Tumor-specific T cells support chemokine-driven spatial organization of intratumoral immune microaggregates needed for long survival

Single-cell spatial transcriptomics unravels cell states and ecosystems associated with clinical response to immunotherapy

BACKGROUND

The tumor microenvironment (TME) is a complex and dynamic ecosystem that is known to influence responses to immunotherapy. We leveraged single-cell spatial transcriptomics to systematically dissect the intricate complexity of the TME, in particular the cellular heterogeneity and spatial interactions. Their collective impact on immunotherapy efficacy was studied in the context of a homogeneous group of patients with vulvar high-grade squamous intraepithelial lesions (vHSIL) treated with an immunotherapeutic tumor-specific peptide vaccine.

METHODS

We performed single-cell spatial transcriptomics on 20 pretreatment vHSIL lesions, stratified by clinical response to immunotherapeutic vaccination into complete responders (CR), partial responders (PR) and non-responders (NR). Using a 1,000-gene panel, we mapped over 274,000 single cells in situ, identifying 18 cell clusters and 99 distinct non-epithelial cell states. Findings were validated against public single-cell transcriptomic data sets to assess their broader relevance across tumor types.

RESULTS

Profound heterogeneity within the TME was detected across the response groups. CR lesions exhibited a higher ratio of immune-supportive to immune-suppressive cells-a pattern mirrored in other solid tumors following neoadjuvant checkpoint blockade. Key immune populations enriched in CRs included CD4+CD161+ effector T cells and chemotactic CD4+ and CD8+ T cells. Conversely, PRs were characterized by increased proportions of T helper 2 cells and CCL18-expressing macrophages, which are associated with the recruitment of type 2 T cells and regulatory T cells. NRs displayed preferential infiltration with immunosuppressive fibroblasts. Distinct spatial immune ecosystems further defined response groups. Although a number of immune cells were detected in all patients, type 1 effector cells dominated interactions in CRs, type 2 cells were prominently interacting in PRs, while NRs lacked organized immune cell interactions.

CONCLUSIONS

This study underscores the dual importance of both cellular composition and spatial organization in steering clinical response to immunotherapy.

Integration of single-cell and bulk RNA sequencing to identify a distinct tumor stem cells and construct a novel prognostic signature for evaluating prognosis and immunotherapy in LUAD

BACKGROUND

Cancer stem cells (CSCs) are crucial for lung adenocarcinoma (LUAD). This study investigates tumor stem cell gene signatures in LUAD using single-cell RNA sequencing (scRNA-seq) and bulk RNA sequencing (RNA-seq), aiming to develop a prognostic tumor stem cell marker signature (TSCMS) model.

METHODS

LUAD scRNA-seq and RNA-seq data were analyzed. CytoTRACE software quantified the stemness score of tumor-derived epithelial cell clusters. Gene Set Variation Analysis (GSVA) identified potential biological functions in different clusters. The TSCMS model was constructed using Lasso-Cox regression, and its prognostic value was assessed through Kaplan-Meier, Cox regression, and receiver-operating characteristic (ROC) curve analyses. Immune infiltration was evaluated using the Cibersortx algorithm, and drug response prediction was performed using the pRRophetic package. TAF10 functional investigations in LUAD cells involved bioinformatics analysis, qRT-PCR, Western blot, immunohistochemistry, and assays for cell proliferation.

RESULTS

Seven distinct cell clusters were identified by CytoTRACE, with epithelial cell cluster 1 (Epi_C1) showing the highest stemness potential. The TSCMS model included 49 tumor stemness-related genes; high-risk patients exhibited lower immune and ESTIMATE scores and increased tumor purity. Significant differences in immune landscapes and chemotherapy sensitivity were observed between risk groups. TAF10 positively correlated with RNA expression-based stemness scores in various tumors, including LUAD. It was over-expressed in LUAD cell lines and clinical tumor tissues, with high expression linked to poor prognosis. Silencing TAF10 inhibited LUAD cell proliferation and tumor sphere formation.

CONCLUSIONS

This study demonstrates the TSCMS model's prognostic value in LUAD, reveals insights into immune infiltration and therapeutic response, and identifies TAF10 as a potential therapeutic target.

NF-κB associated markers of prognosis in early and metastatic triple negative breast cancer

BACKGROUND

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. While PD-1 based immunotherapies overall have led to improved treatment outcomes for this disease, a diverse response to frontline chemotherapy and immunotherapy still exist in TNBC, highlighting the need for more robust prognostic markers.

