Single-Cell Analysis Reveals a CD4+ T-cell Cluster That Correlates with PD-1 Blockade Efficacy

Deciphering CD4+ T cell-mediated responses against cancer

It's been long thought that CD8+ cytotoxic T cells play a major role in T cell-mediated antitumor responses, whereas CD4+ T cells merely provide some assistance to CD8+ T cells as the "helpers." In recent years, numerous studies support the notion that CD4+ T cells play an indispensable role in antitumor responses. Here, we summarize and discuss the current knowledge regarding the roles of CD4+ T cells in antitumor responses and immunotherapy, with a focus on the molecular and cellular mechanisms behind these observations. These new insights on CD4+ T cells may pave the way to further optimize cancer immunotherapy.

Potential predictors of the pathologic response after neoadjuvant chemoimmunotherapy in resectable non-small cell lung cancer: a narrative review

Background and Objective

Neoadjuvant chemoimmunotherapy (NACI) is the standard of care for patients with resectable non-small cell lung cancer (NSCLC). Although the pathological complete response (pCR) after NACI reportedly exceeds 20%, an optimal predictor of pCR is yet to be established. This review aims to examine the possible predictors of pCR after NACI.

Methods

We identified research article published between 2018 and 2022 in English by the PubMed database. Fifty research studies were considered as relevant article, and were examined to edit information for this narrative review.

Key Content and Findings

Recently, several studies have explored potential biomarkers for the pathological response after NACI. For example, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) imaging, tumor microenvironment (TME), genetic alternation such as circulating tumor DNA (ctDNA), and clinical markers such as neutrophil-to-lymphocyte ratio (NLR) and smoking signature were assessed in patients with resectable NSCLC to predict the pathological response after NACI. Based on the PET response criteria, the complete metabolic response (CMR) achieved a positive predictive value (PPV) of 71.4% for predicting pCR, and the decreasing rate of post-therapy maximum standardized uptake value (SUVmax) after NACI substantially correlated with the major pathological response (MPR). TME, as a significant marker for MPR in tumor specimens, was identified as an increase in CD8+ T cells and decrease in CD3+ T cells or Foxp3 T cells. Considering blood samples, TME comprised an increase in CD4+PD-1+ cells or natural killer cells and a decrease in CD3+CD56+CTLA4+ cells, total T cells, Th cells, myeloid-derived suppressor cells (MDSCs), or regulatory T cells. Although low pretreatment levels of ctDNA and undetectable ctDNA levels after NACI were markedly associated with survival, the relationship between ctDNA levels and pCR remains elusive. Moreover, the patients with a high baseline NLR had a low incidence of pCR. Heavy smoking (>40 pack-years) was favorable for predicting pathological response.

Conclusions

A reduced rate of 18F-FDG uptake post-NACI and TME-related surface markers on lymphocytes could be optimal predictors for pCR. However, the role of these pCR predictors for NACI remains poorly validated, warranting further investigations. This review focuses on predictive biomarkers for pathological response after NACI in patients with resectable NSCLC.

Peripheral CD4+ T cells correlate with response and survival in patients with advanced non-small cell lung cancer receiving chemo-immunotherapy

Background

The aim of the present study was to explore the potential of peripheral immune cells in predicting the response and prognosis of patients with advanced non-small cell lung cancer (NSCLC) receiving anti-PD-1 immunotherapy and platinum-based chemotherapy.

Participants and Methods

We utilized flow cytometry to examine the levels and dynamics of blood immune cells in 79 advanced NSCLC patients treated with the chemoimmunotherapy between December 2019 and January 2022. The pre- and post-treatment blood samples were collected within 3 days prior to the initiation of the first and third cycle of combination treatment, respectively. Progression-free survival (PFS) and overall survival (OS) analyses were conducted using Kaplan-Meier method and Cox regression models.

Results

The pre-treatment CD4+/Total T cells ratio was significantly higher in responders than non-responders (P < 0.05). The levels of pre-treatment total lymphocytes (P = 0.012), total B lymphocytes (P = 0.025), and NK cells (P = 0.022), and post-treatment NK cells (P = 0.011) and NKT cells (P = 0.035) were significantly associated with OS. Post-treatment CD8+/Total T cells ratio was positively correlated with OS (P = 0.038). In multivariate analysis, post-treatment NK cells and post-treatment CD4+CD8+/Total T cells ratio were negatively associated with OS (hazard ratio [HR] = 10.30, P = 0.038) and PFS (HR = 1.95, P = 0.022), respectively. Notably, significantly positive correlations were observed between CD4+/Total T cells ratio and prognosis both before and after treatment (P < 0.05).

