PD-1/PD-L1 in disease

Polysaccharide-mediated combination therapy enhances anti-tumor effects by promoting the immune cycle of immunogenic cell death

BACKGROUND

Due to their potent immunomodulatory effects, herbal polysaccharides, are used as immunomodulators in combination with other anti-tumor therapies, demonstrate potential in the treatment of tumors.

METHODS

In this paper, we simulated the immune cycle of immunogenic cell death (ICD) in vitro to investigate the regulatory mechanism of four different polysaccharides-mediated "immuno-photothermal" combination therapies on the immune cycle of ICD, and validated it in vivo.

RESULTS

The experimental results showed that the combination therapy strategies mediated by four different polysaccharides (excluding Poria cocos mushroom polysaccharides) could significantly increase the expression and release of ICD markers in tumor cells (4 T1), which was conducive to enhancing the "immune starting point" of ICD. For the "immune line/bridge", four different polysaccharides-mediated combination therapies significantly increased the number and percentage of mature dendritic cells (DCs) and promoted the proliferation and migration of DCs. For the "immune ending point", the number, proliferation, and migration recruitment of CD3+CD8+ cytotoxic T lymphocyte could significantly increase.

CONCLUSIONS

All four polysaccharides can positive modulate the dynamic process of the immune cycle and enhance anti-tumor efficacy. Highlighting the crucial role and mechanism of polysaccharides in combination therapy. Providing new ideas and rationale for polysaccharide-mediated anti-tumor combination therapy.

The Expression of Programmed Cell Death Ligand-1 and its Relationship with Infiltration, Metastasis and Prognosis in Cervical Squamous Cell Carcinoma

Cervical cancer (CC) represents a major gynecologic health problem. Respecting the role of programmed cell death ligand-1 (PDL-1) in cancer prognosis, we investigated its relationship with cervical squamous cell carcinoma (CSCC) invasion, metastasis and prognosis. A total of 184 CSCC patients were retrospectively selected, with normal paracarcinoma tissues as the Control group. PDL-1 expression was assessed, and its relationship with CSCC prognosis and clinical value on predicting CSCC invasion/metastasis and poor prognosis were determined. PDL-1 was up-regulated in CSCC. CSCC patients at International Federation of Gynecology and Obstetrics stage II/III, and with lymph node metastasis (LNM), parauterine/vascular infiltration, and history of sexually transmitted diseases exhibited up-regulated PDL-1. The areas under the curve of PDL-1 on predicting the invasion and metastasis/poor prognosis of CSCC patients were 0.930 (95%Cl: 0.883-0.962)/0.935 (95%Cl: 0.886-0.967), with cut-off values of 23.27/24.86 (86.76%/80.95% sensitivity, 95.69%/92.68% specificity). The CSCC patients with highly-expressed PDL-1 showed increased cumulative incidence of poor prognosis. Additionally, occurence of vascular infiltration/LNM, and up-regulated PDL-1 were independent risk factors for poor prognosis in CSCC patients. Briefly, PDL-1 expression rised in CSCC. High PDL-1 expression might promote tumor infiltration and LNM, while close monitoring of its expression contributed to evaluating prognosis of CSCC patients.

Unmasking a Paradox: Roles of the PD-1/PD-L1 Axis in Alzheimer's Disease-Associated Neuroinflammation

Alzheimer's disease (AD) represents the most prevalent form of dementia, characterized by progressive cognitive impairment and chronic neuroinflammation. Immune checkpoint inhibitors (ICIs), including anti-programmed cell death (PD)-1 and anti-PD-L1, signify a revolutionary advancement in cancer treatment by preventing T-cell exhaustion; however, their therapeutic application in AD presents a conundrum. Hypothesis: Recent preclinical studies indicate that PD-1 inhibition in AD mouse models induces an interferon-gamma (IFN-γ)-mediated response, leading to increased recruitment of monocyte-derived macrophages into the brain, enhanced clearance of amyloid-beta (Aβ) plaques, and improved cognitive performance. Nonetheless, this therapeutic effect is counterbalanced by the potential for exacerbated neuroinflammation, as PD-1/PD-L1 blockade may potentiate pro-inflammatory T helper (Th)1 and Th17 responses. In this review, we critically discuss the pertinent pro-inflammatory and neuroprotective facets of T cell biology in the pathogenesis of AD, emphasizing the potential for modulation of the PD-1/PD-L1 axis to influence both Aβ clearance and the dynamics of neuroinflammatory processes. In summary, we determine that ICIs are promising tools for reducing AD pathology and improving cognition. However, it is essential to refine treatment protocols and carefully select patients to optimize neuroprotective effects while adequately considering inflammatory risks.

Improved acid-driven inhibition of effector T cell function by a pHLIP variant-conjugated PD-L1

Programmed cell death-ligand 1 (PD-L1)/PD-1 axis is crucial for maintenance of immune homeostasis and its impairment partially accounts for the pathogenesis of inflammatory diseases. Hence, augmenting PD-L1/PD-1 signals represents a novel strategy to prevent destructive inflammation and induce immune tolerance. Recently, we developed a new cargo by conjugating the ectodomain of PD-L1 with pHLIP, a low pH-responding and membrane-inserting peptide, and demonstrated its potent immune-suppressive activity under weakly acidic (pH6.1) conditions in vitro. Herein, we further showed that PD-L1-pHLIP (termed as PD-L1-pHLIPwt) responded well to weakly acidic buffer, but not in nearly neutral pH (pH6.8) solutions. To overcome this obstacle, pHLIPwt was replaced by a variant harboring two mutations (Asp14Gla and Asp25Aad) and PD-L1 ectodomain was conjugated to the N-terminus of pHLIP variant via sulfo-SMCC linker (termed as PD-L1-pHLIPva). PD-L1-pHLIPva potently inhibited T effector function including proliferation, activation as well as proinflammatory cytokine release in nearly neutral pH buffer through PD-L1/PD-1 interaction. The inhibitory function of PD-L1-pHLIPva was attributed to more amounts of PD-L1 anchored on the surface of several types of immune cells compared with PD-L1-pHLIPwt. Given that the niche in the lesions of inflammation is weakly acidic even nearly neutral pH, PD-L1-pHLIPva represents a new arsenal to potentially dampen excessive inflammatory reactions.

Enhanced efficacy of dual chimeric antigen receptor-T cells targeting programmed death-ligand 1 and cancer-associated fibroblasts in colorectal cancer in vitro

Objective

Colorectal cancer (CRC) presents significant treatment challenges, including immune evasion and tumor microenvironment (TME) suppression. Chimeric antigen receptor (CAR) T-cell therapy has shown promise in hematologic malignancies, but its effectiveness against solid tumors is hampered by the detrimental effects of the TME. This article aims to explore the potential of bispecific CAR T cells targeting programmed death-ligand 1 (PD-L1) and cancer-associated fibroblasts (CAFs) in CRC treatment.

Material and Methods

Dual-targeted CAR-T cells against PD-L1 and CAF were engineered using the GV400 lentiviral vector. Programmed death-1 (PD-1)/nanobody (Nb) and fibroblast activation protein (FAP)/Nb-encoding lentiviral vectors were generated, and CAR T cells were produced through a three-plasmid system in 293T cells. Human peripheral blood mononuclear cells (PBMCs) were separated, transduced with these vectors, and then expanded. Functional characterization of CAR-T cells was performed through enzyme-linked immunosorbent assay (ELISA), Western blot analysis, flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays, and cell counting kit-8 (CCK-8) assay. Migration and invasion assays were conducted using Transwell chambers to assess the ability of FAP-PD-1/Nb CAR-T cells to migrate toward tumor cells and invade the extracellular matrix.

Results

We developed dual-targeted CAR-T cells incorporating PD-L1 and CAF Nbs, which continuously secreted PD-1/Nb. Western blot confirmed PD-1/Nb expression in PD-1/Nb and FAP-PD-1/Nb CAR-T cells, with no expression in the untreated (UTD) group (P < 0.01). Flow cytometry showed a significantly higher cluster of differentiation (CD)25 and CD69 expression in FAP-PD-1/Nb CAR-T cells upon stimulation with FAP-positive target cells compared with the other groups (P < 0.01). TUNEL, flow cytometry, and CCK-8 assays revealed that FAP-PD-1/Nb CAR-T cells exhibited superior cytotoxicity and proliferation inhibition against FAP-positive HCT116 cells (P < 0.01). ELISA demonstrated increased interferon-gamma and tumor necrosis factor-alpha levels and reduced interleukin-10 (P < 0.01), suggesting enhanced cytokine modulation and antitumor immunity. Compared with single-target CAR-T cells and UTD, FAP-PD-1/Nb CAR-T cells showed notably enhanced Matrigel penetration and invasion (P < 0.01). Safety tests confirmed minimal cytotoxicity to normal PBMCs, indicating favorable safety.

