunotherapy

Background

Chimeric antigen receptor (CAR)-T cell therapy is a powerful adoptive immunotherapy against both B-cell malignancies and some types of solid tumors. Interleukin (IL) -15 is an important immune stimulator that may provide ideal long-term persistent CAR-T cells. However, higher base line or peak serum IL-15 levels are also related to severe toxicity, such as cytokine release syndrome (CRS), graft-versus-host disease (GVHD), and neurotoxicity.

Methods

We successfully constructed CD19 specific armored CAR-T cells overexpressing IL-I5 and IL-15 receptor alpha (IL-15Ra). In vitro cell differentiation and viability were monitored by flow cytometry, and an in vivo xenograft mouse models was used to evaluate the anti-tumor efficiency and liver damage of CAR-T cells.

Results

CAR-T cells overexpressing IL-15 alone demonstrated enhanced viability, retarded exhaustion in vitro and superior tumor-inhibitory effects in vivo. However, these tumor-free mice had lower survival rates, with serious liver injuries, as a possible result of toxicity. As expected, CAR-T cells overexpressing IL-15 combined with IL-15Ra had reduced CD132 expression and released fewer cytokines (IFNγ, IL-2 and IL-15) in vitro, as well as had the tendency to improve mouse survival via repressing the growth of tumor cells and keeping livers healthier compared to CAR-IL-15 T cells.

Conclusions

These results indicated the importance of IL-15 in enhancing T cells persistence and IL-15Ra in reducing the adverse effects of IL-15, with superior tumor retardation during CAR-T therapy. This study paves the way for the rapid exploitation of IL-15 in adoptive cell therapy in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03626-x.

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.

Metabolic Score for Insulin Resistance (METS-IR) and Circulating Cytokines in Older Persons: The Role of Gender and Body Mass Index

BACKGROUND

Inflammation, along with aging processes, contributes to the development of insulin resistance (IR), but the roles of different inflammatory and other cytokines in this process remain unclear. Thus, we aimed to analyze the association between several plasma cytokines with IR as evaluated by the metabolic score for insulin resistance, METS-IR.

METHODS

We measured the plasma concentrations of thirty cytokines from a cohort of older persons and analyzed their role as independent factors for IR. We used regression analyses adjusted for known IR-associated factors (including age, gender, cholesterol levels, and BMI) to find the determinants of IR.

RESULTS

The study evaluated 132 subjects, mostly women (82F/50M), slightly overweight, and with a mean age of 78.5 ± 6.5 years. In the overall population, IL-15 significantly and negatively correlates with METS-IR (r = -0.183, p = 0.036). A regression model showed that the association between IL-15 and METS-IR was significantly modulated by gender and BMI (R²: 0.831). Only in women, EGF, Eotaxin and MCP-1 significantly correlated with METS-IR even after controlling by age (EGF, r = 0.250 p = 0.025; Eotaxin, r = 0.276 p = 0.13; MCP-1, r = 0.237, p = 0.033). Furthermore, regression models showed that these molecules were associated with METS-IR and were strongly mediated by BMI.

CONCLUSIONS

Our results indicate the association between cytokines and IR has to be interpreted in a gender-specific manner. In women, EGF, Eotaxin, and MCP-1 circulating levels are associated with METS-IR being BMI a significant mediator. Understanding the role of gender in the relationship between cytokines and IR will help to define individualized preventive and treatment interventions to reduce the risk of age-related metabolic disorders.

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.

The Relation of the Viral Structure of SARS-CoV2, High-Risk Condition, and Plasma Levels of IL-4, IL-10, and IL-15 in COVID-19 Patients compared to SARS and MERS Infections

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has high mortality due to the widespread infection and the strong immune system reaction. Interleukins (ILs) are among the main immune factors contributing to the deterioration of the immune response and the formation of cytokine storms in coronavirus disease 2019 (COVID-19) infections.

INTRODUCTION

This review article investigated the relationship between virus structure, risk factors, and patient plasma interleukin levels in infections caused by the coronavirus family.

METHOD

The keywords "interleukin," "coronavirus structure," "plasma," and "risk factors" were the main words searched to find a relationship among different interleukins, coronavirus structures, and risk factors in ISI, PUBMED, SCOPUS, and Google Scholar databases.

RESULT

Patients with high-risk conditions with independent panels of immune system markers are more susceptible to death caused by SARS-CoV2. IL-4, IL-10, and IL-15 are probably secreted at different levels in patients with coronavirus infections despite the similarity of inflammatory markers during coronavirus infections. SARS-CoV2 and SARS-CoV increase the secretion of IL-4 in the Middle East respiratory syndrome coronavirus (MERS-CoV) infection, while it remains unchanged in MERS-CoV infection. MERS-CoV infection demonstrates increased IL-10 levels. However, IL-10 levels increase during SARS-CoV infection, and different levels are recorded in SARS-CoV2. MERS-CoV increases IL-15 secretion while its levels remain unchanged in SARS-CoV2.

CONCLUSION

In conclusion, the different structures of SARS-CoV2, such as length of spike or nonstructural proteins (NSPs), and susceptibility of patients based on their risk factors may lead to differences in immune marker secretion and pathogenicity. Therefore, identifying and controlling interleukin levels can play a significant role in controlling the symptoms and the development of individual-specific treatments.

