Identification and validation of an immunogenic subtype of gastric cancer with abundant intratumoural CD103+CD8+ T cells conferring favourable prognosis

Insights of immune cell heterogeneity, tumor-initiated subtype transformation, drug resistance, treatment and detecting technologies in glioma microenvironment

BACKGROUND

With the gradual understanding of glioma development and the immune microenvironment, many immune cells have been discovered. Despite the growing comprehension of immune cell functions and the clinical application of immunotherapy, the precise roles and characteristics of immune cell subtypes, how glioma induces subtype transformation of immune cells and its impact on glioma progression have yet to be understood.

AIM OF THE REVIEW

In this review, we comprehensively center on the four major immune cells within the glioma microenvironment, particularly neutrophils, macrophages, lymphocytes, myeloid-derived suppressor cells (MDSCs), and other significant immune cells. We discuss (1) immune cell subtype markers, (2) glioma-induced immune cell subtype transformation, (3) the mechanisms of each subtype influencing chemotherapy resistance, (4) therapies targeting immune cells, and (5) immune cell-associated single-cell sequencing. Eventually, we identified the characteristics of immune cell subtypes in glioma, comprehensively summarized the exact mechanism of glioma-induced immune cell subtype transformation, and concluded the progress of single-cell sequencing in exploring immune cell subtypes in glioma.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In conclusion, we have analyzed the mechanism of chemotherapy resistance detailly, and have discovered prospective immunotherapy targets, excavating the potential of novel immunotherapies approach that synergistically combines radiotherapy, chemotherapy, and surgery, thereby paving the way for improved immunotherapeutic strategies against glioma and enhanced patient outcomes.

Exploration of signature based on T cell-related genes in stomach adenocarcinoma by analysis of single cell sequencing data

BACKGROUND

Gastric cancer (GC) is a leading reason for the death of cancer around the world. The immune microenvironment counts a great deal in immunotherapy of advanced tumors, in which T cells exert an indispensable function.

METHODS

Single-cell RNA sequencing data were utilized to characterize the expression profile of T cells, followed by T cell-related genes (TCRGs) to construct signature and measure differences in survival time, enrichment pathways, somatic mutation status, immune status, and immunotherapy between groups.

RESULTS

The complex tumor microenvironment was analyzed by scRNA-seq data of GC patients. We screened for these T cell signature expression genes and the TCRGs-based signature was successfully constructed and relied on the riskscore grouping. In gene set enrichment analysis, it was shown that pro-tumor and suppressive immune pathways were more abundant in the higher risk group. We also found different infiltration of immune cells in two groups, and that the higher risk samples had a poorer response to immunotherapy.

CONCLUSION

Our study established a prognostic model, in which different groups had different prognosis, immune status, and enriched features. These results have provided additional insights into prognostic evaluation and the development of highly potent immunotherapies in GC.

Ubiquilin-4 induces immune escape in gastric cancer by activating the notch signaling pathway

PURPOSE

We aimed to investigate the role of ubiquilin-4 in predicting the immunotherapy response in gastric cancer.

METHODS

Retrospective RNA-sequencing and immunohistochemical analysis were performed for patients with gastric cancer who received programmed death-1 blockade therapy after recurrence. Multiplex immunohistochemistry identified immune cell types in gastric cancer tissues. We used immunocompetent 615 mice and immunodeficient nude mice to perform tumorigenic experiments.

RESULTS

Ubiquilin-4 expression was significantly higher in responders (p < 0.05, false discovery rate > 2.5) and showed slight superiority over programmed death ligand 1 in predicting programmed death-1 inhibitor therapy response (area under the curve: 87.08 vs. 72.50). Ubiquilin-4-high patients exhibited increased CD4+ and CD8+ T cells, T follicular helper cells, monocytes, and macrophages. Ubiquilin-4-overexpressed mouse forestomach carcinoma cells showed significantly enhanced growth in immunocompetent mice but not in immunodeficient mice. Upregulation or downregulation of ubiquilin-4 synergistically affected programmed death ligand 1 at the protein and messenger RNA levels. Functional enrichment analysis revealed significant enrichment of the Notch, JAK-STAT, and WNT signaling pathways in ubiquilin-4-high gastric cancers. Ubiquilin-4 promoted Numb degaration, activating the Notch signaling pathway and upregulating programmed death ligand 1.

CONCLUSIONS

Ubiquilin-4 may contribute to immune escape in gastric cancer by upregulating programmed death ligand 1 expression in tumor cells through Notch signaling activation. Thus, ubiquilin-4 could serve as a predictive marker for programmed death ligand 1 inhibitor therapy response in gastric cancer.