Conclusion

This study successfully developed dual-targeted CAR-T cells against PD-L1 and CAF and demonstrated their superior antitumor activity and immunomodulatory effects on CRC treatment. This novel therapeutic strategy was established using CAR T-cell technology for the treatment of CRC.

Immune Resistance in Glioblastoma: Understanding the Barriers to ICI and CAR-T Cell Therapy

BACKGROUND

Glioblastoma (GBM) is the most common primary malignant brain tumor, with fewer than 5% of patients surviving five years after diagnosis. The introduction of immune checkpoint inhibitors (ICIs), followed by chimeric antigen receptor (CAR) T-cell therapy, marked major advancements in oncology. Despite demonstrating efficacy in other blood and solid cancers, these therapies have yielded limited success in clinical trials for both newly diagnosed and recurrent GBM. A deeper understanding of GBM's resistance to immunotherapy is essential for enhancing treatment responses and translating results seen in other cancer models.

OBJECTIVES

In this review, we examine clinical trial outcomes involving ICIs and CAR-T for GBM patients and explore the evasive mechanisms of GBM and the tumor microenvironment.

FINDINGS AND DISCUSSION

Multiple clinical trials investigating ICIs in GBM have shown poor outcomes, with no significant improvement in progression-free survival (PFS) or overall survival (OS). Results from smaller case studies with CAR-T therapy have warranted further investigation. However, no large-scale trials or robust studies have yet established these immunotherapeutic approaches as definitive treatment strategies. Future research should shift focus from addressing the scarcity of functional T cells to exploiting the abundant myeloid-derived cells within the tumor microenvironment.

CONCLUSIONS

Translating these therapies into effective treatments for glioblastoma in humans remains a significant challenge. The highly immunosuppressive nature of GBM and its tumor microenvironment continue to hinder the success of these innovative immunotherapeutic approaches. Targeting the myeloid-derived compartment may lead to more robust and sustained immune responses.

Interferon Gamma Gene Polymorphisms in Greek Primary Breast Cancer Patients

BACKGROUND

Breast cancer is a heterogeneous disease with distinct clinical subtypes, categorized by hormone receptor status, which exhibits different prognoses and requires personalized treatment approaches. These subtypes included luminal A and luminal B, which have different prognoses. Breast cancer development and progression involve many factors, including interferon-gamma (IFNG). Moreover, single nucleotide polymorphisms (SNPs) in IFNG have been associated with cancer risk. However, the functional role of IFNG polymorphisms in primary breast cancer subtypes, luminal A and luminal B, is unclear.

METHODS

A total of 138 breast cancer tissues were acquired: 81 had luminal A, 42 had luminal B, 10 had triple-negative, and 3 had human epidermal growth factor receptor 2 (HER2) subtypes, while 2 had missing data. The tissues were evaluated in relation to luminal A and luminal B primary breast cancer subtypes. DNA was extracted from freshly frozen samples, and three SNPs (rs1861493 (chr12:68157416 (GRCh38.p13)), rs1861494 (chr12:68157629 (GRCh38.p13)) and rs2430561 (chr12:68158742 (GRCh38.p13))) in the IFNG gene were selected and evaluated based on previously published associations with cancer or other diseases.

RESULTS

The data showed that IFNG polymorphisms rs1861493 and rs1861494 were associated with breast cancer risk, with the A allele of rs1861493 and T allele of rs1861494 being noted as the risk alleles. Furthermore, the IFNG polymorphism rs2430561 was associated with breast cancer risk, with the A allele being the risk allele. In addition, the risk alleles were more prevalent in the more aggressive subtype, luminal B breast cancer, compared to luminal A. Similarly, the rs2430561 AA genotype was associated with the breast cancer severity.

CONCLUSION

IFNG polymorphisms rs1861493, rs1861494, and rs2430561, with their respective risk alleles, are associated with increased breast cancer risk and severity. These risk alleles are more prevalent in the aggressive luminal B subtype compared to luminal A, indicating their role in both the prevalence and prognosis of breast cancer in a Greek population.

Role of PD-1/PD-L1 signaling axis in oncogenesis and its targeting by bioactive natural compounds for cancer immunotherapy

Cancer is a global health problem and one of the leading causes of mortality. Immune checkpoint inhibitors have revolutionized the field of oncology, emerging as a powerful treatment strategy. A key pathway that has garnered considerable attention is programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1). The interaction between PD-L1 expressed on tumor cells and PD-1 reduces the innate immune response and thus compromises the capability of the body's immune system. Furthermore, it controls the phenotype and functionality of innate and adaptive immune components. A range of monoclonal antibodies, including avelumab, atezolizumab, camrelizumab, dostarlimab, durvalumab, sinitilimab, toripalimab, and zimberelimab, have been developed for targeting the interaction between PD-1 and PD-L1. These agents can induce a broad spectrum of autoimmune-like complications that may affect any organ system. Recent studies have focused on the effect of various natural compounds that inhibit immune checkpoints. This could contribute to the existing arsenal of anticancer drugs. Several bioactive natural agents have been shown to affect the PD-1/PD-L1 signaling axis, promoting tumor cell apoptosis, influencing cell proliferation, and eventually leading to tumor cell death and inhibiting cancer progression. However, there is a substantial knowledge gap regarding the role of different natural compounds targeting PD-1 in the context of cancer. Hence, this review aims to provide a common connection between PD-1/PD-L1 blockade and the anticancer effects of distinct natural molecules. Moreover, the primary focus will be on the underlying mechanism of action as well as the clinical efficacy of bioactive molecules. Current challenges along with the scope of future research directions targeting PD-1/PD-L1 interactions through natural substances are also discussed.

Lipid- and Polymer-Based Nanocarrier Platforms for Cancer Vaccine Delivery

Cancer immunotherapy has gained popularity in recent years in the search for effective treatment modalities for various malignancies, particularly those that are resistant to conventional chemo- and radiation therapy. Cancer vaccines target the cancer-immunity cycle by boosting the patient's own immune system to recognize and kill cancer cells, thus serving as both preventative and curative therapeutic tools. Among the different types of cancer vaccines, those based on nanotechnology have shown great promise in advancing the field of cancer immunotherapy. Lipid-based nanoparticles (NPs) have become the most advanced platforms for cancer vaccine delivery, but polymer-based NPs have also received considerable interest. This Review aims to provide an overview of the nanotechnology-enabled cancer vaccine landscape, focusing on recent advances in lipid- and polymer-based nanovaccines and their hybrid structures and discussing the challenges against the clinical translation of these important nanomedicines.

GM130-silencing may aggravate blood-brain barrier damage and affect microglia polarization by down-regulating PD-L1 expression after experimental intracerebral hemorrhage

BACKGROUND

In addition to primary injury, secondary injuries related to BBB disruption and immune-inflammatory response also play an important role in intracerebral hemorrhage (ICH). And the Golgi apparatus play an important role in the state of ICH.

METHODS

ICH model and GM130-silencing ICH model were established in SD rats. The Garcia score was used to score the neurological defects of the rats. Blood-brain barrier (BBB) integrity were assessed by amount of extravasated Evans blue, and tight junction proteins. The expression of PD-L1 and GM130were detected through Western-blot and the subtype of microglia was showing with Immunofluorescence staining.

RESULTS

Compared with the ICH group, GM130-silencing ICH rats got a worsened neurological deficit and enlarged volume of the hematoma. Evan's blue extravasation aggravated as well. The expression of GM130 in peri-hematoma tissue was further decreased, and the morphology and structure of the Golgi apparatus were further damaged. Meanwhile, the GM130 deficit resulted in decreased expression of PD-L1 and more polarization of microglia to the M1 subtype.

CONCLUSION

We demonstrate that GM130 could influence the integrity of BBB and plays a role in neuroinflammation via regulation of PD-L1 after ICH. The manipulation of GM130 might be a promising therapeutical target in ICH.

Revolutionizing adjuvant development: harnessing AI for next-generation cancer vaccines

With the COVID-19 pandemic, the importance of vaccines has been widely recognized and has led to increased research and development efforts. Vaccines also play a crucial role in cancer treatment by activating the immune system to target and destroy cancer cells. However, enhancing the efficacy of cancer vaccines remains a challenge. Adjuvants, which enhance the immune response to antigens and improve vaccine effectiveness, have faced limitations in recent years, resulting in few novel adjuvants being identified. The advancement of artificial intelligence (AI) technology in drug development has provided a foundation for adjuvant screening and application, leading to a diversification of adjuvants. This article reviews the significant role of tumor vaccines in basic research and clinical treatment and explores the use of AI technology to screen novel adjuvants from databases. The findings of this review offer valuable insights for the development of new adjuvants for next-generation vaccines.