METHODS

Tumor-intrinsic immunotranscriptomics, serum cytokine profiling, and tumor burden studies were conducted in two syngeneic mouse models to assess differential effects in both the early-stage and metastatic setting. Bioinformatic analyses of both early and metastatic TNBC patient data were performed to assess if identified NF-κB-associated factors are associated with improved patient clinical outcomes.

RESULTS

NF-κB signaling driven by lymphotoxin beta expression is associated with tumor regression in TNBC mouse models. Furthermore, lymphotoxin beta expression in patient TNBC cohorts is prognostic of improved survival outcomes.

CONCLUSIONS

This study highlights the potential role for NF-κB-associated factors, specifically lymphotoxin beta to be used as prognostic markers in TNBC, which could ultimately provide insight for improved targeted treatment approaches in the clinic.

Activated HLA-DR+CD38+ Effector Th1/17 Cells Distinguish Crohn's Disease-associated Perianal Fistulas from Cryptoglandular Fistulas

BACKGROUND

Perianal fistulas are a debilitating complication of Crohn's disease (CD). Due to unknown reasons, CD-associated fistulas are in general more difficult to treat than cryptoglandular fistulas (non-CD-associated). Understanding the immune cell landscape is a first step towards the development of more effective therapies for CD-associated fistulas. In this work, we characterized the composition and spatial localization of disease-associated immune cells in both types of perianal fistulas by high-dimensional analyses.

METHODS

We applied single-cell mass cytometry (scMC), spectral flow cytometry (SFC), and imaging mass cytometry (IMC) to profile the immune compartment in CD-associated perianal fistulas and cryptoglandular fistulas. An exploratory cohort (CD fistula, n = 10; non-CD fistula, n = 5) was analyzed by scMC to unravel disease-associated immune cell types. SFC was performed on a second fistula cohort (CD, n = 10; non-CD, n = 11) to comprehensively phenotype disease-associated T helper (Th) cells. IMC was used on a third cohort (CD, n = 5) to investigate the spatial distribution/interaction of relevant immune cell subsets.

RESULTS

Our analyses revealed that activated HLA-DR+CD38+ effector CD4+ T cells with a Th1/17 phenotype were significantly enriched in CD-associated compared with cryptoglandular fistulas. These cells, displaying features of proliferation, regulation, and differentiation, were also present in blood, and colocalized with other CD4+ T cells, CCR6+ B cells, and macrophages in the fistula tracts.

CONCLUSIONS

Overall, proliferating activated HLA-DR+CD38+ effector Th1/17 cells distinguish CD-associated from cryptoglandular perianal fistulas and are a promising biomarker in blood to discriminate between these 2 fistula types. Targeting HLA-DR and CD38-expressing CD4+ T cells may offer a potential new therapeutic strategy for CD-related fistulas.

The role of dendritic cells in tertiary lymphoid structures: implications in cancer and autoimmune diseases

Tertiary Lymphoid Structures (TLS) are organized aggregates of immune cells such as T cells, B cells, and Dendritic Cells (DCs), as well as fibroblasts, formed postnatally in response to signals from cytokines and chemokines. Central to the function of TLS are DCs, professional antigen-presenting cells (APCs) that coordinate the adaptive immune response, and which can be classified into different subsets, with specific functions, and markers. In this article, we review current data on the contribution of different DC subsets to TLS function in cancer and autoimmunity, two opposite sides of the immune response. Different DC subsets can be found in different tumor types, correlating with cancer prognosis. Moreover, DCs are also present in TLS found in autoimmune and inflammatory conditions, contributing to disease development. Broadly, the presence of DCs in TLS appears to be associated with favorable clinical outcomes in cancer while in autoimmune pathologies these cells are associated with unfavorable prognosis. Therefore, it is important to analyze the complex functions of DCs within TLS in order to enhance our fundamental understanding of immune regulation but also as a possible route to create innovative clinical interventions designed for the specific needs of patients with diverse pathological diseases.

