Molecular mechanisms of T cell co-stimulation and co-inhibition

Review of Codonopsis Radix biological activities: A plant of traditional Chinese tonic

ETHNOPHARMACOLOGICAL RELEVANCE

Codonopsis Radix, commonly known as Dangshen in Chinese, is frequently used to treat deficiencies of spleen and lung Qi, gastrointestinal discomfort, fatigue, asthmatic breathing, sallow complexion, lack of strength, shortness of breath, deficiencies of both Qi and blood, as well as impairments to both Qi and body fluids in suboptimal health status.

AIM OF THE REVIEW

This review systematically expounds on the modern pharmacological studies related to the use of Codonopsis Radix in invigorating Qi and nourishing the body in recent years. The aim is to provide theoretical research and reference for the in-depth and systematic exploration and development of the applications of Codonopsis Radix in the fields of food and medicine.

MATERIALS AND METHODS

This study employs "Codonopsis Radix," "Codonopsis," and "Dangshen" as keywords to gather pertinent information on Codonopsis Radix medicine through electronic searches of classical literature and databases such as PubMed, Elsevier, Google Scholar, Wiley, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang, VIP, and Baidu Scholar.

RESULTS

From previous studies, activities such as immune system modulation, gastrointestinal motility regulation, cardiac function revitalization, lung function improvement, blood circulation enhancement, aging process deceleration, learning and memory augmentation, fatigue resistance enhancement, and liver and kidney damage protection of Codonopsis Radix have been reported. Recognized as an important medicine and food homologous traditional Chinese herbal remedy for supplementing deficiencies, its mode of action is multi-elemental, multi-systemic, multi-organ, multi-mechanistic, and multi-targeted. Furthermore, the benefits of its tonic surpass its therapeutic value, establishing it as an extraordinary preventive and therapeutic medicine.

CONCLUSIONS

With its long history of traditional applications and the revelations of contemporary pharmacological research, Codonopsis Radix exhibits great potential as both a therapeutic agent and a dietary supplement for further research in medicine, nutrition, and healthcare.

Dehydroepiandrosterone attenuated the immune escape of oral squamous cell carcinoma through NF-κB p65/miR-15b-5p/B7-H4 axis

OBJECTIVES

We aimed to explore the effects and mechanisms of action of dehydroepiandrosterone (DHEA) on immune evasion of oral squamous cell carcinoma (OSCC) to provide evidence for enhancing the effect of immunotherapy.

MATERIALS AND METHODS

A xenograft mouse model and immunohistochemistry were used to reveal the patterns of tumor-infiltrating lymphocytes (TILs). The CAL27 and SCC VII cell lines were used for the in vitro study. Western blotting, qPCR, immunofluorescence, and flow cytometry were used to evaluate the expression of B7-H4. Recombinant mouse B7-H4 protein (rmB7-H4) and PG490, an inhibitor of NF-κB p65 were used for the "rescue study." Gain- and loss-of-function, luciferase reporter, and chromatin immunoprecipitation assays were performed to verify this mechanism.

RESULTS

DHEA inhibited tumor growth in an OSCC xenograft mouse model, increased CD8 + cells, and decreased FOXP3 + cells in TILs. DHEA reduced the expression of B7-H4 in CAL27 and SCC VII cells RmB7-H4 reverses the effect of DHEA on tumor growth and TIL patterns. DHEA increased the expression of miR-15b-5p and activated its transcriptional factor NF-κB p65. Further experiments demonstrated that miR-15b-5p inhibited B7-H4 expression by binding to its 3'-UTR regions, and NF-κB p65 activated miR-15b transcription. PG490 reversed the effects of DHEA on tumor growth, antitumor immunity in the OSCC xenograft model, and the expression/phosphorylation of NF-κB p65, miR-15b-5p, and B7-H4.

CONCLUSIONS

This study indicates that DHEA attenuates the immune escape of OSCC cells by inhibiting B7-H4 expression, providing new insights for cancer immunotherapy.

Immune-inflammatory modulation by natural products derived from edible and medicinal herbs used in Chinese classical prescriptions

BACKGROUND

Edible and medicinal herbs1 (EMHs) refer to a class of substances with dual attribution of food and medicine. These substances are traditionally used as food and also listed in many international pharmacopoeias, including the European Pharmacopoeia, the United States Pharmacopoeia, and the Chinese Pharmacopoeia. Some classical formulas that are widely used in traditional Chinese medicine include a series of EMHs, which have been shown to be effective with obvious characteristics and advantages. Notably, these EMHs and Chinese classical prescriptions2 (CCPs) have also attracted attention in international herbal medicine research because of their low toxicity and high efficiency as well as the rich body of experience for their long-term clinical use.

PURPOSE

Our purpose is to explore the potential therapeutic effect of EMHs with immune-inflammatory modulation for the study of modern cancer drugs.

STUDY DESIGN

In the present study, we present a detailed account of some EMHs used in CCPs that have shown considerable research potential in studies exploring modern drugs with immune-inflammatory modulation.

METHODS

Approximately 500 publications in the past 30 years were collected from PubMed, Web of Science and ScienceDirect using the keywords, such as natural products, edible and medicinal herbs, Chinese medicine, classical prescription, immune-inflammatory, tumor microenvironment and some related synonyms. The active ingredients instead of herbal extracts or botanical mixtures were focused on and the research conducted over the past decade were discussed emphatically and analyzed comprehensively.

RESULTS

More than ten natural products derived from EMHs used in CCPs are discussed and their immune-inflammatory modulation activities, including enhancing antitumor immunity, regulating inflammatory signaling pathways, lowering the proportion of immunosuppressive cells, inhibiting the secretion of proinflammatory cytokines, immunosuppressive factors, and inflammatory mediators, are summarized.

CONCLUSION

Our findings demonstrate the immune-inflammatory modulating role of those EMHs used in CCPs and provide new ideas for cancer treatment in clinical settings.

Identification of ribosomal protein S21 as a potential prognostic and immunotherapy biomarker for hepatocellular carcinoma

BACKGROUND

Recent studies show that ribosomal protein S21 (RPS21) plays a role in the development and progression of various malignancies. However, the biological value of RPS21 in hepatocellular carcinoma (HCC) and its association with immunotherapy remain unknown.

METHODS

Here, we examined the differential expression of RPS21 between HCC and normal liver tissues, using the TCGA, ICGC and GEO databases, followed by verification by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) in LO2, SMMC7721, HepG2, and MHCC-97H cell lines. Kaplan-Meier and Cox regression analyses were applied to investigate how RPS21 expression influenced overall survival, and a nomogram was established to predict prognosis among HCC patients. We further analyzed how RPS21 expression was related to tumor immune microenvironment, immunotherapy efficiency, and genomic alterations, and investigated potential underlying mechanisms.

RESULTS

RPS21 upregulation was observed in HCC tissues and cell lines, compared to normal controls. Survival analysis revealed that RPS21 overexpression was significantly associated with poor clinical outcomes (all p < 0.05). Functional enrichment analyses indicated that differentially expressed genes relative to RPS21 expression were mainly involved in tumor response, proliferation, and metabolism. Additionally, RPS21 expression was positively correlated with the infiltration of activated CD4+ T cells and tumor mutational burden (all p < 0.05). Moreover, RPS21 was co-expressed with immune-related genes and immune checkpoint genes. Analyses of drug sensitivity predict that HCC patients with low RPS21 expression were more sensitive to targeted immunotherapy.

CONCLUSIONS

The present results suggested that RPS21 might be a promising prognostic marker and a potential immunotherapy target for patients with HCC.

Components, Formulations, Deliveries, and Combinations of Tumor Vaccines

Tumor vaccines, an important part of immunotherapy, prevent cancer or kill existing tumor cells by activating or restoring the body's own immune system. Currently, various formulations of tumor vaccines have been developed, including cell vaccines, tumor cell membrane vaccines, tumor DNA vaccines, tumor mRNA vaccines, tumor polypeptide vaccines, virus-vectored tumor vaccines, and tumor-in-situ vaccines. There are also multiple delivery systems for tumor vaccines, such as liposomes, cell membrane vesicles, viruses, exosomes, and emulsions. In addition, to decrease the risk of tumor immune escape and immune tolerance that may exist with a single tumor vaccine, combination therapy of tumor vaccines with radiotherapy, chemotherapy, immune checkpoint inhibitors, cytokines, CAR-T therapy, or photoimmunotherapy is an effective strategy. Given the critical role of tumor vaccines in immunotherapy, here, we look back to the history of tumor vaccines, and we discuss the antigens, adjuvants, formulations, delivery systems, mechanisms, combination therapy, and future directions of tumor vaccines.