Conclusion

To summarize, our finding reveals that high CD4+/total T cells ratio was associated with favorable response and prognosis, highlighting its potential as a predictive biomarker to guide the selection of likely responders to platinum and anti-PD-1 combination therapy.

Clinical Outcome of Nivolumab Plus Ipilimumab in Patients with Locally Advanced Non-Small-Cell Lung Cancer with Relapse after Concurrent Chemoradiotherapy followed by Durvalumab

Nivolumab plus ipilimumab showed promising efficacy in patients with metastatic non-small-cell lung cancer (NSCLC). The efficacy of the nivolumab plus ipilimumab combination regimen in NSCLC patients who relapse after durvalumab consolidation following concurrent chemoradiotherapy (CCRT) has not been determined. Between January 2021 and June 2022, clinical data were retrospectively extracted from the medical records of patients with NSCLC who received nivolumab plus ipilimumab after CCRT and durvalumab consolidation. A total of 30 patients were included in this analysis. The median number of durvalumab treatment cycles was 11. Median PFS and OS with nivolumab plus ipilimumab were 4.2 months (95% confidence interval [CI]: 0.7-7.7) and 18.5 months (95% CI: 3.5-33.5), respectively. The 6-month and 12-month PFS rates were 46.7% (95% CI: 28.8-64.5) and 36.4% (95% CI: 19.0-53.7). In multivariate analysis, a significant correlation was observed between a durvalumab treatment duration of 6 months or more and PFS (p = 0.04) as well as OS (p = 0.001). Grade 3 adverse events, including pneumonitis, dermatitis, and colitis, occurred in 10% of the patients. This study suggests that nivolumab plus ipilimumab is effective, especially in patients who have received durvalumab for 6 months or more, and tolerable for patients who relapsed after durvalumab following CCRT.

Circulating T cells: a promising biomarker of anti-PD-(L)1 therapy

Anti-PD-(L)1 therapy has shown great efficacy in some patients with cancer. However, a significant proportion of patients with cancer do not respond to it. Another unmet clinical need for anti-PD-(L)1 therapy is the dynamic monitoring of treatment effects. Therefore, identifying biomarkers that can stratify potential responders before PD-(L)1 treatment and timely monitoring of the efficacy of PD-(L)1 treatment are crucial in the clinical setting. The identification of biomarkers by liquid biopsy has attracted considerable attention. Among the identified biomarkers, circulating T cells are one of the most promising because of their indispensable contribution to anti-PD-(L)1 therapy. The present review aimed to thoroughly explore the potential of circulating T cells as biomarkers of anti-PD-(L)1 therapy and its advantages and limitations.

Immunotherapy for non-small cell lung cancer

Immune checkpoint inhibitors (ICI) bind to programmed cell death-1 (PD-1)/PD-1 ligand-1 (PD-L1) and Cytotoxic T-lymphocyte antigen-4 (CTLA-4), which suppress T-cell function and inhibit their inhibitory function, resulting in T-cell activation. ICI have been approved for a wide range of cancers, including malignant melanoma, renal cell carcinoma, non-small cell lung cancer, head and neck cancer, Hodgkin's disease, small-cell lung cancer, malignant pleural mesothelioma, gastric cancer, esophageal cancer, breast cancer, uterine cancer, and hepatocellular carcinoma, and the number of indications continues to grow. In addition to the treatment of advanced disease, the anti-tumor effect has been demonstrated across disease stages, from locally advanced disease to early-stage operative disease. The treatment of lung cancer is at the forefront of this trend and long-term durable responses and survival benefits in lung cancer have been exhibited that were unimaginable when cytotoxic anticancer agents were the only treatment options. However, treatment efficacy varies greatly from case to case, and no biomarkers have been developed to accurately predict efficacy. In this article, we discuss the past and future of ICI therapy for lung cancer, based on clinical and basic evidence accumulated to-date.

