Immune Checkpoint Molecules Research Articles

Integrative multimodality spatial biomarker analysis for tailoring checkpoint inhibitor therapies in non-small cell lung cancer.

e14664 Background: Checkpoint inhibitor therapy has become a cornerstone in the treatment of non-small cell lung cancer (NSCLC). However, the response to checkpoint inhibitors varies widely among patients, with some experiencing significant benefits and others facing adverse reactions without therapeutic gain. The ability to accurately predict which patients will benefit from checkpoint inhibitor therapies is essential for enhancing treatment efficacy and minimizing side effects. In this context, the identification and analysis of predictive biomarkers, including the expression of immune checkpoint proteins such as PD-L1 and TIGIT, and the comprehensive profiling of cytokines in the tumor microenvironment, are of paramount importance. Methods: A multimodal strategy was employed to identify predictive biomarkers for checkpoint inhibitor therapy in non-small cell lung cancer (NSCLC). This approach integrated metabolic, transcriptomic, and proteomic data to achieve a thorough insight into the biomarkers likely to influence patient responses. The diverse data sets were fused through advanced machine learning techniques, creating a holistic dataset. Analysis of this integrated dataset facilitated the discovery of multimodal biomarker signatures, offering the potential to predict which NSCLC patients would positively respond to checkpoint inhibitor treatments. Results: Initial observations revealed considerable variability in the expression of PD-L1 and TIGIT alongside other immune checkpoint molecules, across different regions of the tumor microenvironment in non-small cell lung cancer (NSCLC). Multimodal biomarker signatures, encompassing distinct expressions of immune checkpoint inhibitors, cytokine levels, and the presence of immune cells, showed a strong correlation with patient outcomes following treatment with immune checkpoint inhibitors. Conclusions: Our research highlights the significant promise of using a multimodal stratification method to unravel the complexities of non-small cell lung cancer (NSCLC) and to predict patient responses to immune checkpoint inhibitors. Through the integration of metabolomic, transcriptomic, and proteomic data, we discovered distinctive biomarker signatures that were highly predictive of responses to these immunotherapies.

Identification and validation of a novel 17 coagulation-related genes signature for predicting prognostic risk in colorectal cancer

BackgroundPatients with colorectal cancer commonly experience disturbances in coagulation homeostasis. Activation of the coagulation system contributes to cancer-associated thrombosis as the second risk factor for death in cancer patients. This study intended to discover coagulation-related genes and construct a risk model for colorectal cancer patients' prognosis. MethodsCoagulation-related genes were identified by searching coagulation-related pathways in the Molecular Signatures Database. Transcriptomic data and clinical data were downloaded from the Cancer Genome Atlas and Gene Expression Omnibus datasets. Univariate Cox and backward stepwise regression were utilized to identify prognosis-related genes and construct a predictive risk model for the training cohort. Next, survival analysis determines the risk model's predictive power, correlation with clinicopathological characteristics, and nomogram. Additionally, we characterized the variances in immune cell infiltration, somatic mutations, immune checkpoint molecules, biological functions, and drug sensitivity between the high- and low-score patients. ResultEight hundred forty-five genes were obtained by searching the theme term "coagulation" after de-duplication. After univariate regression analysis, 69 genes correlated with prognosis were obtained from the Cancer Genome Atlas dataset. A signature consisting of 17 coagulation-related genes was established through backward stepwise regression. The Kaplan-Meier curve indicated a worse prognosis for high-score patients. Time-dependent receiver operating characteristic curve analysis demonstrated high accuracy in predicting overall survival. Further, the results were validated by two independent datasets (GSE39582 and GSE17536). Combined with clinicopathological characteristics, the risk model was proven to be an independent prognostic factor to predict poor pathological status and worse prognosis. Furthermore, high-score patients had significantly higher stromal cell infiltration. Low-score patients were associated with high infiltration of resting memory CD4+ T cells, activated CD4+ T cells, and T follicular helper cells. The low-score patients exhibited increased expression of immune checkpoint genes, and this might be relevant to their better prognosis. High-score patients exhibited lower IC50 values of Paclitaxel, Rapamycin, Temozolomide, Cyclophosphamide, etc. The differential signaling pathways mainly involve the calcium signaling pathway and the neuroactive ligand-receptor interaction. Lastly, a nomogram was constructed and showed a good prediction. ConclusionThe prognostic signature of 17 coagulation-related genes had significant prognostic value for colorectal cancer patients. We expect to improve treatment modalities and benefit more patients through research on molecular features.