CCL3, CCL5, IL-15, IL-1Ra and VEGF compose a reliable algorithm to discriminate classes of adverse events following 17DD-YF primary vaccination according to cause-specific definitions

In the present study, a range of serum biomarkers were quantified in suspected cases of adverse events following YF immunization (YEL-AEFI) to propose a reliable laboratorial algorithm to discriminate confirmed YEL-AEFI ("A1" class) from cases with other illnesses ("C" class). Our findings demonstrated that increased levels of CXCL8, CCL2, CXCL10, IL-1β, IL-6 and TNF-α were observed in YEL-AEFI ("A1" and "C" classes) as compared to primary vaccines without YEL-AEFI [PV(day 3-28)] and reference range (RR) controls. Notably, increased levels of CCL3, CCL4, CCL2, CCL5, IL-1β, IL-15, IL-1Ra and G-CSF were found in "A1" as compared to "C" class. Venn diagrams analysis allowed the pre-selection of biomarkers for further analysis of performance indices. Data demonstrated that CCL3, CCL5, IL-15 and IL-1Ra presented high global accuracy (AUC = 1.00) to discriminate "A1" from "C". Decision tree was proposed with a reliable algorithm to discriminate YEL-AEFI cases according to cause-specific definitions with outstanding overall accuracy (91%). CCL3, CCL5, IL-15 and IL-1Ra appears as root attributes to identify "A1" followed by VEGF as branch nodes to discriminate Wild Type YFV infection ("C(WT-YFV)") from cases with other illnesses ("C*"). Together, these results demonstrated the applicability of serum biomarker measurements as putative parameters towards the establishment of accurate laboratorial tools for complementary differential diagnosis of YEL-AEFI cases.

An unmet need: Harmonization of IL-7 and IL-15 combination for the ex vivo generation of minimally differentiated T cells

T cell-based adoptive cell transfer therapy is now clinically used to fight cancer with CD19-targeting chimeric antigen receptor T cells. The use of other T cell-based immunotherapies relying on antigen-specific T cells, genetically modified or not, is expanding in various neoplastic diseases. T cell manufacturing has evolved through sophisticated processes to produce T cells with improved therapeutic potential. Clinical-grade manufacturing processes associated with these therapies must meet pharmaceutical requirements and therefore be standardized. Here, we focus on the use of cytokines to expand minimally differentiated T cells, as well as their standardization and harmonization in research and clinical settings.

Is Keratoconus an Inflammatory Disease? The Implication of Inflammatory Pathways

PURPOSE

Keratoconus is considered a non-inflammatory condition. Recently however, increased proinflammatory cytokines have been detected in the tears of keratoconic patients and clinical and immunohistochemical observations reported infiltration of matured dendritic cells and leukocytes. Our laboratory utilized cytokine antibody arrays to elucidate the inflammatory aspects of keratoconus.

METHODS

Protein was extracted from 42 corneal buttons (14 keratoconic and 28 non-keratoconic) and incubated with cytokine antibody arrays scanning 120 cytokines. Mann Whitney U test with a p-value of <0.05 was considered significant.

RESULTS

Pathways for wound healing, neuroprotection, angiogenesis, and inflammation were activated in keratoconic samples with 23 cytokines showing significant elevation. Fifteen were expressed only in keratoconus with 8 cytokines elevated 1.7-42-fold.

CONCLUSION

This study identified elevated inflammatory pathways covering immune responses in keratoconus. Our results support the evidence for inflammatory pathway activation in keratoconus and a possible redefinition of keratoconus as a chronic inflammatory corneal disease.

Modified LDL Particles Activate Inflammatory Pathways in Monocyte-derived Macrophages: Transcriptome Analysis

Background:

A hallmark of atherosclerosis is its complex pathogenesis, which is dependent on altered cholesterol metabolism and inflammation. Both arms of pathogenesis involve myeloid cells. Monocytes migrating into the arterial walls interact with modified low-density lipoprotein (LDL) parti-cles, accumulate cholesterol and convert into foam cells, which promote plaque formation and also con-tribute to inflammation by producing pro-inflammatory cytokines. A number of studies characterized transcriptomics of macrophages following interaction with modified LDL, and revealed alteration of the expression of genes responsible for inflammatory response and cholesterol metabolism. However, it is still unclear how these two processes are related to each other to contribute to atherosclerotic lesion formation.

Methods:

We attempted to identify the main mater regulator genes in macrophages treated with athero-genic modified LDL using a bioinformatics approach.

Results:

We found that most of the identified genes were involved in inflammation, and none of them was implicated in cholesterol metabolism. Among the key identified genes were interleukin (IL)-7, IL-7 receptor, IL-15 and CXCL8.

Conclusion:

Our results indicate that activation of the inflammatory pathway is the primary response of the immune cells to modified LDL, while the lipid metabolism genes may be a secondary response trig-gered by inflammatory signalling

The deubiquitinase Otub1 controls the activation of CD8+ T cells and NK cells by regulating IL-15-mediated priming

CD8 T cells and natural killer (NK) cells, central cellular components of immune responses against pathogens and cancer, rely on IL-15 for homeostasis. Here we show that IL-15 also mediates homeostatic priming of CD8 T cells for antigen-stimulated activation, which is controlled by a deubiquitinase, Otub1. IL-15 mediates membrane recruitment of Otub1, which inhibits ubiquitin-dependent activation of AKT, a pivotal kinase for T cell activation and metabolism. Otub1 deficiency in mice causes aberrant responses of CD8 T cells to IL-15, rendering naive CD8 T cells hyper-sensitive to antigen stimulation characterized by enhanced metabolic reprograming and effector functions. Otub1 also controls the maturation and activation of NK cells. Consistently, Otub1 deletion profoundly enhances anticancer immunity through unleashing the activity of CD8 T cells and NK cells. These findings suggest that Otub1 controls the activation of CD8 T cells and NK cells by functioning as a checkpoint of IL-15-mediated priming.