Clinical significance of antinuclear antibody as prognostic marker for first-line pembrolizumab in advanced non-small cell lung cancer

BACKGROUND

The relationship between antinuclear antibody (ANA) and the efficacy of programmed death-1 (PD-1) blockade remains controversial. Here, we investigated the prognostic significance of ANA titer in patients with non-small cell lung cancer (NSCLC) receiving pembrolizumab monotherapy as the first-line treatment, compared with that of platinum-based chemotherapy with PD-1 blockade.

METHODS

Our clinical data based on the ANA titer (1:80) were retrospectively reviewed for patients with advanced NSCLC, who were treated with first-line pembrolizumab monotherapy and platinum-based chemotherapy with PD-1 blockade. Immunohistochemical staining for tumor-infiltrating lymphocytes such as CD4, CD8 and Foxp3 was performed.

RESULTS

Among 106 patients treated with pembrolizumab, 19 (17.9%) tested high for ANA. Progression-free survival (PFS) and overall survival (OS) were significantly better in patients with high ANA than in those with low ANA, and high ANA was identified as an independent prognostic predictor, particularly in the subgroup with programmed death ligand-1 (PD-L1) ≥ 50%. However, no statistically significant difference in PFS and OS based on the ANA titer was observed in 59 patients treated with combinational chemotherapy and immunotherapy. High numbers of intratumoral Foxp3 and stromal CD8 were significantly associated with low ANA.

CONCLUSIONS

Assessment of preexisting ANA titers was useful to prognose PD-1 blockade as a first-line setting, particularly for the PD-L1 ≥ 50% subgroup, but not in the case of combined immunotherapy and chemotherapy.

Immunogenic PANoptosis-Initiated Cancer Sono-Immune Reediting Nanotherapy by Iteratively Boosting Cancer Immunity Cycle

The cancer-immune cycle conceptualized the mechanisms of driving T cell responses to tumors, but w as limited by immunological ignorance elicited by tumor inherent immunoediting, which failed to initiate and maintain adaptive immunity. Targeting specific vulnerabilities of cell death patterns may provide unique opportunities to boost T cell antitumor immunological effects. Here an ultrasound nanomedicine-triggered tumor immuno-reediting therapeutic strategy using nano/genetically engineered extracellular vesicles, which can induce tumor highly immunogenic PANoptosis and iteratively start-up the energization of cancer innate immunity cycle by repeatedly liberating damage-associated molecular patterns, thereby priming sufficient antigen-specific T cells and shaping protective immune response through activating cGAS-STING signaling pathways, is reported. Aided by immune checkpoint blockade, the reprogramming of immune microenvironment further facilitated a prompt bridging of innate and adaptive immunity, and remarkably suppressed metastatic and rechallenged tumor growth. Thus, targeting PANoptotic cell death provides a catcher against immune escape and a positive-feedback immune activation gateway for overcoming immune resistance to intractable cancers.

Cancer CD39 drives metabolic adaption and mal-differentiation of CD4+ T cells in patients with non-small-cell lung cancer

While ectonucleotidase CD39 is a cancer therapeutic target in clinical trials, its direct effect on T-cell differentiation in human non-small-cell lung cancer (NSCLC) remains unclear. Herein, we demonstrate that human NSCLC cells, including tumor cell lines and primary tumor cells from clinical patients, efficiently drive the metabolic adaption of human CD4+ T cells, instructing differentiation of regulatory T cells while inhibiting effector T cells. Of importance, NSCLC-induced T-cell mal-differentiation primarily depends on cancer CD39, as this can be fundamentally blocked by genetic depletion of CD39 in NSCLC. Mechanistically, NSCLC cells package CD39 into their exosomes and transfer such CD39-containing exosomes into interacting T cells, resulting in ATP insufficiency and AMPK hyperactivation. Such CD39-dependent NSCLC-T cell interaction holds well in patients-derived primary tumor cells and patient-derived organoids (PDOs). Accordingly, genetic depletion of CD39 alone or in combination with the anti-PD-1 immunotherapy efficiently rescues effector T cell differentiation, instigates anti-tumor T cell immunity, and inhibits tumor growth of PDOs. Together, targeting cancer CD39 can correct the mal-differentiation of CD4+ T cells in human NSCLC, providing in-depth insight into therapeutic CD39 inhibitors.