Machine learning‐based identification of a cell death‐related signature associated with prognosis and immune infiltration in glioma

AbstractAccumulating evidence suggests that a wide variety of cell deaths are deeply involved in cancer immunity. However, their roles in glioma have not been explored. We employed a logistic regression model with the shrinkage regularization operator (LASSO) Cox combined with seven machine learning algorithms to analyse the patterns of cell death (including cuproptosis, ferroptosis, pyroptosis, apoptosis and necrosis) in The Cancer Genome Atlas (TCGA) cohort. The performance of the nomogram was assessed through the use of receiver operating characteristic (ROC) curves and calibration curves. Cell‐type identification was estimated by using the cell‐type identification by estimating relative subsets of known RNA transcripts (CIBERSORT) and single sample gene set enrichment analysis methods. Hub genes associated with the prognostic model were screened through machine learning techniques. The expression pattern and clinical significance of MYD88 were investigated via immunohistochemistry (IHC). The cell death score represents an independent prognostic factor for poor outcomes in glioma patients and has a distinctly superior accuracy to that of 10 published signatures. The nomogram performed well in predicting outcomes according to time‐dependent ROC and calibration plots. In addition, a high‐risk score was significantly related to high expression of immune checkpoint molecules and dense infiltration of protumor cells, these findings were associated with a cell death‐based prognostic model. Upregulated MYD88 expression was associated with malignant phenotypes and undesirable prognoses according to the IHC. Furthermore, high MYD88 expression was associated with poor clinical outcomes and was positively related to CD163, PD‐L1 and vimentin expression in the in‐horse cohort. The cell death score provides a precise stratification and immune status for glioma. MYD88 was found to be an outstanding representative that might play an important role in glioma.

Exploration of different immunogenomic TMEs in gastric cancer based on HER2 and PD-L1 expression.

e16073 Background: Recent results from the KEYNOTE-811 study showed that first-line pembrolizumab was superior to placebo with respect to progression-free survival (PFS) in combination with trastuzumab and chemotherapy in patients with HER2 positive metastatic gastric cancer (GC). Interestingly, In the subgroup analysis, the PFS benefit with pembrolizumab was significant in patients with tumors with PD-L1 CPS ≥1, whereas there was no benefit in the small subgroup of patients with tumors with CPS < 1. Therefore, this study is to investigate immune-genomic differences in the tumor microenvironment according to the composition of surrounding cells and the expression status of HER2 and PD-L1. Methods: Utilizing single cell RNA sequencing (scRNA seq) and TCR sequencing, we examined 14 HER2 positive and 18 negative primary GC samples with CPS score based on PD-L1 IHC 22C3 pharmDx. Among the HER2-positive group, there were 4 samples in the CPS < 1 (negative) and 10 samples in the CPS ≥1 (positive) group. In the HER2 negative group, there were 6 samples in the CPS < 1 and 12 samples in the CPS ≥1. Results: First, when analyzing the distribution of total cells according to HER2 status, in the HER2 positive group, more endothelial cells ( p= 0.034) and fibroblasts ( p= 0.054) appeared in the PD-L1 negative group compared to the PD-L1 positive group, while there was no difference in the HER2 negative group. Furthermore, Through TCR analysis, the exhausted and cytotoxic score exhibit contrasting trends between HER2 negative and positive groups. In HER2-positive patients, the exhausted and cytotoxic score appear significantly higher in the CPS negative group. Next, we evaluated the proportion of immune cells according to HER2 status. The observed of CD4 Treg ( p= 0.084) and CD8 exhausted T (Tex), ( p= 0.036) cells was increased in the HER2 positive compared to the negative. When regrouped according to PD-L1 expression, only the HER2 positive group showed a tendency to increase the observation of CD4 Treg and CD8 Tex cells compared to positive in PD-L1 negative. In addition, we investigated whether the expression pattern of other immune checkpoint molecules differed depending on the PD-L1 expression pattern in both HER2 positive and negative patients. In the HER2 negative group, the expression of immune checkpoint proteins was similar regardless of the CPS expression group, or the expression of some proteins was higher in the CPS positive group. In other hands, in HER2 positive, CPS < 1 group had higher expression of immune checkpoint proteins, such as PDCD1, LAG2, BTLA, VISTA and TIGHT. Conclusions: The high proportion of CD4 Tregs, CD8 Tex and the elevated exhausted score in the subgroup with CPS < 1 in HER2 positive GCs suggesting immune exclusive environment compared to her-2 and PD-L1 coexpressing group. Considering increased expression of immune checkpoint proteins other than PD-1/PD-L1, for patients with HER2-positive and CPS < 1, combination therapy with other immune checkpoint inhibitors rather than anti-PD-1/PD-L1 may be suggested.

