Phenotypic plasticity and reduced tissue retention of exhausted tumor-infiltrating T cells following neoadjuvant immunotherapy in head and neck cancer

Tri-Ad5 vaccine plus bintrafusp alfa for newly diagnosed, advanced-stage head and neck cancer not associated with human papillomavirus infection

BACKGROUND

Newly diagnosed, advanced-stage head and neck cancer (HNSCC) not associated with human papillomavirus (HPV) infection has poor survival and functional outcomes despite surgical management. Neoadjuvant immunotherapy is of interest to improve long-term outcomes.

METHODS

Individuals with untreated intermediate/high risk, p16-negative (if oropharyngeal) HNSCC were eligible and underwent pre- and post-treatment tumor biopsies. Primary endpoint was pathologic complete response or clinical-to-pathological downstaging (CPD). Treatment regimen: 5 × 1011 viral particles once, subcutaneously of each component of the Tri-Ad5 vaccine (ETBX-011, ETBX-061, and ETBX-051 targeting tumor-associated antigens (TAA): carcinoembryonic antigen [CEA], MUC-1, and brachyury, respectively) plus 1200 mg IV of bintrafusp alfa (anti-PD-L1 and anti-transforming growth factor-β) every 2 weeks for 2 doses. Participants returned to referring physicians for standard surgery ± adjuvant treatment if indicated.

RESULTS

Of 6 HNSCC patients, 2 (33.3%) had CPD. There were no pathologic complete responses. 2-year recurrence free survival (RFS) was 83.3% (95% CI, 27.3%-97.5%). Adverse events were consistent with known safety profiles of each agent. There were no surgical delays.

CONCLUSIONS

In this small study, Tri-Ad5 vaccine plus bintrafusp alfa resulted in CPD in 2/6 patients. Participants also had favorable 2-year RFS compared to historical values. Ongoing tissue and peripheral immunome analyses may provide mechanistic insight. (ClincalTrials.gov Identifier: NCT04247282; IRB Approved.).

Neoadjuvant anti-4-1BB confers protection against spontaneous metastasis through low-affinity intratumor CD8 + T cells in triple-negative breast cancer

Neoadjuvant immunotherapy seeks to harness the primary tumor as a source of relevant tumor antigens to enhance systemic anti-tumor immunity through improved immunological surveillance. Despite having revolutionized the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC), a significant portion of patients remain unresponsive and succumb to metastatic recurrence post-treatment. Here, we found that optimally scheduled neoadjuvant administration of anti-4-1BB monotherapy was able to counteract metastases and prolong survival following surgical resection. Phenotypic and transcriptional profiling revealed enhanced 4-1BB expression on tumor-infiltrating intermediate (T int ), relative to progenitor (T prog ) and terminally exhausted (T term ) T cells. Furthermore, T int was enriched in low-affinity T cells. Treatment with anti-4-1BB drove clonal expansion of T int , with reduced expression of tissue-retention marker CD103 in T prog . This was accompanied by increased TCR clonotype sharing between paired tumors and pre-metastatic lungs. Further interrogation of sorted intratumor T cells confirmed enhanced T cell egress into circulation following anti-4-1BB treatment. In addition, gene signature extracted from anti-4-1BB treated T int was consistently associated with improved clinical outcomes in BRCA patients. Combinatorial neoadjuvant anti-4-1BB and ablation of tumor-derived CXCL16 resulted in enhanced therapeutic effect. These findings illustrate the intratumor changes underpinning the efficacy of neoadjuvant anti-4-1BB, highlighting the reciprocity between local tissue-retention and distant immunologic fortification, suggesting treatment can reverse the siphoning of intratumor T cells to primary tumor, enabling redistribution to distant tissues and subsequent protection against metastases.

The characterization of tumor immune microenvironment after neoadjuvant immunotherapy in head and neck squamous cell cancer using multiplex immunohistochemistry

OBJECTIVE

Optimizing clinical decision-making in head and neck squamous cell carcinoma (HNSCC) is challenging due to the ambiguous understanding of the immune cell dynamics and immune checkpoints regulation in the disease after the administration of neoadjuvant immunotherapy (NIT).

