Incorporating IL7 receptor alpha signaling in the endodomain of B7H3-targeting chimeric antigen receptor T cells mediates antitumor activity in glioblastoma

CAR-T-cell therapy has shown promise in treating hematological malignancies but faces challenges in treating solid tumors due to impaired T-cell function in the tumor microenvironment. To provide optimal T-cell activation, we developed a B7 homolog 3 protein (B7H3)-targeting CAR construct consisting of three activation signals: CD3ζ (signal 1), 41BB (signal 2), and the interleukin 7 receptor alpha (IL7Rα) cytoplasmic domain (signal 3). We generated B7H3 CAR-T cells with different lengths of the IL7Rα cytoplasmic domain, including the full length (IL7R-L), intermediate length (IL7R-M), and short length (IL7R-S) domains, and evaluated their functionality in vitro and in vivo. All the B7H3-IL7Rα CAR-T cells exhibited a less differentiated phenotype and effectively eliminated B7H3-positive glioblastoma in vitro. Superiority was found in B7H3 CAR-T cells contained the short length of the IL7Rα cytoplasmic domain. Integration of the IL7R-S cytoplasmic domain maintained pSTAT5 activation and increased T-cell proliferation while reducing activation-induced cell death. Moreover, RNA-sequencing analysis of B7H3-IL7R-S CAR-T cells after coculture with a glioblastoma cell line revealed downregulation of proapoptotic genes and upregulation of genes associated with T-cell proliferation compared with those in 2nd generation B7H3 CAR-T cells. In animal models, compared with conventional CAR-T cells, B7H3-IL7R-S CAR-T cells suppressed tumor growth and prolonged overall survival. Our study demonstrated the therapeutic potential of IL7Rα-incorporating CAR-T cells for glioblastoma treatment, suggesting a promising strategy for augmenting the effectiveness of CAR-T cell therapy.

Diminished Interleukin-7 receptor expression on T-cell subsets in tuberculosis patients

Immunopathology in human tuberculosis affects T-cell phenotype and functions. Previous studies identified impaired T-cell sensitivity to Interleukin (IL)-7 accompanied by lower IL-7 receptor α-chain (IL-7Rα) expression in patients with acute tuberculosis. In the present study, we characterized affected T-cell subsets and determined the influence of tuberculosis disease severity and treatment response. Tuberculosis patients (n = 89) as well as age- and gender-matched asymptomatic contacts (controls, n = 47) were recruited in Ghana. Mycobacterium (M.) tuberculosis sputum burden was monitored prior to and during treatment. Blood samples from all patients and controls were analyzed for IL-7Rα expression and T-cell markers by multi-colour flow cytometry. CD4+ and CD8+ T-cells of tuberculosis patients showed generally lower IL-7Rα expression as compared to controls. Concomitantly, tuberculosis patients had higher proportions of naïve and lower proportions of memory CD4+ T-cells. Notably, a subset of CD27 positive central memory T-cells (Tcm), which lacked IL-7Rα expression was enriched in tuberculosis patients as compared to controls. M. tuberculosis sputum burden was not associated with differences in IL-7Rα expression. Treatment duration and response showed no clear effects although IL-7Rα expression patterns were highly variable. These results suggested generally impaired generation of memory CD4+ T-cells and enrichment of a Tcm subset without IL-7Rα expression in patients with tuberculosis.

Improved predictability of pancreatic ductal adenocarcinoma diagnosis using a blood immune cell biomarker panel developed from bulk mRNA sequencing and single-cell RNA-sequencing

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) remains a devastating cancer due to its poor survival rate, early detection, and resectability. This study aimed to determine the peripheral blood mononuclear cell (PBMC) immune biomarkers in patients with PDAC and investigate the PDAC-specific peripheral blood biomarker panel and validate its clinical performance.

METHODS

In this prospective, blinded, case-control study, a biomarker panel formula was generated using a development cohort-including healthy controls, patients at high risk of PDAC, and patients with benign pancreatic disease, PDAC, or other gastrointestinal malignancies-and its diagnostic performance was verified using a validation cohort, including patients with ≥ 1 lesion suspected as PDAC on computed tomography (CT).

RESULTS

RNA-sequencing of PBMCs from patients with PDAC identified three novel immune cell markers, IL-7R, PLD4, and ID3, as specific markers for PDAC. Regarding the diagnostic performance of the regression formula for the three biomarker panels, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 84.0%, 78.8%, 47.2%, 95.6%, and 79.8%, respectively. Based on the formula scores for the biomarker panel, the false-negative rate (FNR) of the biomarkers was 8% (95% confidence interval [CI] 3.0-13.0), which was significantly lower than that based on CT in the validation cohort (29.2%, 95% CI 20.8-37.6).