A four-gene signature for prognosis in breast cancer patients with hypermethylated IL15RA

Previous studies have revealed that upregulation of interleukin 15 receptor α (IL15RA) contributes to improved prognosis of breast cancer. The present study aimed to elucidate the molecular mechanisms underlying the antitumor effect induced by IL15RA upregulation, and to identify a gene signature capable of predicting the survival of patients with breast cancer. Using paired gene expression and methylation data of breast cancer samples from The Cancer Genome Atlas data portal, differentially expressed genes (DEGs) were identified in hypermethylated and hypomethylated IL15RA breast cancer samples. Furthermore, a gene signature-based risk-scoring model was developed according to the Cox regression coefficients of survival-associated DEGS. The gene signature was applied to classify patients with breast cancer and hypermethylated IL15RA into two risk groups via Kaplan-Meier survival analysis of overall survival (OS) time. Functional enrichment analysis was conducted to decipher the biological roles of the DEGs between the two risk groups. A total of 326 DEGs were present in the hypomethylation and hypermethylation samples compared with in the normal samples. A four-gene signature [SH3 and cysteine rich domain 2 (STAC2), proline rich 11 (PRR11), homeobox C11 (HOXC11) and nucleolar and spindle associated protein 1 (NUSAP1)] was identified as able to successfully separate patients with breast cancer and hypermethylated IL15RA into two risk groups with significantly different OS time. The signature revealed similar predictive performance in an independent set. Significant enrichment of the ‘receptor interaction’ and ‘cell adhesion molecules (CAM)’ pathways, which involved the DEGs, occurred between the two risk groups. These findings suggested that IL15RA may participate in the regulation of STAC2, PRR11, HOXC11, NUSAP1, and ‘ECM-receptor interaction’ and ‘cell adhesion molecules’ pathways, and therefore in the suppression of breast cancer development and progression. The four-gene signature may have potential prognostic value for breast cancer.

Conditional Genetic Ablation Mouse Models as a Tool to Study Cancer Immunosurveillance In Vivo

Over the last decades, it has been established that the immune system is crucial for the impediment of cancer development by recognizing and destroying transformed cells. This process has been termed cancer immunosurveillance. Small animal models have significantly facilitated our understanding of it. Dissecting the contribution of any specific immune cell type participating in this process requires the ability to specifically target it while leaving the other immune components as well as the cancer model system unperturbed in vivo. Here, we provide a simple and rapid protocol for the generation of transgenic mice expressing Cre recombinase in a cell type-specific manner-in our example we chose cells expressing Ncr1, which encodes for the surface protein NKp46-and the use of those mice to ablate NKp46+ cells in order to study their role in a model of cancer immunosurveillance against experimental pulmonary metastases. This protocol can easily be adapted to target other cell types and other cancer models.

IL-15 regulates susceptibility of CD4+ T cells to HIV infection

HIV integrates into the host genome to create a persistent viral reservoir. Stimulation of CD4⁺ memory T lymphocytes with common γc-chain cytokines renders these cells more susceptible to HIV infection, making them a key component of the reservoir itself. IL-15 is up-regulated during primary HIV infection, a time when the HIV reservoir established. Therefore, we investigated the molecular and cellular impact of IL-15 on CD4⁺ T-cell infection. We found that IL-15 stimulation induces SAM domain and HD domain-containing protein 1 (SAMHD1) phosphorylation due to cell cycle entry, relieving an early block to infection. Perturbation of the pathways downstream of IL-15 receptor (IL-15R) indicated that SAMHD1 phosphorylation after IL-15 stimulation is JAK dependent. Treating CD4⁺ T cells with Ruxolitinib, an inhibitor of JAK1 and JAK2, effectively blocked IL-15-induced SAMHD1 phosphorylation and protected CD4⁺ T cells from HIV infection. Using high-resolution single-cell immune profiling using mass cytometry by TOF (CyTOF), we found that IL-15 stimulation altered the composition of CD4⁺ T-cell memory populations by increasing proliferation of memory CD4⁺ T cells, including CD4⁺ T memory stem cells (T_SCM). IL-15-stimulated CD4⁺ T_SCM, harboring phosphorylated SAMHD1, were preferentially infected. We propose that IL-15 plays a pivotal role in creating a self-renewing, persistent HIV reservoir by facilitating infection of CD4⁺ T cells with stem cell-like properties. Time-limited interventions with JAK1 inhibitors, such as Ruxolitinib, should prevent the inactivation of the endogenous restriction factor SAMHD1 and protect this long-lived CD4⁺ T-memory cell population from HIV infection.

Cytokine Signaling in the Development and Homeostasis of Regulatory T cells

Cytokine signaling is indispensable for regulatory T-cell (Treg) development in the thymus, and also influences the homeostasis, phenotypic diversity, and function of Tregs in the periphery. Because Tregs are required for establishment and maintenance of immunological self-tolerance, investigating the role of cytokines in Treg biology carries therapeutic potential in the context of autoimmune disease. This review discusses the potent and diverse influences of interleukin (IL)-2 signaling on the Treg compartment, an area of knowledge that has led to the use of low-dose IL-2 as a therapy to reregulate autoaggressive immune responses. Evidence suggesting Treg-specific impacts of the cytokines transforming growth factor β (TGF-β), IL-7, thymic stromal lymphopoietin (TSLP), IL-15, and IL-33 is also presented. Finally, we consider the technical challenges and knowledge limitations that must be overcome to bring other cytokine-based, Treg-targeted therapies into clinical use.

A BACH2 Gene Variant Is Associated with Postoperative Recurrence of Crohn's Disease

BACKGROUND

Crohn's disease often requires intestinal resection, which is not considered curative. Repeat surgical intervention is necessary in more than half of patients after their initial operation. Although many genetic loci are implicated in Crohn's disease, few have been associated with post-resection recurrence.

STUDY DESIGN

A cohort of patients with Crohn's disease who underwent intestinal resection was analyzed to determine genetic and clinical factors associated with post-resection recurrence. Genotype was assessed at 8 loci associated with adaptive immunity (SMAD3, IL10RB, IL15RA, BACH2, IL12B, IL18RAP, IFNGR2, and JAK2). Univariate and multivariable survival analyses were performed using a log-rank test and Cox-proportional hazard model, respectively.

RESULTS

One hundred and ninety-one patients with Crohn's disease and 11.2 years mean postoperative follow-up were included. Forty-six percent experienced a surgical recurrence. Factors associated with increased incidence of recurrence included male sex (p = 0.05) and shortened time to first intestinal operation (5.0 vs 7.3 years; p = 0.03); inflammatory disease behavior was associated with a lower chance of repeat operation (p < 0.01). Of the loci assessed on multivariable analysis, homozygosity for a risk allele at BACH2 (rs1847472) was significantly associated with disease recurrence (hazard ratio 1.54; 95% CI 1.00 to 2.36; p < 0.05).

