Cancer cell-intrinsic resistance to BiTE therapy is mediated by loss of CD58 costimulation and modulation of the extrinsic apoptotic pathway

Understanding and overcoming resistance to immunotherapy in genitourinary cancers

The introduction of novel immunotherapies has significantly transformed the treatment landscape of genitourinary (GU) cancers, even becoming the standard of care in some settings. One such type of immunotherapy, immune checkpoint inhibitors (ICIs) like nivolumab, ipilimumab, pembrolizumab, and atezolizumab play a pivotal role by disturbing signaling pathways that limit the immune system's ability to fight tumor cells. Despite the profound impact of these treatments, not all tumors are responsive. Recent research efforts have been focused on understanding how cancer cells manage to evade the immune response and identifying the possible mechanisms behind resistance to immunotherapy. In response, ICIs are being combined with other treatments to reduce resistance and attack cancer cells through multiple cellular pathways. Additionally, novel, targeted strategies are currently being investigated to develop innovative methods of overcoming resistance and treatment failure. This article presents a comprehensive overview of the mechanisms of immunotherapy resistance in GU cancers as currently described in the literature. It explores studies that have identified genetic markers, cytokines, and proteins that may predict resistance or response to immunotherapy. Additionally, we review current efforts to overcome this resistance, which include combination ICIs and sequential therapies, novel insights into the host immune profile, and new targeted therapies. Various approaches that combine immunotherapy with chemotherapy, targeted therapy, vaccines, and radiation have been studied in an effort to more effectively overcome resistance to immunotherapy. While each of these combination therapies has shown some efficacy in clinical trials, a deeper understanding of the immune system's role underscores the potential of novel targeted therapies as a particularly promising area of current research. Currently, several targeted agents are in development, along with the identification of key immune mediators involved in immunotherapy resistance. Further research is necessary to identify predictors of response.

Mechanisms of resistance against T-cell engaging bispecific antibodies in multiple myeloma: implications for novel treatment strategies

Off-the-shelf T-cell-redirecting bispecific antibodies targeting BCMA, GPRC5D, and FcRH5 have high activity in multiple myeloma with a manageable toxicity profile. However, not all patients respond to bispecific antibodies and patients can develop bispecific antibody resistance after an initial response. Mechanisms that contribute to bispecific antibody resistance are multifactorial and include tumour-related factors, such as high tumour burden, expression of T-cell inhibitory ligands, and antigen loss. Resistance due to antigen escape can be prevented by simultaneously targeting two tumour-associated antigens with a trispecific antibody or a combination of two bispecific antibodies. There is also increasing evidence that primary resistance to bispecific antibodies is associated with impaired baseline T-cell function. Long-term exposure to bispecific antibodies with chronic T-cell stimulation further aggravates T-cell dysfunction, which could contribute to failure of disease control. Therapeutic interference with T-cell exhaustion by targeting inhibitory or costimulatory pathways could improve bispecific antibody-mediated antitumour activity. The immunosuppressive microenvironment also contributes to bispecific antibody resistance. CD38-targeting antibodies hold promise as combination partners for bispecific antibodies because of their potential to eliminate CD38+ immune suppressor cells. In conclusion, a better understanding of the mechanisms underlying the absence of disease response has provided novel insights to optimise T-cell activity and bispecific antibody efficacy in multiple myeloma.

Innovative genetic scissor strategies and their applications in cancer treatment and prevention: CRISPR modules and challenges

There are lots of gene editing tools for targeting genome sequences. Some are almost known, and most are a complete mystery and undiscovered. CRISPR/Cas editing tools have brought about a major revolution in medicine. Researchers have shown that CRISPR can modify DNA much more accurately, economically and easily than previous methods. CRISPR has proven itself effective for the deletion, replacement and insertion of DNA fragments into cell types, tissues and organisms. Recently, combining CRISPR/Cas with factors (transcription factors/repressors, exonucleases, endonucleases, transposons, caspase, fluorescent proteins, oxidoreductive enzymes, DNA/RNA polymerases), and elements (aptamers, barcodes, fluorescent probes, Trigger) have provided genome, transcriptome, proteome and epigenome modification. These modules are being investigated for cancer prevention and therapy and this review focuses on such innovative combinations that hopefully will become a clinical reality in the near future.