Construction of a 5-Gene super-enhancer-related signature for osteosarcoma prognosis and the regulatory role of TNFRSF11B in osteosarcoma

Osteosarcoma, one of the most common primary malignancies in children and adolescents, has the primary characteristics of a poor prognosis and high rate of metastasis. This study used super-enhancer-related genes derived from two different cell lines to construct five novel super-enhancer-related gene prognostic models for patients with osteosarcoma. The training and testing datasets were used to confirm the prognostic models of the five super-enhancer-related genes, which resulted in an impartial predictive element for osteosarcoma. The immunotherapy and prediction of the response to anticancer drugs have shown that the risk signature of the five super-enhancer-related genes positively correlate with chemosensitivity. Furthermore, functional analysis of the risk signature genes revealed a significant relationship between gene groups and the malignant characteristics of tumours. TNF Receptor Superfamily Member 11b (TNFRSF11B) was selected for functional verification. Silencing of TNFRSF11B suppressed the proliferation, migration, and invasion of osteosarcoma cells in vitro and suppressed osteosarcoma growth in vivo. Moreover, transcriptome sequencing was performed on MG-63 cells to study the regulatory mechanism of TNFRSF11B in osteosarcoma cells, and it was discovered that TNFRSF11B is involved in the development of osteosarcoma via the phosphoinositide 3-kinase signalling pathway. Following the identification of TNFRSF11B as a key gene, we selected an inhibitor that specifically targeted this gene and performed molecular docking simulations. In addition, risedronic acid inhibited osteosarcoma growth at both cellular and molecular levels. In conclusion, the super-enhancer-related gene signature is a viable therapeutic tool for osteosarcoma prognosis and treatment.

Neoadjuvant PARPi or chemotherapy in ovarian cancer informs targeting effector Treg cells for homologous-recombination-deficient tumors

Homologous recombination deficiency (HRD) is prevalent in cancer, sensitizing tumor cells to poly (ADP-ribose) polymerase (PARP) inhibition. However, the impact of HRD and related therapies on the tumor microenvironment (TME) remains elusive. Our study generates single-cell gene expression and T cell receptor profiles, along with validatory multimodal datasets from >100 high-grade serous ovarian cancer (HGSOC) samples, primarily from a phase II clinical trial (NCT04507841). Neoadjuvant monotherapy with the PARP inhibitor (PARPi) niraparib achieves impressive 62.5% and 73.6% response rates per RECIST v.1.1 and GCIG CA125, respectively. We identify effector regulatory T cells (eTregs) as key responders to HRD and neoadjuvant therapies, co-occurring with other tumor-reactive T cells, particularly terminally exhausted CD8+ T cells (Tex). TME-wide interferon signaling correlates with cancer cells upregulating MHC class II and co-inhibitory ligands, potentially driving Treg and Tex fates. Depleting eTregs in HRD mouse models, with or without PARP inhibition, significantly suppresses tumor growth without observable toxicities, underscoring the potential of eTreg-focused therapeutics for HGSOC and other HRD-related tumors.

Bispecific and multispecific antibodies in oncology: opportunities and challenges

Research into bispecific antibodies, which are designed to simultaneously bind two antigens or epitopes, has advanced enormously over the past two decades. Owing to advances in protein engineering technologies and considerable preclinical research efforts, bispecific antibodies are constantly being developed and optimized to improve their efficacy and to mitigate toxicity. To date, >200 of these agents, the majority of which are bispecific immune cell engagers, are in either preclinical or clinical evaluation. In this Review, we discuss the role of bispecific antibodies in patients with cancer, including history and development, as well as innovative targeting strategies, clinical applications, and adverse events. We also discuss novel alternative bispecific antibody constructs, such as those targeting two antigens expressed by tumour cells or cells located in the tumour microenvironment. Finally, we consider future research directions in this rapidly evolving field, including innovative antibody engineering strategies, which might enable more effective delivery, overcome resistance, and thus optimize clinical outcomes.

Inhibitory immune checkpoints suppress the surveillance of senescent cells promoting their accumulation with aging and in age-related diseases

The accumulation of pro-inflammatory senescent cells within tissues is a common hallmark of the aging process and many age-related diseases. This modification has been called the senescence-associated secretory phenotype (SASP) and observed in cultured cells and in cells isolated from aged tissues. Currently, there is a debate whether the accumulation of senescent cells within tissues should be attributed to increased generation of senescent cells or to a defect in their elimination from aging tissues. Emerging studies have revealed that senescent cells display an increased expression of several inhibitory immune checkpoint ligands, especially those of the programmed cell death protein-1 (PD-1) ligand-1 (PD-L1) proteins. It is known that the PD-L1 ligands, especially those of cancer cells, target the PD-1 receptor of cytotoxic CD8+ T and natural killer (NK) cells disturbing their functions, e.g., evoking a decline in their cytotoxic activity and promoting their exhaustion and even apoptosis. An increase in the level of the PD-L1 protein in senescent cells was able to suppress their immune surveillance and inhibit their elimination by cytotoxic CD8+ T and NK cells. Senescent cells are known to express ligands for several inhibitory immune checkpoint receptors, i.e., PD-1, LILRB4, NKG2A, TIM-3, and SIRPα receptors. Here, I will briefly describe those pathways and examine whether these inhibitory checkpoints could be involved in the immune evasion of senescent cells with aging and age-related diseases. It seems plausible that an enhanced inhibitory checkpoint signaling can prevent the elimination of senescent cells from tissues and thus promote the aging process.

Targeting CD8+ T cells with natural products for tumor therapy: Revealing insights into the mechanisms

BACKGROUND

Despite significant advances in cancer immunotherapy over the past decades, such as T cell-engaging chimeric antigen receptor (CAR)-T cell therapy and immune checkpoint blockade (ICB), therapeutic failure resulting from various factors remains prevalent. Therefore, developing combinational immunotherapeutic strategies is of great significance for improving the clinical outcome of cancer immunotherapy. Natural products are substances that naturally exist in various living organisms with multiple pharmacological or biological activities, and some of them have been found to have anti-tumor potential. Notably, emerging evidences have suggested that several natural compounds may boost the anti-tumor effects through activating immune response of hosts, in which CD8+ T cells play a pivotal role.

METHODS

The data of this review come from PubMed, Web of Science, Google Scholar, and ClinicalTrials (https://clinicaltrials.gov/) with the keywords "CD8+ T cell", "anti-tumor", "immunity", "signal 1", "signal 2", "signal 3", "natural products", "T cell receptor (TCR)", "co-stimulation", "co-inhibition", "immune checkpoint", "inflammatory cytokine", "hesperidin", "ginsenoside", "quercetin", "curcumin", "apigenin", "dendrobium officinale polysaccharides (DOPS)", "luteolin", "shikonin", "licochalcone A", "erianin", "resveratrol", "procyanidin", "berberine", "usnic acid", "naringenin", "6-gingerol", "ganoderma lucidum polysaccharide (GL-PS)", "neem leaf glycoprotein (NLGP)", "paclitaxel", "source", "pharmacological activities", and "toxicity". These literatures were published between 1993 and 2023.

RESULTS

Natural products have considerable advantages as anti-tumor drugs based on the various species, wide distribution, low price, and few side effects. This review summarized the effects and mechanisms of some natural products that exhibit anti-tumor effects via targeting CD8+ T cells, mainly focused on the three signals that activate CD8+ T cells: TCR, co-stimulation, and inflammatory cytokines.

CONCLUSION

Clarifying the role and underlying mechanism of natural products in cancer immunotherapy may provide more options for combinational treatment strategies and benefit cancer therapy, to shed light on identifying potential natural compounds for improving the clinical outcome in cancer immunotherapy.