METHODS

HNSCC biopsy samples collected before and after the neoadjuvant treatment are classified into the pathologic response (PR) and the non-pathologic response (NPR) groups according to treatment responses and the expression of immune cells and checkpoints was labeled using multiplex immunohistochemistry (m-IHC).

RESULTS

The populations of CD4+ T cells, CD8+ T cells, regulatory T cells (Treg), PD-1, and PD-L1 were particularly higher in the PR group than the NPR group in pre-treatment tissues, with the p-values of log-transformed positive cell density <0.05. Almost all markers showed a lower expression in the PR patients after treatment, resulting lower post/pre-treatment ratios of positive cell densities in the PR patients relative to the NPR patients. Following treatment, TIM3+ T cells and LAG3+ T cells exhibited significantly diminished levels in the PR cohort relative to the NPR cohort, with post/pre-treatment expression ratios showing significant differences (P < 0.05). Tumor infiltration lymphocyte analysis revealed that the PR group exhibited a considerably higher average density of CD8+ T cells infiltrating in the tumor marginal zone.

CONCLUSION

The presence of T cells demonstrated significant predictive capability for responses to neoadjuvant immunotherapy in HNSCC patients. Furthermore, TIM3+ T cells and LAG3+ T cells were found to be remarkably lower in the partial response (PR) cohort than in the non-partial response (NPR) cohort post-treatment. This research contributes critical understanding of the physiological changes occurring in immune cell responses.

T cell dynamics with neoadjuvant immunotherapy in head and neck cancer

Immune-checkpoint inhibitors (ICIs) are being tested as neoadjuvant therapies in various solid tumours, including in patients with head and neck squamous cell carcinoma (HNSCC), with promising results. Key findings thus far include that this approach is well-tolerated with favourable clinical outcomes including promising pathological response rates in initial studies. Pathological responses are likely to be increased by combining other agents with anti-PD-(L)1 antibodies. Comparisons of baseline biopsy samples with post-treatment surgical specimens have enabled correlative studies utilizing multiomic and immunogenomic methods. Data from these studies suggest that pretreatment intratumoural tissue-resident memory CD8+ T cells are key drivers of tumour regression and give rise to both local and systemic antitumour immune responses. Analyses of systemic responses have defined a PD-1+KLRG1- circulating CD8+ T cell subpopulation that is highly predictive of response, and revealed the interrelationships between intratumoural clones and circulating CD8+ T cells. Lastly, interrogation of T cell populations within lymph nodes is beginning to delineate the immune crosstalk between the primary tumour and tumour-draining lymph nodes and how this relationship might be disrupted with tumour infiltration of the latter. In this Review, we examine data from trials testing neoadjuvant ICIs in patients with HNSCC, focusing on human papillomavirus-unrelated disease, and highlight correlative immunogenomic findings from these trials.

Tissue-resident memory T cells in diseases and therapeutic strategies

Tissue-resident memory T (TRM) cells are crucial components of the immune system that provide rapid, localized responses to recurrent pathogens at mucosal and epithelial barriers. Unlike circulating memory T cells, TRM cells are located within peripheral tissues, and they play vital roles in antiviral, antibacterial, and antitumor immunity. Their unique retention and activation mechanisms, including interactions with local epithelial cells and the expression of adhesion molecules, enable their persistence and immediate functionality in diverse tissues. Recent advances have revealed their important roles in chronic inflammation, autoimmunity, and cancer, illuminating both their protective and their pathogenic potential. This review synthesizes current knowledge on TRM cells' molecular signatures, maintenance pathways, and functional dynamics across different tissues. We also explore the interactions of TRM cells with other immune cells, such as B cells, macrophages, and dendritic cells, highlighting the complex network that underpins the efficacy of TRM cells in immune surveillance and response. Understanding the nuanced regulation of TRM cells is essential for developing targeted therapeutic strategies, including vaccines and immunotherapies, to enhance their protective roles while mitigating adverse effects. Insights into TRM cells' biology hold promise for innovative treatments for infectious diseases, cancer, and autoimmune conditions.