CD58 defines regulatory macrophages within the tumor microenvironment

CD58 has been implicated in immune suppression and is associated with stemness in various types of cancer. Nonetheless, efficient biomarkers for assessing cancer patient response to immunotherapy are lacking. The present work focused on assessing the immune predictive significance of CD58 for patients with glioma. The expression of CD58 correlates with the clinicopathologic characteristics of patients with glioma, suggesting CD58high cells to signify glioma with tumorigenic potential. The CD58high cells displayed accelerated tumor formation compared to CD58low cells in vivo. Taken together, CD58 could potentially serve as a marker for glioma. CD58high glioma induces macrophage polarization through CXCL5 secretion, where M2 macrophages regulate PD-L1 expression within CD58high glioma via IL-6 production in vitro. Moreover, it was found that combination treatment with CD58 significantly increased the volume of tumors in the xenograft specimens. Evaluating CD58 expression represents a promising approach for identifying patients who can benefit from immunotherapy.

Targeted desialylation and cytolysis of tumour cells by fusing a sialidase to a bispecific T-cell engager

Bispecific T-cell engagers (BiTEs) bring together tumour cells and cytotoxic T cells by binding to specific cell-surface tumour antigens and T-cell receptors, and have been clinically successful for the treatment of B-cell malignancies. Here we show that a BiTE-sialidase fusion protein enhances the susceptibility of solid tumours to BiTE-mediated cytolysis of tumour cells via targeted desialylation-that is, the removal of terminal sialic acid residues on glycans-at the BiTE-induced T-cell-tumour-cell interface. In xenograft and syngeneic mouse models of leukaemia and of melanoma and breast cancer, and compared with the parental BiTE molecules, targeted desialylation via the BiTE-sialidase fusion proteins enhanced the formation of immunological synapses, T-cell activation and T-cell-mediated tumour-cell cytolysis in the presence of the target antigen. The targeted desialylation of tumour cells may enhance the potency of therapies relying on T-cell engagers.

Clinical significance of immune-related antigen CD58 in gliomas and analysis of its potential core related gene clusters

Background

The clinical significance of immune-related antigen CD58 in gliomas remains uncertain. The aim of this study was to examine the clinical importance and possible core related genes of CD58 in gliomas.

Methods

Pan-cancer analysis was to observe the association between CD58 and different tumors, glioma RNA sequencing data and clinical sample analyses were used to observe the relationship between CD58 and glioma, shRNA interference models were to observe the impact of CD58 on glioma cell function, and four glioma datasets and two online analysis platforms were used to explore the core related genes affecting the correlation between CD58 and glioma.

Results

High CD58 expression was associated with worse prognosis in various tumors and higher malignancy in glioma. Down regulation of CD58 expression was linked to decreased proliferation, increased apoptosis, and reduced metastasis in glioma cells. The pathways involved in CD58-related effects were enriched for immune cell adhesion and immune factor activation, and the core genes were CASP1, CCL2, IL18, MYD88, PTPRC, and TLR2. The signature of CD58 and its core-related genes showed superior predictive power for glioma prognosis.

Conclusion

High CD58 expression is correlated with more malignant glioma types, and also an independent risk factor for mortality in glioma. CD58 and its core-related genes may serve as novel biomarkers for diagnosing and treating glioma.

HSPA4 upregulation induces immune evasion via ALKBH5/CD58 axis in gastric cancer

INTRODUCTION

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide. Recently, targeted therapies including PD1 (programmed cell death 1) antibodies have been used in advanced GC patients. However, identifying new biomarker for immunotherapy is still urgently needed. The objective of this study is to unveil the immune evasion mechanism of GC cells and identify new biomarkers for immune checkpoint blockade therapy in patients with GC.

METHODS

Coimmunoprecipitation and meRIP were performed to investigate the mechanism of immune evasion of GC cells. Cocuture system was established to evaluate the cytotoxicity of cocultured CD8+ T cells. The clinical significance of HSPA4 upregulation was analyzed by multiplex fluorescent immunohistochemistry staining in GC tumor tissues.

RESULTS

Histone acetylation causes HSPA4 upregulation in GC tumor tissues. HSPA4 upregulation increases the protein stability of m6A demethylase ALKBH5. ALKBH5 decreases CD58 in GC cells through m6A methylation regulation. The cytotoxicity of CD8+ T cells are impaired and PD1/PDL1 axis is activated when CD8+ T cells are cocultured with HSPA4 overexpressed GC cells. HSPA4 upregulation is associated with worse 5-year overall survival of GC patients receiving only surgery. It is an independent prognosis factor for worse survival of GC patients. In GC patients receiving the combined chemotherapy with anti-PD1 immunotherapy, HSPA4 upregulation is observed in responders compared with non-responders.