CONCLUSIONS

The regression formula constructed using three PBMC biomarkers is an inexpensive, rapid, and convenient method that shows clinically useful performance for the diagnosis of PDAC. It aids diagnoses and differential diagnoses of PDAC from pancreatic disease by lowering the FNR compared to CT. Clinical trial registration Clinical Research Information Service, KCT0004614 (08 January 2020).

Cytokine-induced transient monocyte IL-7Ra expression and the serum milieu in tuberculosis

Bacterial components and cytokines induce Interleukin-7 receptor (IL-7Rα) expression in monocytes. Aberrant low IL-7Rα expression of monocytes has been identified as a feature of tuberculosis immunopathology. Here, we investigated the mechanisms underlying IL-7Rα regulation of monocytes and tuberculosis serum effects IL-7Rα expression. Serum samples from tuberculosis patients and healthy controls, cytokine candidates, and mycobacterial components were analyzed for in vitro effects on IL-7Rα expression of primary monocytes, monocyte-derived macrophages (MDM), and monocyte cell lines. IL-7Rα regulation during culture and the role of FoxO1 was characterized. In vitro activation induced IL-7Rα expression in human monocytes and serum samples from tuberculosis patients boosted IL-7Rα expression. Although pathognomonic tuberculosis cytokines were not associated with serum effects, we identified cytokines (i.e., GM-CSF, IL-1β, TNFα, IFNγ) that induced IL-7Rα expression in monocytes and/or MDM comparable to mycobacterial components. Blocking of cytokine subsets (i.e., IL-1β/TNFα in monocytes, GM-CSF in MDM) largely diminished IL-7Rα expression induced by mycobacterial components. Finally, we showed that in vitro induced IL-7Rα expression was transient and dependent on constitutive FoxO1 expression in primary monocytes and monocyte cell lines. This study demonstrated the crucial roles of cytokines and constitutive FoxO1 expression for transient IL-7Rα expression in monocytes. This article is protected by copyright. All rights reserved.

Philadelphia-Like Acute Lymphoblastic Leukemia: A Systematic Review

Philadelphia-like (Ph-like) acute lymphoblastic leukemia (ALL) is a subgroup of B-cell precursor ALL (BCP-ALL) with a gene expression profile analogous to Philadelphia-positive ALL and recurrent IKAROS Family Zinc Finger 1 (IKZF1) gene deletion despite lacking BCR-ABL1 (Breakpoint cluster region-ABL protooncogene) translocation. Although recognized to occur at all ages, the proportion of cases among BCP-ALL varies (< 10% in children and up to 30% in adolescents). In all age groups, males are more commonly affected. Generally, Ph-like ALL is associated with adverse clinical features and an increased risk of treatment failure with conventional approaches. Genetic alterations such as aberrant expression, point mutations, or fusion translocations lead to activation of cytokine receptors and signaling kinases, which affect the ABL1 (ABL class fusion) or Janus Kinase (JAK) signaling pathways. Several clinical trials are being conducted to understand whether specific tyrosine kinase inhibitor therapy can improve cure rates. This review summarizes the current literature available about this entity.

Polymorphisms in the canine IL7R 3'UTR are associated with thymic output in Labrador retriever dogs and influence post-transcriptional regulation by microRNA 185

Interleukin-7 (IL-7) and its receptor (IL-7R) are essential for T cell development in the thymus, and changes in the IL-7/IL-7R pathway have been implicated in age-associated thymic involution which results in a reduction of naïve T cell output. The aim of this study was to investigate the relationship between IL7 and IL7R genetic variation and thymic output in dogs. No single nucleotide polymorphisms (SNPs) were identified in the canine IL7 gene, but a number were present in the canine IL7R gene. Polymorphisms in the IL7R exon 8 and 3'UTR were found to be associated with signal joint T cell receptor excision circle (sj-TREC) values (a biomarker of thymic output) in young and geriatric Labrador retrievers. Additionally, one of the SNPs in the IL7R 3'UTR (SNP 14 c.1371 + 446 A > C) was found to cause a change in the seed-binding site for microRNA 185 which, a luciferase reporter assay demonstrated, caused changes in post-transcriptional regulation, and therefore might be capable of influencing IL-7R expression. The research findings suggest a genetic link between IL7R genotype and thymic output in dogs, which might impact on immune function as these animals age and provide further evidence of the involvement of IL-7/IL-7R pathway in age-associated thymic involution.