ALDOB/KAT2A interactions epigenetically modulate TGF-β expression and T cell functions in hepatocellular carcinogenesis

BACKGROUND AND AIMS

Cross talk between tumor cells and immune cells enables tumor cells to escape immune surveillance and dictate responses to immunotherapy. Previous studies have identified that downregulation of the glycolytic enzyme fructose-1,6-bisphosphate aldolase B (ALDOB) in tumor cells orchestrated metabolic programming to favor HCC. However, it remains elusive whether and how ALDOB expression in tumor cells affects the tumor microenvironment in HCC.

APPROACH AND RESULTS

We found that ALDOB downregulation was negatively correlated with CD8 + T cell infiltration in human HCC tumor tissues but in a state of exhaustion. Similar observations were made in mice with liver-specific ALDOB knockout or in subcutaneous tumor models with ALDOB knockdown. Moreover, ALDOB deficiency in tumor cells upregulates TGF-β expression, thereby increasing the number of Treg cells and impairing the activity of CD8 + T cells. Consistently, a combination of low ALDOB and high TGF-β expression exhibited the worst overall survival for patients with HCC. More importantly, the simultaneous blocking of TGF-β and programmed cell death (PD) 1 with antibodies additively inhibited tumorigenesis induced by ALDOB deficiency in mice. Further mechanistic experiments demonstrated that ALDOB enters the nucleus and interacts with lysine acetyltransferase 2A, leading to inhibition of H3K9 acetylation and thereby suppressing TGFB1 transcription. Consistently, inhibition of lysine acetyltransferase 2A activity by small molecule inhibitors suppressed TGF-β and HCC.

CONCLUSIONS

Our study has revealed a novel mechanism by which a metabolic enzyme in tumor cells epigenetically modulates TGF-β signaling, thereby enabling cancer cells to evade immune surveillance and affect their response to immunotherapy.

Clinical and biomarker analyses of SHR-1701 combined with famitinib in patients with previously treated advanced biliary tract cancer or pancreatic ductal adenocarcinoma: a phase II trial

Advanced biliary tract cancer (BTC) and pancreatic ductal adenocarcinoma (PDAC) have poor prognoses and limited treatment options. Here, we conducted this first-in-class phase II study to evaluate the efficacy and safety of SHR-1701, a bifunctional fusion protein targeting programmed death-ligand 1 (PD-L1) and transforming growth factor-beta (TGF-β), combined with famitinib, a multi-targeted receptor tyrosine kinase inhibitor, in patients with advanced BTC or PDAC who failed previous standard treatment (trial registration: ChiCTR2000037927). Among 51 enrolled patients, the BTC cohort showed an objective response rate (ORR) of 28% (including 2 complete responses) and a disease control rate (DCR) of 80%, with a median progression-free survival (mPFS) of 5.1 months and a median overall survival (mOS) of 16.0 months. In the PDAC cohort, the ORR was 15% (2 complete responses), with a DCR of 60%, and the mPFS and mOS were 2.1 months and 5.3 months, respectively. Grade 3 or 4 treatment-related adverse events (TRAEs) occurred in 29.4% of patients, with no grade 5 TRAEs reported. Exploratory analyses revealed that primary tumor resection history, peripheral blood immunophenotype changes, and distinct immune-metabolic profiles were associated with treatment benefits. An immune/metabolism score integrating the features of six genes was developed as a predictive biomarker for immunotherapy response in multiple cohorts, allowing for the selection of patients most likely to experience positive outcomes from this therapy regimen. In conclusion, our study provides proof-of-concept data supporting the potential of SHR-1701 plus famitinib as an effective and safe subsequent-line therapy for refractory BTC and PDAC, highlighting the promise of targeting PD-L1, TGF-β, and angiogenesis pathways simultaneously.