Development of [89Zr]Zr-hCD103.Fab01A and [68Ga]Ga-hCD103.Fab01A for PET imaging to noninvasively assess cancer reactive T cell infiltration: Fab-based CD103 immunoPET

BACKGROUND

CD103 is an integrin specifically expressed on the surface of cancer-reactive T cells. The number of CD103+ T cells significantly increases during successful immunotherapy and might therefore be an attractive biomarker for noninvasive PET imaging of immunotherapy response. Since the long half-life of antibodies preclude repeat imaging of CD103+ T cell dynamics early in therapy, we therefore here explored PET imaging with CD103 Fab fragments radiolabeled with a longer (89Zr) and shorter-lived radionuclide (68Ga).

METHODS

Antihuman CD103 Fab fragment Fab01A was radiolabeled with 89Zr or 68Ga, generating [89Zr]Zr-hCD103.Fab01A and [68Ga]Ga-hCD103.Fab01A, respectively. In vivo evaluation of these tracers was performed in male nude mice (BALB/cOlaHsd-Foxn1nu) with established CD103-expressing CHO (CHO.CD103) or CHO-wildtype (CHO.K1) xenografts, followed by serial PET imaging and ex vivo bio-distribution.

RESULTS

[89Zr]Zr-hCD103.Fab01A showed high tracer uptake in CD103+ xenografts as early as 3 h post-injection. However, the background signal remained high in the 3- and 6-h scans. The background was relatively low at 24 h after injection with sufficient tumor uptake. [68Ga]Ga-hCD103.Fab01Ashowed acceptable uptake and signal-to-noise ratio in CD103+ xenografts after 3 h, which decreased at subsequent time points.

CONCLUSION

[89Zr]Zr-hCD103.Fab01A demonstrated a relatively low background and high xenograft uptake in scans as early as 6 h post-injection and could be explored for repeat imaging during immunotherapy in clinical trials. 18F or 64Cu could be explored as alternative to 68Ga in optimizing half-life and radiation burden of the tracer.

Antigenicity and adjuvanticity co-reinforced personalized cell vaccines based on self-adjuvanted hydrogel for post-surgical cancer vaccination

Cancer vaccine-based postsurgical immunotherapy is emerging as a promising approach in patients following surgical resection for inhibition of tumor recurrence. However, low immunogenicity and insufficient cancer antigens limit the widespread application of postoperative cancer vaccines. Here, we propose a "trash to treasure" cancer vaccine strategy to enhance postsurgical personalized immunotherapy, in which antigenicity and adjuvanticity of purified surgically exfoliated autologous tumors (with whole antigen repertoire) were co-reinforced. In the antigenicity and adjuvanticity co-reinforced personalized vaccine (Angel-Vax), polyriboinosinic: polyribocytidylic acid (pIC) and tumor cells that have undergone immunogenic death are encapsulated in a self-adjuvanted hydrogel formed by cross-linking of mannan and polyethyleneimine. Angel-Vax exhibits an enhanced capacity on antigen-presenting cells stimulation and maturation compared to its individual components in vitro. Immunization with Angel-Vax provokes an efficient systemic cytotoxic T-cell immune response, contributing to the satisfied prophylactic and therapeutic efficacy in mice. Furthermore, when combined with immune checkpoint inhibitors (ICI), Angel-Vax effectively prevented postsurgical tumor recurrence, as evidenced by an increase in median survival of approximately 35% compared with ICI alone. Unlike the cumbersome preparation process of postoperative cancer vaccines, the simple and feasible approach herein may represent a general strategy for various kinds of tumor cell-based antigens in the inhibition of postsurgical tumor relapse by reinforced immunogenicity.

Tumor-resident memory T cells as a biomarker of the response to cancer immunotherapy