CONCLUSION

HSPA4 upregulation causes the decrease of CD58 in GC cells via HSPA4/ALKBH5/CD58 axis, followed by PD1/PDL1 activation and impairment of CD8+ T cell's cytotoxicity, finally induces immune evasion of GC cells. HSPA4 upregulation is associated with worse overall survival of GC patients with only surgery. Meanwhile, HSPA4 upregulation predicts for better response in GC patients receiving the combined immunotherapy.

Exploiting autophagy balance in T and NK cells as a new strategy to implement adoptive cell therapies

Autophagy is an essential cellular homeostasis pathway initiated by multiple stimuli ranging from nutrient deprivation to viral infection, playing a key role in human health and disease. At present, a growing number of evidence suggests a role of autophagy as a primitive innate immune form of defense for eukaryotic cells, interacting with components of innate immune signaling pathways and regulating thymic selection, antigen presentation, cytokine production and T/NK cell homeostasis. In cancer, autophagy is intimately involved in the immunological control of tumor progression and response to therapy. However, very little is known about the role and impact of autophagy in T and NK cells, the main players in the active fight against infections and tumors. Important questions are emerging: what role does autophagy play on T/NK cells? Could its modulation lead to any advantages? Could specific targeting of autophagy on tumor cells (blocking) and T/NK cells (activation) be a new intervention strategy? In this review, we debate preclinical studies that have identified autophagy as a key regulator of immune responses by modulating the functions of different immune cells and discuss the redundancy or diversity among the subpopulations of both T and NK cells in physiologic context and in cancer.

Oncolytic virotherapy: basic principles, recent advances and future directions

Oncolytic viruses (OVs) have attracted growing awareness in the twenty-first century, as they are generally considered to have direct oncolysis and cancer immune effects. With the progress in genetic engineering technology, OVs have been adopted as versatile platforms for developing novel antitumor strategies, used alone or in combination with other therapies. Recent studies have yielded eye-catching results that delineate the promising clinical outcomes that OVs would bring about in the future. In this review, we summarized the basic principles of OVs in terms of their classifications, as well as the recent advances in OV-modification strategies based on their characteristics, biofunctions, and cancer hallmarks. Candidate OVs are expected to be designed as "qualified soldiers" first by improving target fidelity and safety, and then equipped with "cold weapons" for a proper cytocidal effect, "hot weapons" capable of activating cancer immunotherapy, or "auxiliary weapons" by harnessing tactics such as anti-angiogenesis, reversed metabolic reprogramming and decomposing extracellular matrix around tumors. Combinations with other cancer therapeutic agents have also been elaborated to show encouraging antitumor effects. Robust results from clinical trials using OV as a treatment congruously suggested its significance in future application directions and challenges in developing OVs as novel weapons for tactical decisions in cancer treatment.

PAX5 epigenetically orchestrates CD58 transcription and modulates blinatumomab response in acute lymphoblastic leukemia

Blinatumomab is an efficacious immunotherapeutic agent in B cell acute lymphoblastic leukemia (B-ALL). However, the pharmacogenomic basis of leukemia response to blinatumomab is unclear. Using genome-wide CRISPR, we comprehensively identified leukemia intrinsic factors of blinatumomab sensitivity, i.e., the loss of CD58 as a top driver for resistance, in addition to CD19. Screening 1639 transcription factor genes, we then identified PAX5 as the key activator of CD58. ALL with the PAX5 P80R mutation also expressed the lowest level of CD58 among 20 ALL molecular subtypes in 1988 patients. Genome editing confirmed the effects of this mutation on CD58 expression and blinatumomab sensitivity in B-ALL, with validation in patient leukemic blasts. We described a PAX5-driven enhancer at the CD58 locus, which was disrupted by PAX5 P80R, and the loss of CD58 abolished blinatumomab-induced T cell activation with global changes in transcriptomic/epigenomic program. In conclusion, we identified previously unidentified genetic mechanisms of blinatumomab resistance in B-ALL, suggesting strategies for genomics-guided treatment individualization.