CONCLUSIONS

We identify BACH2 as a susceptibility locus for postoperative recurrence of Crohn's disease in our cohort. BACH2 is critical in the differentiation and function of T cells, as a regulator of B-cell activity, and is associated with several dysregulated immunologic phenomena. Its identification as a risk locus in postoperative Crohn's disease recurrence suggests a potential role for regulatory T cells, effector T cells, humoral immunity, and immunologic memory in the development of this disease process.

Intestinal overexpression of interleukin (IL)-15 promotes tissue eosinophilia and goblet cell hyperplasia

Interleukin (IL)-15 overexpression in eosinophilic gastrointestinal disorders is reported, but IL-15's role in promoting eosinophilic gastroenteritis is largely unknown. Therefore, we generated enterocyte-overexpressed IL-15 transgenic mice using Fabpi promoter. The Fabpi-IL-15 (iIL-15) transgenic mice showed induced IL-15 levels in the jejunum with a marked increase in jejunum eosinophils. However, no induction of eosinophilia in the blood or any other gastrointestinal segment was observed. Eosinophilia in the jejunum villus was substantially higher in iIL-15 mice compared to wild-type mice. In addition, goblet cell hyperplasia was also observed in the jejunum of iIL-15 mice. Furthermore, a significant correlation between induced IL-15 transcript and the IL-18 transcripts was observed. Therefore, to further understand the role of IL-18 in IL-15 mice associated gastrointestinal disorders, we generated iIL-15/IL-18Rα^-/- mice. Using these mice, we found that IL-18 has an important role in promoting IL-15-induced eosinophilia. As intestinal IL-15 overexpression is reported in food intolerance, we examined OVA intolerance in iIL-15 mice. The OVA-sensitized and challenged iIL-15 mice experienced weight loss, diarrhea and eosinophilia in the jejunum. Taken together, our findings demonstrate that intestinal IL-15 overexpression induces IL-18-dependent eosinophilia and immunoglobulins in the intestine that promotes food allergic responses.

Immunobiology of the IL-15/IL-15Rα complex as an antitumor and antiviral agent

Interleukin (IL)-15 is essential for natural killer (NK), NKT and memory (m) CD8⁺ T cell development and function, and is currently under investigation as an immunotherapeutic agent for the treatment of cancer. Recently, the creation of IL-15 superagonist by complexing IL-15 and its high affinity receptor alpha (IL-15 Rα) in solution, inspired by the natural trans-presentation of IL-15, advances the potential of IL-15-based tumor immunotherapy. IL-15 superagonist shows promising advantages over monomeric IL-15 such as sustaining high circulating concentrations due to prolonged half-life and more potently stimulating NK and CD8⁺ T effector lymphocytes. So far, there are three different forms of recombinant IL-15 superagonist fusion protein based on configurational modifications. Gene therapy using engineered cells co-expressing IL-15/IL-15 Rα complex for cancer treatment is also emerging. All forms have demonstrated efficacy in causing tumor regression in animal studies, which provides strong rationale for advancing IL-15 superagonist through clinical trials. To date, there are fourteen phase I/II IL-15 superagonist trials in cancer patients and one phase I trial in HIV patients. Information generated by ongoing trials regarding the toxicity and efficacy of IL-15 superagonist is awaited. Finally, we elaborate on immunotoxicity caused by IL-15 superagonist in preclinical studies and discuss important safety considerations.

Impact of the body mass index on perioperative immunological disturbances in patients with hip and knee arthroplasty

BACKGROUND

Obesity increases the risk for knee and hip joint implantation and negatively contributes to wound healing. In this study, in 52 patients undergoing hip and knee arthroplasty the amount of peripheral immune effector cells pre- and post-operative, as well as the expression of certain soluble factors affecting the functions of immune effector cells were investigated.

METHODS

The peripheral immune cells and the expression of the soluble factors were determined by flow cytometry and correlated to each other in dependency of the BMI, the sex, and the kind of arthroplasty.

RESULTS

The pre-operative amounts of peripheral NK cells and cytotoxic T cells significantly decreased with increasing BMI. Furthermore, the expression of the immunomodulatory adipokine leptin nicely correlated to the BMI. These effects were stronger in males than in females. Furthermore, the correlation of the activation marker sTNF-R and peripheral T cells strongly decreased with increasing BMI. While IL-6, CD40L, and MPO were significantly induced after surgery, there were no correlations to the BMI.

CONCLUSIONS

The known wound-healing problems in obese patients and the osteoarthritis per se can be linked to the BMI. While obese patients exerted reduced peripheral NK cells and cytotoxic T cells (CTLs), IL-6 showed no involvement. However, the adipokine leptin strongly increased with the BMI strengthening its role as immunomodulatory molecule negatively interfering the functions of immune effector cells.

Transpresentation of interleukin-15 by IL-15/IL-15Rα mRNA-engineered human dendritic cells boosts antitumoral natural killer cell activity

In cancer immunotherapy, the use of dendritic cell (DC)-based vaccination strategies can improve overall survival, but until now durable clinical responses remain scarce. To date, DC vaccines are designed primarily to induce effective T-cell responses, ignoring the antitumor activity potential of natural killer (NK) cells. Aiming to further improve current DC vaccination outcome, we engineered monocyte-derived DC to produce interleukin (IL)-15 and/or IL-15 receptor alpha (IL-15Rα) using mRNA electroporation. The addition of IL-15Rα to the protocol, enabling IL-15 transpresentation to neighboring NK cells, resulted in significantly better NK-cell activation compared to IL-15 alone. Next to upregulation of NK-cell membrane activation markers, IL-15 transpresentation resulted in increased NK-cell secretion of IFN-γ, granzyme B and perforin. Moreover, IL-15-transpresenting DC/NK cell cocultures from both healthy donors and acute myeloid leukemia (AML) patients in remission showed markedly enhanced cytotoxic activity against NK cell sensitive and resistant tumor cells. Blocking IL-15 transpresentation abrogated NK cell-mediated cytotoxicity against tumor cells, pointing to a pivotal role of IL-15 transpresentation by IL-15Rα to exert its NK cell-activating effects. In conclusion, we report an attractive approach to improve antitumoral NK-cell activity in DC-based vaccine strategies through the use of IL-15/IL-15Rα mRNA-engineered designer DC.