Tumor-infiltrating lymphocytes (TIL) often include a substantial subset of CD8+ tissue-resident memory T (TRM) cells enriched in tumor-specific T cells. These TRM cells play a major role in antitumor immune response. They are identified on the basis of their expression of the CD103 (αE(CD103)β7) and/or CD49a (α1(CD49a)β1) integrins, and the C-type lectin CD69, which are involved in tissue residency. TRM cells express several T-cell inhibitory receptors on their surface but they nevertheless react strongly to malignant cells, exerting a strong cytotoxic function, particularly in the context of blocking interactions of PD-1 with PD-L1 on target cells. These TRM cells form stable conjugates with autologous tumor cells and interact with dendritic cells and other T cells within the tumor microenvironment to orchestrate an optimal in situ T-cell response. There is growing evidence to indicate that TGF-β is essential for the formation and maintenance of TRM cells in the tumor, through the induction of CD103 expression on activated CD8+ T cells, and for the regulation of TRM effector functions through bidirectional integrin signaling. CD8+ TRM cells were initially described as a prognostic marker for survival in patients with various types of cancer, including ovarian, lung and breast cancers and melanoma. More recently, these tumor-resident CD8+ T cells have been shown to be a potent predictive biomarker of the response of cancer patients to immunotherapies, including therapeutic cancer vaccines and immune checkpoint blockade. In this review, we will highlight the major characteristics of tumor TRM cell populations and the possibilities for their exploitation in the design of more effective immunotherapy strategies for cancer.

Programmed Death Ligand 1 (PD-L1) Expression and CD8 + Tumor-infiltrating Lymphocyte-based Tumor Immune Microenvironment Classification in Gynecologic Carcinosarcoma: Prognostic Impact and Implications for Therapy

To investigate the prevalence and prognostic significance of programmed death ligand-1 (PD-L1) expression and CD8 + tumor-infiltrating lymphocytes (TILs) in gynecologic carcinosarcoma, 81 cases (68 uterine, 12 ovarian, and 1 fallopian tube) were immunostained with PD-L1 and CD8 using tissue microarrays (3 mm core diameter) from intratumoral areas with the highest TILs. Tumor proportion score (TPS) ≥1% and combined positive score (CPS) ≥1 were considered positive for PD-L1. CD8 + TILs were counted in each core, and CD8 + TIL density (CD8TILD) was calculated. Cases were classified as CD8 Neg (<1.4/mm 2 CD8TILD), CD8 Pos (≥1.4/mm 2 CD8TILD) and CD8 HIGH (≥14/mm 2 CD8TILD) and grouped into 4 tumor immune microenvironment (TIME) groups: (1) PD-L-1 Pos /CD8 Pos , (2) PD-L1 Neg /CD8 Neg , (3) PD-L1 Pos /CD8 Neg , and (4) PD-L1 Neg /CD8 Pos . PD-L1 expression by TPS and CPS was detected in 19.8% and 39.6% cases, respectively. Kaplan-Meier curves with log-rank analysis showed that higher density of CD8 + TILs were associated with longer overall survival (OS) ( P =0.05 for CD8 Pos and P =0.014 for CD8 HIGH ), and CD8 HIGH status was associated with longer OS irrespective of tumor stage ( P =0.045, hazard ratio: 0.11, 95% confidence interval: 0.014-0.951). Thirty-three percent of patients belonged to TIME group 1. PD-L1 expression and TIME groups were not associated with OS or progression-free survival. We found that high density of CD8 + TILs is an independent indicator of better OS. In 33% cases PD-L1 expression is associated with increased CD8 + TILs ("acquired immune evasion" pattern of PD-L1 expression), hence they may benefit from anti PD-1/PD-L1 therapy. PD-L1 expression alone and TIME groups do not affect survival in gynecologic carcinosarcoma.

Prognostic values of tissue-resident CD8+T cells in human hepatocellular carcinoma and intrahepatic cholangiocarcinoma

BACKGROUND

Tissue-resident CD8⁺T cells (CD103⁺CD8⁺T cells) are the essential effector cell population of anti-tumor immune response in tissue regional immunity. And we have reported that IL-33 can promote the proliferation and effector function of tissue-resident CD103⁺CD8⁺T cells. As of now, the immunolocalization and the prognostic values of tissue-resident CD8⁺T cells in human hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) still remain to be illustrated.

METHODS

In our present study, we used the tissue microarrays of HCC and ICC, the multicolor immunohistochemistry (mIHC), and imaging analysis to characterize the tissue-resident CD8⁺T cells in HCC and ICC tissues. The prognostic values and clinical associations were also analyzed. We also studied the biological functions and the cell-cell communication between tumor-infiltrating CD103⁺CD8⁺T cells and other cell types in HCC and ICC based on the published single-cell RNA sequencing (scRNA-seq) data.