Transferrin receptor-targeted immunostimulant for photodynamic immunotherapy against metastatic tumors through β-catenin/CREB interruption

The immunosuppressive phenotype of tumor cells extensively attenuates the immune activation effects of traditional treatments. In this work, a transferrin receptor (TfR) targeted immunostimulant (PTI) is fabricated for photodynamic immunotherapy against metastatic tumors by interrupting β-catenin signal pathway. To synthesize PTI, the photosensitizer conjugated TfR targeting peptide moiety (Palmitic-K(PpIX)-HAIYPRH) is unitized to encapsulate the transcription interrupter of ICG-001. On the one hand, the recognition of PTI and TfR can promote drug delivery into tumor cells to destruct primary tumors through photodynamic therapy and initiate an immunogenic cell death with the release of tumor-associated antigens. On the other hand, PTI will interrupt the binding between β-catenin and cAMP response element-binding protein (CREB), regulating the gene transcription to downregulate programmed death ligand 1 (PD-L1) while upregulating C-C motif chemokine ligand 4 (CCL4). Furthermore, the elevated CCL4 can recruit the dendritic cells to present tumor-specific antigens and promote T cells activation and infiltration, and the downregulated PD-L1 can avoid the immune evasion of tumor cells and activate systemic anti-tumor immunity to eradicate lung metastasis. This work may inspire the development of antibody antibody-free strategy to activate systemic immune response in consideration of immunosuppressive conditions.

Monocyte infiltration is an independent positive prognostic biomarker in vulvar squamous cell carcinoma

BACKGROUND

Vulvar squamous cell carcinoma (VSCC) arises after an HPV infection or the mutation of p53 or other driver genes and is treated by mutilating surgery and/or (chemo) radiation, with limited success and high morbidity. In-depth information on the immunological make up of VSCC is pivotal to assess whether immunotherapy may form an alternative treatment.

METHODS

A total of 104 patient samples, comprising healthy vulva (n = 27) and VSCC (n = 77), were analyzed. Multispectral immunofluorescence (15 markers) was used to study both the myeloid and lymphoid immune cell composition, and this was linked to differences in transcriptomics (NanoString nCounter, 1258 genes) and in survival (Kaplan-Meier analyses).

RESULTS

Healthy vulva and VSCC are both well infiltrated but with different subpopulations of lymphoid and myeloid cells. In contrast to the lymphoid cell infiltrate, the density and composition of the myeloid cell infiltrate strongly differed per VSCC molecular subtype. A relative strong infiltration with epithelial monocytes (HLADR-CD11c-CD14+CD68-CD163-CD33-) was prognostic for improved survival, independent of T cell infiltration, disease stage or molecular subtype. A strong infiltration with T cells and/or monocytes was associated with drastic superior survival: 5-year survival > 90% when either one is high, versus 40% when both are low (p < 0.001).

CONCLUSION

A hot myeloid and/or lymphoid infiltrate predicts excellent survival in VSCC. Based on the response of similarly high-infiltrated other tumor types, we have started to explore the potential of neoadjuvant checkpoint blockade in VSCC.

[Clinicopathological characteristics of the CD8+ T lymphocytes infiltration and its mechanism in distinct molecular subtype of medulloblastoma]

OBJECTIVE

To investigate the characteristics of the CD8+ T cells infiltration from the 4 subtypes in medulloblastoma (MB), to analyze the relationship between CD8+ T cells infiltration and prognosis, to study the function of C-X-C motif chemokine ligand 11 (CXCL11) and its receptor in CD8+ T cells infiltration into tumors and to explore the potential mechanism, and to provide the necessary clinicopathological basis for exploring the immunotherapy of MB.

METHODS

In the study, 48 clinical MB samples (12 cases in each of 4 subtypes) were selected from the multiple medical center from 2012 to 2019. The transcriptomics analysis for the tumor of 48 clinical samples was conducted on the NanoString PanCancer IO360TM Panel (NanoString Technologies). Immunohistochemistry (IHC) staining of formalin-fixed, paraffin-embedded sections from MB was carried out using CD8 primary antibody to analyze diffe-rential quantities of CD8+ T cells in the MB four subtypes. Through bioinformatics analysis, the relationship between CD8+T cells infiltration and prognosis of the patients and the expression differences of various chemokines in the different subtypes of MB were investigated. The expression of CXCR3 receptor on the surface of CD8+T cells in MB was verified by double immunofluorescence staining, and the underlying molecular mechanism of CD8+T cells infiltration into the tumor was explored.