A Bayesian framework for inferring dynamic intercellular interactions from time-series single-cell data

Characterizing cell-cell communication and tracking its variability over time are crucial for understanding the coordination of biological processes mediating normal development, disease progression, and responses to perturbations such as therapies. Existing tools fail to capture time-dependent intercellular interactions and primarily rely on databases compiled from limited contexts. We introduce DIISCO, a Bayesian framework designed to characterize the temporal dynamics of cellular interactions using single-cell RNA-sequencing data from multiple time points. Our method utilizes structured Gaussian process regression to unveil time-resolved interactions among diverse cell types according to their coevolution and incorporates prior knowledge of receptor-ligand complexes. We show the interpretability of DIISCO in simulated data and new data collected from T cells cocultured with lymphoma cells, demonstrating its potential to uncover dynamic cell-cell cross talk.

Immune checkpoint blockade: timing is everything

Neoadjuvant immunotherapy effectively uses the in situ tumor as a reservoir of tumor antigens to promote systemic antitumor immunity. Studies indicate that intratumoral responses to immune checkpoint inhibitors (ICIs) are mediated by resident memory T cells cells that are sequestered in tumors and have specificity for a wide range of tumor antigens ICI treatment produces de novo priming of CD8+ T cells in tumor and in tumor-draining lymph nodes, and can boost the antitumor immune response by blocking inhibitory checkpoint proteins that can turn off T cells within the tumor. Neoadjuvant ICI treatment can enhance both intratumoral and systemic antitumor immunity, including expansion of intratumoral T-cell clones which is strongly associated with pathological treatment response. Recent data have shown high rates of pathological response to neoadjuvant immunotherapy with prolongation of survival compared with adjuvant ICI therapy alone in patients with unresectable or advanced melanoma. These data suggest that removal of the reservoir of tumor-specific T cells in the tumor and draining nodes by surgical resection may remove a significant proportion of the patient's antitumor immunity with the potential to compromise ICI outcomes.

TGF-β neutralization attenuates tumor residency of activated T cells to enhance systemic immunity in mice

A tissue resident-like phenotype in tumor infiltrating T cells can limit systemic anti-tumor immunity. Enhanced systemic anti-tumor immunity is observed in head and neck cancer patients after neoadjuvant PD-L1 immune checkpoint blockade (ICB) and transforming growth factor β (TGF-β) neutralization. Using T cell receptor (TCR) sequencing and functional immunity assays in a syngeneic model of oral cancer, we dissect the relative contribution of these treatments to enhanced systemic immunity. The addition of TGF-β neutralization to ICB resulted in the egress of expanded and exhausted CD8+ tumor infiltrating lymphocytes (TILs) into circulation and greater systemic anti-tumor immunity. This enhanced egress associated with reduced expression of Itgae (CD103) and its upstream regulator Znf683. Circulating CD8+ T cells expressed higher Cxcr3 after treatment, an observation also made in samples from patients treated with dual TGF-β neutralization and ICB. These findings provide the scientific rationale for the use of PD-L1 ICB and TGF-β neutralization in newly diagnosed patients with carcinomas prior to definitive treatment of locoregional disease.

The role of transforming growth factor-β (TGF-β) in the formation of exhausted CD8 + T cells

CD8 + T cells exert a critical role in eliminating cancers and chronic infections, and can provide long-term protective immunity. However, under the exposure of persistent antigen, CD8 + T cells can differentiate into terminally exhausted CD8 + T cells and lose the ability of immune surveillance and disease clearance. New insights into the molecular mechanisms of T-cell exhaustion suggest that it is a potential way to improve the efficacy of immunotherapy by restoring the function of exhausted CD8 + T cells. Transforming growth factor-β (TGF-β) is an important executor of immune homeostasis and tolerance, inhibiting the expansion and function of many components of the immune system. Recent studies have shown that TGF-β is one of the drivers for the development of exhausted CD8 + T cells. In this review, we summarized the role and mechanisms of TGF-β in the formation of exhausted CD8 + T cells and discussed ways to target those to ultimately enhance the efficacy of immunotherapy.