CircRNAs in Pancreatic Cancer: New Tools for Target Identification and Therapeutic Intervention

We have reviewed the literature for circular RNAs (circRNAs) with efficacy in preclinical pancreatic-cancer related in vivo models. The identified circRNAs target chemoresistance mechanisms (n=5), secreted proteins and transmembrane receptors (n=15), transcription factors (n=9), components of the signaling- (n=11), ubiquitination- (n=2), autophagy-system (n=2), and others (n=9). In addition to identifying targets for therapeutic intervention, circRNAs are potential new entities for treatment of pancreatic cancer. Up-regulated circRNAs can be inhibited by antisense oligonucleotides (ASO), small interfering RNAs (siRNAs), short hairpin RNAs (shRNAs) or clustered regularly interspaced short-palindromic repeats-CRISPR associated protein (CRISPR-CAS)-based intervention. The function of down-regulated circRNAs can be reconstituted by replacement therapy using plasmids or virus-based vector systems. Target validation experiments and the development of improved delivery systems for corresponding agents were examined.

Effect of Cyclosporine A on Th1/Th2 Cytokine Production by Decidual Stromal Cells Mediated by Trophoblast-derived Galectin-9

This study aimed to investigate the effect of cyclosporine A (CsA) on secretion of Th1 and Th2 cytokines by decidual stromal cells (DSCs) mediated by galectin (Gal)-9.HTR8/SVneo cells and primary trophoblasts were used for in vitro studies. Gal-9 expression was measured using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, CsA was used to regulate Gal-9 expression in trophoblasts. DSCs were treated with trophoblast supernatant and changes in Th1 and Th2 cytokine levels were analyzed. Changes in DSC levels of the T-cell immunoglobulin mucin receptor 3 (TIM-3) levels in DSCs after treatment with Gal-9 were assessed. Western blotting and ERK and AKT inhibitors were used to assess the involvement of the corresponding signaling pathways. Gal-9 was expressed by both primary trophoblasts and HTR8/SVneo cells. CsA treatment increased Gal-9 secretion by trophoblasts, which in turn increased IL-6 (Th2 cytokine) and decreased TNF-α and IFN-γ (Th1 cytokines) secretion in DSCs. Upon downregulation of trophoblast Gal-9 secretion, DSCs secreted lower levels of Th2 cytokines and higher levels of Th1 cytokines, and the effect was reversed by addition of CsA. TIM-3 expression changed in parallel with Gal-9 secretion. CsA treatment upregulated expression of Gal-9 in trophoblasts, promoted secretion of Th2 cytokines, and inhibited secretion of Th1 cytokines via ERK signaling.

HLA-A+ tertiary lymphoid structures with reactivated tumor infiltrating lymphocytes are associated with a positive immunotherapy response in esophageal squamous cell carcinoma

BACKGROUND

Immune checkpoint blockade (ICB) therapy provides remarkable clinical benefits for multiple cancer types. However, the overall response rate to ICB therapy remains low in esophageal squamous cell carcinoma (ESCC). This study aimed to identify biomarkers of ICB therapy for ESCC and interrogate its potential clinical relevance.

METHODS

We investigated gene expression in 42 treatment-naïve ESCC tumor tissues and identified differentially expressed genes, tumor-infiltrating lymphocytes and immune-related genes signatures associated with differential immunotherapy responses. We systematically assessed the tumor microenvironment using the NanoString GeoMx digital spatial profiler, single-cell RNA-seq and multiplex immunohistochemistry in ESCC. Finally, we evaluated the associations between HLA-A-positive tertiary lymphoid structures (TLSs) and patients' responses to ICB in 60 ESCC patients.

RESULTS

Tumor infiltrating B lymphocytes and several immune-related gene signatures, such as the antigen presenting machinery (APM) signature, are significantly elevated in ICB treatment responders. Multiplex immunohistochemistry identified the presence of HLA-A+ TLSs and showed that TLS-resident cells increasingly express HLA-A as TLSs mature. Most TLS-resident HLA-A+ cells are tumor-infiltrating T (TIL-T) or tumor-infiltrating B (TIL-B) lymphocytes. Digital spatial profiling of spatially distinct TIL-T lymphocytes and single-cell RNA-seq data from 60 ESCC tumor tissues revealed that CXCL13-expressing exhausted TIL-Ts inside TLSs are reactivated with elevated expression of the APM signature as TLSs mature. Finally, we demonstrated that HLA-A+ TLSs and their major cellular components, TIL-Ts and TIL-Bs, are associated with a clinical benefit from ICB treatment for ESCC.

CONCLUSIONS

HLA-A+ TLSs are present in ESCC tumor tissues. TLS-resident TIL-Ts with elevated expression of the APM signature may be reactivated. HLA-A+ TLSs and their major cellular components, TIL-Ts and TIL-Bs, may serve as biomarkers for ICB-treated ESCC patients.

Pharmacological inhibition of HPK1 synergizes with PD-L1 blockade to provoke antitumor immunity against tumors with low antigenicity

Immune checkpoint inhibitors have significantly transformed the landscape of cancer therapy. Nevertheless, while these inhibitors are highly effective for certain patient groups, many do not benefit due to primary or acquired resistance. Specifically, these treatments often lack sufficient therapeutic efficacy against cancers with low antigenicity. Thus, the development of an effective strategy to overcome cancers with low antigenicity is imperative for advancing next-generation cancer immunotherapy. Here, we show that small molecule inhibitor of hematopoietic progenitor kinase 1 (HPK1) combined with programmed cell death ligand 1 (PD-L1) blockade can enhance T-cell response to tumor with low antigenicity. We found that treatment of OT-1 splenocytes with HPK1 inhibitor enhanced the activation of signaling molecules downstream of T-cell receptor provoked by low-affinity-antigen stimulation. Using an in vivo OT-1 T-cell transfer model, we demonstrated that combining the HPK1 inhibitor with the anti-PD-L1 antibody significantly suppressed the growth of tumors expressing low-affinity altered peptide ligand of chicken ovalbumin, while anti-PD-L1 antibody monotherapy was ineffective. Our findings offer crucial insights into the potential for overcoming tumors with low antigenicity by combining conventional immune checkpoint inhibitors with HPK1 inhibitor.

Immunological Drug-Drug Interactions Affect the Efficacy and Safety of Immune Checkpoint Inhibitor Therapies

With the rapid expansion in the development and clinical utility of immune checkpoint inhibitors (ICIs) for oncology, the continual evaluation of the safety profile of such agents is imperative. The safety profile of ICIs as monotherapy is dominated by immune-related adverse events, which can be considered as an extension of the mechanism of action of these immunomodulatory drugs. Further to this, an emerging theme is that ICI treatment can significantly impact upon the tolerability of coadministered medications. Numerous reports in literature indicate that ICIs may alter the immunological perception of coadministered drugs, resulting in undesirable reactions to a variety of concomitant medications. These reactions can be severe in manifestation, including hepatotoxicity and Stevens-Johnson Syndrome (SJS)/toxic epidermal necrolysis (TEN), but may also have detrimental impact on malignancy control. To minimize the impact of such drug-drug interactions on patients, it is imperative to identify medications that may cause these reactions, understand the underlying mechanisms, consider the timing and dosing of comedication, and explore alternative medications with comparable efficacies. Improving our understanding of how concomitant medications affect the safety and efficacy of ICIs can allow for potential culprit drugs to be identified/removed/desensitized. This approach will allow the continuation of ICI therapy that may have been discontinued otherwise, thereby improving malignant control and patient and drug development outcomes.

Takotsubo syndrome as an outcome of the use of checkpoint inhibitor therapy in patients with COVID-19

Takotsubo Syndrome (TS) is a heart disease caused by extreme exposure of the body to physical or psychological stress. In the context of COVID-19, the virus can be a significant source of stress, with particular attention being paid to the cytokine storm as a cause of damage to the body. New research shows that the production of specific cytokines is linked to the activation of immune checkpoint proteins such as PD-1, PD-L1, and CTLA-4 on T cells. Although initially beneficial in combating infections, it can suppress defense and aid in disease progression. Therefore, checkpoint inhibitor therapy has been highlighted beyond oncological therapies, given its effectiveness in strengthening the immune system. However, this treatment can lead to excessive immune responses, inflammation, and stress on the heart, which can cause Takotsubo Syndrome in patients. Several studies investigate the direct link between this therapy and cardiac injuries in these patients, which can trigger TS. From this perspective, we must delve deeper into this treatment and consider its effects on the prognosis against SARS-CoV-2 infection.