RESULTS

The characteristic index of CD8+T cells in the WNT subtype of MB was relatively high, suggesting that the number of CD8+T cells in the WNT subtype was significantly higher than that in the other three subtypes, which was confirmed by CD8 immunohistochemical staining and Gene Expression Omnibus (GEO) database analysis by using R2 online data analysis platform. And the increase of CD8+T cells infiltration was positively correlated with the patient survival. The expression level of CXCL11 in the WNT subtype MB was significantly higher than that of the other three subtypes. Immunofluorescence staining showed the presence of CXCL11 receptor, CXCR3, on the surface of CD8+T cells, suggesting that the CD8+T cells might be attracted to the MB microenvironment by CXCL11 through CXCR3.

CONCLUSION

The CD8+T cells infiltrate more in the WNT subtype MB than other subtypes. The mechanism may be related to the activation of CXCL11-CXCR3 chemokine system, and the patients with more infiltration of CD8+T cells in tumor have better prognosis. This finding may provide the necessary clinicopathological basis for the regulatory mechanism of CD8+T cells infiltration in MB, and give a new potential therapeutic target for the future immunotherapy of MB.

Identifying the Spatial Architecture That Restricts the Proximity of CD8+ T Cells to Tumor Cells in Pancreatic Ductal Adenocarcinoma

The anti-tumor function of CD8+ T cells is dependent on their proximity to tumor cells. Current studies have focused on the infiltration level of CD8+ T cells in the tumor microenvironment, while further spatial information, such as spatial localization and inter-cellular communication, have not been defined. In this study, co-detection by indexing (CODEX) was designed to characterize PDAC tissue regions with seven protein markers in order to identify the spatial architecture that regulates CD8+ T cells in human pancreatic ductal adenocarcinoma (PDAC). The cellular neighborhood algorithm was used to identify a total of six conserved and distinct cellular neighborhoods. Among these, one unique spatial architecture of CD8+ T and CD4+ T cell-enriched neighborhoods enriched the majority of CD8+ T cells, but heralded a poor prognosis. The proximity analysis revealed that the CD8+ T cells in this spatial architecture were significantly closer to themselves and the CD4+ T cells than to the tumor cells. Collectively, we identified a unique spatial architecture that restricted the proximity of CD8+ T cells to tumor cells in the tumor microenvironment, indicating a novel immune evasion mechanism of pancreatic ductal adenocarcinoma in a topologically regulated manner and providing new insights into the biology of PDAC.

CD4+ T cells produce IFN-I to license cDC1s for induction of cytotoxic T-cell activity in human tumors

CD4+ T cells can "help" or "license" conventional type 1 dendritic cells (cDC1s) to induce CD8+ cytotoxic T lymphocyte (CTL) anticancer responses, as proven in mouse models. We recently identified cDC1s with a transcriptomic imprint of CD4+ T-cell help, specifically in T-cell-infiltrated human cancers, and these cells were associated with a good prognosis and response to PD-1-targeting immunotherapy. Here, we delineate the mechanism of cDC1 licensing by CD4+ T cells in humans. Activated CD4+ T cells produce IFNβ via the STING pathway, which promotes MHC-I antigen (cross-)presentation by cDC1s and thereby improves their ability to induce CTL anticancer responses. In cooperation with CD40 ligand (L), IFNβ also optimizes the costimulatory and other functions of cDC1s required for CTL response induction. IFN-I-producing CD4+ T cells are present in diverse T-cell-infiltrated cancers and likely deliver "help" signals to CTLs locally, according to their transcriptomic profile and colocalization with "helped/licensed" cDCs and tumor-reactive CD8+ T cells. In agreement with this scenario, the presence of IFN-I-producing CD4+ T cells in the TME is associated with overall survival and the response to PD-1 checkpoint blockade in cancer patients.