Pro- and anti-inflammatory cytokines in cutaneous leishmaniasis: a review

Cutaneous leishmaniasis (CL) is caused by different species of the genus Leishmania. Pro- and anti-inflammatory cytokines play different roles in resistance/susceptibility and the immunopathogenesis of Leishmania infection. The balance and dynamic changes in cytokines may control or predict clinical outcome. T helper 1 (Th1) inflammatory cytokines (especially interferon-γ, tumor necrosis factor-α and interleukin-12) are the crucial factors in the initiation of protective immunity against L. major infection, whereas T helper 2 cytokines including IL-5, IL-4, and IL-13 facilitate the persistence of parasites by downregulating the Th1 immune response. On the other hand, aggravation of inflammatory reactions leads to collateral tissue damage and formation of ulcer. For this reason, immunity system such as T regulatory cells produce regulatory cytokines such as transforming growth factor-β and IL-10 to inhibit possible injures caused by increased inflammatory responses in infection site. In this article, we review the role of pro- and anti-inflammatory cytokines in the immunoprotection and immunopathology of CL.

Sarcopenia is a risk factor for the recurrence of hepatocellular carcinoma after curative treatment

BACKGROUND AND AIM

Sarcopenia, initially proposed as decreased of muscle mass and strength, is associated with aging and malignant diseases. The aim of the present study was to determine whether there is a correlation between sarcopenia and the recurrence of hepatocellular carcinoma (HCC) after curative treatment.

METHODS

We conducted a retrospective analysis of consecutive naive patients with HCC who underwent curative resection or radiofrequency ablation. To eliminate the influence of cause or the severity of liver damage, subjects were limited to those with HCC with hepatitis C-related cirrhosis and Child-Pugh class A liver function. Patients were assessed using computed tomographic measurement of muscle mass at the level of the third lumbar (L3) vertebrae, the L3 skeletal muscle index (L3 SMI). Sarcopenia was defined by using previously published, sex-specific cut-off value.

RESULTS

Sarcopenia was present in 61 of 92 patients. Patients' median age was 71.5 years (range, 47-84), and the baseline characteristics of patients were comparable between patients with and without sarcopenia except for sex, serum albumin level, prothrombin time, diabetes mellitus and body mass index. Recurrence rates at 1, 3 and 5 years were 39.1%,77.1%,81.7% for patients with sarcopenia and 23.5%,59.5% and 75.7% for patients without sarcopenia, respectively (P = 0.03). Multivariate Cox analysis revealed that sarcopenia and preoperative α-fetoprotein of more than 40 ng/mL were significant independent factors for recurrence.

CONCLUSION

Sarcopenia is a risk factor for recurrence in patients with HCC who were treated with curative treatment.

Post-weaning blood transcriptomic differences between Yorkshire pigs divergently selected for residual feed intake

Background

Improving feed efficiency (FE) of pigs by genetic selection is of economic and environmental significance. An increasingly accepted measure of feed efficiency is residual feed intake (RFI). Currently, the molecular mechanisms underlying RFI are largely unknown. Additionally, to incorporate RFI into animal breeding programs, feed intake must be recorded on individual pigs, which is costly and time-consuming. Thus, convenient and predictive biomarkers for RFI that can be measured at an early age are greatly desired. In this study, we aimed to explore whether differences exist in the global gene expression profiles of peripheral blood of 35 to 42 day-old pigs with extremely low (more efficient) and high RFI (less efficient) values from two lines that were divergently selected for RFI during the grow-finish phase, to use such information to explore the potential molecular basis of RFI differences, and to initiate development of predictive biomarkers for RFI.

Results

We identified 1972 differentially expressed genes (DEGs) (q ≤ 0.15) between the low (n = 15) and high (n = 16) RFI groups of animals by using RNA sequencing technology. We validated 24 of 37 selected DEGs by reverse transcription-quantitative PCR (RT-qPCR) in a joint analysis of 24 (12 per line) of the 31 samples already used for RNA-seq plus 24 (12 per line) novel samples from the same contemporary group of pigs. Using an analysis of the 24 novel samples alone, only nine of the 37 selected DEGs were validated. Genes involved in small molecule biosynthetic process, antigen processing and presentation of peptide antigen via major histocompatibility complex (MHC) class I, and steroid biosynthetic process were overrepresented among DEGs that had higher expression in the low versus high RFI animals. Genes known to function in the proteasome complex or mitochondrion were also significantly enriched among genes with higher expression in the low versus high RFI animals. Alternatively, genes involved in signal transduction, bone mineralization and regulation of phosphorylation were overrepresented among DEGs with lower expression in the low versus high RFI animals. The DEGs significantly overlapped with genes associated with disease, including hyperphagia, eating disorders and mitochondrial diseases (q < 1E-05). A weighted gene co-expression network analysis (WGCNA) identified four co-expression modules that were differentially expressed between the low and high RFI groups. Genes involved in lipid metabolism, regulation of bone mineralization, cellular immunity and response to stimulus were overrepresented within the two modules that were most significantly differentially expressed between the low and high RFI groups. We also found five of the DEGs and one of the co-expression modules were significantly associated with the RFI phenotype of individual animals (q < 0.05).