A novel nomogram model for lung adenocarcinoma subtypes based on RNA-modification regulatory genes

BackgroundIn non-small cell lung cancer (NSCLC), lung adenocarcinoma (LUAD) is the most common subtype. RNA modification has become the frontier and hotspot of current tumor research. ResultsIn this study, 109 genes that regulate RNA modifications were identified according to The Cancer Genome Atlas (TCGA). A differential gene expression analysis identified 46 differentially expressed RNA modification regulatory genes (DERRGs). LUAD samples were stratified into two distinct clusters based on the expression of these DERRGs. A significant correlation was observed between these clusters and patient survival rates, as well as clinical features. Furthermore, a four-DERRG signature (EIF3B, HNRNPC, IGF2BP1, and METTL3) developed using LASSO regression. According to the calculated risk scores from this signature, LUAD patients were categorized into high-risk and low-risk groups. Patients in the low-risk group exhibited a more favorable prognosis. A prognostic nomogram was crafted, integrating the four-DERRGs signature with clinical parameters. The nomogram was revealed that OS, age, clinical stage, immune cell infiltration, and immune checkpoint molecule expression were significantly linked to the OS of LUAD. GSEA analysis found that the DERRGs were primarily regulated immune pathways. ConclusionsThis study developed four DERRGs signatures and formulated a nomogram model for precise prognosis estimation in LUAD patients. The study's insights are instrumental for advancing diagnosis, prognosis, and therapeutic strategies for LUAD.

Targeting Histone 3 Variants Epigenetic Landscape and Inhibitory Immune Checkpoints: An Option for Paediatric Brain Tumours Therapy.

Despite little progress in survival rates with regular therapies, which do not provide complete care for curing pediatric brain tumors (PBTs), there is an urgent need for novel strategies to overcome the toxic effects of conventional therapies to treat PBTs. The co-inhibitory immune checkpoint molecules, e.g., CTLA-4, PD-1/PD-L1, etc., and epigenetic alterations in histone variants, e.g., H3K27me3 that help in immune evasion at tumor microenvironment have not gained much attention in PBTs treatment. However, key epigenetic mechanistic alterations, such as acetylation, methylation, phosphorylation, sumoylation, poly (ADP)-ribosylation, and ubiquitination in histone protein, are greatly acknowledged. The crucial checkpoints in pediatric brain tumors are cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed cell death protein-1 (PD-1) and programmed death-ligand 1 (PDL1), OX-2 membrane glycoprotein (CD200), and indoleamine 2,3-dioxygenase (IDO). This review covers the state of knowledge on the role of multiple co-inhibitory immunological checkpoint proteins and histone epigenetic alterations in different cancers. We further discuss the processes behind these checkpoints, cell signalling, the current scenario of clinical and preclinical research and potential futuristic opportunities for immunotherapies in the treatment of pediatric brain tumors. Conclusively, this article further discusses the possibilities of these interventions to be used for better therapy options.

Novel HLA-Ilo/HLA-IIhi phenotype and immune evasion in triple-negative breast cancer.