RESULTS

Our work unveiled the expressions of CD8 and CD103 and immunolocalization of tissue-resident CD8⁺T cells in human HCC and ICC. Elevated CD8⁺T cells indicated a better overall survival (OS) rate, implying that tumor-infiltrating CD8⁺T cells in HCC and ICC could serve as an independent prognostic factor. Moreover, the number of CD103⁺CD8⁺T cells was increased in HCC and ICC tissues compared with adjacent normal tissues. HCC patients defined as CD8^highCD103^high had a better OS, and the CD8^lowCD103^low group tended to have a poorer prognosis in ICC. Evaluation of the CD103⁺CD8⁺T-cell ratio in CD8⁺T cells could also be a prognostic predictor for HCC and ICC patients. A higher ratio of CD103⁺CD8⁺T cells over total CD8⁺T cells in HCC tissues was negatively and significantly associated with the advanced pathological stage. The percentage of higher numbers of CD103⁺CD8⁺T cells in ICC tissues was negatively and significantly associated with the advanced pathological stage. In contrast, the higher ratio of CD103⁺CD8⁺T cells over total CD8⁺T cells in ICC tissues was negatively and significantly associated with the advanced pathological stage. In addition, single-cell transcriptomics revealed that CD103⁺CD8⁺T cells were enriched in genes associated with T-cell activation, proliferation, cytokine function, and T-cell exhaustion.

CONCLUSION

The CD103⁺ tumor-specific T cells signified an important prognostic marker with improved OS, and the evaluation of the tissue-resident CD103⁺CD8⁺T cells might be helpful in assessing the on-treatment response of liver cancer.

CD103 blockade impair anti-CTLA-4 immunotherapy in oral cancer

OBJECTIVES

CD103⁺CD8⁺T cells is a subtype of T cells with excellent tumor killing ability and it could response to immune checkpoint blockade therapy in several types of cancer, but the phenotype, role and molecular mechanism CD103⁺CD8⁺T cells in the OSCC still unclear.

MATERIALS AND METHODS

The distribution and phenotype of CD103⁺CD8⁺T cells were investigated by performing multiplexed immunohistochemistry on human OSCC tissue microarray and flow cytometric analysis of fresh OSCC tumor-infiltrating lymphocytes (TILs). By in vivo use of anti-CD103 monoclonal antibody (mAb) in the 4MOSC1 tumor-bearing mouse model, CD103⁺CD8⁺T cell infiltration and cytotoxicity was clarified.

RESULTS

The majority of CD8⁺T cells in both human and animal OSCC intra-tumoral region were CD103⁺CD8⁺T cells with high expression levels of cytotoxic molecules, which can be impaired by CD103 blockade. In addition, combined use of anti-CD103 mAb with anti-CTLA-4 mAb displayed impaired immune checkpoint blockade therapy efficiency.

CONCLUSION

CD103⁺CD8⁺T cells are the major intra-tumoral subset of CD8⁺T cells in both animal and human OSCC, and that CD103⁺CD8⁺T cells demonstrate remarkable tumor-infiltrating and tumor-killing properties, thereby CD103⁺CD8⁺T cells may critical for anti-CTLA-4 immunotherapy in OSCC.

Tumour-infiltrating lymphocytes: from prognosis to treatment selection

Tumour-infiltrating lymphocytes (TILs) are considered crucial in anti-tumour immunity. Accordingly, the presence of TILs contains prognostic and predictive value. In 2011, we performed a systematic review and meta-analysis on the prognostic value of TILs across cancer types. Since then, the advent of immune checkpoint blockade (ICB) has renewed interest in the analysis of TILs. In this review, we first describe how our understanding of the prognostic value of TIL has changed over the last decade. New insights on novel TIL subsets are discussed and give a broader view on the prognostic effect of TILs in cancer. Apart from prognostic value, evidence on the predictive significance of TILs in the immune therapy era are discussed, as well as new techniques, such as machine learning that strive to incorporate these predictive capacities within clinical trials.

The tissue-resident marker CD103 on peripheral blood T cells predicts responses to anti-PD-1 therapy in gastric cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. Since clinical benefits are limited to a subset of patients, we aimed to identify peripheral blood biomarkers that predict the efficacy of the anti-programmed cell death protein 1 (PD-1) antibody (nivolumab) in patients with gastric cancer.

METHODS

We collected peripheral blood samples from gastric cancer patients (n = 29) before and after treatment with nivolumab and investigated the relationship between the frequency of surface or intracellular markers among nivolumab-binding PD-1⁺CD8⁺ T cells and treatment responses using multicolor flow cytometry. The tumors, lymph nodes, and peripheral blood of gastric cancer patients who underwent gastrectomy following nivolumab treatment were collected, and nivolumab-binding PD-1⁺CD8⁺ T cells in these tissue samples were characterized.

