Purity of transferred CD8(+) T cells is crucial for safety and efficacy of combinatorial tumor immunotherapy in the absence of SHP-1

Association of Long Non-coding RNA C1RL-AS1 and PTPN6 Gene Polymorphisms with Ocular Behcet's Disease in Han Chinese

PURPOSE

To explore the association of the polymorphisms in PTPN6 and LncRNA C1RL-AS1 genes with ocular BD in Han Chinese patients.

METHODS

Correlation study was performed using the iPLEX system on a cohort of ocular BD patients andcontrols. The genotyping of 7 SNPs for LncRNA C1RL-AS1 and PTPN6 genes in ocular BD patients was performed using the iPLEX Gold genotype.

RESULTS

The frequencies of rs4013722 AG genotype/A allele in LncRNA C1RL-AS1 were significantly decreased in BD patients, and the frequency of GG genotype was significantly increased in BD patients. The rs4013722 was associated with ocular BD in male patients, but not in female patients. The AG and GG genotype of rs4013722 were associated with skin lesions in male patients. The gene polymorphisms of PTPN6 were not associated with BD patients.

CONCLUSIONS

The LncRNA C1RL-AS1/rs4013722 polymorphism conferred susceptibility to ocular BD in Han Chinese patients, which was influenced by sex.Abbreviations: LncRNA: Long Non-coding RNA; BD: Behcet's disease; SNP: single nucleotide polymorphism; PBMCs: peripheral blood mononuclear cells; PTPs: Protein tyrosine phosphatases; PTPN6: protein tyrosine phosphatase non-receptor 6; GWAS: genome-wide association study; HWE: Hardy-Weinberg equilibrium; LD: linkage disequilibrium; OR: odds ratio; CI: confidence interval; eQTL: expression quantitative trait loci; IBD: inflammatory bowel disease; RA: rheumatoid arthritis; Padj: Bonferroni corrected P value; NS: non-significant.

Targeting Protein Tyrosine Phosphatases to Improve Cancer Immunotherapies

Advances in immunotherapy have brought significant therapeutic benefits to many cancer patients. Nonetheless, many cancer types are refractory to current immunotherapeutic approaches, meaning that further targets are required to increase the number of patients who benefit from these technologies. Protein tyrosine phosphatases (PTPs) have long been recognised to play a vital role in the regulation of cancer cell biology and the immune response. In this review, we summarize the evidence for both the pro-tumorigenic and tumour-suppressor function of non-receptor PTPs in cancer cells and discuss recent data showing that several of these enzymes act as intracellular immune checkpoints that suppress effective tumour immunity. We highlight new data showing that the deletion of inhibitory PTPs is a rational approach to improve the outcomes of adoptive T cell-based cancer immunotherapies and describe recent progress in the development of PTP inhibitors as anti-cancer drugs.

Small molecule inhibitors for cancer immunotherapy and associated biomarkers - the current status

Following the success of cancer immunotherapy using large molecules against immune checkpoint inhibitors, the concept of using small molecules to interfere with intracellular negative regulators of anti-tumor immune responses has emerged in recent years. The main targets for small molecule drugs currently include enzymes of negative feedback loops in signaling pathways of immune cells and proteins that promote immunosuppressive signals within the tumor microenvironment. In the adaptive immune system, negative regulators of T cell receptor signaling (MAP4K1, DGKα/ζ, CBL-B, PTPN2, PTPN22, SHP1), co-receptor signaling (CBL-B) and cytokine signaling (PTPN2) have been preclinically validated as promising targets and initial clinical trials with small molecule inhibitors are underway. To enhance innate anti-tumor immune responses, inhibitory immunomodulation of cGAS/STING has been in the focus, and inhibitors of ENPP1 and TREX1 have reached the clinic. In addition, immunosuppressive signals via adenosine can be counteracted by CD39 and CD73 inhibition, while suppression via intratumoral immunosuppressive prostaglandin E can be targeted by EP2/EP4 antagonists. Here, we present the status of the most promising small molecule drug candidates for cancer immunotherapy, all residing relatively early in development, and the potential of relevant biomarkers.