Blockade of TGF-β and PD-L1 by bintrafusp alfa promotes survival in preclinical ovarian cancer models by promoting T effector and NK cell responses

BACKGROUND

Failure of immunotherapy in high-grade serous ovarian cancer (HGSC) may be due to high levels of transforming growth factor-β (TGF-β) in ascites or tumour immune microenvironment (TIME). Here, we test whether coordinated blockade of TGF-β and PD-L1 with bintrafusp alfa (BA) can provoke anti-tumour immune responses in preclinical HGSC models.

METHODS

BA is a first-in-class bifunctional inhibitor of TGF-β and PD-L1, and was tested for effects on overall survival and altered TIME in syngeneic HGSC models.

RESULTS

Using a mouse ID8-derived HGSC syngeneic model with IFNγ-inducible PD-L1 expression, BA treatments significantly reduced ascites development and tumour burden. BA treatments depleted TGF-β and VEGF in ascites, and skewed the TIME towards cytotoxicity compared to control. In the BR5 HGSC syngeneic model, BA treatments increased tumour-infiltrating CD8 T cells with effector memory and cytotoxic markers, as well as cytolytic NK cells. Extended BA treatments in the BR5 model produced ∼50% BA-cured mice that were protected from re-challenge. These BA-cured mice had increased peritoneal T-effector memory and NK cells compared to controls.

CONCLUSIONS

Our preclinical studies of BA in advanced ovarian cancer models support further testing of BA as an improved immunotherapy option for patients with advanced ovarian cancer.

New insights into immune cells in cancer immunotherapy: from epigenetic modification, metabolic modulation to cell communication

Cancer is one of the leading causes of death worldwide, and more effective ways of attacking cancer are being sought. Cancer immunotherapy is a new and effective therapeutic method after surgery, radiotherapy, chemotherapy, and targeted therapy. Cancer immunotherapy aims to kill tumor cells by stimulating or rebuilding the body's immune system, with specific efficiency and high safety. However, only few tumor patients respond to immunotherapy and due to the complex and variable characters of cancer immune escape, the behavior and regulatory mechanisms of immune cells need to be deeply explored from more dimensions. Epigenetic modifications, metabolic modulation, and cell-to-cell communication are key factors in immune cell adaptation and response to the complex tumor microenvironment. They collectively determine the state and function of immune cells through modulating gene expression, changing in energy and nutrient demands. In addition, immune cells engage in complex communication networks with other immune components, which are mediated by exosomes, cytokines, and chemokines, and are pivotal in shaping the tumor progression and therapeutic response. Understanding the interactions and combined effects of such multidimensions mechanisms in immune cell modulation is important for revealing the mechanisms of immunotherapy failure and developing new therapeutic targets and strategies.

Tumor-specific T cells in head and neck cancer have rescuable functionality and can be identified through single-cell co-culture

BACKGROUND

Human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC) remains a treatment-resistance disease with limited response to immunotherapy. While T cells in HNSCC are known to display phenotypic dysfunction, whether they retain rescuable functional capacity and tumor-killing capability remains unclear.

METHODS

To investigate the functionality and tumor-specificity of tumor-infiltrating lymphocytes (TILs) across HNSCCs, malignant cell lines and TILs were derived from 31 HPV-negative HNSCCs at the time of standard surgical resection. T cell functional capacity was evaluated through ex vivo expansion, immunophenotyping, and IsoLight single-cell proteomics. Tumor-specificity was investigated through both bulk and single-cell tumor-TIL co-culture.

RESULTS

TILs could be successfully generated from 24 patients (77%), including both previously untreated and radiation recurrent HNSCCs. We demonstrate that across HNSCCs, TILs express multiple exhaustion markers but maintain a predominantly effector memory phenotype. After ex vivo expansion, TILs retain immunogenic functionality even from radiation-resistant, exhausted, and T cell-depleted disease. We further demonstrate tumor-specificity of T cells across HNSCC patients through patient-matched malignant cell-T cell co-culture. Finally, we use optofluidic technology to establish an autologous single tumor cell-single T cell co-culture platform for HNSCC. Cells derived from three HNSCC patients underwent single-cell co-culture which enabled identification and visualization of individual tumor-killing TILs in real-time in all patients.