From the outside, from within: Biological and therapeutic relevance of signal transduction in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological cancer that arises from clonal expansion of transformed T-cell precursors. In this review we summarize the current knowledge on the external stimuli and cell-intrinsic lesions that drive aberrant activation of pivotal, pro-tumoral intracellular signaling pathways in T-cell precursors, driving transformation, leukemia expansion, spread or resistance to therapy. In addition to their pathophysiological relevance, receptors and kinases involved in signal transduction are often attractive candidates for targeted drug development. As such, we discuss also the potential of T-ALL signaling players as targets for therapeutic intervention.

Smoking activates cytotoxic CD8+ T cells and causes survivin release in rheumatoid arthritis

CD8⁺ T cells have an emerging role in RA. Resent research indicates a causal relationship between the non-exhausted state of CD8⁺ T cells, defined by lost function of PD-1, and development of arthritis. We investigated how smoking contributes to the non-exhausted phenotype of CD8⁺ T cells and cause survivin release to serum. We compared serum survivin levels between smokers and non-smokers in 252 RA and 168 healthy subjects. Nicotine effects on CD8⁺ T cells were studied in peripheral blood of smoking women, bone marrow of nicotine treated mice and in sorted CD8 spleen cells in vitro using flow cytometry and quantitative PCR. Smoking increased the frequency of survivin release in serum of healthy women (OR 3.64, p = 0.025) and in RA patients (OR 1.98, p = 0.039). CD8⁺ T cells of smokers gained a non-exhausted PD-1 deficient phenotype. Expression of the cytotoxic marker CD107 correlated to survivin levels in serum. In the experimental setting, nicotine exposure led to an accumulation of non-exhausted PD-1^-IL-7R⁺ CD8⁺ T cells in the bone marrow that is abundant with survivin producing cells. The production of the cytolytic protein perforin in bone marrow correlated to serum survivin levels. In vitro stimulation of nicotinic receptors on murine CD8⁺ T cells induced repressive transcription factors T-bet and Blimp-1 in support of the non-exhausted phenotype. We conclude that nicotine contributes to autoimmunity by supporting the non-exhausted state of CD8⁺ T cells resulting in the release of survivin. This presents a new mechanism by which smoking may contribute to the pathogenesis of RA.

Hepatitis B virus X protein promotes interleukin-7 receptor expression via NF-κB and Notch1 pathway to facilitate proliferation and migration of hepatitis B virus-related hepatoma cells

Background

Interleukin-7 receptor (IL-7R) is involved in the abnormal function of solid tumors, but the role and regulatory mechanisms of IL-7R in HBV-related hepatocellular carcinoma (HCC) are still unclear.

Methods

Gene and protein expression levels of IL-7R were examined in hepatoma cells transfected with hepatitis B virus (HBV) plasmids and in hepatoma cells transfected with the multifunctional nonstructural protein X (HBX). The expression of HBX and IL-7R was measured by immunohistochemical analysis in HBV-related HCC tissues. The role of NF-κB and Notch1 pathways in HBX-mediated expression of IL-7R in hepatoma cells was examined. Activation of IL-7R downstream of intracellular signaling proteins AKT, JNK, STAT5, and the associated molecules CyclinD1 and matrix metalloproteinase-9 (MMP)-9, was assessed in HBX-positive cells with or without treatment with IL-7R short hairpin RNA (shRNA). Additionally, the role of IL-7R in HBX-mediated proliferation and migration of hepatoma cells was investigated.

Results

The expression of IL-7R was increased in hepatoma cells transfected with HBV plasmids; HBX was responsible for the HBV-mediated upregulation of IL-7R. Compared to adjacent tissues, the expression of HBX and IL-7R was increased in HBV-related HCC tissues. Additionally, the relative expression levels of HBX were associated with IL-7R in HBV-related HCC tissues. The activation of NF-κB pathways and expression of Notch1 were increased in hepatoma cells transfected with HBX, and inhibition of NF-κB and Notch1 pathways significantly decreased HBX-mediated expression of IL-7R. The activation of AKT and JNK and the expression of CyclinD1 and MMP-9 were increased in HBX-positive cells. When cells were treated with IL-7R shRNA, the activation of AKT and JNK, as well as the expression of CyclinD1 and MMP-9, were significantly inhibited. Additionally, IL-7R was responsible for HBX-induced proliferation and migration ability of hepatoma cells.

Conclusions

Our data demonstrate that HBX can upregulate IL-7R via NF-κB and Notch1 pathways to facilitate the activation of intracellular pathways and expression of associated molecules, and contribute to proliferation and migration of hepatoma cells.