Platelet ITGA2B inhibits caspase-8 and Rip3/Mlkl-dependent platelet death though PTPN6 during sepsis

Platelets play an important role in the pathogenesis of sepsis and platelet transfusion is a therapeutic option for sepsis patients, although the exact mechanisms have not been elucidated so far. ITGA2B encodes the αIIb protein in platelets, and its upregulation in sepsis is associated with increased mortality rate. Here, we generated a Itga2b (Q887X) knockin mouse, which significantly reduced ITGA2B expression of platelet and megakaryocyte. The decrease of ITGA2B level aggravated the death of septic mice. We analyzed the transcriptomic profiles of the platelets using RNA sequencing. Our findings suggest that ITGA2B upregulates PTPN6 in megakaryocytes via the transcription factors Nfkb1 and Rel. Furthermore, PTPN6 inhibits platelet apoptosis and necroptosis during sepsis by targeting the Ripk1/Ripk3/Mlkl and caspase-8 pathways. This prevents Kupffer cells from rapidly clearing activated platelets, and eventually maintains vascular integrity during sepsis. Our findings indicate a new function of ITGA2B in the regulation of platelet death during sepsis.

Targeting protein phosphatases in cancer immunotherapy and autoimmune disorders

Protein phosphatases act as key regulators of multiple important cellular processes and are attractive therapeutic targets for various diseases. Although extensive effort has been dedicated to phosphatase-targeted drug discovery, early expeditions for competitive phosphatase inhibitors were plagued by druggability issues, leading to the stigmatization of phosphatases as difficult targets. Despite challenges, persistent efforts have led to the identification of several drug-like, non-competitive modulators of some of these enzymes - including SH2 domain-containing protein tyrosine phosphatase 2, protein tyrosine phosphatase 1B, vascular endothelial protein tyrosine phosphatase and protein phosphatase 1 - reigniting interest in therapeutic targeting of phosphatases. Here, we discuss recent progress in phosphatase drug discovery, with emphasis on the development of selective modulators that exhibit biological activity. The roles and regulation of protein phosphatases in immune cells and their potential as powerful targets for immuno-oncology and autoimmunity indications are assessed.

Prognostic Signature Development on the Basis of Macrophage Phagocytosis-Mediated Oxidative Phosphorylation in Bladder Cancer

Background

Macrophages are correlated with the occurrence and progression of bladder cancer (BCa). However, few research has focused on the predictive relevance of macrophage phagocytosis-mediated oxidative phosphorylation (MPOP) with BCa overall survival. Herein, we aimed to propose the targeted macrophage control based on MPOP as a treatment method for BCa immunotherapy.

Methods

The mRNA expression data sets and clinical data of bladder cancer originated from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) data set. A systematic study of several GEO data sets found differentially expressed macrophage phagocytosis regulators (DE-MPR) between BCa and normal tissues. To discover overall survival-associated DE-MPR and develop prognostic gene signature with performance validated based on receiver operating curves and Kaplan-Meier curves, researchers used univariate and Lasso Cox regression analysis (ROC). External validation was done with GSE13057 and GSE69795. To clarify its molecular mechanism and immune relevance, GO/KEGG enrichment analysis and tumor immune analysis were used. To find independent bladder cancer prognostic variables, researchers employed multivariate Cox regression analysis. Finally, using TCGA data set, a predictive nomogram was built.

Results

In BCa, a four-gene signature of oxidative phosphorylation composed of PTPN6, IKZF3, HDLBP, and EMC1 was found to predict overall survival. With the MPOP feature, the ROC curve showed that TCGA data set and the external validation data set performed better in predicting overall survival than the traditional AJCC stage. The four-gene signature can identify cancers from normal tissue and separate patients into the high-risk and low-risk groups with different overall survival rates. The four MPOP-gene signature was an independent predictive factor for BCa. In predicting overall survival, a nomogram integrating genetic and clinical prognostic variables outperformed AJCC staging. Multiple oncological features and invasion-associated pathways were identified in the high-risk group, which were also correlated with significantly lower levels of immune cell infiltration.

Conclusion

This paper found the MPOP-feature gene and developed a predictive nomogram capable of accurately predicting bladder cancer overall survival. The above discoveries can contribute to the development of personalized treatments and medical decisions.

Critical roles of PTPN family members regulated by non-coding RNAs in tumorigenesis and immunotherapy