Tumor cells inhibit the activation of ILC2s through up-regulating PD-1 expression

OBJECTIVE

Up-regulating programmed cell death ligand-1(PD-L1) expressed on tumor cells and tumor-infiltrating myeloid cells interacting with up-regulated programmed cell death-1 (PD-1) expressed on tumor-infiltrating lymphoid cells greatly hinder their tumor-inhibiting effect. It is necessary to explore the deep mechanism of this negative effect, so as to find the potential methods to improve the immunotherapy efficiency.

METHODS AND RESULTS

In this study, we found that the PD-1 expression in lung cancer-infiltrating type II innate lymphoid cells (ILC2s) was highly up-regulated, which greatly restrained the activation and function of ILC2s. Furthermore, anti-PD-1 could restore the inhibition and effective cytokine secretion of ILC2s when co-cultured with tumor cells. In vivo studies proved that anti-PD-1 treatment promoted the activation of tumor-infiltrating ILC2s and inhibited the tumor growth of LLC-bearing nude mice.

DISCUSSION

Our studies demonstrate a new PD-1/PD-L1 axis regulating mechanism on innate immune cells, which provide a useful direction to ILC2s-based immunotherapy to cancer diseases.

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.

A new era of immune therapeutics for pancreatic cancer: Monoclonal antibodies paving the way

Pancreatic cancer, particularly pancreatic ductal adenocarcinoma, remains a devastating disease with a dismal prognosis and limited survival rates. Despite various drug treatments and regimens showing promise in managing the disease, the clinical outcomes have not significantly improved. Immunotherapy however, has become a forefront area in pancreatic cancer treatment. This approach comprises a range of agents, including small molecule drugs, antibodies, combination therapies, and vaccines. In the last 5-8 years, there has been an upsurge of research into the use of monoclonal antibodies to block receptors on cancer or immune cells, revolutionising cancer treatment and management. Several targets have been identified and studied, with the most encouraging noted in relation to checkpoint markers, namely, antibodies targeting anti-programmed cell death 1 (PD-1) and its receptor PD-L1. Herein, we present the clinical developments in immunotherapy in the last 5 years especially those which have been tested in humans against pancreatic cancer.

Drug Repurposing of ACT001 to Discover Novel Promising Sulfide Prodrugs with Improved Safety and Potent Activity for Neutrophil-Mediated Antifungal Immunotherapy

Neutrophil-mediated immunotherapy is a promising strategy for treating Candida albicans infection due to its potential in dealing with drug-resistant events. Our previous study found that ACT001 exhibited good antifungal immunotherapeutic activity by inhibiting PD-L1 expression in neutrophils, but its strong cytotoxicity and high BBB permeability hindered its antifungal application. To address these deficiencies, a series of novel sulfide derivatives were designed and synthesized based on a slow-release prodrug strategy. Among these derivatives, compound 16 exhibited stronger inhibition of PD-L1 expression, less cytotoxicity to neutrophils, and lower BBB permeability than ACT001. Compound 16 also significantly enhanced neutrophil-mediated antifungal immunity in C. albicans infected mice, with acceptable pharmacokinetic properties and good oral safety. Moreover, pharmacological mechanism studies demonstrated that ACT001 and compound 16 reduced PD-L1 expression in neutrophils by directly targeting STAT3. Briefly, this study provided a novel prototype compound 16 which exhibited great potential in neutrophil-mediated antifungal immunotherapy.

Immune checkpoint inhibitors break whose heart? Perspectives from cardio-immuno-oncology

Immune checkpoint inhibitors (ICIs) are monoclonal antibody antagonists, which can block cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed death-1/ligand-1 (PD-1/PD-L1) pathways, and other molecules exploited by tumor cells to evade T cell-mediated immune response. ICIs have transformed the treatment landscape for various cancers due to their amazing efficacy. Many anti-tumor therapies, including targeted therapy, radiotherapy, and chemotherapy, combine ICIs to make the treatment more effective. However, the off-target immune activation caused by ICIs may lead to a broad spectrum of immune-related adverse events (irAEs) affecting multiple organ systems. Among irAEs, cardiotoxicity induced by ICIs, uncommon but fatal, has greatly offset survival benefits from ICIs, which is heartbreaking for both patients and clinicians. Consequently, such cardiotoxicity requires special vigilance, and it has become a common challenge both for patients and clinicians. This article reviewed the clinical manifestations and influence of cardiotoxicity from the view of patients and clinicians, elaborated on the underlying mechanisms in conjunction with animal studies, and then attempted to propose management strategies from a cardio-immuno-oncology multidisciplinary perspective.

CXCR5+TIM-3-PD-1+ stem-like cytotoxic CD8+ T cells: elevated in chronic rhinosinusitis and associated with disease severity

Background

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease with an autoimmune background. Altered expression levels of T cell immunoglobulin and mucin-domain containing-3 (TIM-3), C-X-C chemokine receptor type 5 (CXCR5), and programmed cell death protein 1 (PD-1) are implicated in the progression of inflammatory and autoimmune diseases. Moreover, CXCR5+TIM-3-PD-1+ stem-like cytotoxic T cells function as memory stem cells during chronic disease processes and retain cytotoxicity-related gene networks.

Objectives

To explore the expressions of CXCR5, TIM-3, and PD-1 on T cells and their correlation with clinical parameters in CRS.

Methods

Flow cytometry was used to assess the expressions and co-expressions of CXCR5, TIM-3, and PD-1 on T cells in the tissues of the paranasal sinus and peripheral blood of patients with CRS as well as healthy controls. Immunofluorescence was used to assess the co-localization of TIM-3, CXCR5, and PD-1 with T cells. The disease severity of our patients with CRS was evaluated using the Lund-Mackay score. A complete blood count was also performed for the patients with CRS.

Results

Expression levels of CXCR5 and PD-1 on T cells were significantly increased in the nasal tissues of patients with CRS. Compared with those in healthy controls, patients with CRS had high percentages of CXCR5+TIM-3-PD-1+ CD8+ and CD4+ T cells in nasal tissues, while no significant difference was observed in peripheral blood levels. Patients with CRS had a higher density of nasal CXCR5+TIM-3-PD-1+ T cells than that in healthy controls. CXCR5+TIM-3-PD-1+ CD8+ T cell levels in the nasal polyps of patients with CRS were negatively correlated with the patients' Lund-Mackay scores. The levels of CXCR5+TIM-3-PD-1+ T cells in nasal tissues were also negatively associated with disease duration and positively associated with the chronic inflammatory state of CRS.

Conclusions

The level of CXCR5+TIM-3-PD-1+ stem cell-like T cells, especially CXCR5+TIM-3-PD-1+ CD8+ T cells, is increased in CRS. Therefore, inducing CXCR5+TIM-3-PD-1+ T cell exhaustion may be an effective immunotherapy for CRS.

cGAS-STING and PD1/PDL-1 pathway in breast cancer: a window to new therapies

Breast cancer is a complex malignancy with diverse molecular and cellular subtypes and clinical outcomes. Despite advances in treatment, breast cancer remains a significant health challenge. However, recent advances in cancer immunotherapy have shown promising results in the treatment of breast cancer, particularly the use of inhibitors that target the immune checkpoint PD1/PDL1. Also, the cGAS-STING pathway, an important part of the innate immune response, has been considered as a major potential therapeutic target for breast cancer. In this narrative review, we provide an overview of the cGAS-STING and PD1/PDL-1 pathway in breast cancer, including their role in tumor development, progression, and response to treatment. We also discuss potential future directions for research.

Lysine demethylase 5B (KDM5B): A key regulator of cancer drug resistance

Chemoresistance, a roadblock in the chemotherapy process, has been impeding its effective treatment. KDM5B, a member of the histone demethylase family, has been crucial in the emergence and growth of malignancies. More significantly, KDM5B has recently been linked closely to cancer's resistance to chemotherapy. In this review, we explain the biological properties of KDM5B, its function in the emergence and evolution of cancer treatment resistance, and our hopes for future drug resistance-busting combinations involving KDM5B and related targets or medications.

Chronic non-bacterial osteomyelitis and immune checkpoint molecules

OBJECTIVE

We aimed to investigate the plasma levels and cell surface expression of two checkpoint molecules, TIM-3 (T cell immunoglobulin and mucin domain-containing protein 3) and PD-1 (programmed cell death protein 1), in pediatric patients with chronic non-bacterial osteomyelitis (CNO).