The Prognostic Value of CD39 as a Marker of Tumor-Specific T Cells in Triple-Negative Breast Cancer in Asian Women

Triple-negative breast cancer (TNBC) has a poor prognosis with limited therapeutic options available for affected patients. Efforts are ongoing to identify surrogate markers for tumor-specific CD8+ T cells that can predict the response to immune checkpoint inhibitor (ICI) therapies, such as programmed cell death protein 1 or programmed cell death ligand-1 blockade. We have previously identified tumor-specific CD39+CD8+ T cells in non-small cell lung cancer that might help predict patient responses to programmed cell death protein 1 or programmed cell death ligand-1 blockade. Based on this finding, we conducted a comparative interrogation of TNBC in an Asian cohort to evaluate the potential of CD39 as a surrogate marker of tumor-specific CD8+ T cells. Using ICI-treated TNBC mouse models (n = 24), flow cytometric analyses of peripheral blood mononuclear cells and tumor-infiltrating lymphocytes revealed that >99% of tumor-specific CD8+ T cells also expressed CD39. To investigate the relationship between CD39+CD8+ T-cell density and CD39 expression with disease prognosis, we performed multiplex immunohistochemistry staining on treatment-naive human TNBC tissues (n = 315). We saw that the proportion of CD39+CD8+ T cells in human TNBC tumors correlated with improved overall survival, as did the densities of other CD39+ immune cell infiltrates, such as CD39+CD68+ macrophages. Finally, increased CD39 expression on CD8+ T cells was also found to predict the response to ICI therapy (pembrolizumab) in a separate cohort of 11 TNBC patients. These findings support the potential of CD39+CD8+ T-cell density as a prognostic factor in Asian TNBC patients.

Predicting HPV association using deep learning and regular H&E stains allows granular stratification of oropharyngeal cancer patients

Human Papilloma Virus (HPV)-associated oropharyngeal squamous cell cancer (OPSCC) represents an OPSCC subgroup with an overall good prognosis with a rising incidence in Western countries. Multiple lines of evidence suggest that HPV-associated tumors are not a homogeneous tumor entity, underlining the need for accurate prognostic biomarkers. In this retrospective, multi-institutional study involving 906 patients from four centers and one database, we developed a deep learning algorithm (OPSCCnet), to analyze standard H&E stains for the calculation of a patient-level score associated with prognosis, comparing it to combined HPV-DNA and p16-status. When comparing OPSCCnet to HPV-status, the algorithm showed a good overall performance with a mean area under the receiver operator curve (AUROC) = 0.83 (95% CI = 0.77-0.9) for the test cohort (n = 639), which could be increased to AUROC = 0.88 by filtering cases using a fixed threshold on the variance of the probability of the HPV-positive class - a potential surrogate marker of HPV-heterogeneity. OPSCCnet could be used as a screening tool, outperforming gold standard HPV testing (OPSCCnet: five-year survival rate: 96% [95% CI = 90-100%]; HPV testing: five-year survival rate: 80% [95% CI = 71-90%]). This could be confirmed using a multivariate analysis of a three-tier threshold (OPSCCnet: high HR = 0.15 [95% CI = 0.05-0.44], intermediate HR = 0.58 [95% CI = 0.34-0.98] p = 0.043, Cox proportional hazards model, n = 211; HPV testing: HR = 0.29 [95% CI = 0.15-0.54] p < 0.001, Cox proportional hazards model, n = 211). Collectively, our findings indicate that by analyzing standard gigapixel hematoxylin and eosin (H&E) histological whole-slide images, OPSCCnet demonstrated superior performance over p16/HPV-DNA testing in various clinical scenarios, particularly in accurately stratifying these patients.

Human T cells loaded with superparamagnetic iron oxide nanoparticles retain antigen-specific TCR functionality

Background

Immunotherapy of cancer is an emerging field with the potential to improve long-term survival. Thus far, adoptive transfer of tumor-specific T cells represents an effective treatment option for tumors of the hematological system such as lymphoma, leukemia or myeloma. However, in solid tumors, treatment efficacy is low owing to the immunosuppressive microenvironment, on-target/off-tumor toxicity, limited extravasation out of the blood vessel, or ineffective trafficking of T cells into the tumor region. Superparamagnetic iron oxide nanoparticles (SPIONs) can make cells magnetically controllable for the site-specific enrichment.

Methods

In this study, we investigated the influence of SPION-loading on primary human T cells for the magnetically targeted adoptive T cell therapy. For this, we analyzed cellular mechanics and the T cell response after stimulation via an exogenous T cell receptor (TCR) specific for the melanoma antigen MelanA or the endogenous TCR specific for the cytomegalovirus antigen pp65 and compared them to T cells that had not received SPIONs.

Results

SPION-loading of human T cells showed no influence on cellular mechanics, therefore retaining their ability to deform to external pressure. Additionally, SPION-loading did not impair the T cell proliferation, expression of activation markers, cytokine secretion, and tumor cell killing after antigen-specific activation mediated by the TCR.