Hypomethylation-enhanced CRTC2 expression drives malignant phenotypes and primary resistance to immunotherapy in hepatocellular carcinoma

The cyclic AMP-responsive element-binding protein (CREB)-regulated transcription coactivator 2 (CRTC2) is a crucial regulator of hepatic lipid metabolism and gluconeogenesis and correlates with tumorigenesis. However, the mechanism through which CRTC2 regulates hepatocellular carcinoma (HCC) progression is largely unknown. Here, we found that increased CRTC2 expression predicted advanced tumor grade and stage, as well as worse prognosis in patients with HCC. DNA promoter hypomethylation led to higher CRTC2 expression in HCC. Functionally, CRTC2 contributed to HCC malignant phenotypes through the activated Wnt/β-catenin pathway, which could be abrogated by the small-molecular inhibitor XAV-939. Moreover, Crtc2 facilitated tumor growth while concurrently downregulating the PD-L1/PD-1 axis, resulting in primary resistance to immunotherapy. In immunocompetent mice models of HCC, targeting Crtc2 in combination with anti-PD-1 therapy prominently suppressed tumor growth by synergistically enhancing responsiveness to immunotherapy. Collectively, targeting CRTC2 might be a promising therapeutic strategy to sensitize immunotherapy in HCC.

Current advances in photocatalytic proximity labeling

Understanding the intricate network of biomolecular interactions that govern cellular processes is a fundamental pursuit in biology. Over the past decade, photocatalytic proximity labeling has emerged as one of the most powerful and versatile techniques for studying these interactions as well as uncovering subcellular trafficking patterns, drug mechanisms of action, and basic cellular physiology. In this article, we review the basic principles, methodologies, and applications of photocatalytic proximity labeling as well as examine its modern development into currently available platforms. We also discuss recent key studies that have successfully leveraged these technologies and importantly highlight current challenges faced by the field. Together, this review seeks to underscore the potential of photocatalysis in proximity labeling for enhancing our understanding of cell biology while also providing perspective on technological advances needed for future discovery.

Regulation of temporal cytokine production by co-stimulation receptors in TCR-T cells is lost in CAR-T cells

CD8+ T cells contribute to immune responses by producing cytokines when their T-cell receptors (TCRs) recognise peptide antigens on major-histocompability-complex class I. However, excessive cytokine production can be harmful. For example, cytokine release syndrome is a common toxicity observed in treatments that activate T cells, including chimeric antigen receptor (CAR)-T-cell therapy. While the engagement of costimulatory receptors is well known to enhance cytokine production, we have limited knowledge of their ability to regulate the kinetics of cytokine production by CAR-T cells. Here we compare early (0-12 h) and late (12-20 h) production of IFN-gg, IL-2, and TNF-a production by T cells stimulated via TCR or CARs in the presence or absence ligands for CD2, LFA-1, CD28, CD27, and 4-1BB. For T cells expressing TCRs and 1st-generation CARs, activation by antigen alone was sufficient to stimulate early cytokine production, while co-stimulation by CD2 and 4-1BB was required to maintain late cytokine production. In contrast, T cells expressing 2nd-generation CARs, which have intrinsic costimulatory signalling motifs, produce high levels of cytokines in both early and late periods in the absence of costimulatory receptor ligands. Losing the requirement for costimulation for sustained cytokine production may contribute to the effectiveness and/or toxicity of 2nd-generation CAR-T-cell therapy.

Nicotinamide metabolism face-off between macrophages and fibroblasts manipulates the microenvironment in gastric cancer

Immune checkpoint blockade has led to breakthroughs in the treatment of advanced gastric cancer. However, the prominent heterogeneity in gastric cancer, notably the heterogeneity of the tumor microenvironment, highlights the idea that the antitumor response is a reflection of multifactorial interactions. Through transcriptomic analysis and dynamic plasma sample analysis, we identified a metabolic "face-off" mechanism within the tumor microenvironment, as shown by the dual prognostic significance of nicotinamide metabolism. Specifically, macrophages and fibroblasts expressing the rate-limiting enzymes nicotinamide phosphoribosyltransferase and nicotinamide N-methyltransferase, respectively, regulate the nicotinamide/1-methylnicotinamide ratio and CD8+ T cell function. Mechanistically, nicotinamide N-methyltransferase is transcriptionally activated by the NOTCH pathway transcription factor RBP-J and is further inhibited by macrophage-derived extracellular vesicles containing nicotinamide phosphoribosyltransferase via the SIRT1/NICD axis. Manipulating nicotinamide metabolism through autologous injection of extracellular vesicles restored CD8+ T cell cytotoxicity and the anti-PD-1 response in gastric cancer.

Protein Haptenation and Its Role in Allergy

Humans are exposed to numerous electrophilic chemicals either as medicines, in the workplace, in nature, or through use of many common cosmetic and household products. Covalent modification of human proteins by such chemicals, or protein haptenation, is a common occurrence in cells and may result in generation of antigenic species, leading to development of hypersensitivity reactions. Ranging in severity of symptoms from local cutaneous reactions and rhinitis to potentially life-threatening anaphylaxis and severe hypersensitivity reactions such as Stephen-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), all these reactions have the same Molecular Initiating Event (MIE), i.e. haptenation. However, not all individuals who are exposed to electrophilic chemicals develop symptoms of hypersensitivity. In the present review, we examine common chemistry behind the haptenation reactions leading to formation of neoantigens. We explore simple reactions involving single molecule additions to a nucleophilic side chain of proteins and complex reactions involving multiple electrophilic centers on a single molecule or involving more than one electrophilic molecule as well as the generation of reactive molecules from the interaction with cellular detoxification mechanisms. Besides generation of antigenic species and enabling activation of the immune system, we explore additional events which result directly from the presence of electrophilic chemicals in cells, including activation of key defense mechanisms and immediate consequences of those reactions, and explore their potential effects. We discuss the factors that work in concert with haptenation leading to the development of hypersensitivity reactions and those that may act to prevent it from developing. We also review the potential harnessing of the specificity of haptenation in the design of potent covalent therapeutic inhibitors.

Progress and prospects of biomarker-based targeted therapy and immune checkpoint inhibitors in advanced gastric cancer

Gastric cancer and gastroesophageal junction cancer represent the leading cause of tumor-related death worldwide. Although advances in immunotherapy and molecular targeted therapy have expanded treatment options, they have not significantly altered the prognosis for patients with unresectable or metastatic gastric cancer. A minority of patients, particularly those with PD-L1-positive, HER-2-positive, or MSI-high tumors, may benefit more from immune checkpoint inhibitors and/or HER-2-directed therapies in advanced stages. However, for those lacking specific targets and unique molecular features, conventional chemotherapy remains the only recommended effective and durable regimen. In this review, we summarize the roles of various signaling pathways and further investigate the available targets. Then, the current results of phase II/III clinical trials in advanced gastric cancer, along with the superiorities and limitations of the existing biomarkers, are specifically discussed. Finally, we will offer our insights in precision treatment pattern when encountering the substantial challenges.

Immunotherapy for hepatocellular carcinoma

ABSTRACT

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Its high recurrence rate and lack of effective control drugs result in a 5-year survival rate of only about 10%. HCC is a tumor regulated by the immune system. Significant breakthroughs have occurred in treating solid tumors with immunotherapy in recent years. Various immunotherapies, such as immune checkpoint inhibitors (ICIs), including combination therapies, have demonstrated promising therapeutic effects in both clinical applications and research. Other immunotherapies, such as adoptive cell therapies and oncolytic viruses, are also emerging, offering hope for addressing long-term survival issues in HCC. This article reviews current commonly used immunotherapy strategies and the latest research findings for reference.