Conclusions

The post-weaning blood transcriptome was clearly different between the low and high RFI groups. The identified DEGs suggested potential differences in mitochondrial and proteasomal activities, small molecule biosynthetic process, and signal transduction between the two RFI groups and provided potential new insights into the molecular basis of RFI in pigs, although the observed relationship between the post-weaning blood gene expression and RFI phenotype measured during the grow-finish phase was not strong. DEGs and representative genes in co-expression modules that were associated with RFI phenotype provide a preliminary list for developing predictive biomarkers for RFI in pigs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2395-x) contains supplementary material, which is available to authorized users.

Molecular characterization of interleukin 15 mRNA from rohu, Labeo rohita (Hamilton): Its prominent role during parasitic infection as indicated from infection studies

Interleukin 15 (IL-15) is an important cytokine of fish immune system. Sequence characterization of IL-15 from rohu, Labeo rohita revealed a mRNA sequence of 1064 bp with coding sequence of 567 bp and signal peptide of 16 amino acids. There are four characteristic sequence features viz., presence of four out-of-frame AUG initiation codons, four highly conserved cysteine residues, constitutive expression in all tissues and evolutionary similarity. The ontogeny study revealed maternal transfer of this molecule and higher expression up to 3 h post-fertilization in fertilized embryos. Its expression was down-regulated in anterior and posterior kidneys, intestine and liver tissues of rohu infected with Aeromonas hydrophila. Mild up-regulation in liver and higher expression in spleen was noticed in rohu stimulated with poly I:C (poly ionosinic:cytidylic), whereas down-regulation was observed in intestine and kidney tissues. However, a consistent higher expression was noticed in kidney and skin tissues during Argulus siamensis infection. Therefore, rohu IL-15 might possess more defensive role during early development and parasitic infection.

Interleukin-15: new kid on the block for antitumor combination therapy

Interleukin (IL)-15 is one of the most promising molecules to be used in antitumor immune therapy, as it is able to stimulate the main killer cells of both the innate and adaptive immune system. Although this cytokine can be used as a stand-alone immunotherapeutic agent, IL-15 will probably be most efficient in combination with other strategies to overcome high tumor burden, immune suppression of the tumor microenvironment and/or the short half-life of IL-15. In this review, we will discuss the combination strategies with IL-15 that have been tested to date in different animal tumor models, which include chemotherapy, other immunostimulatory cytokines, targeted therapy, adoptive cell transfer and gene therapy. In addition, we give an overview of IL-15 combination therapies that are currently tested in clinical studies to treat patients with hematological or advanced solid tumors.

Activation of innate immune system in response to lipopolysaccharide in chicken Sertoli cells

Sertoli cells (SCs) play an important physiological role in the testis, as they support, nourish, and protect the germ cells. As protection of the developing spermatozoa is an emerging aspect of reproductive physiology, this study examined the expression pattern of innate immune-related genes, including avian β-defensins (AvBDs), Toll-like receptors (TLRs), and cytokines, and investigated the time course of an inflammatory response in rooster SCs triggered by exposure to the bacterial endotoxin lipopolysaccharide (LPS). SCs were isolated from 6-week-old chicken, culturedin vitro, and stimulated with 1 μg/ml LPS at different time courses (0, 6, 12, 24, and 48 h). Data on expression analysis revealed that all ten members of the chickenTLRfamily, nine members of theAvBDfamily, as well as eight cytokine genes were expressed in SCs. Quantitative real-time PCR analysis revealed that LPS treatment resulted in significant induction of the expression levels of sixTLRs, sixAvBDs, and four cytokine genes, while two cytokine genes were downregulated and two other genes were unchanged. The increasing interleukin 1β (IL1β) production was confirmed in the conditioned medium. Furthermore, the phagocytosis of SCs was increased after LPS treatment. In conclusion, these findings provide evidence that SCs express innate immune-related genes and respond directly to bacterial ligands. These genes represent an important component of the immune system, which could be integrated into semen, and present a distinctive constituent of the protective repertoire of the testis against ascending infections.

Clearance of acute myeloid leukemia by haploidentical natural killer cells is improved using IL-2 diphtheria toxin fusion protein

Haploidentical natural killer (NK) cell infusions can induce remissions in some patients with acute myeloid leukemia (AML) but regulatory T-cell (Treg) suppression may reduce efficacy. We treated 57 refractory AML patients with lymphodepleting cyclophosphamide and fludarabine followed by NK cell infusion and interleukin (IL)-2 administration. In 42 patients, donor NK cell expansion was detected in 10%, whereas in 15 patients receiving host Treg depletion with the IL-2-diphtheria fusion protein (IL2DT), the rate was 27%, with a median absolute count of 1000 NK cells/μL blood. IL2DT was associated with improved complete remission rates at day 28 (53% vs 21%; P = .02) and disease-free survival at 6 months (33% vs 5%; P < .01). In the IL2DT cohort, NK cell expansion correlated with higher postchemotherapy serum IL-15 levels (P = .002), effective peripheral blood Treg depletion (<5%) at day 7 (P < .01), and decreased IL-35 levels at day 14 (P = .02). In vitro assays demonstrated that Tregs cocultured with NK cells inhibit their proliferation by competition for IL-2 but not for IL-15. Together with our clinical observations, this supports the need to optimize the in vivo cytokine milieu where adoptively transferred NK cells compete with other lymphocytes to improve clinical efficacy in patients with refractory AML. This study is registered at clinicaltrials.gov, identifiers: NCT00274846 and NCT01106950.

Influence of interleukin-15 polymorphism on the survival of adult patients with acute lymphoblastic leukemia in Egypt

The aim of this study was to analyze the association of the rs10519612 and rs17007695 polymorphisms with the risk of acute lymphoblastic leukemia (ALL) and also to evaluate their impact on the survival of adult patients with ALL. The study included 164 adult patients with ALL and 158 healthy subjects as a control group who were genotyped for the interleukin-15 (IL-15) gene using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. We observed a higher risk of developing ALL for rs10519612 CC, rs17007695 TC and rs17007695 CC genotype carriers. There was increased risk for T-cell type in patients with the rs10519612 CC genotype. Notably, increased risk to develop B-cell type was found with rs17007695 TC and CC genotypes. There was no impact on overall survival or disease-free survival at 3 years. It is concluded that there is an association between both gene polymorphisms and the risk of ALL and with disease immunophenotype. However, there was no impact on the outcome of patients.