Conclusion

In summary, we demonstrated that SPION-loading of T cells did not affect cellular mechanics or the functionality of the endogenous or an exogenous TCR, which allows future approaches using SPIONs for the magnetically enrichment of T cells in solid tumors.

Development and validation of two redox-related genes associated with prognosis and immune microenvironment in endometrial carcinoma

In recent studies, the tumourigenesis and development of endometrial carcinoma (EC) have been correlated significantly with redox. We aimed to develop and validate a redox-related prognostic model of patients with EC to predict the prognosis and the efficacy of immunotherapy. We downloaded gene expression profiles and clinical information of patients with EC from the Cancer Genome Atlas (TCGA) and the Gene Ontology (GO) dataset. We identified two key differentially expressed redox genes (CYBA and SMPD3) by univariate Cox regression and utilised them to calculate the risk score of all samples. Based on the median of risk scores, we composed low-and high-risk groups and performed correlation analysis with immune cell infiltration and immune checkpoints. Finally, we constructed a nomogram of the prognostic model based on clinical factors and the risk score. We verified the predictive performance using receiver operating characteristic (ROC) and calibration curves. CYBA and SMPD3 were significantly related to the prognosis of patients with EC and used to construct a risk model. There were significant differences in survival, immune cell infiltration and immune checkpoints between the low-and high-risk groups. The nomogram developed with clinical indicators and the risk scores was effective in predicting the prognosis of patients with EC. In this study, a prognostic model constructed based on two redox-related genes (CYBA and SMPD3) were proved to be independent prognostic factors of EC and associated with tumour immune microenvironment. The redox signature genes have the potential to predict the prognosis and the immunotherapy efficacy of patients with EC.

Mature dendritic cells enriched in immunoregulatory molecules (mregDCs): A novel population in the tumour microenvironment and immunotherapy target

BACKGROUND

Dendritic cells (DCs) mediate divergent immune effects by activating T cells or negatively regulating the immune response to promote immune tolerance. They perform specific functions determined by their tissue distribution and maturation state. Traditionally, immature and semimature DCs were described to have immunosuppressive effects, leading to immune tolerance. Nonetheless, recent research has demonstrated that mature DCs can also suppress the immune response under certain circumstances.

MAIN BODY

Mature DCs enriched in immunoregulatory molecules (mregDCs) have emerged as a regulatory module across species and tumour types. Indeed, the distinct roles of mregDCs in tumour immunotherapy have sparked the interest of researchers in the field of single-cell omics. In particular, these regulatory cells were found to be associated with a positive response to immunotherapy and a favourable prognosis.

CONCLUSION

Here, we provide a general overview of the latest and most notable advances and recent findings regarding the basic features and complex roles of mregDCs in nonmalignant diseases and the tumour microenvironment. We also emphasise the important clinical implications of mregDCs in tumours.

Single-cell high-dimensional imaging mass cytometry: one step beyond in oncology

Solid tumors have a dynamic ecosystem in which malignant and non-malignant (endothelial, stromal, and immune) cell types constantly interact. Importantly, the abundance, localization, and functional orientation of each cell component within the tumor microenvironment vary significantly over time and in response to treatment. Such intratumoral heterogeneity influences the tumor course and its sensitivity to treatments. Recently, high-dimensional imaging mass cytometry (IMC) has been developed to explore the tumor ecosystem at the single-cell level. In the last years, several studies demonstrated that IMC is a powerful tool to decipher the tumor complexity. In this review, we summarize the potential of this technology and how it may be useful for cancer research (from preclinical to clinical studies).

Response to primary chemoradiotherapy of locally advanced oropharyngeal carcinoma is determined by the degree of cytotoxic T cell infiltration within tumor cell aggregates

Background

Effective anti-tumor immune responses are mediated by T cells and require organized, spatially coordinated interactions within the tumor microenvironment (TME). Understanding coordinated T-cell-behavior and deciphering mechanisms of radiotherapy resistance mediated by tumor stem cells will advance risk stratification of oropharyngeal cancer (OPSCC) patients treated with primary chemoradiotherapy (RCTx).

Methods

To determine the role of CD8 T cells (CTL) and tumor stem cells for response to RCTx, we employed multiplex immunofluorescence stains on pre-treatment biopsy specimens from 86 advanced OPSCC patients and correlated these quantitative data with clinical parameters. Multiplex stains were analyzed at the single-cell level using QuPath and spatial coordination of immune cells within the TME was explored using the R-package Spatstat.