METHODS

Plasma samples of CNO patients were collected at diagnosis or during biologic agent treatment. Plasma levels of TIM-3 and PD-1 were measured using the sandwich enzyme-linked immunosorbent assay method, and the expression of the two immune checkpoint molecules on the cell surface was analyzed by isolating peripheral blood mononuclear cells by density gradient centrifugation technique.

RESULTS

Twenty-seven patients with CNO (14 boys, 51.9%) and six healthy controls (3 boys, 50%) were enrolled in the study. There were no age differences between CNO patients and healthy controls (median age 14.5 vs. 13.5 years, respectively, p=0.762). Of the CNO patients, 18 were included at the time of diagnosis while 9 were receiving biologic treatment at enrollment. The median plasma PD-1 levels were significantly lower in the CNO group than in the healthy controls (p=0.011). However, no significant difference was found in the cellular expression of PD-1 and TIM-3 on CD3+CD4+ T cells in patients and healthy controls (p=0.083 and p=0.245, respectively). There was also no statistically significant difference in plasma TIM-3 levels of the patient and control groups (p=0.981).

CONCLUSION

CNO is an autoinflammatory disease, and overall, our results suggest that T cell exhaustion may not be significant in CNO. Further research is needed to find out whether the immune checkpoints are mainly associated with autoimmunity but not autoinflammation. Key Points • The median plasma PD-1 levels were significantly lower in the CNO group than in the healthy controls. • No significant difference was found in the cellular expression of PD-1 and TIM-3 on CD3+CD4+ T cells in patients and healthy controls. • Our results suggest that T cell exhaustion may not be significant in CNO pathogenesis.

Altered levels of cytokine, T- and B-lymphocytes, and PD-1 expression rates in drug-naïve schizophrenia patients with acute phase

Many studies have investigated the changes of immune cells and proinflammatory cytokines in patients with acute schizophrenia, but few studies have investigated the functional phenotypes of immune cells and the expression rate of programmed cell death protein 1 (PD-1)/ programmed cell death-Ligand 1 (PD-L1). The aim of this study was to investigate the extent of immune cells activation, PD-1/PD-L1 expressions, and altered cytokine levels in drug-naïve schizophrenia patients with acute-phase. 23 drug-naïve schizophrenia patients in acute-phase and 23 healthy individuals were enrolled in this study as experimental and control groups, separately. Socio-demographic information including gender, age, duration of illness, and smoking status was collected for each subject. Beckman DXFLEX triple laser thirteen-color flow cytometer and self-contained software CytoFLEX flow cytometric analysis software were used to detect the expressions of PD-1/PD-L1 on CD4+/CD8+ T lymphocytes, B lymphocytes, monocytes and NK cells. BD Bioscience was used to examine the levels of cytokines including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, Interleukin (IL)-2, IL-4, IL-6, and IL-10. Drug-naïve schizophrenia patients in acute-phase had higher levels of peripheral blood CD4+ T lymphocytes and B lymphocytes, higher PD-1 expression in B lymphocytes, and lower levels of CD8+ T lymphocytes. In addition, IL-6 levels of peripheral blood were higher in schizophrenia patients (all P < 0.05). Significant immune stress was present in schizophrenia patients with acute-phase.

Boningmycin induces AMPK-mediated endoplasmic reticulum-associated degradation of PD-L1 protein in human cancer cells

Anti-PD-1/PD-L1 monoclonal antibodies have displayed remarkable clinical benefits and revolutionized the treatment of multiple tumor types, but the low response rates and immune-related adverse events limit their application, which promoting the development of small molecule agents to improve the efficacy of PD-1/PD-L1 blockade therapy. Boningmycin (BON), a new small molecule belonging to bleomycin (BLM) family, exhibits potent anticancer activity in vitro and in vivo, as well as negligible lung toxicity, thereby can be an alternative of BLM. However, understandings about the anticancer mechanism of BLM-related compounds are extremely rare, it remains unclear if they affect PD-L1 level in a manner similar to that of other antitumor drugs. In this study, we discover that BON significantly reduces PD-L1 protein level in NCI-H460 and HT-1080 cells. Meanwhile, BON decreases the protein level of PD-L1 in a tumor xenograft model of NCI-H460 cells. Nevertheless, the mRNA level is not influenced after BON exposure. Furthermore, BON-induced PD-L1 reduction is proteasome- dependent. By using specific inhibitors and RNA interference technology, we confirm that the decline of PD-L1 protein by BON is mediated by AMPK-activated endoplasmic reticulum-associated degradation pathway, which is like to the action of metformin. Last but not the least, BON has synergism on gefitinib in vitro and in vivo. In conclusion, it is the first report demonstrating that BON decreases PD-L1 protein level through AMPK-mediated endoplasmic reticulum-associated degradation pathway. These findings will benefit the clinical transformation of BON and aid in the elucidation of molecular mechanism of BLM-related compounds.

Cholinergic signaling influences the expression of immune checkpoint inhibitors, PD-L1 and PD-L2, and tumor hallmarks in human colorectal cancer tissues and cell lines

BACKGROUND

Cancer cells express immunosuppressive molecules, such as programmed death ligands (PD-L)1 and PD-L2, enabling evasion from the host's immune system. Cancer cells synthesize and secrete acetylcholine (ACh), acting as an autocrine or paracrine hormone to promote their proliferation, differentiation, and migration.

METHODS

We correlated the expression of PD-L1, PD-L2, cholinergic muscarinic receptor 3 (M3R), alpha 7 nicotinic receptor (α7nAChR), and choline acetyltransferase (ChAT) in colorectal cancer (CRC) tissues with the stage of disease, gender, age, risk, and patient survival. The effects of a muscarinic receptor blocker, atropine, and a selective M3R blocker, 4-DAMP, on the expression of immunosuppressive and cholinergic markers were evaluated in human CRC (LIM-2405, HT-29) cells.

RESULTS

Increased expression of PD-L1, M3R, and ChAT at stages III-IV was associated with a high risk of CRC and poor survival outcomes independent of patients' gender and age. α7nAChR and PD-L2 were not changed at any CRC stages. Atropine and 4-DAMP suppressed the proliferation and migration of human CRC cells, induced apoptosis, and decreased PD-L1, PD-L2, and M3R expression in CRC cells via inhibition of EGFR and phosphorylation of ERK.

CONCLUSIONS

The expression of immunosuppressive and cholinergic markers may increase the risk of recurrence of CRC. These markers might be used in determining prognosis and treatment regimens for CRC patients. Blocking cholinergic signaling may be a potential therapeutic for CRC through anti-proliferation and anti-migration via inhibition of EGFR and phosphorylation of ERK. These effects allow the immune system to recognize and eliminate cancer cells.

Structure of PD1 and its mechanism in the treatment of autoimmune diseases

PD-1 and CTLA-4 can play an important role in addressing the issue of autoimmune diseases. PD-1 is a transmembrane glycoprotein expressed on T, B, and Dentric cells. This molecule functions as a checkpoint in T cell proliferation. Ligation of PD-1 with its ligands inhibits the production of IL-2, IL-7, IL-10, and IL-12 as well as other cytokines by macrophages, natural killer (NK) cells, and T cells, which can suppress cell proliferation and inflammation. Today, scientists attempt to protect against autoimmune diseases by PD-1 inhibitory signals. In this review, we discuss the structure, expression, and signaling pathway of PD-1. In addition, we discuss the importance of PD-1 in regulating several autoimmune diseases, reflecting how manipulating this molecule can be an effective method in the immunotherapy of some autoimmune diseases.

Differential Gene Expression of Checkpoint Markers and Cancer Markers in Mouse Models of Spontaneous Chronic Colitis

The presence of checkpoint markers in cancer cells aids in immune escape. The identification of checkpoint markers and early cancer markers is of utmost importance to gain clarity regarding the relationship between colitis and progressive inflammation leading to cancer. Herein, the gene expression levels of checkpoint makers, cancer-related pathways, and cancer genes in colon tissues of mouse models of chronic colitis (Winnie and Winnie-Prolapse mice) using next-generation sequencing are determined. Winnie mice are a result of a Muc2 missense mutation. The identification of such genes and their subsequent expression and role at the protein level would enable novel markers for the early diagnosis of cancer in IBD patients. The differentially expressed genes in the colonic transcriptome were analysed based on the Kyoto Encyclopedia of Genes and Genomes pathway. The expression of several oncogenes is associated with the severity of IBD, with Winnie-Prolapse mice expressing a large number of key genes associated with development of cancer. This research presents a number of new targets to evaluate for the development of biomarkers and therapeutics.