Factors Affecting the Cancer Immunotherapeutic Efficacy of T Cell Bispecific Antibodies and Strategies for Improvement

T-cell bispecific antibodies (T-BsAbs) are a new class of cancer immunotherapy drugs that can simultaneously bind to tumor-associated antigens on target cells and to the CD3 subunit of the T-cell receptor (TCR) on T cells. In the last decade, numerous T-BsAbs have been developed for the treatment of both hematological malignancies and solid tumors. Among them, blinatumomab has been successfully used to treat CD19 positive malignancies and has been approved by the FDA as standard care for acute lymphoblastic leukemia (ALL). However, in many clinical scenarios, the efficacy of T-BsAbs remains unsatisfactory. To further improve T-BsAb therapy, it will be crucial to better understand the factors affecting treatment efficacy and the nature of the T-BsAb-induced immune response. Herein, we first review the studies on the potential mechanisms by which T-BsAbs activate T-cells and how they elicit efficient target killing despite suboptimal costimulatory support. We focus on analyzing reports from clinical trials and preclinical studies, and summarize the factors that have been identified to impact the efficacy of T-BsAbs. Lastly, we review current and propose new approaches to improve the clinical efficacy of T-BsAbs.

Multidimensional single-cell analysis identifies a role for CD2-CD58 interactions in clinical antitumor T cell responses

The in vivo persistence of adoptively transferred T cells is predictive of antitumor response. Identifying functional properties of infused T cells that lead to in vivo persistence and tumor eradication has remained elusive. We profiled CD19-specific chimeric antigen receptor (CAR) T cells as the infusion products used to treat large B cell lymphomas using high-throughput single-cell technologies based on time-lapse imaging microscopy in nanowell grids (TIMING), which integrates killing, cytokine secretion, and transcriptional profiling. Our results show that the directional migration of CD19-specific CAR T cells is correlated with multifunctionality. We showed that CD2 on T cells is associated with directional migration and that the interaction between CD2 on T cells and CD58 on lymphoma cells accelerates killing and serial killing. Consistent with this, we observed that elevated CD58 expression on pretreatment tumor samples in patients with relapsed or refractory large B cell lymphomas treated with CD19-specific CAR T cell therapy was associated with complete clinical response and survival. These results highlight the importance of studying dynamic T cell–tumor cell interactions in identifying optimal antitumor responses.

Salt-inducible kinase 3 protects tumor cells from cytotoxic T-cell attack by promoting TNF-induced NF-κB activation

BACKGROUND

Cancer immunotherapeutic strategies showed unprecedented results in the clinic. However, many patients do not respond to immuno-oncological treatments due to the occurrence of a plethora of immunological obstacles, including tumor intrinsic mechanisms of resistance to cytotoxic T-cell (TC) attack. Thus, a deeper understanding of these mechanisms is needed to develop successful immunotherapies.

METHODS

To identify novel genes that protect tumor cells from effective TC-mediated cytotoxicity, we performed a genetic screening in pancreatic cancer cells challenged with tumor-infiltrating lymphocytes and antigen-specific TCs.

RESULTS

The screening revealed 108 potential genes that protected tumor cells from TC attack. Among them, salt-inducible kinase 3 (SIK3) was one of the strongest hits identified in the screening. Both genetic and pharmacological inhibitions of SIK3 in tumor cells dramatically increased TC-mediated cytotoxicity in several in vitro coculture models, using different sources of tumor and TCs. Consistently, adoptive TC transfer of TILs led to tumor growth inhibition of SIK3-depleted cancer cells in vivo. Mechanistic analysis revealed that SIK3 rendered tumor cells susceptible to tumor necrosis factor (TNF) secreted by tumor-activated TCs. SIK3 promoted nuclear factor kappa B (NF-κB) nuclear translocation and inhibited caspase-8 and caspase-9 after TNF stimulation. Chromatin accessibility and transcriptome analyses showed that SIK3 knockdown profoundly impaired the expression of prosurvival genes under the TNF-NF-κB axis. TNF stimulation led to SIK3-dependent phosphorylation of the NF-κB upstream regulators inhibitory-κB kinase and NF-kappa-B inhibitor alpha on the one side, and to inhibition of histone deacetylase 4 on the other side, thus sustaining NF-κB activation and nuclear stabilization. A SIK3-dependent gene signature of TNF-mediated NF-κB activation was found in a majority of pancreatic cancers where it correlated with increased cytotoxic TC activity and poor prognosis.

CONCLUSION

Our data reveal an abundant molecular mechanism that protects tumor cells from cytotoxic TC attack and demonstrate that pharmacological inhibition of this pathway is feasible.