Recent advances in understanding the immune microenvironment in ovarian cancer

The occurrence of ovarian cancer (OC) is a major factor in women's mortality rates. Despite progress in medical treatments, like new drugs targeting homologous recombination deficiency, survival rates for OC patients are still not ideal. The tumor microenvironment (TME) includes cancer cells, fibroblasts linked to cancer (CAFs), immune-inflammatory cells, and the substances these cells secrete, along with non-cellular components in the extracellular matrix (ECM). First, the TME mainly plays a role in inhibiting tumor growth and protecting normal cell survival. As tumors progress, the TME gradually becomes a place to promote tumor cell progression. Immune cells in the TME have attracted much attention as targets for immunotherapy. Immune checkpoint inhibitor (ICI) therapy has the potential to regulate the TME, suppressing factors that facilitate tumor advancement, reactivating immune cells, managing tumor growth, and extending the survival of patients with advanced cancer. This review presents an outline of current studies on the distinct cellular elements within the OC TME, detailing their main functions and possible signaling pathways. Additionally, we examine immunotherapy rechallenge in OC, with a specific emphasis on the biological reasons behind resistance to ICIs.

A journey to your self: The vague definition of immune self and its practical implications

The identification of immunogenic peptides has become essential in an increasing number of fields in immunology, ranging from tumor immunotherapy to vaccine development. The nature of the adaptive immune response is shaped by the similarity between foreign and self-protein sequences, a concept extensively applied in numerous studies. Can we precisely define the degree of similarity to self? Furthermore, do we accurately define immune self? In the current work, we aim to unravel the conceptual and mechanistic vagueness hindering the assessment of self-similarity. Accordingly, we demonstrate the remarkably low consistency among commonly employed measures and highlight potential avenues for future research.

Genomic Insights into the Role of TOP Gene Family in Soft-Tissue Sarcomas: Implications for Prognosis and Therapy

This study focuses on the role of topoisomerases (TOPs) in sarcomas (SARCs), highlighting TOPs' influence on sarcoma prognosis through mRNA expression, genetic mutations, immune infiltration, and DNA methylation analysis using transcriptase sequencing and other techniques. The findings indicate that TOP gene mutations correlate with increased inflammation, immune cell infiltration, DNA repair abnormalities, and mitochondrial fusion genes alterations, all of which negatively affect sarcoma prognosis. Abnormal TOP expression may independently affect sarcoma patients' survival. Cutting-edge genomic tools such as Oncomine, gene expression profiling interactive analysis (GEPIA), and cBio Cancer Genomics Portal (cBioPortal) are utilized to explore the TOP gene family (TOP1/1MT/2A/2B/3A/3B) in soft-tissue sarcomas (STSs). This in-depth analysis reveals a notable upregulation of TOP mRNA in STS patients arcoss various SARC subtypes, French Federation Nationale des Centres de Lutte Contre le Cancer classification (FNCLCC) grades, and specific molecular profiles correlating with poorer clinical outcomes. Furthermore, this investigation identifies distinct patterns of immune cell infiltration, genetic mutations, and somatic copy number variations linked to TOP genes that inversely affect patient survival rates. These findings underscore the diagnostic and therapeutic relevance of the TOP gene suite in STSs.

Dendritic Cells: A Bridge between Tolerance Induction and Cancer Development in Transplantation Setting

Dendritic cells (DCs) are a heterogeneous group of antigen-presenting cells crucial for fostering allograft tolerance while simultaneously supporting host defense against infections and cancer. Within the tumor microenvironment, DCs can either mount an immune response against cancer cells or foster immunotolerance, presenting a dual role. In immunocompromised individuals, posttransplant malignancies pose a significant health concern, with DCs serving as vital players in immune responses against cancer cells. Both recipient- and donor-derived DCs play a critical role in the rejection process, infiltrating the transplanted organ and sustaining T-cell responses. The use of immunosuppressive drugs represents the predominant approach to control this immunological barrier in transplanted organs. Evidence has shed light on the immunopharmacology of these drugs and novel strategies for manipulating DCs to promote allograft survival. Therefore, comprehending the mechanisms underlying this intricate microenvironment and the effects of immunosuppressive therapy on DCs is crucial for developing targeted therapies to reduce graft failure rates. This review will delve into the fundamental immunobiology of DCs and provide a detailed exploration of their clinical significance concerning alloimmune responses and posttransplant malignancies.

Immune checkpoint molecules in solid organ transplantation: A promising way to prevent rejection

Immune checkpoint (IC) molecules modulate immune responses upon antigen presentation; the interaction between different IC molecules will result in the stimulation or, rather, the thwarting of such responses. Tumor cells express increased amounts of inhibitory IC molecules in an attempt to evade immune responses; therapeutic agents have been developed that bind inhibitory IC molecules, restoring tumor-directed immune responses and changing the prognosis of a number of cancers. Stimulation of inhibitory IC molecules could be beneficial in preventing rejection in the setting of solid organ transplantation (SOT), and in vivo as well as in vivo results obtained in animal models show this to indeed to be the case. With the exception of belatacept, a monoclonal antibody (mAb) in which an IgG Fc fragment is linked to the extracellular domain of CTLA-4, this has not yet translated into the generation of novel therapeutic approaches to prevent SOT rejection. We provide a review of state-of-the art knowledge on the role played by IC molecules in transplantation, confident that innovative research will lead to new avenues to manage rejection in solid organ transplant.

Discovery of 4-phenyl-1H-indazole derivatives as novel small-molecule inhibitors targeting the PD-1/PD-L1 interaction

The inhibition of the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) pathway with small molecules is a promising approach for cancer immunotherapy. Herein, novel small molecules compounds bearing various scaffolds including thiophene, thiazole, tetrahydroquinoline, benzimidazole and indazole were designed, synthesized and evaluated for their inhibitory activity against the PD-1/PD-L1 interaction. Among them, compound Z13 exhibited the most potent activity with IC50 of 189.6 nM in the homogeneous time-resolved fluorescence (HTRF) binding assay. Surface plasmon resonance (SPR) assay demonstrated that Z13 bound to PD-L1 with high affinity (KD values of 231 nM and 311 nM for hPD-L1 and mPD-L1, respectively). In the HepG2/Jurkat T co-culture cell model, Z13 decreased the viability rate of HepG2 cells in a concentration-dependent manner. In addition, Z13 showed significant in vivo antitumor efficacy (TGI = 52.6 % at 40 mg/kg) without obvious toxicity in the B16-F10 melanoma model. Furthermore, flow cytometry analysis demonstrated that Z13 inhibited tumor growth in vivo by activating the tumor immune microenvironment. These findings indicate that Z13 is a promising PD-1/PD-L1 inhibitor deserving further investigation.

Multiplex, high-throughput method to study cancer and immune cell mechanotransduction

Studying cellular mechanoresponses during cancer metastasis is limited by sample variation or complex protocols that current techniques require. Metastasis is governed by mechanotransduction, whereby cells translate external stimuli, such as circulatory fluid shear stress (FSS), into biochemical cues. We present high-throughput, semi-automated methods to expose cells to FSS using the VIAFLO96 multichannel pipetting device custom-fitted with 22 G needles, increasing the maximum FSS 94-fold from the unmodified tips. Specifically, we develop protocols to semi-automatically stain live samples and to fix, permeabilize, and intracellularly process cells for flow cytometry analysis. Our first model system confirmed that the pro-apoptotic effects of TRAIL therapeutics in prostate cancer cells can be enhanced via FSS-induced Piezo1 activation. Our second system implements this multiplex methodology to show that FSS exposure (290 dyn cm-2) increases activation of murine bone marrow-derived dendritic cells. These methodologies greatly improve the mechanobiology workflow, offering a high-throughput, multiplex approach.

zDHHC20-driven S-palmitoylation of CD80 is required for its costimulatory function

CD80 is a transmembrane glycoprotein belonging to the B7 family, which has emerged as a crucial molecule in T cell modulation via the CD28 or CTLA4 axes. CD80-involved regulation of immune balance is a finely tuned process and it is important to elucidate the underlying mechanism for regulating CD80 function. In this study we investigated the post-translational modification of CD80 and its biological relevance. By using a metabolic labeling strategy, we found that CD80 was S-palmitoylated on multiple cysteine residues (Cys261/262/266/271) in both the transmembrane and the cytoplasmic regions. We further identified zDHHC20 as a bona fide palmitoyl-transferase determining the S-palmitoylation level of CD80. We demonstrated that S-palmitoylation protected CD80 protein from ubiquitination degradation, regulating the protein stability, and ensured its accurate plasma membrane localization. The palmitoylation-deficient mutant (4CS) CD80 disrupted these functions, ultimately resulting in the loss of its costimulatory function upon T cell activation. Taken together, our results describe a new post-translational modification of CD80 by S-palmitoylation as a novel mechanism for the regulation of CD80 upon T cell activation.