Results

Our observations demonstrate that a strong CTL-infiltration into the epithelial tumor compartment (HR for overall survival, OS: 0.35; p<0.001) and the expression of PD-L1 on CTL (HR: 0.36; p<0.001) were both associated with a significantly better response and survival upon RCTx. As expected, p16 expression was a strong predictor of improved OS (HR: 0.38; p=0.002) and correlated with overall CTL infiltration (r: 0.358, p<0.001). By contrast, tumor cell proliferative activity, expression of the tumor stem cell marker CD271 and overall CTL infiltration, regardless of the affected compartment, were not associated with response or survival.

Conclusion

In this study, we could demonstrate the clinical relevance of the spatial organization and the phenotype of CD8 T cells within the TME. In particular, we found that the infiltration of CD8 T cells specifically into the tumor cell compartment was an independent predictive marker for response to chemoradiotherapy, which was strongly associated with p16 expression. Meanwhile, tumor cell proliferation and the expression of stem cell markers showed no independent prognostic effect for patients with primary RCTx and thus requires further study.

Immune-based biomarker accurately predicts response to imiquimod immunotherapy in cervical high-grade squamous intraepithelial lesions

BACKGROUND

The complete response rate of cervical high-grade squamous intraepithelial lesion (cHSIL) patients to imiquimod immunotherapy is approximately 60%. Consequently, many patients are exposed to unnecessary adverse effects of imiquimod. On the other hand, conventional surgical large loop excision therapy is associated with increased risk of premature births in subsequent pregnancies. An in-depth analysis of the cHSIL immune microenvironment was performed in order to identify and develop a predictive biomarker for response to imiquimod, to maximize therapy efficacy and to avoid adverse effects in patients unlikely to respond.

METHODS

Biopsies of 35 cHSIL patients, before and 10 weeks on imiquimod treatment, were analyzed by two multispectral seven-color immunofluorescence panels for T cell and myeloid cell composition in relation to treatment response. Based on these results a simplified immunohistochemical detection protocol was developed. Samples were scanned with the Vectra multispectral imaging system and cells were automatically identified using machine learning.

RESULTS

The immune microenvironment of complete responders (CR) is characterized by a strong and coordinated infiltration by T helper cells (activated PD1⁺/type 1 Tbet⁺), M1-like macrophages (CD68⁺CD163^-) and dendritic cells (CD11c⁺) prior to imiquimod. The lesions of non-responders (NRs) displayed a high infiltration by CD3⁺FOXP3⁺ regulatory T cells. At 10 weeks on imiquimod, a strong influx of intraepithelial and stromal CD4⁺ T cells was observed in CR but not NR patients. A steep decrease in macrophages occurred both in CR and NR patients, leveling the pre-existing differences in myeloid cell composition between the two groups. Based on the pre-existing immune composition differences, the sum of intraepithelial CD4 T cell, macrophage and dendritic cell counts was used to develop a quantitative simplified one color immunohistochemical biomarker, the CHSIL immune biomarker for imiquimod (CIBI), which can be automatically and unbiasedly quantified and has an excellent predictive capacity (receiver operating characteristic area under the curve 0.95, p<0.0001).

CONCLUSION

The capacity of cHSIL patients to respond to imiquimod is associated with a pre-existing coordinated local immune process, fostering an imiquimod-mediated increase in local T cell infiltration. The CIBI immunohistochemical biomarker has strong potential to select cHSIL patients with a high likelihood to experience a complete response to imiquimod immunotherapy.

The immune microenvironment of HPV-positive and HPV-negative oropharyngeal squamous cell carcinoma: a multiparametric quantitative and spatial analysis unveils a rationale to target treatment-naïve tumors with immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICI) are approved for treatment of recurrent or metastatic oropharyngeal head and neck squamous cell carcinoma in the first- and second-line settings. However, only 15-20% of patients benefit from this treatment, a feature increasingly ascribed to the peculiar characteristics of the tumor immune microenvironment (TIME).