RESULTS

Patients with a high frequency of CD103 among PD-1⁺CD8⁺ T cells in peripheral blood 2 weeks after the start of treatment had significantly better progression-free survival than the low group (P = 0.032). This CD103⁺PD-1⁺CD8⁺ T cell population mainly consisted of central memory T cells, showing the high expression of Ki-67 and few cytotoxic granules. In contrast, effector memory T cells were more frequently observed among CD103⁺PD-1⁺CD8⁺ T cells in tumors, which implied a change in the differentiated status of central memory T cells in lymph nodes and peripheral blood to effector memory T cells in tumors during the treatment with ICIs.

CONCLUSIONS

A high frequency of CD103 among PD-1⁺CD8⁺ T cells 2 weeks after nivolumab treatment in patients with advanced gastric cancer may be a useful biomarker for predicting the efficacy of anti-PD-1 therapy.

Tissue-resident memory T cells in gastrointestinal tumors: turning immune desert into immune oasis

Tissue-resident memory T cells (Trm) are a particular type of T cell subgroup, which stably reside in tissues and have been revealed to be the most abundant memory T cell population in various tissues. They can be activated in the local microenvironment by infection or tumor cells and rapidly clean them up to restore homeostasis of local immunity in gastrointestinal tissues. Emerging evidence has shown that tissue-resident memory T cells have great potential to be mucosal guardians against gastrointestinal tumors. Therefore, they are considered potential immune markers for immunotherapy of gastrointestinal tumors and potential extraction objects for cell therapy with essential prospects in clinical translational therapy. This paper systematically reviews the role of tissue-resident memory T cells in gastrointestinal tumors and looks to the future of their prospect in immunotherapy to provide a reference for clinical application.

Development of 89Zr-anti-CD103 PET imaging for non-invasive assessment of cancer reactive T cell infiltration

PURPOSE

CD103, an integrin specifically expressed on the surface of cancer-reactive T cells, is significantly increased during successful immunotherapy across human malignancies. In this study, we describe the generation and zirconium-89 (⁸⁹Zr) radiolabeling of monoclonal antibody (mAb) clones that specifically recognize human CD103 for non-invasive immune positron-emission tomography (PET) imaging of T cell infiltration as potential biomarker for effective anticancer immune responses.

EXPERIMENTAL DESIGN

First, to determine the feasibility of anti-CD103 immuno-PET to visualize CD103-positive cells at physiologically and clinically relevant target densities, we developed an ⁸⁹Zr-anti-murine CD103 PET tracer. Healthy, non-tumor bearing C57BL/6 mice underwent serial PET imaging after intravenous injection, followed by ex vivo biodistribution. Tracer specificity and macroscopic tissue distribution were studied using autoradiography combined with CD103 immunohistochemistry. Next, we generated and screened six unique mAbs that specifically target human CD103 positive cells. Optimal candidates were selected for ⁸⁹Zr-anti-human CD103 PET development. Nude mice (BALB/cOlaHsd-Foxn1nu) with established CD103 expressing Chinese hamster ovary (CHO) or CHO wild-type xenografts were injected with ⁸⁹Zr-anti-human CD103 mAbs and underwent serial PET imaging, followed by ex vivo biodistribution.

RESULTS

⁸⁹Zr-anti-murine CD103 PET imaging identified CD103-positive tissues at clinically relevant target densities. For human anti-human CD103 PET development two clones were selected based on strong binding to the CD103⁺ CD8⁺ T cell subpopulation in ovarian cancer tumor digests, non-overlapping binding epitopes and differential CD103 blocking properties. In vivo, both ⁸⁹Zr-anti-human CD103 tracers showed high target-to-background ratios, high target site selectivity and a high sensitivity in human CD103 positive xenografts.

CONCLUSION

CD103 immuno-PET tracers visualize CD103 T cells at relevant densities and are suitable for future non-invasive assessment of cancer reactive T cell infiltration.

Combining single-cell sequencing data to construct a prognostic signature to predict survival, immune microenvironment, and immunotherapy response in gastric cancer patients

Background and objective

Gastric cancer (GC) represents a major factor inducing global cancer-associated deaths, but specific biomarkers and therapeutic targets for GC are lacking at present. Therefore, the present work focused on developing an immune-related genetic signature at the single-cell level for categorizing GC cases and predicting patient prognostic outcome, immune status as well as treatment response.