Systematic decoding of cis gene regulation defines context-dependent control of the multi-gene costimulatory receptor locus in human T cells

Cis-regulatory elements (CREs) interact with trans regulators to orchestrate gene expression, but how transcriptional regulation is coordinated in multi-gene loci has not been experimentally defined. We sought to characterize the CREs controlling dynamic expression of the adjacent costimulatory genes CD28, CTLA4 and ICOS, encoding regulators of T cell-mediated immunity. Tiling CRISPR interference (CRISPRi) screens in primary human T cells, both conventional and regulatory subsets, uncovered gene-, cell subset- and stimulation-specific CREs. Integration with CRISPR knockout screens and assay for transposase-accessible chromatin with sequencing (ATAC-seq) profiling identified trans regulators influencing chromatin states at specific CRISPRi-responsive elements to control costimulatory gene expression. We then discovered a critical CCCTC-binding factor (CTCF) boundary that reinforces CRE interaction with CTLA4 while also preventing promiscuous activation of CD28. By systematically mapping CREs and associated trans regulators directly in primary human T cell subsets, this work overcomes longstanding experimental limitations to decode context-dependent gene regulatory programs in a complex, multi-gene locus critical to immune homeostasis.

A 67-Year-Old Man with Grade 3 Reactive Cutaneous Capillary Endothelial Proliferation Induced by Camrelizumab First Manifested in the Oral Mucosa - A Case Report

Reactive cutaneous capillary endothelial proliferation (RCCEP) is the most common immune-related adverse event induced by camrelizumab (SHR-1210). Very rare cases have been reported in oral tissues, especially the oral mucosa. We reported a 67-year-old male with Grade 3 RCCEP. Multiple dome-shaped and bright red papules were first observed in the oral mucosa, which gradually developed on his lip, face, scalp, neck, foot, calf, abdomen and groin. The patient's symptoms gradually improved at 4 weeks after SHR-1210 discontinuation and were mostly relieved at 7 weeks after discontinuation. Our findings revealed that oral examination should be performed regularly during SHR-1210 treatment.

Expression of HLA-DR and KLRG1 enhances the cytotoxic potential and cytokine secretion capacity of CD3+ T cells in tuberculosis patients

BACKGROUND

Human T cells play an important role in immunity against tuberculosis (TB) infection. Activating receptor HLA-DR and inhibitory receptor KLRG1 are critical regulators of T cell function during viral infection and tumorigenesis, but they have been less studied in TB infection.

METHODS

In this study, we explored the relationship between CD3+ T cell expression of HLA-DR and KLRG1 receptors and function against TB infection. Flow cytometry was conducted to assess the immunomodulatory effects of HLA-DR and KLRG1 receptors on CD3+ T cells in patients with different TB infection status.

RESULTS

We found activating receptors HLA-DR, NKG2C, CD57 and NKP46, and inhibitory receptors KLRG1 and KIR on CD3+ T cells in different TB infection status showed different distribution patterns; the cytotoxic potential and cytokine secretion capacity of CD3+ T cells after Mtb-specific antigen stimulation were significantly enhanced in TB infection groups. Further studies revealed HLA-DR+ T and KLRG1+ T cells expressed higher activating and inhibitory receptors than the negative population. In addition, the expression of cytotoxic potential and cytokine secretion capacity of HLA-DR+ T and KLRG1+ T cells was significantly higher than that of HLA-DR- T and KLRG1- T cells.

CONCLUSIONS

Expression of HLA-DR and KLRG1 enhances the cytotoxic potential and cytokine secretion capacity of CD3+ T cells in TB patients, suggesting CD3+ T cells expressing HLA-DR and KLRG1 are important effector cell phenotypes involved in the host anti-TB infection. HLA-DR and KLRG1 expressed by CD3+ T cells may be potential predictive markers of TB disease progression and clinical immune assessment.

Nanomaterial-Driven Precision Immunomodulation: A New Paradigm in Therapeutic Interventions

Immunotherapy is a rapidly advancing field of research in the treatment of conditions such as cancer and autoimmunity. Nanomaterials can be designed for immune system manipulation, with precise targeted delivery and improved immunomodulatory efficacy. Here, we elaborate on various strategies using nanomaterials, including liposomes, polymers, and inorganic NPs, and discuss their detailed design intricacies, mechanisms, and applications, including the current regulatory issues. This type of nanomaterial design for targeting specific immune cells or tissues and controlling release kinetics could push current technological frontiers and provide new and innovative solutions for immune-related disorders and diseases without off-target effects. These materials enable targeted interactions with immune cells, thereby enhancing the effectiveness of checkpoint inhibitors, cancer vaccines, and adoptive cell therapies. Moreover, they allow for fine-tuning of immune responses while minimizing side effects. At the intersection of nanotechnology and immunology, nanomaterial-based platforms have immense potential to revolutionize patient-centered immunotherapy and reshape disease management. By prioritizing safety, customization, and compliance with regulatory standards, these systems can make significant contributions to precision medicine, thereby significantly impacting the healthcare landscape.

TWIST1 Drives Cytotoxic CD8+ T-Cell Exhaustion through Transcriptional Activation of CD274 (PD-L1) Expression in Breast Cancer Cells

In breast cancer, epithelial-mesenchymal transition (EMT) is positively associated with programmed death ligand 1 (PD-L1) expression and immune escape, and TWIST1 silences ERα expression and induces EMT and cancer metastasis. However, how TWIST1 regulates PD-L1 and immune evasion is unknown. This study analyzed TWIST1 and PD-L1 expression in breast cancers, investigated the mechanism for TWIST1 to regulate PD-L1 transcription, and assessed the effects of TWIST1 and PD-L1 in cancer cells on cytotoxic CD8+ T cells. Interestingly, TWIST1 expression is correlated with high-level PD-L1 expression in ERα-negative breast cancer cells. The overexpression and knockdown of TWIST1 robustly upregulate and downregulate PD-L1 expression, respectively. TWIST1 binds to the PD-L1 promoter and recruits the TIP60 acetyltransferase complex in a BRD8-dependent manner to transcriptionally activate PD-L1 expression, which significantly accelerates the exhaustion and death of the cytotoxic CD8+ T cells. Accordingly, knockdown of TWIST1 or BRD8 or inhibition of PD-L1 significantly enhances the tumor antigen-specific CD8+ T cells to suppress the growth of breast cancer cells. These results demonstrate that TWIST1 directly induces PD-L1 expression in ERα-negative breast cancer cells to promote immune evasion. Targeting TWIST1, BRD8, and/or PD-L1 in ERα-negative breast cancer cells with TWIST1 expression may sensitize CD8+ T-cell-mediated immunotherapy.