Combined treatment of rapamycin and dietary restriction has a larger effect on the transcriptome and metabolome of liver

Rapamycin (Rapa) and dietary restriction (DR) have consistently been shown to increase lifespan. To investigate whether Rapa and DR affect similar pathways in mice, we compared the effects of feeding mice ad libitum (AL), Rapa, DR, or a combination of Rapa and DR (Rapa + DR) on the transcriptome and metabolome of the liver. The principal component analysis shows that Rapa and DR are distinct groups. Over 2500 genes are significantly changed with either Rapa or DR when compared with mice fed AL; more than 80% are unique to DR or Rapa. A similar observation was made when genes were grouped into pathways; two-thirds of the pathways were uniquely changed by DR or Rapa. The metabolome shows an even greater difference between Rapa and DR; no metabolites in Rapa-treated mice were changed significantly from AL mice, whereas 173 metabolites were changed in the DR mice. Interestingly, the number of genes significantly changed by Rapa + DR when compared with AL is twice as large as the number of genes significantly altered by either DR or Rapa alone. In summary, the global effects of DR or Rapa on the liver are quite different and a combination of Rapa and DR results in alterations in a large number of genes and metabolites that are not significantly changed by either manipulation alone, suggesting that a combination of DR and Rapa would be more effective in extending longevity than either treatment alone.

IL-15 controls T cell functions through its influence on CD30 and OX40 antigens in Celiac Disease

AIM

To evaluate the ability of interleukin (IL)-15 to control T cell functions through its influence on CD30 and OX40 expressing cells in Celiac Disease (CD). In peripheral blood (PB), by examining the expression of OX40 in conventional effectors cells and T cells with a phenotypic specialization of regulatory cells [CD4+CD25high forkhead box protein 3 (Foxp3)+], and the co stimulation of IFN-γ and IL-4 production within CD30 and OX40 positive subsets of T cells. At the duodenal mucosa, by assessing the expression of CD30 and OX40 in intraepithelial (IE) and lamina propria (LP) lymphocytes (IEL, LPL).

PATIENTS AND METHODS

PB and duodenal mucosal biopsies were obtained from 38 patients with classic CD (Cel) and 38 healthy controls (HC). Analysis of cell surface and/or intracellular antigens was performed in anti-CD3-treated PB mononuclear cells (PBMC) before and after treatment with recombinant IL-15 (rIL-15), and in IE and LP cellular suspensions prepared from duodenal biopsies pre-treated with/without rIL-15.

RESULTS

A subpopulation of CD3+OX40+ T blasts was induced in Cel and HC by a 3days treatment of PBMC with anti-CD3 and decreased its size thereafter, regardless of the presence of rIL-15. However, the addition of rIL-15 to T blasts distinctively induced the survival of T cells with a regulatory phenotype that expresses OX40 antigen in Cel (p<0.05). Celiac patients showed higher frequencies of IFN-γ-producing CD3+CD30+ blasts before and after treatment with rIL-15 (p<0.05, vs. HC). IL-15 increased the frequencies of CD3+CD30+ LPL (HC: p<0.05, Cel: p<0.05) but not of CD3+OX40+ LPL, and CD30 or OX40 positive IEL.

CONCLUSIONS

The distinctive control of OX40+ cells with a T regulatory phenotype mediated by the influence of IL-15 comes out as new function of this cytokine in the context of CD. The higher production of IFN-γ by a subpopulation of peripheral CD3+CD30+ cells contributes to the type I biased immune response.

The pathogenesis and treatment of large granular lymphocyte leukemia

Large granular lymphocyte (LGL) leukemia is a spectrum of rare lymphoproliferative diseases of T lymphocytes and natural killer cells. These diseases frequently present with splenomegaly, neutropenia, and autoimmune diseases like rheumatoid arthritis. LGL leukemia is more commonly of a chronic, indolent nature; however, rarely, they have an aggressive course. LGL leukemia is thought to arise from chronic antigen stimulation, which drives long-term cell survival through the activation of survival signaling pathways and suppression of pro-apoptotic signals. These include Jak-Stat, Mapk, Pi3k-Akt, sphingolipid, and IL-15/Pdgf signaling. Treatment traditionally includes immunosuppression with low dose methotrexate, cyclophosphamide, and other immunosuppressive agents; however, prospective and retrospective studies reveal very limited success. New studies surrounding Jak-Stat signaling suggest this may reveal new avenues for LGL leukemia therapeutics.

Decidualized human endometrial stromal cells are sensors of hormone withdrawal in the menstrual inflammatory cascade

Menstruation is a complex process dependent on premenstrual release of inflammatory mediators and proteolytic enzymes from endometrial cells. Endometrial leukocytes are traditionally considered to be the major source of the inflammatory factors. However, evidence is emerging to suggest a role for decidualized endometrial stromal cells in the premenstrual inflammatory cascade. We sought to determine if withdrawal of hormone support (estrogen and progesterone) from decidualized endometrial stromal cells, in a model mimicking the precise timing leading to menstruation, activated inflammatory signaling pathways and downstream release of inflammatory mediators. Human endometrial stromal cells decidualized gradually over 12 days of estradiol and progestin treatment as evidenced by an increase in prolactin secretion. Withdrawal of hormone support from decidualized stromal cells resulted in a decrease in cytoplasmic IkappaB and a progressive increase in nuclear accumulation of NF-kappaB, as demonstrated by Western immunoblot and immunocytochemical analyses. Concomitant with nuclear translocation of NF-kappaB, hormone withdrawal led to production of a host of inflammatory mediators by the decidualized stromal cells, including IFN-alpha, IL-6, CCL11, GM-CSF, CCL2, IL1-RA, CXCL10, CXCL8, IL-12, IL-15, VEGF, and CCL5. Elevation of inflammatory mediators was not observed, however, upon hormone withdrawal in cells treated with the NF-kappaB inhibitor BAY 11-7085. Decidualized stromal cells are likely highly sensitive sensors of changing hormone levels. This provides a mechanism by which decidualized stromal cells may recruit inflammatory leukocytes into the premenstrual endometrium and contribute to the intense inflammation underlying this unique physiological process.