1095 Background: Immune checkpoint inhibitors (ICIs) are a therapeutic option for patients with triple-negative breast cancer (TNBC), however resistance and non-response remain an unmet clinical need. Human leukocyte antigens (HLAs) play an important role in induction and regulation of host immune responses. Downregulation of HLA class I expression is one mechanism by which cancer cells evade the immune control. HLA typing and understanding the role of HLAs can provide valuable insight into optimizing immunotherapy efficacy in TNBC. In this study, we evaluate the association of HLA I/II phenotypes with biomarkers of tumor immune interaction and overall survival (OS) in a real-world breast cancer cohort. Methods: A targeted RNA-seq assay was performed on 142 breast cancer samples. HLA I and HLA II expressions were estimated as average expression of HLA-A, HLA-B, HLA-C and HLA-DP, HLA-DQ, HLA-DR genes, respectively, by a percentile rank values [0-100]. Cohen D index was used to estimate ratio of HLA-I and II in each specimen. We particularly focused on the HLA-Ilow(lo)/HLA-IIhigh(hi) ratio given a proposed mechanism of immune escape by tumor cells (low expression of HLA-I) in response to a highly immune infiltrated state where there is increased expression of HLA-II by the immune cells. We studied the co-expression of HLA-Ilo/HLA-IIhi with other checkpoint targets using Spearman correlation(rs). The impact of HLA phenotypes on OS were analyzed using Kaplan-Meier analysis and Chi-squared assessed associations. Results: The cohort consisted of 106 non-TNBC (ER+/HER2- or HER2+) and 36 TNBC tumors. Most samples originated from metastatic visceral sites (96, 68%) followed by primary breast (33, 23%), and lymph nodes (13, 9%). Among TNBC, HLA-Ilo/HLA-IIhi phenotype displayed a significantly higher co-expression of immune checkpoint targets such as PD-1, PD-L1, TIM3 and LAG-3 than HLA-Ihi/HLA-IIlo phenotype (p<0.001). However, this difference was not observed between HLA-Ilo/HLA-IIhi and HLA-Ihi/HLA-IIlo phenotypes in non-TNBC tumors. In TNBC, there was no significant difference in OS between HLA-Ilo/HLA-IIhi when compared to HLA-Ihi/HLA-IIlo (43 vs. 37 months, p=0.21). Similarly, in non-TNBC, there were no significant differences in OS between HLA-Ilo/HLA-IIhi when compared to HLA-Ihi/HLA-IIlo (107 vs. 66 months, p=0.5). Conclusions: Concurrent loss of HLA I with increased HLA II expression was associated with co-expression of immune checkpoint molecules indicative of immune escape mechanism but not survival outcomes in TNBC. This same effect was not seen in non-TNBC with a more immunologically silent environment. Characterization of HLA phenotypes by immune profiling provides insight into the complex interplay of tumor immune microenvironment and offers an opportunity for developing novel approaches to overcome the immune evasion with cancer vaccines and adoptive cell therapies in TNBC.

Leukocyte immunoglobulin-like receptor (LILRB2)-targeted JTX-8064 plus the anti-PD1 inhibitor JTX-4014 (pimivalimab) in immune-checkpoint inhibitor (ICl) pretreated patients (pts) with advanced or metastatic renal cell cancer (mRCC): Results from the multi-stage phase 1-2 INNATE trial.

4531 Background: Disease progression following treatment of mRCC pts with ICl-based therapy (tx) is nearly universal, warranting evaluation of novel immunotherapeutic approaches. LILRB2 is an immune checkpoint molecule expressed primarily in cells of myeloid origin (e.g., monocytes/macrophages). Inhibition of LILRB2 reprograms macrophages from an immunosuppressive (M2) to an immunostimulatory (M1) phenotype. JTX-8064 is a humanized monoclonal antibody that binds to LILRB2, blocking its interaction with MHC1 molecules. Preclinical studies suggest that JTX-8064 can overcome anti-PD(L)1 resistance mechanisms. Here we report the results of an expansion cohort of previously-treated mRCC pts in INNATE, a multi-stage phase 1-2 trial of JTX-8064 in combination with anti-PD1 agents in solid tumors. Methods: Pts with pathologically-confirmed clear cell mRCC progressing on or after anti-PD(L)1 tx in the most recent prior line, acceptable end-organ function, and ECOG PS 0-1 were treated with JTX-8064 700 mg and JTX-4014 500 mg IV q3 weeks. Primary endpoint was overall response rate (ORR); secondary endpoints were safety, disease control rate (DCR), progression-free survival (PFS), & overall survival (OS). A Simon 2-stage design (n=10+19) was employed where ORR >= 20% was deemed to be of further interest versus null hypothesis of ORR <= 5%, with alpha=0.05. Results: 31 pts were enrolled, with median age of 64 years (range 38-85); 84% males; 16% Hispanic; 93% White; 45% PS=0; 71% one prior tx line. Of 28 pts evaluable for response, 1 CR, 1 PR, 14 SD (6 SD>= 6 months), and 11 PD were seen for an ORR of 7% & DCR of 54%.Median PFS was 4 months (95%CI: 2, 6.8); 12-month OS was 75% (95%CI: 55,88). Tx-related adverse events (AE) of all grades were reported in 11 pts (45%), most commonly fatigue (16%) & diarrhea (10%). Only 4 protocol-related G3-4 AEs were reported: thrombocytopenia (G4); diplopia, diarrhea, & bradycardia (all G3). Three on-study deaths (hypotension; cardiorespiratory arrest; & unknown) were deemed unrelated to protocol tx. Conclusions: While ORR did not meet the protocol-defined efficacy target, evidence of anti tumor activity was seen in ICI pre-treated mRCC pts with combination JTC-8064 + JTX-4014. Treatment was reasonably well-tolerated. Identification & evaluation of clinical and molecular phenotypes most likely to benefit from LILRB2-targeted therapies are warranted. Clinical trial information: NCT04669899 .