Regulatory mechanisms of PD-1/PD-L1 in cancers

Immune evasion contributes to cancer growth and progression. Cancer cells have the ability to activate different immune checkpoint pathways that harbor immunosuppressive functions. The programmed death protein 1 (PD-1) and programmed cell death ligands (PD-Ls) are considered to be the major immune checkpoint molecules. The interaction of PD-1 and PD-L1 negatively regulates adaptive immune response mainly by inhibiting the activity of effector T cells while enhancing the function of immunosuppressive regulatory T cells (Tregs), largely contributing to the maintenance of immune homeostasis that prevents dysregulated immunity and harmful immune responses. However, cancer cells exploit the PD-1/PD-L1 axis to cause immune escape in cancer development and progression. Blockade of PD-1/PD-L1 by neutralizing antibodies restores T cells activity and enhances anti-tumor immunity, achieving remarkable success in cancer therapy. Therefore, the regulatory mechanisms of PD-1/PD-L1 in cancers have attracted an increasing attention. This article aims to provide a comprehensive review of the roles of the PD-1/PD-L1 signaling in human autoimmune diseases and cancers. We summarize all aspects of regulatory mechanisms underlying the expression and activity of PD-1 and PD-L1 in cancers, including genetic, epigenetic, post-transcriptional and post-translational regulatory mechanisms. In addition, we further summarize the progress in clinical research on the antitumor effects of targeting PD-1/PD-L1 antibodies alone and in combination with other therapeutic approaches, providing new strategies for finding new tumor markers and developing combined therapeutic approaches.

The role of extracellular vesicle immune checkpoints in cancer

Immune checkpoints (ICPs) play a crucial role in regulating the immune response. In the tumor, malignant cells can hijack the immunosuppressive effects of inhibitory ICPs to promote tumor progression. Extracellular vesicles (EVs) are produced by a variety of cells and contain bioactive molecules on their surface or within their lumen. The expression of ICPs has also been detected in EVs. In vitro and in vivo studies have shown that extracellular vesicle immune checkpoints (EV ICPs) have immunomodulatory effects and are involved in tumor immunity. EV ICPs isolated from the peripheral blood of cancer patients are closely associated with the tumor progression and the prognosis of cancer patients. Blocking inhibitory ICPs has been recognized as an effective strategy in cancer treatment. However, the efficacy of immune checkpoint inhibitors (ICIs) in cancer treatment is hindered by the emergence of therapeutic resistance, which limits their widespread use. Researchers have demonstrated that EV ICPs are correlated with clinical response to ICIs therapy and were involved in therapeutic resistance. Therefore, it is essential to investigate the immunomodulatory effects, underlying mechanisms, and clinical significance of EV ICPs in cancer. This review aims to comprehensively explore these aspects. We have provided a comprehensive description of the cellular origins, immunomodulatory effects, and clinical significance of EV ICPs in cancer, based on relevant studies.

Single-Cell RNA Sequencing Shows T-Cell Exhaustion Landscape in the Peripheral Blood of Patients with Hepatitis B Virus-Associated Acute-on-Chronic Liver Failure

Background/Aims

The occurrence and development of hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) is closely related to the immune pathway. We explored the heterogeneity of peripheral blood T cell subsets and the characteristics of exhausted T lymphocytes, in an attempt to identify potential therapeutic target molecules for immune dysfunction in ACLF patients.

Methods

A total of 83,577 T cells from HBV-ACLF patients and healthy controls were screened for heterogeneity by single-cell RNA sequencing. In addition, exhausted T-lymphocyte subsets were screened to analyze their gene expression profiles, and their developmental trajectories were investigated. Subsequently, the expression of exhausted T cells and their capacity in secreting cytokines (interleukin 2, interferon γ, and tumor necrosis factor α) were validated by flow cytometry.

Results

A total of eight stable clusters were identified, among which CD4+ TIGIT+ subset and CD8+ LAG-3+ subset, with high expression of exhaust genes, were significantly higher in the HBV-ACLF patients than in normal controls. As shown by pseudotime analysis, T cells experienced a transition from naïve T cells to effector T cells and then exhausted T cells. Flow cytometry confirmed that the CD4+TIGIT+ subset and CD8+LAG-3+ subset in the peripheral blood of the ACLF patients were significantly higher than those in the healthy controls. Moreover, in vitro cultured CD8+LAG-3+ T cells were significantly fewer capable of secreting cytokines than CD8+LAG-3- subset.

Conclusions

Peripheral blood T cells are heterogeneous in HBV-ACLF. The exhausted T cells markedly increase during the pathogenesis of ACLF, suggesting that T-cell exhaustion is involved in the immune dysfunction of HBV-ACLF patients.

The cholera toxin B subunit induces trained immunity in dendritic cells and promotes CD8 T cell antitumor immunity

Introduction

Innate immune training is a metabolic, functional, and epigenetic long-term reprogramming of innate cells triggered by different stimuli. This imprinting also reaches hematopoietic precursors in the bone marrow to sustain a memory-like phenotype. Dendritic cells (DCs) can exhibit memory-like responses, enhanced upon subsequent exposure to a pathogen; however, whether this imprinting is lineage and stimulus-restricted is still being determined. Nevertheless, the functional consequences of DCs training on the adaptive and protective immune response against non-infectious diseases remain unresolved.

Methods

We evaluated the effect of the nontoxic cholera B subunit (CTB), LPS and LTA in the induction of trained immunity in murine DCs revealed by TNFa and LDH expression, through confocal microscopy. Additionally, we obtained bone marrow DCs (BMDCs) from mice treated with CTB, LPS, and LTA and evaluated training features in DCs and their antigen-presenting cell capability using multiparametric cytometry. Finally, we design an experimental melanoma mouse model to demonstrate protection induced by CTB-trained DCs in vivo.

Results

CTB-trained DCs exhibit increased expression of TNFa, and metabolic reprogramming indicated by LDH expression. Moreover, CTB training has an imprint on DC precursors, increasing the number and antigen-presenting function in BMDCs. We found that training by CTB stimulates the recruitment of DC precursors and DCs infiltration at the skin and lymph nodes. Interestingly, training-induced by CTB promotes a highly co-stimulatory phenotype in tumor-infiltrating DCs (CD86+) and a heightened functionality of exhausted CD8 T cells (Ki67+, GZMB+), which were associated with a protective response against melanoma challenge in vivo.

Conclusion

Our work indicates that CTB can induce innate immune training on DCs, which turns into an efficient adaptive immune response in the melanoma model and might be a potential immunotherapeutic approach for tumor growth control.

Modulation of the tumor microenvironment and mechanism of immunotherapy-based drug resistance in breast cancer

Breast cancer, the most frequent female malignancy, is often curable when detected at an early stage. The treatment of metastatic breast cancer is more challenging and may be unresponsive to conventional therapy. Immunotherapy is crucial for treating metastatic breast cancer, but its resistance is a major limitation. The tumor microenvironment (TME) is vital in modulating the immunotherapy response. Various tumor microenvironmental components, such as cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs), are involved in TME modulation to cause immunotherapy resistance. This review highlights the role of stromal cells in modulating the breast tumor microenvironment, including the involvement of CAF-TAM interaction, alteration of tumor metabolism leading to immunotherapy failure, and other latest strategies, including high throughput genomic screening, single-cell and spatial omics techniques for identifying tumor immune genes regulating immunotherapy response. This review emphasizes the therapeutic approach to overcome breast cancer immune resistance through CAF reprogramming, modulation of TAM polarization, tumor metabolism, and genomic alterations.

Emerging strategies for treating autoimmune disease with genetically modified dendritic cells

Gene editing of living cells has become a crucial tool in medical research, enabling scientists to address fundamental biological questions and develop novel strategies for disease treatment. This technology has particularly revolutionized adoptive transfer cell therapy products, leading to significant advancements in tumor treatment and offering promising outcomes in managing transplant rejection, autoimmune disorders, and inflammatory diseases. While recent clinical trials have demonstrated the safety of tolerogenic dendritic cell (TolDC) immunotherapy, concerns remain regarding its effectiveness. This review aims to discuss the application of gene editing techniques to enhance the tolerance function of dendritic cells (DCs), with a particular focus on preclinical strategies that are currently being investigated to optimize the tolerogenic phenotype and function of DCs. We explore potential approaches for in vitro generation of TolDCs and provide an overview of emerging strategies for modifying DCs. Additionally, we highlight the primary challenges hindering the clinical adoption of TolDC therapeutics and propose future research directions in this field.

Microbiome dynamics in immune checkpoint blockade

Immune checkpoint blockade (ICB) is one of the leading immunotherapies, although a variable extent of resistance has been observed among patients and across cancer types. Among the efforts underway to overcome this challenge, the microbiome has emerged as a factor affecting the responsiveness and efficacy of ICB. Active research, facilitated by advances in sequencing techniques, is assessing the predominant influence of the intestinal microbiome, as well as the effects of the presence of an intratumoral microbiome. In this review, we describe recent findings from clinical trials, observational studies of human patients, and animal studies on the impact of the microbiome on the efficacy of ICB, highlighting the role of the intestinal and tumor microbiomes and the contribution of methodological advances in their study.