ExoPD-L1: an assistant for tumor progression and potential diagnostic marker

The proliferation and function of immune cells are often inhibited by the binding of programmed cell-death ligand 1 (PD-L1) to programmed cell-death 1 (PD-1). So far, many studies have shown that this combination poses significant difficulties for cancer treatment. Fortunately, PD-L1/PD-1 blocking therapy has achieved satisfactory results. Exosomes are tiny extracellular vesicle particles with a diameter of 40~160 nm, formed by cells through endocytosis. The exosomes are a natural shelter for many molecules and an important medium for information transmission. The contents of exosomes are composed of DNA, RNA, proteins and lipids etc. They are crucial to antigen presentation, tumor invasion, cell differentiation and migration. In addition to being present on the surface of tumor cells or in soluble form, PD-L1 is carried into the extracellular environment by tumor derived exosomes (TEX). At this time, the exosomes serve as a medium for communication between tumor cells and other cells or tissues and organs. In this review, we will cover the immunosuppressive role of exosomal PD-L1 (ExoPD-L1), ExoPD-L1 regulatory factors and emerging approaches for quantifying and detecting ExoPD-L1. More importantly, we will discuss how targeted ExoPD-L1 and combination therapy can be used to treat cancer more effectively.

Clinical Significance of Non-Coding RNA Regulation of Programmed Cell Death in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a widely prevalent and malignantly progressive tumor. Most patients are typically diagnosed with HCC at an advanced stage, posing significant challenges in the execution of curative surgical interventions. Non-coding RNAs (ncRNAs) represent a distinct category of RNA molecules not directly involved in protein synthesis. However, they possess the remarkable ability to regulate gene expression, thereby exerting significant regulatory control over cellular processes. Notably, ncRNAs have been implicated in the modulation of programmed cell death (PCD), a crucial mechanism that various therapeutic agents target in the fight against HCC. This review summarizes the clinical significance of ncRNA regulation of PCD in HCC, including patient diagnosis, prognosis, drug resistance, and side effects. The aim of this study is to provide new insights and directions for the diagnosis and drug treatment strategies of HCC.

Prognostic Role of CD68+ and CD163+ Tumour-Associated Macrophages and PD-L1 Expression in Oral Squamous Cell Carcinoma: A Meta-Analysis

Background: Oral squamous cell carcinoma (OSCC) is a common malignant cancer in humans. An abundance of tumour associated macrophages (TAMs) create an immunosuppressive tumour microenvironment (TME). TAM markers (CD163 and CD68) are seen to serve as prognostic factors in OSCC. PD-L1 has seen to widely modulate the TME but its prognostic significance remains controversial. The aim of this meta-analysis is to evaluate the prognostic role of CD163⁺, CD68⁺ TAMs and PD-L1 in OSCC patients. Methods: Searches in PubMed, Scopus and Web of Science were performed; 12 studies were included in this meta-analysis. Quality assessment of included studies was performed according to REMARK guidelines. Risk of bias across studies was investigated according to the rate of heterogeneity. Meta-analysis was performed to investigate the association of all three biomarkers with overall survival (OS). Results: High expression of CD163⁺ TAMs were associated with poor overall survival (HR = 2.64; 95% Cl: [1.65, 4.23]; p < 0.0001). Additionally, high stromal expression of CD163⁺ TAMs correlated with poor overall survival (HR = 3.56; 95% Cl: [2.33, 5.44]; p < 0.00001). Conversely, high CD68 and PD-L1 expression was not associated with overall survival (HR = 1.26; 95% Cl: [0.76, 2.07]; p = 0.37) (HR = 0.64; 95% Cl: [0.35, 1.18]; p = 0.15). Conclusion: In conclusion, our findings indicate CD163⁺ can provide prognostic utility in OSCC. However, our data suggests CD68⁺ TAMs were not associated with any prognostic relevance in OSCC patients, whereas PD-L1 expression may prove to be a differential prognostic marker dependent on tumour location and stage of progression.

Overexpression of complement C5a indicates poor survival and therapeutic response in metastatic renal cell carcinoma

INTRODUCTION

Complement C5a is an important component of the innate immune system. An increasing number of reports have revealed the relevance of C5a in tumor progression; however, its exact role in metastatic renal cell carcinoma (mRCC) remains unknown.

METHODS

We evaluated C5a expression in tumor tissue microarrays of 231 mRCC patients and analyzed the relationship between C5a levels and clinical outcomes, and the expression of epithelial-mesenchymal transition (EMT)-related proteins, programmed cell death protein 1 (PD-1), and programmed cell death-ligand 1 (PD-L1). In-vitro functional experiments using exogenous C5a stimulation and C5a silencing in renal cell carcinoma cells were used to validate the tissue findings.

RESULTS

High C5a expression was associated with poor therapeutic responses, poor overall and progression-free survival, and high expression of EMT-related proteins and PD-1/PD-L1 in mRCC patients. Exogenous C5a promoted proliferation, migration, and invasion of renal cell carcinoma cells, and induced the expression of EMT-related proteins and PD-1/PD-L1. Conversely, C5a silencing inhibited migration and invasion of renal cell carcinoma cells and decreased the expression of EMT-related proteins and PD-1/PD-L1.

CONCLUSIONS

Our findings indicate that elevated C5a expression is associated with poor outcomes in patients with mRCC, and this effect may be partly attributed to the ability of C5a to promote EMT and PD-1/PD-L1 expression. C5a may be a potential novel target for the treatment of mRCC.

PD-1/PD-L1 axis in organ fibrosis

Fibrosis is a pathological tissue repair activity in which many myofibroblasts are activated and extracellular matrix are excessively accumulated, leading to the formation of permanent scars and finally organ failure. A variety of organs, including the lung, liver, kidney, heart, and skin, can undergo fibrosis under the stimulation of various exogenous or endogenous pathogenic factors. At present, the pathogenesis of fibrosis is still not fully elucidated, but it is known that the immune system plays a key role in the initiation and progression of fibrosis. Immune checkpoint molecules are key regulators to maintain immune tolerance and homeostasis, among which the programmed cell death protein 1/programmed death ligand 1 (PD-1/PD-L1) axis has attracted much attention. The exciting achievements of tumor immunotherapy targeting PD-1/PD-L1 provide new insights into its use as a therapeutic target for other diseases. In recent years, the role of PD-1/PD-L1 axis in fibrosis has been preliminarily explored, further confirming the close relationship among PD-1/PD-L1 signaling, immune regulation, and fibrosis. This review discusses the structure, expression, function, and regulatory mechanism of PD-1 and PD-L1, and summarizes the research progress of PD-1/PD-L1 signaling in fibrotic diseases.

Transarterial Chemoembolization Combined With Apatinib Plus PD-1 Inhibitors for Hepatocellular Carcinoma With Portal Vein Tumor Thrombus: A Multicenter Retrospective Study

INTRODUCTION

The aim of this study was to compare transarterial chemoembolization (TACE) combined with apatinib and PD-1 inhibitors (TACE-AP) with TACE combined with apatinib alone (TACE-A) in the treatment of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) and to explore the prognostic factors affecting the survival of patients.

METHODS

This retrospective study analyzed data of patients with HCC with PVTT who were treated with TACE-AP or TACE-A between December 2018 and June 2021. The primary end points of the study were progression-free survival (PFS) and overall survival (OS), and the secondary end points were objective response rate (ORR) and adverse events (AEs). Propensity score matching (PSM) and stabilized inverse probability weighting (sIPTW) analyses were used to reduce patient selection bias, and Cox regression analysis was used to analyze prognostic factors affecting patient survival.

RESULTS

Sixty-nine and 40 patients were included in the TACE-A and TACE-AP groups, respectively. After PSM and IPTW analyses, the median PFS and median OS in the TACE-AP group were significantly higher than those in the TACE-A group (PFS: after PSM, 6.9 vs 4.0 months, P < 0.001, after IPTW, 6.5 vs 5.1 months, P < 0.001; OS: after PSM, 14.6 vs 8.5 months P < 0.001, after IPTW, 16.1 vs 10.5 months, P < 0.001). After PSM and IPTW analyses, the tumor ORR in the TACE-AP group was significantly higher than that in the TACE-A group (PSM, 53.6% vs 17.9%, P = 0.005; IPTW, 52.5% vs 28.6%, P = 0.013). All treatment-related AEs were observed to be tolerated. Multivariate Cox regression analysis showed that the main prognostic factors affecting the survival of patients were tumor number, PVTT type, alpha-fetoprotein, and treatment mode.

DISCUSSION

In the treatment of patients with HCC with PVTT, TACE-AP significantly improved PFS, OS, and ORR, and the AEs were safe and controllable.