SAT-396 Differences in the intrahepatic expression of immune checkpoint molecules on T cells and natural killer cells in chronic HBV patients

SAT-396 Differences in the intrahepatic expression of immune checkpoint molecules on T cells and natural killer cells in chronic HBV patients

Definitive chemoradiotherapy induces T-cell-inflamed tumor microenvironment in unresectable locally advanced esophageal squamous cell carcinoma.

Chemoradiotherapy (CRT) modulates the tumor immune microenvironment of multiple cancer types, including esophageal cancer, which potentially induces both immunogenicity and immunosuppression by upregulating the presentation of tumor-specific antigens and immune checkpoint molecules in tumors, respectively. The prognostic effects of immune modification by CRT in esophageal squamous cell carcinoma (ESCC) remain controversial because of the lack of detailed immunological analyses using paired clinical specimens before and after CRT. We aimed to clarify the immunological changes in the tumor microenvironment caused by CRT and elucidate the predictive importance of clinical response and prognosis and the rationale for the necessity of subsequent programmed cell death protein 1 (PD-1) inhibitor treatment. In this study, we performed a comprehensive immunological analysis of paired biopsy specimens using multiplex immunohistochemistry before and after CRT in patients with unresectable locally advanced ESCC. CRT significantly increased the intra-tumoral infiltration and PD-1 expression of CD8+ T cells and conventional CD4+ T cells but decreased those of regulatory T cells and the accumulation of tumor-associated macrophages. Multivariate analysis of tumor-infiltrating T-cell phenotypes revealed that the density of PD-1+CD8+ T cells in the tumor after CRT could predict a confirmed complete response and favorable survival. This study showed that CRT improved the immunological characteristics of unresectable locally advanced ESCC and identified the density of PD-1+CD8+ T cells as a predictive factor for prognosis. This finding supports the rationale for the necessity of subsequent PD-1 inhibitor treatment.

Integrative analysis indicates the potential values of ANKRD53 in stomach adenocarcinoma.

Ankyrin repeat domain 53 (ANKRD53) plays an important role in maintaining chromosome integrity and stability, and chromosome instability is associated with cancer. Through integrative analysis, this study investigates the potential value of ANKRD53 in stomach adenocarcinoma (STAD). RNA-seq and scRNA-seq data were used for integrative analysis based on online databases. Expression of ANKRD53 was confirmed by RT-PCR after bioinformatic analysis. Kaplan-Meier and Cox regression analyses were performed to evaluate the prognostic value of ANKRD53 in STAD. Gene set enrichment analysis (GSEA) was performed to evaluate ANKRD53-related signaling pathways. In addition, the interaction of ANKRD53 with immunity was also investigated. RT-PCR in STAD cell lines confirmed that ANKRD53 was downregulated in STAD samples compared to normal samples in the online databases. As an independent predictive biomarker, ANKRD53 was combined with other clinicopathological parameters to create a prognostic nomogram. Using GSEA, ANKRD53 was found to be involved in five pathways, including the TGF-β signaling pathway. Further investigation revealed that ANKRD53 was associated with immune checkpoint molecules, immunological pathways, and immunotherapy, in addition to MSI, TMB and neoantigens. In addition, scRNA-seq data revealed that ANKRD53 is mainly expressed in CD8+ T and dendritic cells. ANKRD53 is an important biomarker for STAD that deserves further attention.

Evaluation of ARID1A as a Potential Biomarker for Predicting Response to Immune Checkpoint Inhibitors in Patients with Endometrial Cancer.