Progresses in biomarkers for cancer immunotherapy

Currently, checkpoint inhibitor-based immunotherapy has emerged as prevailing treatment modality for diverse cancers. However, immunotherapy as a first-line therapy has not consistently yielded durable responses. Moreover, the risk of immune-related adverse events increases with combination regimens. Thus, the development of predictive biomarkers is needed to optimize individuals benefit, minimize risk of toxicities, and guide combination approaches. The greatest focus has been on tumor programmed cell death-ligand 1 (PD-L1), microsatellite instability (MSI), and tumor mutational burden (TMB). However, there remains a subject of debate due to thresholds variability and significant heterogeneity. Major unmet challenges in immunotherapy are the discovery and validation of predictive biomarkers. Here, we show the status of tumor PD-L1, MSI, TMB, and emerging data on novel biomarker strategies with oncogenic signaling and epigenetic regulation. Considering the exploration of peripheral and intestinal immunity has served as noninvasive alternative in predicting immunotherapy, this review also summarizes current data in systemic immunity, encompassing solute PD-L1 and TMB, circulating tumor DNA and infiltrating lymphocytes, routine emerging inflammatory markers and cytokines, as well as gut microbiota. This review provides up-to-date information on the evolving field of currently available biomarkers in predicting immunotherapy. Future exploration of novel biomarkers is warranted.

A Th1-like CD4+ T-cell Cluster That Predicts Disease-free Survival in Early-stage Lung Cancer

Perioperative immune checkpoint inhibitors have been shown to improve prognosis in early-stage lung cancer. However, no biomarkers are known to indicate the requirement for treatment. This study aimed to identify T-cell clusters responsible for antitumor immunity in patients with early-stage lung cancer. Preoperative blood samples from 50 consecutive patients with lung cancer who were diagnosed as operable and underwent complete resection were analyzed by mass cytometry. Patients were divided into two groups: no recurrence at a minimum observation period of 851 days (median observation period: 1,031.5 days) and recurrence by the last observation date. Mass cytometry and single-cell RNA sequencing analysis of lymph nodes (LN) and tumor-infiltrating T cells were also performed. CCR4-CCR6+ Th7R showed discriminative ability between recurrence and non-recurrence patients with lung cancer. Patients with more than 3.04% Th7R showed significantly favorable disease-free survival. Th7R was a major component of CD4+ T cells in tumor microenvironments and LNs adjacent to lung cancer tissues and was the only cluster that decreased in peripheral blood after the removal of cancer tissues, suggesting that Th7R was primed and proliferated in tumor-draining LNs in the presence of cancer tissues. Th7R had the kinetics that antitumor T cells should have, as indicated by the cancer immunity cycle; thus, peripheral blood Th7R could represent the potency of tumor immunity by reflecting priming and proliferation in tumor-draining LNs and Th7R in the tumor microenvironment. Prediction using peripheral Th7R before surgery could allow the selection of patients who require perioperative drug therapy and optimize therapeutic interventions with clinical implications.

Significance

Peripheral Th7R, a Th1-like CD4+ T-cell cluster reflecting priming status in draining LNs and immune status in the tumor microenvironment, predicts disease-free survival after complete resection and has significant clinical relevance in selecting appropriate therapeutic interventions in patients with early-stage lung cancer.

Traditional Chinese medicine inhibits PD-1/PD-L1 axis to sensitize cancer immunotherapy: a literature review

The Programmed death-1 (PD-1) and its programmed death-ligand 1 (PD-L1) comprise the PD-1/PD-L1 axis and maintain tumor immune evasion. Cancer immunotherapy based on anti-PD-1/PD-L1 antibodies is the most promising anti-tumor treatment available but is currently facing the thorny problem of unsatisfactory outcomes. Traditional Chinese Medicine (TCM), with its rich heritage of Chinese medicine monomers, herbal formulas, and physical therapies like acupuncture, moxibustion, and catgut implantation, is a multi-component and multi-target system of medicine known for enhancing immunity and preventing the spread of disease. TCM is often used as an adjuvant therapy for cancer in clinical practices, and recent studies have demonstrated the synergistic effects of combining TCM with cancer immunotherapy. In this review, we examined the PD-1/PD-L1 axis and its role in tumor immune escape while exploring how TCM therapies can modulate the PD-1/PD-L1 axis to improve the efficacy of cancer immunotherapy. Our findings suggest that TCM therapy can enhance cancer immunotherapy by reducing the expression of PD-1 and PD-L1, regulating T-cell function, improving the tumor immune microenvironment, and regulating intestinal flora. We hope this review may serve as a valuable resource for future studies on the sensitization of immune checkpoint inhibitors (ICIs) therapy.