METHODS

Immune-related gene expression profiling (GEP) and multiplex immunofluorescence (mIF) including spatial proximity analysis, were used to characterize the TIME of 39 treatment-naïve oropharyngeal squamous cell carcinomas (OPSCC) and the corresponding lymph node metastases. GEP and mIF results were correlated with disease-free survival (DFS). HPV-positive tumors disclosed a stronger activation of several immune signalling pathways, as well as a higher expression of genes related to total tumor-infiltrating lymphocytes, CD8 T cells, cytotoxic cells and exhausted CD8 cells, than HPV-negative patients. Accordingly, mIF revealed that HPV-positive lesions were heavily infiltrated as compared to HPV-negative counterparts, with a higher density of T cells and checkpoint molecules. CD8+ T cells appeared in closer proximity to tumor cells, CD163+ macrophages and FoxP3+ cells in HPV-positive primary tumors, and related metastases. In HPV-positive lesions, PD-L1 expression was increased as compared to HPV-negative samples, and PD-L1+ tumor cells and macrophages were closer to PD-1+ cytotoxic T lymphocytes. Considering the whole cohort, a positive correlation was observed between DFS and higher levels of activating immune signatures and T cell responses, higher density of PD-1+ T cells and their closer proximity to tumor cells or PD-L1+ macrophages. HPV-positive patients with higher infiltration of T cells and macrophages had a longer DFS, while CD163+ macrophages had a negative role in prognosis of HPV-negative patients.

CONCLUSIONS

Our results suggest that checkpoint expression may reflect an ongoing antitumor immune response. Thus, these observations provide the rationale for the incorporation of ICI in the loco-regional therapy strategies for patients with heavily infiltrated treatment-naïve OPSCC, and for the combination of ICI with tumor-specific T cell response inducers or TAM modulators for the "cold" OPSCC counterparts.

Pivotal roles of tumor-draining lymph nodes in the abscopal effects from combined immunotherapy and radiotherapy

BACKGROUND

Currently, due to synergy enhancement of anti-tumor effects and potent stimulation of abscopal effects, combination therapy with irradiation and programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint inhibition (immuno-radiotherapy, iRT) has revolutionized the therapeutic guidelines. It has been demonstrated that tumor-draining lymph nodes (TDLN) are essential for effective antitumor immunity induced by radiotherapy, immunotherapy, or iRT. Given that the function of TDLN in iRT remains unclear, this study aimed to investigate the function and mechanism of TDLN in iRT-induced abscopal effects.

METHODS

The function of TDLN was evaluated using unilateral or bilateral MC38 and B16F10 subcutaneous tumor models with or without indicated TDLN. The flow cytometry, multiple immunofluorescence analysis, and NanoString analysis were utilized to detect the composition and function of the immune cells in the primary and abscopal tumor microenvironment. Additionally, we tempted to interrogate the possible mechanisms via RNA-sequencing of tumor-infiltrating lymphocytes and TDLN.

RESULTS

TDLN deficiency impaired the control of tumor growth by monotherapy. Bilateral TDLN removal rather than unilateral TDLN removal substantially curtailed iRT-stimulated anti-tumor and abscopal effects. Furthermore, in the absence of TDLN, the infiltration of CD45⁺ and CD8⁺ T cells was substantially reduced in both primary and abscopal tumors, and the anti-tumor function of CD8⁺ T cells was attenuated as well. Additionally, the polarization of tumor-associated macrophages in primary and abscopal tumors were found to be dependent on intact bilateral TDLN. RNA-sequencing data indicated that impaired infiltration and anti-tumor effects of immune cells partially attributed to the altered secretion of components from the tumor microenvironment.

CONCLUSIONS

TDLN play a critical role in iRT by promoting the infiltration of CD8⁺ T cells and maintaining the M1/M2 macrophage ratio.

Opportunities and Challenges in Understanding Atherosclerosis by Human Biospecimen Studies

Over the last few years, new high-throughput biotechnologies and bioinformatic methods are revolutionizing our way of deep profiling tissue specimens at the molecular levels. These recent innovations provide opportunities to advance our understanding of atherosclerosis using human lesions aborted during autopsies and cardiac surgeries. Studies on human lesions have been focusing on understanding the relationship between molecules in the lesions with tissue morphology, genetic risk of atherosclerosis, and future adverse cardiovascular events. This review will highlight ways to utilize human atherosclerotic lesions in translational research by work from large cardiovascular biobanks to tissue registries. We will also discuss the opportunities and challenges of working with human atherosclerotic lesions in the era of next-generation sequencing.