Methods

Single-cell RNA-sequencing (scRNA-seq) data were combined with bulk RNA-seq data in GC patients for subsequent analyses. Differences in overall survival (OS), genomic alterations, immune status, together with estimated immunotherapeutic outcomes were measured between different groups.

Results

Nine cell types were identified by analyzing scRNA-seq data from GC patients, and marker genes of immune cells were also selected for subsequent analysis. In addition, an immune-related signature was established to predict OS while validating the prediction power for GC patients. Afterwards, a nomogram with high accuracy was constructed for improving our constructed signature’s clinical utility. The low-risk group was featured by high tumor mutation burden (TMB), increased immune activation, and microsatellite instability-high (MSI-H), which were related to the prolonged OS and used in immunotherapy. By contrast, high-risk group was associated with microsatellite stability (MSS), low TMB and immunosuppression, which might be more suitable for targeted therapy. Meanwhile, the risk score generated by our signature was markedly related to the cancer stem cell (CSC) index. In addition, the immunotherapeutic response prediction accuracy of our signature was validated in an external dataset IMvigor210 cohort.

Conclusion

A signature was constructed according to scRNA-seq data analysis. The signature-screened low- and high-risk patients had different prognoses, immune statuses and enriched functions and pathways. Such results shed more lights on immune status of GC, prognosis assessment, and development of efficient immunotherapeutic treatments.

TIGIT and PD-1 expression atlas predicts response to adjuvant chemotherapy and PD-L1 blockade in muscle-invasive bladder cancer

BACKGROUND

TIGIT and PD-1 are checkpoint receptors that could regulate the functional status of immune cells through independent pathways. However, the clinical significance of immune classification based on TIGIT and PD-1 expression remains unclear in muscle-invasive bladder cancer (MIBC).

METHODS

Patients with MIBC from four independent cohorts were categorised into three clusters. Survival analysis conducted through Kaplan-Meier curves and Cox regression model. Immune contexture was measured by immunohistochemistry and CIBERSORT algorithm. Twenty-five fresh tumour tissue samples were utilised to evaluate functional state of CD8⁺ T cells by flow cytometry.

RESULTS

Cluster I (TIGIT^lowPD-1^low) contained widely poor immune infiltrates with higher FGFR3 mutation, Cluster II (TIGIT^lowPD-1^high) exhibited a highly infiltrated contexture with increased cytolytic CD8⁺ T cells and had the best prognosis, Cluster III (TIGIT^high) presented a suppressive tumour microenvironment (TME) featured by exhausted CD8⁺ T cells and basal molecular subtype. Patients of Cluster III had the worst survival but could benefit more from adjuvant chemotherapy and anti-PD-L1 immunotherapy, and also presented limited FGFR3 signalling signature but activated immunotherapeutic and EGFR-associated pathway.

CONCLUSIONS

TIGIT/PD-1-based risk stratification with distinct immune and molecular features could be served as a predictor for systematic therapeutic response including adjuvant chemotherapy and immunotherapy in MIBC patients.

Identification of immune infiltration-related genes as prognostic indicators for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has a high degree of malignancy and a poor prognosis. Immune infiltration-related genes have shown good predictive value in the prognosis of many solid tumours. In this study, we established and verified prognostic biomarkers consisting of immune infiltration-related genes in HCC. Gene expression data and clinical data were downloaded from The Cancer Genome Atlas (TCGA) database. Differential gene expression analysis, univariate Cox regression analysis and the least absolute shrinkage and selection operator (LASSO) regression algorithm were used to screen prognostic immune infiltration-related genes and to construct a risk scoring model. Kaplan-Meier (KM) survival plots and receiver operating characteristic (ROC) curve analysis were used to evaluate the prognostic performance of the risk scoring model in the TCGA-HCC cohort. In addition, a nomogram model with a risk score was established, and its predictive performance was verified by ROC analysis and calibration plot analysis in the TCGA-HCC cohort. Gene set enrichment analysis (GSEA) identified pathways and biological processes that may be enriched in the high-risk group. Finally, immune infiltration analysis was used to explore the characteristics of the tumour microenvironment related to the risk score. We identified 17 immune infiltration-related genes with prognostic value and constructed a risk scoring model. ROC analysis showed that the risk scoring model can accurately predict the 1-year, 3-year, and 5-year overall survival (OS) of HCC patients in the TCGA-HCC cohort. KM analysis showed that the OS of the high-risk group was significantly lower than that of the low-risk group (P < 0.001). The nomogram model effectively predicted the OS of HCC patients in the TCGA-HCC cohort. GSEA indicated that the immune infiltration-related genes may be involved in biological processes such as amino acid and lipid metabolism, matrisome and small molecule transportation, immune system regulation, and hepatitis virus infection. Immune infiltration analysis showed that the level of immune cell infiltration in the high-risk group was low, and the risk score was negatively correlated with infiltrating immune cells. Our prognostic model based on immune infiltration-related genes in HCC could help the prognostic assessment of HCC patients and provide potential targets for HCC inhibition.