CONCLUSIONS

These studies show that cancer-specific T cells exist across HNSCC patients with rescuable immunogenicity and can be identified on a single-cell level. These data lay the foundation for development of patient-specific T cell immunotherapies in HNSCC.

A novel molecular subtyping based on multi-omics analysis for prognosis predicting in colorectal melanoma: A 16-year prospective multicentric study

Colorectal melanoma (CRM) is a rare malignant tumor with severe complications, and there is currently a lack of systematic research. We conducted a study that combined proteomics and mutation data of CRM from a cohort of three centers over a 16-years period (2005-2021). The patients were divided into a training set consisting of two centers and a testing set comprising the other center. Unsupervised clustering was conducted on the training set to form two molecular subtypes for clinical characterization and functional analysis. The testing set was used to validate the survival differences between the two subtypes. The comprehensive analysis identified two subtypes of CRM: immune exhausted C1 cluster and DNA repair C2 cluster. The former subtype exhibited characteristics of metabolic disturbance, immune suppression, and poor prognosis, along with APC mutations. A machine learning algorithm named Support Vector Machine (SVM) was applied to predict the classification of CRM patients based on protein expression in the external testing cohort. Two subtypes of primary CRM with clinical and proteomic characteristics provides a reference for subsequent diagnosis and treatments.

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.

Unlocking the potential of T-cell metabolism reprogramming: Advancing single-cell approaches for precision immunotherapy in tumour immunity

As single-cell RNA sequencing enables the detailed clustering of T-cell subpopulations and facilitates the analysis of T-cell metabolic states and metabolite dynamics, it has gained prominence as the preferred tool for understanding heterogeneous cellular metabolism. Furthermore, the synergistic or inhibitory effects of various metabolic pathways within T cells in the tumour microenvironment are coordinated, and increased activity of specific metabolic pathways generally corresponds to increased functional activity, leading to diverse T-cell behaviours related to the effects of tumour immune cells, which shows the potential of tumour-specific T cells to induce persistent immune responses. A holistic understanding of how metabolic heterogeneity governs the immune function of specific T-cell subsets is key to obtaining field-level insights into immunometabolism. Therefore, exploring the mechanisms underlying the interplay between T-cell metabolism and immune functions will pave the way for precise immunotherapy approaches in the future, which will empower us to explore new methods for combating tumours with enhanced efficacy.

DIISCO: A Bayesian framework for inferring dynamic intercellular interactions from time-series single-cell data

Characterizing cell-cell communication and tracking its variability over time is essential for understanding the coordination of biological processes mediating normal development, progression of disease, or responses to perturbations such as therapies. Existing tools lack the ability to capture time-dependent intercellular interactions, such as those influenced by therapy, and primarily rely on existing databases compiled from limited contexts. We present DIISCO, a Bayesian framework for characterizing the temporal dynamics of cellular interactions using single-cell RNA-sequencing data from multiple time points. Our method uses structured Gaussian process regression to unveil time-resolved interactions among diverse cell types according to their co-evolution and incorporates prior knowledge of receptor-ligand complexes. We show the interpretability of DIISCO in simulated data and new data collected from CAR-T cells co-cultured with lymphoma cells, demonstrating its potential to uncover dynamic cell-cell crosstalk.

New perspectives on biology, disease progression, and therapy response of head and neck cancer gained from single cell RNA sequencing and spatial transcriptomics

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent cancers worldwide. The main risk factors are consumption of tobacco products and alcohol, as well as infection with human papilloma virus. Approved therapeutic options comprise surgery, radiation, chemotherapy, targeted therapy through epidermal growth factor receptor inhibition, and immunotherapy, but outcome has remained unsatisfactory due to recurrence rates of ~50% and the frequent occurrence of second primaries. The availability of the human genome sequence at the beginning of the millennium heralded the omics era, in which rapid technological progress has advanced our knowledge of the molecular biology of malignant diseases, including HNSCC, at an unprecedented pace. Initially, microarray-based methods, followed by approaches based on next-generation sequencing, were applied to study the genetics, epigenetics, and gene expression patterns of bulk tumors. More recently, the advent of single-cell RNA sequencing (scRNAseq) and spatial transcriptomics methods has facilitated the investigation of the heterogeneity between and within different cell populations in the tumor microenvironment (e.g., cancer cells, fibroblasts, immune cells, endothelial cells), led to the discovery of novel cell types, and advanced the discovery of cell-cell communication within tumors. This review provides an overview of scRNAseq, spatial transcriptomics, and the associated bioinformatics methods, and summarizes how their application has promoted our understanding of the emergence, composition, progression, and therapy responsiveness of, and intercellular signaling within, HNSCC.