Targeting KRASG12V mutations with HLA class II-restricted TCR for the immunotherapy in solid tumors

KRAS mutation is a significant driving factor of tumor, and KRAS^G12V mutation has the highest incidence in solid tumors such as pancreatic cancer and colorectal cancer. Thus, KRAS^G12V neoantigen-specific TCR-engineered T cells could be a promising cancer treatment approach for pancreatic cancer. Previous studies had reported that KRAS^G12V-reactive TCRs originated from patients' TILs could recognized KRAS^G12V neoantigen presented by specific HLA subtypes and remove tumor persistently in vitro and in vivo. However, TCR drugs are different from antibody drugs in that they are HLA-restricted. The different ethnic distribution of HLA greatly limits the applicability of TCR drugs in Chinese population. In this study, we have identified a KRAS^G12V-specific TCR which recognized classII MHC from a colorectal cancer patient. Interestingly, we observed that KRAS^G12V-specific TCR-engineered CD4⁺ T cells, not CD8⁺ T cells, demonstrated significant efficacy in vitro and in xenograft mouse model, exhibiting stable expression and targeting specificity of TCR when co-cultured with APCs presenting KRAS^G12V peptides. TCR-engineered CD4⁺ T cells were co-cultured with APCs loaded with neoantigen, and then HLA subtypes were identified by the secretion of IFN-γ. Collectively, our data suggest that TCR-engineered CD4⁺ T cells can be used to target KRAS^G12V mutation presented by HLA-DPB1*03:01 and DPB1*14:01, which provide a high population coverage and are more suitable for the clinical transformation for Chinese, and mediate tumor killing effect like CD8⁺ T cells. This TCR hold promise for precision therapy in immunotherapy of solid tumors as an attractive candidate.

Establishing a whole blood CD4+ T cell immunity measurement to predict response to anti-PD-1

BACKGROUND

Biomarkers that can accurately predict the efficacy of immune checkpoint inhibitors (ICIs) against programmed death 1 (PD-1) ligand in cancer immunotherapy are urgently needed. We have previously reported a novel formula that predicts the response to treatment with second-line nivolumab with high sensitivity and specificity in patients with non-small cell lung cancer (NSCLC) previously treated with chemotherapy. The formula was based on the percentages of CD62L^lowCD4⁺ T cells (effector T cells; %Teff) and CD4⁺CD25⁺FOXP3⁺ T cells (regulatory T cells; %Treg) in the peripheral blood before treatment estimated using the peripheral blood mononuclear cell (PBMC) method. Here, we investigated the applicability of the formula (K-index) to predict the response to treatment with another ICI to expand its clinical applicability. Furthermore, we developed a simpler assay method based on whole blood (WB) samples to overcome the limitations of the PBMC method, such as technical difficulties, in obtaining the K-index.

METHODS

The K-index was evaluated using the PBMC method in 59 patients with NSCLC who received first-line pembrolizumab treatment. We also assessed the K-index using the WB method and estimated the correlation between the measurements obtained using both methods in 76 patients with lung cancer.

RESULTS

This formula consistently predicted the response to first-line pembrolizumab therapy in patients with NSCLC. The WB method correlated well with the PBMC method to obtain %Teff, %Treg, and the formula value. The WB method showed high repeatability (coefficient of variation, < 10%). The data obtained using WB samples collected in tubes containing either heparin or EDTA-2K and stored at room temperature (18-24 °C) for one day after blood sampling did not differ. Additionally, the performance of the WB method was consistent in different flow cytometry instruments.

CONCLUSIONS

The K-index successfully predicted the response to first-line therapy with pembrolizumab, as reported earlier for the second-line therapy with nivolumab in patients with NSCLC. The WB method established in this study can replace the cumbersome PBMC method in obtaining the K-index. Overall, this study suggests that the K-index can predict the response to anti-PD-1 therapy in various cancers, including NSCLC.