Association of immune cells and the risk of esophageal cancer: A Mendelian randomization study in a East Asian population

Immunotherapy has been used in esophageal cancer (EC), but the causal relationship between EC and immune cells is not clear. Although the cellular phenotype has been reported as a biomarker for immunotherapy, the biomarker studies for immunotherapy in EC still face great challenges. Comprehensive 2-sample Mendelian randomization (MR) analysis was performed to determine the causal association between immune cell signatures and EC in this study. Based on publicly available genetic data, we explored causal associations between 731 immune cell signatures and EC risk. EC had no statistically significant effect on immunophenotypes. Nine immunophenotype types were positively associated with the risk of EC: CD20-%B cell, CD20% lymphocytes, CD25 on IgD- CD27-, CD25 on IgD+ CD24+, CD27 on IgD+ CD24+, CD28+ CD45RA- CD8br AC, CD3 on TD CD8br, IgD-CD38dim%B cells, and Mo MDSC AC. In addition, a total of 15 immunophenotypes were identified as causally associated with EC. IgD+ CD38- %B cell, IgD- CD24- %lymphocyte, CD19 on IgD- CD38dim, CD20 on IgD+ CD24+, CD62L-myeloid DC AC, CD4+ AC, Lymphocyte %leukocyte, CD3 on HLA-DR+ T cell, CD3 on CD45RA- CD4+, HVEM on naive CD4+ AC, HVEM on CD45RA- CD4+, CD4 on TD CD4+, CD4 on CD4 Treg, and CD4 on CD39+ resting Treg, and CD4 on activated & secreting Treg. Our study has demonstrated the close connection between immune cells and EC by genetic means, thus providing guidance for future clinical research.

The ATP-exporting channel Pannexin-1 promotes CD8+ T cell effector and memory responses

Sensing of extracellular ATP (eATP) controls CD8+ T cell function. Their accumulation can occur through export by specialized molecules, such as the release channel Pannexin-1 (Panx1). Whether Panx1 controls CD8+ T cell immune responses in vivo, however, has not been previously addressed. Here, we report that T cell-specific Panx1 is needed for CD8+ T cell responses to viral infections and cancer. We found that CD8-specific Panx1 promotes both effector and memory CD8+ T cell responses. Panx1 favors initial effector CD8+ T cell activation through extracellular ATP (eATP) export and subsequent P2RX4 activation, which helps promote full effector differentiation through extracellular lactate accumulation and its subsequent recycling. In contrast, Panx1 promotes memory CD8+ T cell survival primarily through ATP export and subsequent P2RX7 engagement, leading to improved mitochondrial metabolism. In summary, Panx1-mediated eATP export regulates effector and memory CD8+ T cells through distinct purinergic receptors and different metabolic and signaling pathways.

Integration Analysis of Single-Cell Multi-Omics Reveals Prostate Cancer Heterogeneity

Prostate cancer (PCa) is an extensive heterogeneous disease with a complex cellular ecosystem in the tumor microenvironment (TME). However, the manner in which heterogeneity is shaped by tumors and stromal cells, or vice versa, remains poorly understood. In this study, single-cell RNA sequencing, spatial transcriptomics, and bulk ATAC-sequence are integrated from a series of patients with PCa and healthy controls. A stemness subset of club cells marked with SOX9highARlow expression is identified, which is markedly enriched after neoadjuvant androgen-deprivation therapy (ADT). Furthermore, a subset of CD8+CXCR6+ T cells that function as effector T cells is markedly reduced in patients with malignant PCa. For spatial transcriptome analysis, machine learning and computational intelligence are comprehensively utilized to identify the cellular diversity of prostate cancer cells and cell-cell communication in situ. Macrophage and neutrophil state transitions along the trajectory of cancer progression are also examined. Finally, the immunosuppressive microenvironment in advanced PCa is found to be associated with the infiltration of regulatory T cells (Tregs), potentially induced by an FAP+ fibroblast subset. In summary, the cellular heterogeneity is delineated in the stage-specific PCa microenvironment at single-cell resolution, uncovering their reciprocal crosstalk with disease progression, which can be helpful in promoting PCa diagnosis and therapy.

Recent development of oral vaccines (Review)

Oral immunization can elicit an effective immune response and immune tolerance to specific antigens. When compared with the traditional injection route, delivering antigens via the gastrointestinal mucosa offers superior immune effects and compliance, as well as simplicity and convenience, making it a more optimal route for immunization. At present, various oral vaccine delivery systems exist. Certain modified bacteria, such as Salmonella, Escherichia coli and particularly Lactobacillus, are considered promising carriers for oral vaccines. These carriers can significantly enhance immunization efficiency by actively replicating in the intestinal tract following oral administration. The present review provided a discussion of the main mechanisms of oral immunity and the research progress made in the field of oral vaccines. Additionally, it introduced the advantages and disadvantages of the currently more commonly administered injectable COVID-19 vaccines, alongside the latest advancements in this area. Furthermore, recent developments in oral vaccines are summarized, and their potential benefits and side effects are discussed.

Therapeutic induction of antigen-specific immune tolerance

The development of therapeutic approaches for the induction of robust, long-lasting and antigen-specific immune tolerance remains an important unmet clinical need for the management of autoimmunity, allergy, organ transplantation and gene therapy. Recent breakthroughs in our understanding of immune tolerance mechanisms have opened new research avenues and therapeutic opportunities in this area. Here, we review mechanisms of immune tolerance and novel methods for its therapeutic induction.

Plant-derived Durvalumab variants show efficient PD-1/PD-L1 blockade and therapeutically favourable FcR binding

Immune checkpoint blocking therapy targeting the PD-1/PD-L1 inhibitory signalling pathway has produced encouraging results in the treatment of a variety of cancers. Durvalumab (Imfinzi®) targeting PD-L1 is currently used for immunotherapy of several tumour malignancies. The Fc region of this IgG1 antibody has been engineered to reduce FcγR interactions with the aim of enhancing blockade of PD-1/PD-L1 interactions without the depletion of PD-L1-expressing immune cells. Here, we used Nicotiana benthamiana to produce four variants of Durvalumab (DL): wild-type IgG1 and its 'Fc-effector-silent' variant (LALAPG) carrying further modifications to increase antibody half-life (YTE); IgG4S228P and its variant (PVA) with Fc mutations to decrease binding to FcγRI. In addition, DL variants were produced with two distinct glycosylation profiles: afucosylated and decorated with α1,6-core fucose. Plant-derived DL variants were compared to the therapeutic antibody regarding their ability to (i) bind to PD-L1, (ii) block PD-1/PD-L1 inhibitory signalling and (iii) engage with the neonatal Fc receptor (FcRn) and various Fcγ receptors. It was found that plant-derived DL variants bind to recombinant PD-L1 and to PD-L1 expressed in gastrointestinal cancer cells and are able to effectively block its interaction with PD-1 on T cells, thereby enhancing their activation. Furthermore, we show a positive impact of Fc amino acid mutations and core fucosylation on DL's therapeutic potential. Compared to Imfinzi®, DL-IgG1 (LALAPG) and DL-IgG4 (PVA)S228P show lower affinity to CD32B inhibitory receptor which can be therapeutically favourable. Importantly, DL-IgG1 (LALAPG) also shows enhanced binding to FcRn, a key determinant of serum half-life of IgGs.

The Current and Future of Biomarkers of Immune Related Adverse Events

With their groundbreaking clinical responses, immune checkpoint inhibitors (ICIs) have ushered in a new chapter in cancer therapeutics. However, they are often associated with life-threatening or organ-threatening autoimmune/autoinflammatory phenomena, collectively termed immune-related adverse events (irAEs). In this review, we will first describe the mechanisms of action of ICIs as well as irAEs. Next, we will review biomarkers for predicting the development of irAEs or stratifying risks.