Structure-based small inhibitors search combined with molecular dynamics driven energies for human programmed cell death-1 (PD-1) protein

Human immune system is specialized in distinguishing normal cells from foreign particles mainly through proteins expressed on immune cells called 'checkpoints'. Immune checkpoints work as a switch to activate and deactivate immune responses. T cells express one of the immune checkpoint, human programmed cell death-1 (PD-1), which normally operates as an off-switch function to protect the normal cell from T-cell attack. Binding of PD-1 to its ligand, the programmed cell death ligand (PD-L1/2) expressed on myeloid/cancer cells, induce downstream inhibitory signals, leading to tumor immune evasion. Targeting PD-1 or PD-L1 can boost the immune response against cancer cells. To design novel small molecule inhibitors for the PD-1, in silico structure-based screening on pharmacophoric points and molecular docking were performed. Based on the docking score and significant binding interaction with the crucial residues of PD-1 (Thr59, Glu61, Ser62, Glu84, Arg86 and Ala132), compounds were selected from the ZINC20 database, and their dynamic behavior and conformational stability were examined through molecular dynamic simulations. Besides, the Molecular Mechanics/Generalized Born Surface Area (MM/GBSA) method was used to calculate the binding strength of each selected inhibitor complexed with PD-1. The binding energy calculations revealed that these selected inhibitors show a considerable affinity for PD-1. The selected novel inhibitors exhibit excellent drug-like and pharmacokinetic properties (absorption, distribution, metabolism, excretion and toxicity). In conclusion, the identified novel compounds (ZINC1443480030, ZINC1002854123, ZINC988238128, ZINC1481242350, ZINC1001739421, ZINC1220816434 and ZINC1167786692) from the current study can be validated in-vitro as potential PD-1 inhibitors and for discovery of novel drugs against PD-1 in the future.Communicated by Ramaswamy H. Sarma.

Porphyromonas gingivalis regulates atherosclerosis through an immune pathway

Atherosclerosis (AS) is a chronic inflammatory disease, involving a pathological process of endothelial dysfunction, lipid deposition, plaque rupture, and arterial occlusion, and is one of the leading causes of death in the world population. The progression of AS is closely associated with several inflammatory diseases, among which periodontitis has been shown to increase the risk of AS. Porphyromonas gingivalis (P. gingivalis), presenting in large numbers in subgingival plaque biofilms, is the “dominant flora” in periodontitis, and its multiple virulence factors are important in stimulating host immunity. Therefore, it is significant to elucidate the potential mechanism and association between P. gingivalis and AS to prevent and treat AS. By summarizing the existing studies, we found that P. gingivalis promotes the progression of AS through multiple immune pathways. P. gingivalis can escape host immune clearance and, in various forms, circulate with blood and lymph and colonize arterial vessel walls, directly inducing local inflammation in blood vessels. It also induces the production of systemic inflammatory mediators and autoimmune antibodies, disrupts the serum lipid profile, and thus promotes the progression of AS. In this paper, we summarize the recent evidence (including clinical studies and animal studies) on the correlation between P. gingivalis and AS, and describe the specific immune mechanisms by which P. gingivalis promotes AS progression from three aspects (immune escape, blood circulation, and lymphatic circulation), providing new insights into the prevention and treatment of AS by suppressing periodontal pathogenic bacteria.

Mediastinal lymph node removal ameliorates cytotoxic T-lymphocyte functions in patients with non-small cell lung cancer

INTRODUCTION

Mediastinal lymph node (MLN) removal by video-assisted mediastinoscopic lymphadenectomy (VAMLA) for preoperative cancer staging was reported to be associated with increased survival. The aim of this study was to evaluate the immunologic effects of complete MLN removal by VAMLA on cytotoxic T lymphocyte (CTL) phenotype and function.

METHODS

Seventeen patients with non-small cell lung cancer (NSCLC) (stage cT1-4N0-3M0-1A) and 20 healthy participants were included in this study. Blood samples were collected before and 4 weeks after the procedure. Lymphocytes were isolated from the removed MLNs. CTL phenotypes and functions were evaluated by flow cytometry. Plasma levels of soluble programmed cell death protein 1 (sPD-1), soluble programmed cell death protein 1 ligand, and soluble CTL antigen 4 (sCTLA-4) were measured with enzyme-linked immunosorbent assay.

RESULTS

The ratio of the immunosenescent CTLs (CD3⁺CD8⁺CD28^-) was increased in peripheral blood and MLNs of the patients with NSCLC compared to controls (p = 0.037), and MLN removal did not change this ratio. PD-1 and CTL antigen 4 expressions were significantly reduced in peripheral blood CTLs after MLN removal by VAMLA (p = 0.01 and p = 0.01, respectively). Granzyme A expression was significantly reduced in the peripheral blood CTLs of the patients compared to controls (p = 0.006) and MLN removal by VAMLA significantly improved Granzyme A expression in CTLs (p = 0.003). Plasma concentrations of sPD-1 and sCTLA-4 remained unchanged after VAMLA.

CONCLUSION

CTLs in the MLNs and peripheral blood of the patients with NSCLC had an immunosenescent phenotype, increased immune checkpoint receptor expression, and impaired cytotoxicity. MLN removal by VAMLA improved these phenotypic and functional characteristics of CTLs. These changes may explain the potential contribution of VAMLA to improved survival.

Configuring Therapeutic Aspects of Immune Checkpoints in Lung Cancer

Immune checkpoints are unique components of the body's defense mechanism that safeguard the body from immune responses that are potent enough to harm healthy body cells. When proteins present on the surface of T cells recognize and bind to the proteins present on other tumor cells, immune checkpoints are triggered. These proteins are called immunological checkpoints. The T cells receive an on/off signal when the checkpoints interact with companion proteins. This might avert the host's immune system from eliminating cancer cells. The standard care plan for the treatment of non-small cell lung cancer (NSCLC) has been revolutionized with the use of drugs targeting immune checkpoints, in particular programmed cell death protein 1. These drugs are now extended for their potential to manage SCLC. However, it is acknowledged that these drugs have specific immune related adverse effects. Herein, we discuss the use of immune checkpoint inhibitors in patients with NSCLC and SCLC, their outcomes, and future perspectives.

Siah2 inhibitor and the metabolic antagonist Oxamate retard colon cancer progression and downregulate PD1 expression

BACKGROUND

Solid tumors such as colon cancer are characterized by rapid and sustained cell proliferation, which ultimately results in hypoxia, induction of hypoxia-inducible factor-1α (HIF-1α), and activation of glycolysis to promote tumor survival and immune evasion. We hypothesized that a combinatorial approach of menadione (MEN) as an indirect HIF-1α inhibitor and sodium oxamate (OX) as a glycolysis inhibitor may be a promising treatment strategy for colon cancer.

OBJECTIVES

We investigated the potential efficacy of this combination for promoting an antitumor immune response and suppressing tumor growth in a rat model of colon cancer.

METHODS

Colon cancer was induced by once-weekly subcutaneous injection of 20 mg/kg dimethylhydrazine (DMH) for 16 weeks. Control rats received the vehicle and then no further treatment (negative control) or MEN plus OX for 4 weeks (drug control). Dimethylhydrazine-treated rats were then randomly allocated to four groups: DMH alone group and other groups treated with MEN, OX, and a combination of (MEN and OX) for 4 weeks. Serum samples were assayed for the tumor marker carbohydrate antigen (CA19.9), while expression levels of HIF-1α, caspase-3, PHD3, LDH, and PD1 were evaluated in colon tissue samples by immunoassay and qRT-PCR. Additionally, Ki-67 and Siah2 expression levels were examined by immunohistochemistry.

RESULTS

The combination of MEN plus OX demonstrated a greater inhibitory effect on the expression levels of HIF-1α, Siah2, LDH, Ki-67, and PD1, and greater enhancement of caspase-3 and PHD3 expression in colon cancer tissues than either drug alone.

CONCLUSION

Simultaneous targeting of hypoxia and glycolysis pathways by a combination of MEN and OX could be a promising therapy for inhibiting colon cancer cell growth and promoting antitumor immunity [1].

Cold Nanozyme for Precise Enzymatic Antitumor Immunity

Precise catalysis is pursued for the biomedical applications of artificial enzymes. It is feasible to precisely control the catalysis of artificial enzymes via tunning the temperature-dependent enzymatic kinetics. The safety window of cold temperatures (4-37 °C) for the human body is much wider than that of thermal temperatures (37-42 °C). Although the development of cold-activated artificial enzymes is promising, there is currently a lack of suitable candidates. Herein, a cold-activated artificial enzyme is presented with Bi₂Fe₄O₉ nanosheets (NSs) as a paradigm. The as-obtained Bi₂Fe₄O₉ NSs possess glutathione oxidase (GSHOx)-like activity under cold temperature due to their pyroelectricity. Bi₂Fe₄O₉ NSs trigger the cold-enzymatic death of tumor cells via apoptosis and ferroptosis, and minimize the off-target toxicity to normal tissues. Moreover, an interventional device is fabricated to intelligently and remotely control the enzymatic activity of Bi₂Fe₄O₉ NSs on a smartphone. With Bi₂Fe₄O₉ NSs as an in situ vaccine, systemic antitumor immunity is successfully activated to suppress tumor metastasis and relapse. Moreover, blood biochemistry analysis and histological examination indicate the high biosafety of Bi₂Fe₄O₉ NSs for in vivo applications. This cold nanozyme provides a strategy for cancer vaccines, which can benefit the precise control over catalytic nanomedicines.