Since tyrosine phosphorylation is reversible and dynamic in vivo, the phosphorylation state of proteins is controlled by the opposing roles of protein tyrosine kinases (PTKs) and protein tyrosine phosphatase (PTPs), both of which perform critical roles in signal transduction. Of these, intracellular non-receptor PTPs (PTPNs), which belong to the largest class I cysteine PTP family, are essential for the regulation of a variety of biological processes, including but not limited to hematopoiesis, inflammatory response, immune system, and glucose homeostasis. Additionally, a substantial amount of PTPNs have been identified to hold crucial roles in tumorigenesis, progression, metastasis, and drug resistance, and inhibitors of PTPNs have promising applications due to striking efficacy in antitumor therapy. Hence, the aim of this review is to summarize the role played by PTPNs, including PTPN1/PTP1B, PTPN2/TC-PTP, PTPN3/PTP-H1, PTPN4/PTPMEG, PTPN6/SHP-1, PTPN9/PTPMEG2, PTPN11/SHP-2, PTPN12/PTP-PEST, PTPN13/PTPL1, PTPN14/PEZ, PTPN18/PTP-HSCF, PTPN22/LYP, and PTPN23/HD-PTP, in human cancer and immunotherapy and to comprehensively describe the molecular pathways in which they are implicated. Given the specific roles of PTPNs, identifying potential regulators of PTPNs is significant for understanding the mechanisms of antitumor therapy. Consequently, this work also provides a review on the role of non-coding RNAs (ncRNAs) in regulating PTPNs in tumorigenesis and progression, which may help us to find effective therapeutic agents for tumor therapy.

LRG1 destabilizes tumor vessels and restricts immunotherapeutic potency

BACKGROUND

A poorly functioning tumor vasculature is pro-oncogenic and may impede the delivery of therapeutics. Normalizing the vasculature, therefore, may be beneficial. We previously reported that the secreted glycoprotein leucine-rich α-2-glycoprotein 1 (LRG1) contributes to pathogenic neovascularization. Here, we investigate whether LRG1 in tumors is vasculopathic and whether its inhibition has therapeutic utility.

METHODS

Tumor growth and vascular structure were analyzed in subcutaneous and genetically engineered mouse models in wild-type and Lrg1 knockout mice. The effects of LRG1 antibody blockade as monotherapy, or in combination with co-therapies, on vascular function, tumor growth, and infiltrated lymphocytes were investigated.

FINDINGS

In mouse models of cancer, Lrg1 expression was induced in tumor endothelial cells, consistent with an increase in protein expression in human cancers. The expression of LRG1 affected tumor progression as Lrg1 gene deletion, or treatment with a LRG1 function-blocking antibody, inhibited tumor growth and improved survival. Inhibition of LRG1 increased endothelial cell pericyte coverage and improved vascular function, resulting in enhanced efficacy of cisplatin chemotherapy, adoptive T cell therapy, and immune checkpoint inhibition (anti-PD1) therapy. With immunotherapy, LRG1 inhibition led to a significant shift in the tumor microenvironment from being predominantly immune silent to immune active.

CONCLUSIONS

LRG1 drives vascular abnormalization, and its inhibition represents a novel and effective means of improving the efficacy of cancer therapeutics.

FUNDING

Wellcome Trust (206413/B/17/Z), UKRI/MRC (G1000466, MR/N006410/1, MC/PC/14118, and MR/L008742/1), BHF (PG/16/50/32182), Health and Care Research Wales (CA05), CRUK (C42412/A24416 and A17196), ERC (ColonCan 311301 and AngioMature 787181), and DFG (CRC1366).

Tumour targetable and microenvironment-responsive nanoparticles simultaneously disrupt the PD-1/PD-L1 pathway and MAPK/ERK/JNK pathway for efficient treatment of colorectal cancer

The present study was aimed to develop a novel combination therapeutic strategy of gene therapy and immunotherapy for efficiently treatment of colorectal cancer (CRC). To achieve that goal, the polyethylene glycol-modified poly (2-(N,N-dimethylamino) ethyl methacrylate) (PEG-PDMAEMA)-based nanoparticles loaded with protein tyrosine phosphatase non-receptor type 6 (PTPN6) (NP-PTPN6) was developed first followed by conjugation with anti-PD-L1 monoclonal antibodies (aPD-L1) atezolizumab (aPD-L1NP-PTPN6). Importantly, the aPD-L1 was conjugated on the surface of NP-PTPN6 by the matrix metalloproteinases (MMPs)-cleavable linkage PLGLAG. Therefore, the aPD-L1 would be completely released once the aPD-L1NP-PTPN6 was entrapped into tumour tissues as demonstrated by the release assay. Tumour targeting assay demonstrated the aPD-L1NP-PTPN6 have high affinity to CRC cells and resulted in excellent tumour targeting drug delivery efficacy. Additionally, anti-tumour effect evaluation revealed that the aPD-L1NP-PTPN6 has greater ability to inhibit the growth, invasion and migration of CRC cells and finally led to longer survival time of tumour-bearing mice than other treatments. Further mechanisms studies demonstrated that treatment of CRC cells with aPD-L1NP-PTPN6 contributed to significant suppression of the MAPK/ERK signalling pathway. Besides, it was further demonstrated that treating CRC with aPD-L1NP-PTPN6 resulted in up-regulation of NK cells and T cells percentage within the tumour tissues.