Egress of resident memory T cells from tissue with neoadjuvant immunotherapy: Implications for systemic anti-tumor immunity

INTRODUCTION

Resident memory T (TRM) cells are embedded in peripheral tissue and capable of acting as sentinels that can respond quickly to repeat pathogen exposure as part of an endogenous anti-microbial immune response. Recent evidence suggests that chronic antigen exposure and other microenvironment cues may promote the development of TRM cells within solid tumors as well, and that this TRM phenotype can sequester tumor-specific T cells into tumors and out of circulation resulting in limited systemic antitumor immunity. Here, we perform a review of the published English literature and describe tissue-specific mediators of TRM cell differentiation in states of infection and malignancy with special focus on the role of TGF-β and how targeting TGF-β signaling could be used as a therapeutical approach to promote tumor systemic immunity.

DISCUSSION

The presence of TRM cells with antigen specificity to neoepitopes in tumors associates with positive clinical prognosis and greater responsiveness to immunotherapy. Recent evidence indicates that solid tumors may act as reservoirs for tumor specific TRM cells and limit their circulation - possibly resulting in impaired systemic antitumor immunity. TRM cells utilize specific mechanisms to egress from peripheral tissues into circulation and other peripheral sites, and emerging evidence indicates that immunotherapeutic approaches may initiate these processes and increase systemic antitumor immunity.

CONCLUSIONS

Reversing tumor sequestration of tumor-specific T cells prior to surgical removal or radiation of tumor may increase systemic antitumor immunity. This finding may underlie the improved recurrence free survival observed with neoadjuvant immunotherapy in clinical trials.

BMI1-induced CD127+KLRG1+ memory T cells enhance the efficacy of liver cancer immunotherapy

The efficacy of HCC (hepatocellular carcinoma) immunotherapy is hindered by the limited reactivity and short duration of tumor-infiltrating T cells. These deficiencies may be ascribed to the proliferative ability of T cells. The primary objective of this study was to identify the key factor regulating tumor-infiltrating lymphocytes (TIL) proliferation within the HCC microenvironment. Through the utilization of tissue-infiltrated T cell proteomics and fraction proteomics, we analyzed the differential proteins in T cells among HCC, liver fibrosis, and hemangioma (serving as controls) groups. Additionally, we examined the differential regulatory TFs of T cells between the HCC and VH (volunteer healthy, as a control) groups. Using cyTOF and flow cytometry technologies, as well as generating CD8+ T-specific BMI1 knockout mice, we confirmed that BMI1 controls CD127+KLRG1+ memory cell differentiation. Through RNA-seq and MeRIP-seq, we verified that BMI1 regulates TCF1 expression independently of its classical function. Furthermore, by conducting Tyramide signal amplification (TSA) IHC analysis, employing a hydrodynamic mouse HCC model, and utilizing liver-specific nanoparticle targeting therapy, we demonstrated that BMI1 in HCC influences the proliferation of infiltrating CD8+T. BMI1 inhibition promotes effector T cell differentiation while suppressing memory T cell differentiation. Moreover, liver-specific BMI1 knockdown proves beneficial in ameliorating T cell dysfunction and decelerating HCC progression. Our research group has pioneered the exploration of the proteomics of HCC-infiltrated T cells, shedding light on the pivotal role of BMI1 in controlling CD127+KLRG1+ memory CD8+ T cell differentiation, which serves as the cornerstone for achieving immunotherapy efficacy in HCC.