AT-rich interaction domain 1A (ARID1A) has been proposed as a new biomarker for predicting response to immune checkpoint inhibitors (ICIs). The predictive value of ARID1A for predicting ICI effectiveness has not been reported for endometrial cancer. Therefore, we investigated whether ARID1A negativity predicts ICI effectiveness for endometrial cancer treatment. We evaluated ARID1A expression, tumor-infiltrating lymphocytes (CD8+), and immune checkpoint molecules (PD-L1/PD-1) by immunostaining endometrial samples from patients with endometrial cancer. Samples in which any of the four mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) were determined to be negative via immunostaining were excluded. In the ARID1A-negative group, microsatellite instability (MSI) status was confirmed via MSI analysis. Of the 102 samples investigated, 25 (24.5%) were ARID1A-negative. CD8 and PD-1 expression did not differ significantly between the ARID1A-negative group and the ARID1A-positive group; however, the ARID1A-negative group showed significantly lower PD-L1 expression. Only three samples (14.2%) in the ARID1A-negative group showed high MSI. Sanger sequencing detected three cases of pathological mutation in the MSH2-binding regions. We also established an ARID1A-knockout human ovarian endometriotic epithelial cell line (HMOsisEC7 ARID1A KO), which remained microsatellite-stable after passage. ARID1A negativity is not suitable as a biomarker for ICI effectiveness in treating endometrial cancer.

TIGIT stimulation suppresses autoimmune uveitis by inhibiting Th17 cell infiltration.

T cell immunoglobulin and ITIM domain (TIGIT) is an immune checkpoint molecule that suppresses T cell activation and promotes an immunosuppressive environment to suppress autoimmune diseases. However, the impact of a TIGIT agonist as a treatment for ocular autoimmune disease has not been investigated. We examined TIGIT expression on T helper 17 (Th17) and regulatory T cells (Tregs), the role of TIGIT on experimental autoimmune uveitis and Th17 cells, and the impact of Treg generation following TIGIT stimulation. TIGIT stimulation at the onset of clinical symptoms reduced the severity of uveitis and suppressed infiltration of Th17 cells into the eye. Further, Tregs from mice treated with the TIGIT agonist were capable of suppressing experimental autoimmune uveitis in recipient mice. This report demonstrates that stimulation of TIGIT at onset of disease suppresses symptoms and allows for induction of regulatory immunity that provides resistance to uveitis.

FAP Serves as a Prognostic Biomarker in Head and Neck Squamous Cell Carcinoma.

Head and neck squamous cell carcinoma (HNSCC) poses significant challenges with poor survival rates and limited therapeutic strategies. Our study, using The Cancer Genome Atlas (TCGA) data, assesses cancer-associated fibroblast (CAF) gene signatures' clinical relevance. In our analysis across TCGA tumor types, differential gene expression analysis revealed that fibroblast activation protein (FAP) is upregulated in tumor tissues and associated with poorer survival rates in HNSCC. Furthermore, mechanistic studies employing gene-silencing techniques substantiated that FAP knockout led to a significant decrease in cellular proliferation, invasion, and migration in HNSCC cell lines. Through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses, we established that high FAP expression correlates with vital biological processes such as extracellular matrix organization, angiogenesis, and cellular motility. Importantly, FAP was found to regulate these processes by promoting the expression of key proteins involved in epithelial-mesenchymal transition-related pathways. Additionally, our analysis revealed a significant correlation between FAP expression and the expression profiles of immune checkpoint molecules, underscoring its potential role in immune modulation. Collectively, our findings illuminate FAP's pivotal role in HNSCC pathogenesis and its potential as a prognostic biomarker and therapeutic target. This research lays the groundwork for understanding the multifaceted roles and regulatory mechanisms of CAFs in HNSCC, thereby offering valuable perspectives for the development of targeted therapeutic strategies aimed at improving patient outcomes.

Immune checkpoint inhibitors: breakthroughs in cancer treatment.

Over the past two decades, immunotherapies have increasingly been considered as first-line treatments for most cancers. One such treatment is immune checkpoint blockade (ICB), which has demonstrated promising results against various solid tumors in clinical trials. Monoclonal antibodies (mAbs) are currently available as immune checkpoint inhibitors (ICIs). These ICIs target specific immune checkpoints, including cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed cell death protein 1 (PD-1). Clinical trial results strongly support the feasibility of this immunotherapeutic approach. However, a substantial proportion of patients with cancer develop resistance or tolerance to treatment, owing to tumor immune evasion mechanisms that counteract the host immune response. Consequently, substantial research focus has been aimed at identifying additional ICIs or synergistic inhibitory receptors to enhance the effectiveness of anti-PD-1, anti-programmed cell death ligand 1 (anti-PD-L1), and anti-CTLA-4 treatments. Recently, several immune checkpoint molecular targets have been identified, such as T cell immunoreceptor with Ig and ITIM domains (TIGIT), mucin domain containing-3 (TIM-3), lymphocyte activation gene-3 (LAG-3), V-domain immunoglobulin suppressor of T cell activation (VISTA), B and T lymphocyte attenuator (BTLA), and signal-regulatory protein α (SIRPα). Functional mAbs targeting these molecules are under development. CTLA-4, PD-1/PD-L1, and other recently discovered immune checkpoint proteins with distinct structures are at the forefront of research. This review discusses these structures, as well as clinical progress in mAbs targeting these immune checkpoint molecules and their potential applications.