Cancer Immunotherapy: The Checkpoint between Chronic Colitis and Colorectal Cancer

Inflammatory Bowel Disease (IBD) is a group of diseases that cause intestinal inflammation and lesions because of an abnormal immune response to host gut microflora. Corticosteroids, anti-inflammatories, and antibiotics are often used to reduce non-specific inflammation and relapse rates; however, such treatments are ineffective over time. Patients with chronic colitis are more susceptible to developing colorectal cancer, especially those with a longer duration of colitis. There is often a limit in using chemotherapy due to side effects, leading to reduced efficacy, leaving an urgent need to improve treatments and identify new therapeutic targets. Cancer immunotherapy has made significant advances in recent years and is mainly categorized as cancer vaccines, adoptive cellular immunotherapy, or immune checkpoint blockade therapies. Checkpoint markers are expressed on cancer cells to evade the immune system, and as a result checkpoint inhibitors have transformed cancer treatment in the last 5-10 years. Immune checkpoint inhibitors have produced long-lasting clinical responses in both single and combination therapies. Winnie mice are a viable model of spontaneous chronic colitis with immune responses like human IBD. Determining the expression levels of checkpoint markers in tissues from these mice will provide insights into disease initiation, progression, and cancer. Such information will lead to identification of novel checkpoint markers and the development of treatments with or without immune checkpoint inhibitors or vaccines to slow or stop disease progression.

Peptide-Drug Conjugates: A New Hope for Cancer Management

Cancer remains the leading cause of death worldwide despite advances in treatment options for patients. As such, safe and effective therapeutics are required. Short peptides provide advantages to be used in cancer management due to their unique properties, amazing versatility, and progress in biotechnology to overcome peptide limitations. Several appealing peptide-based therapeutic strategies have been developed. Here, we provide an overview of peptide conjugates, the better equivalents of antibody-drug conjugates, as the next generation of drugs for required precise targeting, enhanced cellular permeability, improved drug selectivity, and reduced toxicity for the efficient treatment of cancers. We discuss the basic components of drug conjugates and their release action, including the release of cytotoxins from the linker. We also present peptide-drug conjugates under different stages of clinical development as well as regulatory and other challenges.

EIF2S2 is a novel independent prognostic biomarker and correlated with immune infiltrates in hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) is a highly malignant disease with poor prognosis. It is urgent to find effective biomarkers. Eukaryotic Translation Initiation Factor 2 Subunit Beta (EIF2S2) is a subunit of heterotrimeric G protein EIF2, and its function is still unclear. We studied the role of EIF2S2 in the malignant progression of liver cancer and its relationship with immune infiltration.

Methods: Download the RNA expression and clinical information of EIF2S2 from the Cancer Genome Atlas (TCGA) database, analyze the relationship between the expression of EIF2S2 and the prognosis and clinicopathological characteristics of HCC, analyze the differential genes by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and tumor related immune infiltrating cells. The Protein expression level of EIF2S2 was obtained from Human Protein Atlas (HPA) databases. The relationship between EIF2S2 expression and immune infiltrates in HCC was analyzed on TIMER 2.0. The data processing analysis based on R language. Drug Sensitivity data from Genomics of Drug Sensitivity in Cancer (GDSC).

Results: EIF2S2 is highly expressed in HCC patients and is associated with poor prognosis. The expression of EIF2S2 was also correlated with age, clinical stage and pathological grade. Univariate and multivariate COX regression analysis showed that EIF2S2 was an independent risk factor for survival. The receiver operating characteristic (ROC) curve of EIF2S2 also confirmed the diagnostic value of EIF2S2 in HCC patients. Through GO and KEGG enrichment analysis, EIF2S2 expression was found to be closely related to some immune pathways. The expression of EIF2S2 was correlated with memory B cell, plasma B cell, CD8+ T cell, CD4+ resting memory T cell and the expression of some immune checkpoints, such as PDCD1, TIGIT and CTLA-4. It is also more sensitive to paclitaxel, sunitinib and other drugs.

Conclusion: This study shows that EIF2S2 can be used as a prognostic factor for HCC, which is closely related to immune infiltration and immune checkpoints, and may play a potential regulatory role in predicting drug sensitivity.

Soluble programmed cell death-ligand 1 as a new potential biomarker associated with acute coronary syndrome

Background

Soluble programmed cell death-ligand 1 (sPD-L1) has been well documented to activate immunosuppression and is considered an essential predictor of negative clinical outcomes for several malignances and inflammatory conditions. However, the clinical significance of sPD-L1 in the peripheral blood of patients with coronary artery disease (CAD) remains unclear. The aim of this study was to assess the correlations of sPD-L1 with clinical features in CAD patients and evaluate the diagnostic value of this protein in CAD.

Methods

A total of 111 CAD patients and 97 healthy volunteers who served as healthy controls (HCs) were consecutively enrolled. Plasma levels of sPD-L1 were measured with an amplified enzyme-linked immunosorbent assay (ELISA), and hs-CRP was measured with a C-reactive protein assay kit. The levels of other inflammatory cytokines were assessed in 88 CAD patients and 47 HCs by a multiparameter immunoluminescence flow cytometry detection technique. A logistic regression model was used to assess the independent association of sPD-L1 with acute coronary syndrome (ACS). The correlation between sPD-L1 and inflammatory cytokines in ACS was also assessed.

Results

Plasma levels of sPD-L1 were significantly increased in CAD patients, especially those with ACS. Univariate logistic regression analysis revealed that sPD-L1 (OR: 3.382, 95% CI: 2.249–5.084, p &lt; 0.001), BMI, hypertension, diabetes, dyslipidemia, previous MI, and the levels of HDL-C, LDL-C and hs-CRP were significantly associated with ACS. sPD-L1 (OR: 3.336, 95% CI: 1.084–6.167, p = 0.001) was found to be independently and significantly associated with ACS in the subsequent multivariable logistic regression analysis. Additionally, elevated plasma sPD-L1 levels were associated with increased interleukin-6 and interleukin-8 levels in ACS patients. Receiver operating characteristic (ROC) analysis showed that the AUC of sPD-L1 for diagnosing ACS was 0.778, with a sensitivity of 73.9% and a specificity of 73.4%, which was comparable with that of the inflammatory biomarker hs-CRP.

Conclusion

The plasma sPD-L1 level reflects the severity of CAD, is associated with inflammatory responses and is a potential new biomarker for the diagnosis of ACS.

Activation Markers on B and T Cells and Immune Checkpoints in Autoimmune Rheumatic Diseases

In addition to identifying the major B- and T-cell subpopulations involved in autoimmune rheumatic diseases (ARDs), in recent years special attention has been paid to studying the expression of their activation markers and immune checkpoints (ICPs). The activation markers on B and T cells are a consequence of the immune response, and these molecules are considered as sensitive specific markers of ARD activity and as promising targets for immunotherapy. ICPs regulate the activation of the immune response by preventing the initiation of autoimmune processes, and they modulate it by reducing immune cell-induced organ and tissue damage. The article considers the possible correlation of ICPs with the activity of ARDs, the efficacy of specific ARD treatments, and the prospects for the use of activation molecules and activation/blocking ICPs for the treatment of ARDs.

