Prospect for immune checkpoint blockade: dynamic and comprehensive monitorings pave the way

Biomarkers of immunotherapy in non-small cell lung cancer

Immunotherapy has markedly improved the survival rate of patients with non-small cell lung cancer (NSCLC) and has introduced a new era in lung cancer treatment. However, not all patients with lung cancer benefit from checkpoint blockade, and some suffer from notable immunotoxicities. Thus, it is crucial to identify potential biomarkers suitable for screening the population that may benefit from immunotherapy. Based on the current clinical trials, the aim of the present study was to review the biomarkers for immune checkpoint inhibition, as well as other effective, invalid and hyperprogression markers that may have the potential to better predict responders to immunotherapy among patients with NSCLC. All these biomarkers may be incorporated into the predictive utility of bio-score systems and decision-making algorithms, to better guide the application of immunotherapy in the clinical setting.

Tumour immune cell infiltration and survival after platinum-based chemotherapy in high-grade serous ovarian cancer subtypes: A gene expression-based computational study

Background

Increasing evidence supports that the immune infiltration of tumours is associated with prognosis. Here, we sought to assess the relevance of the cellular composition of the immune infiltrate to survival after platinum-based chemotherapy amongst patients with high-grade serous ovarian cancer and evaluate these effects by molecular subtype.

Methods

We searched publicly available databases and identified 13 studies with more than 2000 patients. We estimated the proportions of 22 immune cell subsets by using a computational approach (CIBERSORT). Then, we investigated the associations between each immune cell subset and progression-free survival (PFS) and overall survival (OS), with cellular proportions modelled as quartiles.

Findings

A high fraction of M1 [hazard ratio (HR) = 0.92, 95% confidence interval (CI) = 0.86–0.99] and M0 (HR = 0.93, 95% CI = 0.87–0.99) macrophages emerged as the most closely associated with favourable OS. Neutrophils were associated with poor OS (HR = 1.06, 95% CI = 1.00–1.13) and PFS (HR = 1.10, 95% CI = 1.02–1.13). Amongst the immunoreactive tumours, the M0 macrophages and the CD8+ T cells were associated with improved OS, whereas the M2 macrophages conferred worse OS. Interestingly, PD-1 was associated with good OS (HR=0.89, 95% CI = 0.80–1.00) and PFS (HR=0.89, 95% CI = 0.79–1.01) in this subtype. Four subgroups of tumours with distinct survival patterns were identified using immune cell proportions with unsupervised clustering.

Interpretation

Further investigations of the quantitative cellular immune infiltrations in tumours may contribute to therapeutic advances.

NEDD4 Negatively Regulates GITR via Ubiquitination in Immune Microenvironment of Melanoma

Introduction

Melanoma is a common skin cancer that is usually associated with poor clinical outcomes. Recently, the immune checkpoint GITR has been identified as a promising target for immunotherapy of melanoma. In this study, we aimed to investigate the post-translational regulation mechanism of GITR in melanoma.

Methods

Western blotting was used to evaluate the protein expression of NEDD4, GITR and Foxp3. Real-time PCR (RT-PCR) was performed to determine expression levels of NEDD4, GITR, Foxp3 and IL-2. Cell viability was detected by MTT assay. The ubiquitination of GITR was evaluated by immunoprecipitation. NEDD4 expression data and melanoma survival data were obtained from The Cancer Genome Atlas (TCGA) and cBioPortal databases.

Results

We demonstrate that E3 ligase NEDD4 binds to GITR and mediates ubiquitination and degradation of GITR. Overexpression of NEDD4 inhibits anti-tumor immunity mediated by T cells against melanoma cells. We also found that the expression of NEDD4 is increased in metastatic melanoma. High NEDD4 expression level is correlated with the poor prognosis of melanoma patients.

Discussion

In summary, our findings demonstrated that E3 ligase NEDD4 mediates ubiquitination and degradation of GITR and suppresses T-cell-mediated-killings on melanoma cells. Our work highlighted the E3 ligase NEDD4 as a novel prognosis biomarker and therapeutic target for melanoma.

Checkpoint blockade in solid tumors and B-cell malignancies, with special consideration of the role of CD200

In the ontogeny of a normal immune response, a series of checkpoints must be overcome to ensure that unwanted and/or harmful self-directed activation responses are avoided. Many of the molecules now known to be active in this overseeing of the evolving immune activation cascade, contributing inhibitory signals to dampen an overexuberant response, belong to the immunoglobulin supergene family. These include members of the CD28/CTLA-4:B7.1/B7.2 receptor/ligand family, PD-1 and PDL-1, CD200 and CD200R, and the more recently described V-domain immunoglobulin suppressor of T-cell activation and its ligand (VSIG-3/IGSF11). Unfortunately, from the point of view of improving immunotargeting of cancer cells, triggering these checkpoint inhibitory signaling pathways, so necessary to maintain self-tolerance, simultaneously acts to prevent effective tumor immunity. The recent development of reagents, predominantly antibodies, to act as checkpoint blockade agents, has had a dramatic effect on human cancer treatment, with a marked reported success for anti-CTLA-4 and PD-1 in particular in clinical trials. This review provides a general overview of the data now available showing the promise of such treatments to our cancer armamentarium and elaborates in depth on the potential promise of what can be regarded as an underappreciated target molecule for checkpoint blockade in chronic lymphocytic leukemia and solid tumors, CD200.