Neoadjuvant chemotherapy enhances tumor-specific T cell immunity in patients with HPV-associated oropharyngeal cancer

BACKGROUND

Treatment of patients with newly diagnosed HPV-associated oropharyngeal squamous cell carcinoma (OPSCC) with neoadjuvant chemotherapy (NAC) results in a high rate of 5-year recurrence free survival with few patients requiring adjuvant treatment. We hypothesized that NAC enhances primary tumor HPV-specific T cell responses.

METHODS

HPV-specific responses in tumor infiltrating lymphocytes (TILs) before and after NAC were determined using autologous co-culture assays.

RESULTS

Greater HPV16-specific TIL responses, sometimes polyclonal, were observed after NAC compared to before in 8 of 10 patients (80%) with PCR-verified HPV16-positive tumors. A significant association was observed between net-negative change in HPV-specific TIL response and disease relapse (p = 0.04, Mann-Whitney test), whereas pathologic complete response at time of surgery did not correlate with recurrence.

CONCLUSIONS

NAC induces HPV-specific tumor T cell responses in patients with newly diagnosed HPV-associated OPSCC; whereas lack of an increase following NAC may associate with risk of relapse.

Construction and validation of an immune infiltration-related risk model for predicting prognosis and immunotherapy response in low grade glioma

BACKGROUND

Low grade glioma (LGG) is considered a heterogeneous tumor with highly variable survival and limited efficacy of immunotherapy. To identify high-risk subsets and apply immunotherapy effectively in LGG, the status and function of immune infiltration in the glioma microenvironment must be explored.

METHODS

Four independent glioma cohorts comprising 1,853 patients were enrolled for bioinformatics analysis. We used ConsensusClusterPlus to cluster patients into four different immune subtypes based on immune infiltration. The immune-infiltration signature (IIS) was constructed by LASSO regression analysis. Somatic mutation and copy number variation (CNV) analyses were performed to explore genomic and transcriptomic traits in the high- and low- risk groups. The correlation between response to programmed cell death 1 (PD-1) blockade and the IIS risk score was confirmed in an in vivo glioma model.

RESULTS

Patients were clustered into four different immune subtypes based on immune infiltration, and the high immune infiltration subtype was associated with worse survival in LGG. The high immune infiltration subtype had stronger inflammatory response, immune response and immune cell chemotaxis. The IIS, consisting of EMP3, IQGAP2, METTL7B, SLC1A6 and TNFRSF11B, could predict LGG malignant progression, which was validated with internal clinical samples. M2 macrophage infiltration positively correlated with the IIS risk score. The high-risk group had significantly more somatic mutations and CNVs. The IIS risk score was related to immunomodulatory molecules and could predict immunotherapy clinical benefit. In vivo, immunotherapy-sensitive glioma model exhibited higher IIS risk score and more infiltration of immune cells, especially M2 macrophages. The IIS risk score was decreased in an immunotherapy-sensitive glioma model after anti-PD1 immunotherapy.

CONCLUSION

Different immune subtypes of LGG had unique immune cell infiltration characteristics, and the high immune infiltration subtype was associated with immunosuppressive signaling pathways. A novel IIS prognostic model based on immune infiltration status was constructed for immunophenotypic classification, risk stratification, prognostication and immunotherapy response prediction in LGG.

The diverse effects of transforming growth factor-β and SMAD signaling pathways during the CTL response

Cytotoxic T lymphocytes (CTLs) play an important role in defense against infections with intracellular pathogens and anti-tumor immunity. Efficient migration is required to locate and destroy infected cells in different regions of the body. CTLs accomplish this task by differentiating into specialized subsets of effector and memory CD8 T cells that traffic to different tissues. Transforming growth factor-beta (TGFβ) belongs to a large family of growth factors that elicit diverse cellular responses via canonical and non-canonical signaling pathways. Canonical SMAD-dependent signaling pathways are required to coordinate changes in homing receptor expression as CTLs traffic between different tissues. In this review, we discuss the various ways that TGFβ and SMAD-dependent signaling pathways shape the cellular immune response and transcriptional programming of newly activated CTLs. As protective immunity requires access to the circulation, emphasis is placed on cellular processes that are required for cell-migration through the vasculature.