Pilot Study: Immune Checkpoints Polymorphisms in Greek Primary Breast Cancer Patients

Background: Breast cancer is the most prevalent and second leading cause of cancer-related death in women worldwide. Despite early detection and better treatment therapies, 30% of early-stage breast cancer patients still develop recurrent disease. Breast cancer is a heterogeneous disease comprising several molecular subtypes, commonly classified into clinical subtypes based on the hormone receptor status. These subtypes included luminal A and luminal B, which have different prognoses. Breast cancer development and progression involve many factors. Polymorphisms of PD-1, PD-L1, and PD-L2 genes have been previously associated with high risk and prognosis of cancer. However, no studies have associated PD-1, PD-L1, and PD-L2 polymorphisms with primary breast cancer subtypes. Hence, this study evaluated functional single nucleotide polymorphisms of PD-1, PD-L1, and PD-L2 with primary breast cancer subtypes, luminal A, and luminal B. In addition, we evaluated the PD-L1 protein expression in relation to primary breast cancer subtypes and stages. Results: There were no significant differences in the allele frequencies of PD-1 polymorphisms (rs2227981 G>A, rs7421861 A>G, and rs11568821 C>T) and PD-L1 polymorphisms (rs10815225 C>T and rs2282055 T>G) when compared with the general European population. However, a significant difference was detected in one of the PD-L2 polymorphisms (rs1009759 A>G), with the G allele higher in breast cancer patients than in the general European population. A higher prevalence of the T allele of PD-L1 polymorphism rs2282055 T>G was observed in luminal B breast cancer patients compared with luminal A. No significant difference was detected in other polymorphisms. We also observed that the PD-L1 rs2282055 TT genotype was more prevalent in luminal B breast cancer patients compared with luminal A. Our results found no association of the selected SNPs in the PDCD1 gene with breast cancer risk. Similarly, the protein expression data showed that PD-L1 and PD-L2 are associated with an aggressive phenotype, Luminal B, and advanced breast cancer stage. Conclusion: These findings suggest that immune checkpoint polymorphisms are associated with the risk and subtypes of breast cancer.

Bifidobacterium infantis regulates the programmed cell death 1 pathway and immune response in mice with inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is caused by an abnormal immune response. Programmed cell death 1 (PD-1) is an immunostimulatory molecule, which interacts with PD ligand (PD-L1) playing a prime important role among autoimmune diseases. Bifidobacterium infantis (B. infantis) can promote the differentiation of CD (cluster of differentiation) 4⁺ T cells into regulatory T cells (Tregs). Tregs participate in the development of IBD and may be related to disease activity. B. infantis amplify the expression level of PD-1, PD-L1 and Tregs’ nuclear transcription factor forkhead box protein 3 (Foxp3). But the mechanism of B. infantis on PD-1/PD-L1 signaling remains unclear.

AIM

To explore the mechanism of B. infantis regulating the immune response in IBD.

METHODS

Forty-eight-week-old BALB/c mice were randomly divided into five groups: The control group, dextran sulphate sodium (DSS) model group, DSS + B. infantis group, DSS + B. infantis + anti-PD-L1 group, and DSS + anti-PD-L1 group. The control group mice were given drinking water freely, the other four groups were given drinking water containing 5% DSS freely. The control group, DSS model group, and DSS + anti-PD-L1 group were given normal saline (NS) 400 μL daily by gastric lavage, and the DSS + B. infantis group and DSS + B. infantis + anti-PD-L1 group were given NS and 1 × 10⁹ colony-forming unit of B. infantis daily by gastric lavage. The DSS + B. infantis + anti-PD-L1 group and DSS + anti-PD-L1 group were given 200 μg of PD-L1 blocker intraperitoneally at days 0, 3, 5, and 7; the control group, DSS + anti-PD-L1 group, and DSS + B. infantis group were given an intraperitoneal injection of an equal volume of phosphate buffered saline (PBS). Changes in PD-L1, PD-1, Foxp3, interleukin (IL)-10, and transforming growth factor β (TGF-β) 1 protein and gene expression were observed. Flow cytometry was used to observe changes in CD4⁺, CD25⁺, Foxp3⁺ cell numbers in the blood and spleen.

RESULTS

Compared to the control group, the expression of PD-1, Foxp3, IL-10, and TGF-β1 was significantly decreased in the intestinal tract of the DSS mice (P < 0.05). Compared to the control group, the proportion of CD4⁺, CD25⁺, Foxp3⁺ cells in spleen and blood of DSS group was visibly katabatic (P < 0.05). B. infantis upgraded the express of PD-L1, PD-1, Foxp3, IL-10, and TGF-β1 (P < 0.05) and increased the proportion of CD4⁺, CD25⁺, Foxp3⁺ cells both in spleen and blood (P < 0.05). After blocking PD-L1, the increase in Foxp3, IL-10, and TGF-β1 protein and gene by B. infantis was inhibited (P < 0.05), and the proliferation of CD4⁺, CD25⁺, Foxp3⁺ cells in the spleen and blood was also inhibited (P < 0.05). After blocking PD-L1, the messenger ribonucleic acid and protein expression of PD-1 were invariant.

CONCLUSION

It is potential that B. infantis boost the proliferation of CD4⁺, CD25⁺, Foxp3⁺ T cells in both spleen and blood, as well as the expression of Foxp3 in the intestinal tract by activating the PD-1/PD-L1 pathway.

Characteristics of changes in double positive CD4+CD8+ T cells in liver transplantation

Although double positive CD4⁺CD8⁺ T (DPT) cells has been reported to be involved in some diseases, their trajectory and function as associated with liver transplantation (LT) remain unclear. In the present study, we found that the number of DPT cells was increased in the blood and liver tissue of LT patients. Meanwhile, we compared the distribution of DPT cells in peripheral blood samples and in penetrating liver tissue between liver rejection versus non-rejection patients, as well as the proportion of DPT cells as a function of the extent of liver rejection. The number of DPT cells in the rejection group was significantly increased. An analysis of the spatial distance and correlations between DPT and Treg cells, revealed that these cells showed a high degree of contiguity. In a mouse liver transplant model, the number of DPT cells were significantly increased in liver tissue, and the number of CD8⁺ T cells gradually increased, while CD4⁺ T cells decreased as a function of time post-transplantation. Expression level of PD-1 in DPT cells also increased in a temporally-dependent manner post liver transplantation and the changes of PD-1⁺ DPT cells were related to the degree of liver transplant rejection. In DPT cells interacting with Treg, there was an increased expression of PD-1, which enhanced cellular exhaustion. In conclusion, the capacity for DPT cells to induce immune tolerance may represent a new and important protocol for use in targeting treatments for the prevention of liver transplant rejection.

PD-1 inhibitor induces myocarditis by reducing regulatory T cells, activating inflammatory responses, promoting myocardial apoptosis and autophagy

The present study aimed to explore the pathogenesis of autoimmune myocarditis induced by PD-1 inhibitors and their potential therapeutic targets. Mouse models of autoimmune myocarditis induced by PD-1 inhibitor in mouse models of polymyositis were established. The expression level of PD-1 and regulatory T cells (Tregs), CD4, CD8 + T cells, inflammation, apoptosis and autophagy-related factors, including IL-6, TGF-β, AMA-M2, Fas/FasL, LC3 and p62 were detected in peripheral blood, muscle or myocardium of mice in each group, using ELISA, RT-PCR, Western Blot and immunofluorescence. In addition, HE and TUNEL staining and ultrastructural scanning were performed on the myocardium of mice in each group. Results showed that the expression level of PD-1 in the two myositis groups was significantly lower than that in the control group, and the level of PD-1 was lower in the myocarditis group than that in the polymyositis group. In the myocardium, TGF-β, p62, and Tregs proportion showed the same expression level trend as PD-1, while CD8, IL-6, IL-10 and LC3 showed the opposite trend. Levels of Fas/FasL were significantly higher in both myositis groups, but were slightly lower in the myocarditis group, as was AMA-M2. Inflammation, apoptosis, and autophagy were observed in both myositis groups, but were more severe in the myocarditis group. In summary, the decreased expression level of PD-1 leads to decreased Tregs level in the myocardium, aggravated inflammatory response, apoptosis and autophagy, which may be the pathological mechanism of myocarditis induced by PD-1 inhibitors.

Treatment of patients with cancer using PD‑1/PD‑L1 antibodies: Adverse effects and management strategies (Review)

In 2020, there were an estimated 19.3 million new cancer cases and close to 10 million cancer deaths worldwide. Cancer remains one of the leading causes of death. In recent years, with the continuous improvement of our understanding of tumor immunotherapy, immunotherapeutics, such as immune checkpoint inhibitors, have gradually become a hot spot for tumor treatment. Amongst these, programmed cell death protein 1/programmed cell death protein ligand 1 (PD‑1/PD‑L1) related inhibitors, such as nivolumab and pembrolizumab, atezolizumab, avelumab and durvalumab have been shown to exhibit a high level of efficacy in several types of tumors. It has been confirmed that these inhibitors play an important role in the anti‑tumor process, significantly improving the survival rate of patients and delaying the progress of the underlying cancer. However, its method of therapeutic interference and potential for damaging the immune system has caused concern regarding its suitability. As these adverse effects are caused by an immune response to endogenous tissues, they are designated as immune‑related adverse events (irAEs). In this review, the typical irAEs reported in recent years and the management strategies adopted are highlighted, to serve as a reference in assessing the clinical response to these adverse reactions.