Checkpoint Inhibitors in Dogs: Are We There Yet?

Immune checkpoint inhibitors (ICI) have revolutionised cancer treatment in people. Immune checkpoints are important regulators of the body's reaction to immunological stimuli. The most studied immune checkpoint molecules are programmed death (PD-1) with its ligand (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) with its ligands CD80 (B7-1) and CD86 (B7-2). Certain tumours can evade immunosurveillance by activating these immunological checkpoint targets. These proteins are often upregulated in cancer cells and tumour-infiltrating lymphocytes, allowing cancer cells to evade immune surveillance and promote tumour growth. By blocking inhibitory checkpoints, ICI can help restore the immune system to effectively fight cancer. Several studies have investigated the expression of these and other immune checkpoints in human cancers and have shown their potential as therapeutic targets. In recent years, there has been growing interest in studying the expression of immune checkpoints in dogs with cancer, and a few small clinical trials with ICI have already been performed on these species. Emerging studies in veterinary oncology are centred around developing and validating canine-targeted antibodies. Among ICIs, anti-PD-1 and anti-PD-L1 treatments stand out as the most promising, mirroring the success in human medicine over the past decade. Nevertheless, the efficacy of caninized antibodies remains suboptimal, especially for canine oral melanoma. To enhance the utilisation of ICIs, the identification of predictive biomarkers for treatment response and the thorough screening of individual tumours are crucial. Such endeavours hold promise for advancing personalised medicine within veterinary practice, thereby improving treatment outcomes. This article aims to review the current research literature about the expression of immune checkpoints in canine cancer and the current results of ICI treatment in dogs.

STAT3 Expression and Its Correlation with PD-L1 Expression in Non-Hodgkin's Lymphoma and Hodgkin's Lymphoma at Dr. Saiful Anwar Regional Public Hospital in Malang, Indonesian Population.

Lymphomas are malignant lymphocyte neoplasms that globally account for 10% of cancers in individuals aged <20 years. Malignant lymphomas are divided into Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). Despite the availability of many therapeutic modalities for lymphoma, such as Brentuximab vedotin, Nivolumab, and Pembrolizumab, it is still necessary to identify appropriate strategies with minimal side effects. Immunotherapy is a promising approach, exemplified by targeting JAK/STAT3 signaling, which can inhibit tumor growth and enhance antitumor immune responses. Hence, STAT3 (signal transducer and activator of transcription 3) is a promising therapeutic target. PD-L1 (programmed death-ligand 1), an immune checkpoint molecule, is used as a frontline treatment for various cancers. This study aims to determine STAT3 expression and its correlation with PD-L1 expression in NHL and HL to serve as a basis for further research on anti-STAT3 and its combination with other therapy targets. Samples were obtained from paraffin blocks of patients with confirmed diagnoses of NHL and HL, and then immunohistochemical staining was carried out with PD-L1 and STAT3 antibodies. The collected data were then analyzed using SPSS. Among the 10 HL patients, no patients (0%) expressed STAT3, while nine patients (90%) expressed PD-L1. Among the 10 NHL patients, 1 patient (10%) expressed STAT3, while six patients (60%) expressed PD-L1. There were no significant differences in STAT3 expression and PD-L1 expression between HL patients and NHL patients. There was no correlation between STAT3 and PD-L1 expression in HL and NHL because almost all STAT3 expressions were negative. Although this study revealed no differences between STAT3 and PD-L1 expression in HL and NHL and no significant correlation between STAT3 and PD-L1 expression in HL and NHL, this may serve as the basis for understanding the role of STAT3 and PD-L1 in the regulation of HL and NHL, which may be useful for further research targeting STAT3 and PD-L1 immunotherapy in HL and NHL.

GAS-Luc2 Reporter Cell Lines for Immune Checkpoint Drug Screening in Solid Tumors.