Association of CD103+ T cell infiltration with overall survival in solid tumors of the digestive duct and its potential in anti-PD-1 treatment: A review and meta-analysis

We looked into the most recent studies of digestive tumor patients and performed a meta-analysis to explore the association of CD103+ T cell infiltration with overall survival (OS) in solid tumors of the digestive duct. Major databases were searched. The hazard ratios (HR) and 95% confidence intervals (CI) for overall survival were extracted and pooled. A total of 1915 patients from 11 cohorts were included into the present meta-analysis. The pooled HR was 0.64 (95% CI: 0.42-0.96, P=0.03), suggesting that high CD103+ T cell infiltration is associated with better prognosis. Yet significant heterogeneity was revealed and located in the subgroup of CD4+CD103+ T cells. The pooled result indicated that CD103+ T cell infiltration in solid tumors of the digestive duct may possess predictive value for prognosis. Preclinical studies suggested that CD103+ T cell infiltration could predict response to anti-PD-1/PD-L1 treatment.

Immune-Related lncRNAs Pairs to Construct a Novel Signature for Predicting Prognosis in Gastric Cancer

Background

Immune-related long non-coding RNAs (irlncRNAs) appear valuable in predicting prognosis in patients with cancer. In this study, we used a fresh modeling algorithm to construct irlncRNAs signature and then assessed its predictive value for prognosis, tumor immune infiltration, and chemotherapy efficacy in gastric cancer (GC) patients.

Materials and Methods

The raw transcriptome data were extracted from the Cancer Genome Atlas (TCGA). Patients were randomly divided into the training and testing cohort. irlncRNAs were identified through co-expression analysis, after which differentially expressed irlncRNA (DEirlncRNA) pairs were identified. Next, we developed a model to distinguish between high- or low-risk groups in GC patients through univariate and LASSO regression analyses. A ROC curve was used to verify this model. After subgrouping patients according to the median risk score, we investigated the connection between the risk score of GC and clinicopathological characteristics. Functional enrichment analysis was also performed.

Results

We find that the results indicate that immune-related lncRNA signaling has essential value in predicting prognosis, and it may be potential to measure the Efficacy for immunotherapy. This feature may be a guide to the selection of GC immunotherapy.

Conclusion

Our data revealed that immune-related lncRNA signaling had essential value in predicting prognosis, and it may be potentially used to measure the efficacy for immunotherapy. This feature may also be used to guide the selection of GC immunotherapy.

The Emerging Role of Tissue-Resident Memory CD8+ T Lymphocytes in Human Digestive Tract Cancers

Malignant digestive tract tumors are a great threat to human public health. In addition to surgery, immunotherapy brings hope for the treatment of these tumors. Tissue-resident memory CD8⁺ T (Trm) cells are a focus of tumor immunology research and treatment due to their powerful cytotoxic effects, ability to directly kill epithelial-derived tumor cells, and overall impact on maintaining mucosal homeostasis and antitumor function in the digestive tract. They are a group of noncirculating immune cells expressing adhesion and migration molecules such as CD69, CD103, and CD49a that primarily reside on the barrier epithelium of nonlymphoid organs and respond rapidly to both viral and bacterial infection and tumorigenesis. This review highlights new research exploring the role of CD8⁺ Trm cells in a variety of digestive tract malignant tumors, including esophageal cancer, gastric cancer, colorectal cancer, and hepatocellular carcinoma. A summary of CD8⁺ Trm cell phenotypes and characteristics, tissue distribution, and antitumor functions in different tumor environments is provided, illustrating how these cells may be used in immunotherapies against digestive tract tumors.