Oncogenic Tyrosine Phosphatases: Novel Therapeutic Targets for Melanoma Treatment

Despite a large number of therapeutic options available, malignant melanoma remains a highly fatal disease, especially in its metastatic forms. The oncogenic role of protein tyrosine phosphatases (PTPs) is becoming increasingly clear, paving the way for novel antitumor treatments based on their inhibition. In this review, we present the oncogenic PTPs contributing to melanoma progression and we provide, where available, a description of new inhibitory strategies designed against these enzymes and possibly useful in melanoma treatment. Considering the relevance of the immune infiltrate in supporting melanoma progression, we also focus on the role of PTPs in modulating immune cell activity, identifying interesting therapeutic options that may support the currently applied immunomodulating approaches. Collectively, this information highlights the value of going further in the development of new strategies targeting oncogenic PTPs to improve the efficacy of melanoma treatment.

The Analysis of PTPN6 for Bladder Cancer: An Exploratory Study Based on TCGA

PTPN6 (protein tyrosine phosphatase nonreceptor type 6), a tyrosine phosphatase, is known to be signaling molecules that regulate a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. Previous studies have demonstrated that PTPN6 expression is relatively elevated in several malignancies. However, the role of PTPN6 in bladder cancer (BC) remains unclear. The purpose of this study was to explore the prognostic value of PTPN6 in BC. RNA-seq data from The Cancer Genome Atlas (TCGA) was used to identify the expression level of PTPN6 in BC. The relationship between clinical pathologic features and PTPN6 were analyzed with the Wilcoxon signed-rank test. The prognostic and predictive value of PTPN6 was evaluated by survival analysis and nomogram. Gene Set Enrichment Analysis (GSEA) was conducted to explore the potential molecular mechanisms of PTPN6 in BC. Finally, Tumor Immune Estimation Resource (TIMER) was applied to investigate the relationship between PTPN6 and immune cell infiltration in the tumor microenvironment. Results indicated that PTPN6 was overexpressed in BC tissues compared with normal bladder tissues and was significantly correlated with grade, stage, T, and N. Survival analysis showed that low expression of PTPN6 was significantly related to the poor overall survival (OS) in BC patients. Coexpression analysis showed that PTPN6 and TNFRSF14 (Tumor necrosis factor receptor superfamily member 14) have a close correlation in BC. GSEA showed that multiple cancer-associated signaling pathways are differentially enriched in the PTPN6 high expression phenotype. Moreover, the expression level of PTPN6 was positively associated with the infiltration of B cells, CD4+T cells, dendritic cells, and neutrophils and negatively associated with CD8+ T cells and macrophages in BC. In conclusion, we identified that PTPN6 may be a novel prognostic biomarker in BC based on the TCGA database. Further clinical trials are needed to confirm our observations and mechanisms underlying the prognostic value of PTPN6 in BC also deserve further experimental exploration.

Ptpn6 inhibits caspase-8- and Ripk3/Mlkl-dependent inflammation

Ptpn6 is a cytoplasmic phosphatase that functions to prevent autoimmune and interleukin-1 (IL-1) receptor-dependent, caspase-1-independent inflammatory disease. Conditional deletion of Ptpn6 in neutrophils (Ptpn6^∆PMN) is sufficient to initiate IL-1 receptor-dependent cutaneous inflammatory disease, but the source of IL-1 and the mechanisms behind IL-1 release remain unclear. Here, we investigate the mechanisms controlling IL-1α/β release from neutrophils by inhibiting caspase-8-dependent apoptosis and Ripk1-Ripk3-Mlkl-regulated necroptosis. Loss of Ripk1 accelerated disease onset, whereas combined deletion of caspase-8 and either Ripk3 or Mlkl strongly protected Ptpn6^∆PMN mice. Ptpn6^∆PMN neutrophils displayed increased p38 mitogen-activated protein kinase-dependent Ripk1-independent IL-1 and tumor necrosis factor production, and were prone to cell death. Together, these data emphasize dual functions for Ptpn6 in the negative regulation of p38 mitogen-activated protein kinase activation to control tumor necrosis factor and IL-1α/β expression, and in maintaining Ripk1 function to prevent caspase-8- and Ripk3-Mlkl-dependent cell death and concomitant IL-1α/β release.