Transcriptional regulation of the IL-7Rα gene by dexamethasone and IL-7 in primary human CD8 T cells

Interleukin-7 is essential for the development and maintenance of T cells, and the expression of the IL-7 receptor is tightly regulated at every stage of the T cell's lifespan. In mature CD8 T cells, IL-7 plays important roles in cell survival, peripheral homeostasis, and cytolytic function. The IL-7 receptor alpha-chain (CD127) is expressed at high levels on naïve and memory cells, but it is rapidly downregulated upon IL-7 stimulation. In this study, we illustrate the dynamicity of the CD127 promoter and show that it possesses positive as well as negative regulatory sites involved in upregulating and downregulating CD127 expression, respectively. We cloned the CD127 gene promoter and identified key cis-regulatory elements required for CD127 expression in mature resting primary CD8 T cells. The core promoter necessary for efficient basal transcription is contained within the first 262 bp upstream of the TATA box. Additional positive regulatory elements are located between -1200 and -2406 bp, conferring a further 2- to 4-fold enhancement in gene expression. While transcription of the CD127 gene is increased directly through a glucocorticoid response element located between -2255 and -2269 bp upstream of the TATA box, we identified a suppressive region that lies upstream of 1760 bp from the TATA box, which is likely involved in the IL-7-mediated suppression of CD127 transcription. Finally, we illustrated IL-7 does not bias alternative splicing of CD127 transcripts in primary human CD8 T cells.

IL-7 receptor deletion ameliorates diet-induced obesity and insulin resistance in mice

AIM/HYPOTHESIS

Obesity-induced inflammation plays an important role in the development of insulin resistance and type 2 diabetes. Recent studies have demonstrated that adiposity can be improved by ablating certain inflammatory signalling pathways. Although the IL-7 receptor (IL-7R) is mostly known as a key regulator of T lymphocyte development and homeostasis, its role in obesity and metabolic diseases is unknown. Because IL-7 is markedly increased in the serum of obese individuals and IL-7R (also known as IL7R) is overexpressed in white adipose tissue (WAT) in obesity, we studied the metabolic consequences of genetic Il-7r ablation in mice.

METHODS

Age-matched Il-7r-deficient (Il-7r KO) and wild-type (WT) littermates were fed a standard chow or high-fat diet (HFD) for 14 weeks. Their serum metabolic variables were measured. The expression of genes and proteins related to insulin resistance and inflammation was evaluated in WAT.

RESULTS

We demonstrated that Il-7r KO mice exhibited significantly reduced body weight gain and visceral adiposity compared with WT controls on both chow and HFD. The expression of signalling molecules involved in adipogenesis was reduced in the WAT of Il-7r KO mice. We also found that Il-7r KO mice had significantly enhanced glucose homeostasis and insulin sensitivity. Consistent with an improved metabolic phenotype, proinflammatory cytokine production and macrophage infiltration was attenuated in the WAT of Il-7r KO mice.

CONCLUSIONS/INTERPRETATION

The IL-7R plays an important role in the induction of HFD-induced adipogenesis and insulin resistance in mice.

T-cell homeostasis in chronic HCV-infected patients treated with interferon and ribavirin or an interferon-free regimen

Direct-acting antiviral has replaced pegylated interferon-α and ribavirin-based treatment in the treatment of chronic hepatitis C virus (HCV) infection. While interferon-α is immune modulating and causes lymphopenia, interferon-free regimens seem to be well-tolerated. This study aimed to compare T-cell homeostasis before, during, and after HCV treatment with or without interferon-α in patients with chronic HCV infection. A total of 20 patients with chronic HCV infection were treated with pegylated interferon-α and ribavirin, and six patients were treated with an interferon-free regimen. All patients were treated for a minimum of 12 weeks. Interferon-α treatment caused an increase in the density of the receptor for IL-7 (IL-7Rα) during treatment, while interferon-free regimens caused a decrease in IL-7Rα density. After a sustained viral response, proportions of IL-7Rα+ T cells and IL-7Rα density decreased compared to prior treatment values. Finally, a proportion of CD8+ effector memory was lower while proportion of apoptotic T cells was higher after sustained virologic response compared to prior treatment. Despite lymphopenia during interferon, alterations in T-cell homeostasis during treatment were relatively similar in patients receiving interferon-based treatment and in patients receiving interferon-free treatment, and alterations during and after treatment seem to illustrate a reduced need for high levels of T cells aimed at controlling infection.