Targeting IL-15 in large granular lymphocyte leukemia

IL-15 is a cytokine that stimulates the proliferation of NK and T cells. Previous studies have shown that IL-15 is critical to the induction of T-cell large granular lymphocyte (T-LGL) leukemia. A Phase I trial of a humanized antibody (Hu-Mikβ1) to the IL2/IL15Rβ receptor, expressed on T-LGL, is explored in this trial to evaluate the safety, pharmacokinetics, specificity and clinical efficacy of Hu-Mikβ1. The study demonstrated no toxicity and favorable saturation of IL2/IL15Rβ receptor, but no clinical efficacy in this Phase I study.

Molecular cloning and expression analysis of interleukin (IL)-15 and IL-15 receptor α from rock bream, Oplegnathus fasciatus

Mammalian interleukin (IL)-15 plays an important role in the activation of CD8(+) T cells and natural killer (NK) cells along with its receptor α (IL-15Rα). To understand the potential roles of IL-15 and IL-15Rα in fish, we identified IL-15 and IL-15Rα cDNA from rock bream (Oplegnathus fasciatus) and investigated their gene expression profiles after bacterial and viral infection. Coding regions of rock bream (Rb) IL-15 and RbIL-15Rα cDNAs were 534 and 402 bp encoding 177 and 133 amino acid residues, respectively. The sushi domain of IL-15Rα was highly conserved between rock bream and other species. Unlike other IL-15Rαs, RbIL-15Rα does not have a transmembrane region. Gene expression of RbIL-15 and RbIL-15Rα was widely expressed in different tissues of healthy fish, especially immune-related tissues. RbIL-15 and RbIL-15Rα were highly induced in the kidney and spleen after infection with Edwardsiella tarda, Streptococcus iniae and red seabream iridovirus. Gene expression patterns of RbIL-15 and RbIL-15Rα were similar in the kidney and spleen after pathogen infection. However, these genes were differentially induced in the liver after pathogen infection. These results suggest that the different responses of RbIL-15 and RbIL-15Rα to pathogen infection may be induced by different tissues or cell types.

Delivery of interleukin-15 to B16 melanoma by electroporation leads to tumor regression and long-term survival

Electroporation (EP) is a method used to physically deliver therapeutic molecules such as plasmid DNA directly to tissues. It has been used safely and successfully in clinical studies and preclinical cancer models to deliver genes to a variety of tissues. In cancer research cytokine therapy is emerging as a promising tool that can be used to boost the host response to tumor antigens. The delivery of cytokines as recombinant proteins can result in toxicity and other adverse effects; however the delivery of cytokine genes using EP has been shown to be safe and effective. Interleukin 15 (IL-15) is a cytokine that promotes the innate as well as the adaptive immune response to cancer cells and bacterial pathogens. In this study we used EP to deliver a human IL-15 plasmid (phIL-15) directly to tumors to examine its anti-cancer effects. B16.F10 melanoma tumors were induced in C57BL/6J mice and phIL-15 was delivered three times over the course of a week. Expression of the transgene, tumor volume, long-term survival and resistance to challenge were monitored in these animals. Delivery of IL-15 plasmid by EP resulted in increased IL-15 expression within the tumor compared to the injection only control. This expression peaked at 12 to 18 hours after the first delivery and was sustained at lower levels after the second and third deliveries. The delivery of the phIL-15 resulted in tumor regression, long-term survival and greater protection against tumor recurrence when cancer cells were reintroduced compared to control plasmid. From these results we can conclude that the delivery of IL-15 plasmid to tumors using EP is a promising avenue to investigate for its anti-tumor effects, however more work needs to be done to increase the stability of the gene once it is delivered and to elucidate the anti-tumor mechanism.

Signal transducer and activator of transcription 3 (STAT3) mutations underlying autosomal dominant hyper-IgE syndrome impair human CD8(+) T-cell memory formation and function

BACKGROUND

The capacity of CD8(+) T cells to control infections and mediate antitumor immunity requires the development and survival of effector and memory cells. IL-21 has emerged as a potent inducer of CD8(+) T-cell effector function and memory development in mouse models of infectious disease. However, the role of IL-21 and associated signaling pathways in protective CD8(+) T-cell immunity in human subjects is unknown.

OBJECTIVE

We sought to determine which signaling pathways mediate the effects of IL-21 on human CD8(+) T cells and whether defects in these pathways contribute to disease pathogenesis in patients with primary immunodeficiencies caused by mutations in components of the IL-21 signaling cascade.

METHODS

Human primary immunodeficiencies resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Lymphocytes from patients with loss-of-function mutations in signal transducer and activator of transcription 1 (STAT1), STAT3, or IL-21 receptor (IL21R) were used to assess the respective roles of these genes in human CD8(+) T-cell differentiation in vivo and in vitro.

RESULTS

Mutations in STAT3 and IL21R, but not STAT1, led to a decrease in multiple memory CD8(+) T-cell subsets in vivo, indicating that STAT3 signaling, possibly downstream of IL-21R, regulates the memory cell pool. Furthermore, STAT3 was important for inducing the lytic machinery in IL-21-stimulated naive CD8(+) T cells. However, this defect was overcome by T-cell receptor engagement.

CONCLUSION

The IL-21R/STAT3 pathway is required for many aspects of human CD8(+) T-cell behavior but in some cases can be compensated by other signals. This helps explain the relatively mild susceptibility to viral disease observed in STAT3- and IL-21R-deficient subjects.