L-Selectin Enhanced T Cells Improve the Efficacy of Cancer Immunotherapy

The homing molecule, L-selectin (CD62L), is commonly used as a T cell activation marker, since expression is downregulated following engagement of the T cell receptor. Studies in mice have shown that CD62L+ central memory T cells are better at controlling tumor growth than CD62L- effector memory T cells, while L-selectin knockout T cells are poor at controlling tumor growth. Here, we test the hypothesis that T cells expressing genetically modified forms of L-selectin that are maintained following T cell activation (L-selectin enhanced T cells) are better at controlling tumor growth than wild type T cells. Using mouse models of adoptive cell therapy, we show that L-selectin enhancement improves the efficacy of CD8+ T cells in controlling solid and disseminated tumor growth. L-selectin knockout T cells had no effect. Checkpoint blockade inhibitors synergized with wild type and L-selectin enhanced T cells but had no effect in the absence of T cell transfers. Reduced tumor growth by L-selectin enhanced T cells correlated with increased frequency of CD8+ tumor infiltrating T cells 21 days after commencing therapy. Longitudinal tracking of Zirconium-89 (89Zr) labeled T cells using PET-CT showed that transferred T cells localize to tumors within 1 h and accumulate over the following 7 days. L-selectin did not promote T cell homing to tumors within 18 h of transfer, however the early activation marker CD69 was upregulated on L-selectin positive but not L-selectin knockout T cells. L-selectin positive and L-selectin knockout T cells homed equally well to tumor-draining lymph nodes and spleens. CD69 expression was upregulated on both L-selectin positive and L-selectin knockout T cells but was significantly higher on L-selectin expressing T cells, particularly in the spleen. Clonal expansion of isolated L-selectin enhanced T cells was slower, and L-selectin was linked to expression of proliferation marker Ki67. Together these findings demonstrate that maintaining L-selectin expression on tumor-specific T cells offers an advantage in mouse models of cancer immunotherapy. The beneficial role of L-selectin is unrelated to its' well-known role in T cell homing and, instead, linked to activation of therapeutic T cells inside tumors. These findings suggest that L-selectin may benefit clinical applications in T cell selection for cancer therapy and for modifying CAR-T cells to broaden their clinical scope.

ADAM17-dependent proteolysis of L-selectin promotes early clonal expansion of cytotoxic T cells

L-selectin on T-cells is best known as an adhesion molecule that supports recruitment of blood-borne naïve and central memory cells into lymph nodes. Proteolytic shedding of the ectodomain is thought to redirect activated T-cells from lymph nodes to sites of infection. However, we have shown that activated T-cells re-express L-selectin before lymph node egress and use L-selectin to locate to virus-infected tissues. Therefore, we considered other roles for L-selectin proteolysis during T cell activation. In this study, we used T cells expressing cleavable or non-cleavable L-selectin and determined the impact of L-selectin proteolysis on T cell activation in virus-infected mice. We confirm an essential and non-redundant role for ADAM17 in TCR-induced proteolysis of L-selectin in mouse and human T cells and show that L-selectin cleavage does not regulate T cell activation measured by CD69 or TCR internalisation. Following virus infection of mice, L-selectin proteolysis promoted early clonal expansion of cytotoxic T cells resulting in an 8-fold increase over T cells unable to cleave L-selectin. T cells unable to cleave L-selectin showed delayed proliferation in vitro which correlated with lower CD25 expression. Based on these results, we propose that ADAM17-dependent proteolysis of L-selectin should be considered a regulator of T-cell activation at sites of immune activity.

Regulation of autoimmune and anti-tumour T-cell responses by PTPN22

A number of polymorphisms in immune-regulatory genes have been identified as risk factors for the development of autoimmune disease. PTPN22 (that encodes a tyrosine phosphatase) has been associated with the development of several autoimmune diseases, including type 1 diabetes, rheumatoid arthritis and systemic lupus erythematosus. PTPN22 regulates the activity and effector functions of multiple important immune cell types, including lymphocytes, granulocytes and myeloid cells. In this review, we describe the role of PTPN22 in regulating T-cell activation and effector responses. We discuss progress in our understanding of the impact of PTPN22 in autoimmune disease in humans and mouse models, as well as recent evidence suggesting that genetic manipulation of PTPN22 expression might enhance the efficacy of anti-tumour T-cell responses.

Shp1 function in myeloid cells

The motheaten mouse was first described in 1975 as a model of systemic inflammation and autoimmunity, as a result of immune system dysregulation. The phenotype was later ascribed to mutations in the cytoplasmic tyrosine phosphatase Shp1. This phosphatase is expressed widely throughout the hematopoietic system and has been shown to impact a multitude of cell signaling pathways. The determination of which cell types contribute to the different aspects of the phenotype caused by global Shp1 loss or mutation and which pathways within these cell types are regulated by Shp1 is important to further our understanding of immune system regulation. In this review, we focus on the role of Shp1 in myeloid cells and how its dysregulation affects immune function, which can impact human disease.