Recent studies highlight the integral role of the interferon gamma receptor (IFNγR) pathway in T cell-mediated cytotoxicity against solid but not liquid tumors. IFNγ not only directly facilitates tumor cell death by T cells but also indirectly promotes cytotoxicity via myeloid phagocytosis in the tumor microenvironment. Meanwhile, full human ex vivo immune checkpoint drug screening remains challenging. We hypothesized that an engineered gamma interferon activation site response element luciferase reporter (GAS-Luc2) can be utilized for immune checkpoint drug screening in diverse ex vivo T cell-solid tumor cell co-culture systems. We comprehensively profiled cell surface proteins in ATCC's extensive collection of human tumor and immune cell lines, identifying those with endogenously high expression of established and novel immune checkpoint molecules and binding ligands. We then engineered three GAS-Luc2 reporter tumor cell lines expressing immune checkpoints PD-L1, CD155, or B7-H3/CD276. Luciferase expression was suppressed upon relevant immune checkpoint-ligand engagement. In the presence of an immune checkpoint inhibitor, T cells released IFNγ, activating the JAK-STAT pathway in GAS-Luc2 cells, and generating a quantifiable bioluminescent signal for inhibitor evaluation. These reporter lines also detected paracrine IFNγ signaling for immune checkpoint-targeted ADCC drug screening. Further development into an artificial antigen-presenting cell line (aAPC) significantly enhanced T cell signaling for superior performance in these ex vivo immune checkpoint drug screening platforms.

A Prospective Study Investigating Immune Checkpoint Molecule and CD39 Expression on Peripheral Blood Cells for the Prognostication of COVID-19 Severity and Mortality.

In patients with COVID-19, broad panels of immune checkpoint molecules (ICPMs) and the purinergic signaling have not been studied in parallel. We aimed to perform in-depth immunophenotyping of major cell subsets present in human peripheral blood of COVID-19 patients and controls using PD1, TIM3, LAG3, TIGIT, and CD200R, as well as CD39, as markers for the purinergic signaling pathway. We studied 76 COVID-19 patients and 12 healthy controls using peripheral blood mononuclear cells on flow cytometry. Univariable and multivariable statistics were performed. All ICPMs studied were significantly overexpressed on different cell subsets of COVID-19 patients when compared with healthy controls. Elevated lactate dehydrogenase; C-reactive protein; age; and high expression of CD45+, CD39+CD45+, TIM3+CD39+CD4+CD45+, and TIM3+CD39+CD8+CD3+CD4+ cells were significantly associated with severe COVID-19. On multivariable analysis, however, only high expression of CD39+CD45+ (OR 51.4, 95% CI 1.5 to 1763) and TIM3+CD39+CD4+CD3+CD45+ (OR 22.6, 95% CI 1.8 to 277) cells was an independent predictor for severe COVID-19. In conclusion, numerous ICPMs are overexpressed in COVID-19 patients when compared with healthy controls, suggesting a pathophysiological role of these molecules in SARS-CoV-2 infection. However, only TIM3 in co-expression with CD39 remained as a significant independent prognostic ICPM on multivariable analysis. The flow cytometric evaluation of TIM3+CD39+CD4+CD3+CD45+, as well as CD39+CD45+, is a powerful tool for the prognostication of COVID-19 patients on hospital admission.

Immune checkpoint inhibition as a therapeutic strategy for HIV eradication: current insights and future directions.

HIV-1 infection contributes substantially to global morbidity and mortality, with no immediate promise of an effective prophylactic vaccine. Combination antiretroviral therapy (ART) suppresses HIV replication, but latent viral reservoirs allow the virus to persist and reignite active replication if ART is discontinued. Moreover, inflammation and immune disfunction persist despite ART-mediated suppression of HIV. Immune checkpoint molecules facilitate immune dysregulation and viral persistence. However, their therapeutic modulation may offer an avenue to enhance viral immune control for patients living with HIV-1 (PLWH). The success of immune checkpoint inhibitor (ICI) therapy in oncology suggests that targeting these same immune pathways might be an effective therapeutic approach for treating PLWH. Several ICIs have been evaluated for their ability to reinvigorate exhausted T cells, and possibly reverse HIV latency, in both preclinical and clinical HIV-1 studies. Although there are very encouraging findings showing enhanced CD8 + T-cell function with ICI therapy in HIV infection, it remains uncertain whether ICIs alone could demonstrably impact the HIV reservoir. Moreover, safety concerns and significant clinical adverse events present a hurdle to the development of ICI approaches. This review provides an update on the current knowledge regarding the development of ICIs for the remission of HIV-1 in PWH. We detail recent findings from simian immunodeficiency virus (SIV)-infected rhesus macaque models, clinical trials in PLWH, and the role of soluble immune checkpoint molecules in HIV pathogenesis.