Mapping the genomic diaspora of gastric cancer

Gastric cancer (GC) is a leading contributor to global cancer incidence and mortality. Pioneering genomic studies, focusing largely on primary GCs, revealed driver alterations in genes such as ERBB2, FGFR2, TP53 and ARID1A as well as multiple molecular subtypes. However, clinical efforts targeting these alterations have produced variable results, hampered by complex co-alteration patterns in molecular profiles and intra-patient genomic heterogeneity. In this Review, we highlight foundational and translational advances in dissecting the genomic cartography of GC, including non-coding variants, epigenomic aberrations and transcriptomic alterations, and describe how these alterations interplay with environmental influences, germline factors and the tumour microenvironment. Mapping of these alterations over the GC life cycle in normal gastric tissues, metaplasia, primary carcinoma and distant metastasis will improve our understanding of biological mechanisms driving GC development and promoting cancer hallmarks. On the translational front, integrative genomic approaches are identifying diverse mechanisms of GC therapy resistance and emerging preclinical targets, enabled by technologies such as single-cell sequencing and liquid biopsies. Validating these insights will require specifically designed GC cohorts, converging multi-modal genomic data with longitudinal data on therapeutic challenges and patient outcomes. Genomic findings from these studies will facilitate 'next-generation' clinical initiatives in GC precision oncology and prevention.

Human mucosal tissue-resident memory T cells in health and disease

Memory T cells are fundamental to maintain immune surveillance of the human body. During the past decade, it has become apparent that non-recirculating resident memory T cells (TRMs) form a first line memory response in tissues to tackle re-infections. The fact that TRMs are essential for local immunity highlights the therapeutic potential of targeting this population against tumors and infections. However, similar to other immune subsets, TRMs are heterogenous and may form distinct effector populations with unique functions at diverse tissue sites. Further insight into the mechanisms of how TRM function and respond to pathogens and malignancies at different mucosal sites will help to shape future vaccine and immunotherapeutic approaches. Here, we review the current understanding of TRM function and biology at four major mucosal sites: gastrointestinal tract, lung, head and neck, as well as female reproductive tract. We also summarize our current knowledge of how TRM targets invading pathogens and developing tumor cells at these mucosal sites and contemplate how TRMs may be exploited to protect from infections and cancer.

Integrin αE(CD103)β7 in Epithelial Cancer

Interactions of both the innate and the adaptive immune system with tumors are complex and often influence courses and therapeutic treatments in unanticipated ways. Based on the concept that CD8+T cells can mediate important antitumor effects, several therapies now aim to amplify their specific activity. A subpopulation of CD8+ tissue-resident T lymphocytes that express the αE(CD103)β7 integrin has raised particular interest. This receptor presumably contributes to the recruitment and retention of tumor-infiltrating immune cells through interaction with its ligand, E-cadherin. It appears to have regulatory functions and is thought to be a component of some immunological synapses. In TGF-rich environments, the αE(CD103)β7/E-cadherin-interaction enhances the binding strength between tumor cells and infiltrating T lymphocytes. This activity facilitates the release of lytic granule contents and cytokines as well as further immune responses and the killing of target cells. Expression of αE(CD103)β7 in some tumors is associated with a rather favorable prognosis, perhaps with the notable exception of squamous cell carcinoma of the skin. Although epithelial skin tumors are by far the most common tumors of fair-skinned people, there have been very few studies on the distribution of αE(CD103)β7 expressing cells in these neoplasms. Given this background, we describe here that αE(CD103)β7 is scarcely present in basal cell carcinomas, but much more abundant in squamous cell carcinomas with heterogeneous distribution. Notwithstanding a substantial number of studies, the role of αE(CD103)β7 in the tumor context is still far from clear. Here, we summarize the essential current knowledge on αE(CD103)β7 and outline that it is worthwhile to further explore this intriguing receptor with regard to the pathophysiology, therapy, and prognosis of solid tumors.

Distribution, phenotype, functional and clinical relevance of CD8+CD103+ tissue-resident memory T cells in human gastric cancer

CD8⁺CD103⁺ tissue-resident memory T cells (TRMs) are involved in tumor immune response and linked to favorable clinical outcome in human cancer. However, the distribution, phenotype, functional properties and clinical relevance of these cells in gastric cancer (GC) remain elusive. Here, our data show that, in comparison to non-tumor tissues, the percentages of CD8⁺CD103⁺ TRMs in tumors are significantly decreased. Most tumor-infiltrating CD8⁺CD103⁺ TRMs are CD45RA^-CCR7^- effector-memory cells with higher PD-1 and 4-1BB expression than those from non-tumor tissues. Further, tumor-infiltrating CD8⁺CD103⁺ TRMs show impaired cytolytic capacity due to decreased granzyme B and perforin expression. Moreover, ex vivo PD-1 blockade could restore the cytolytic capacity of tumor-infiltrating CD8⁺CD103⁺ TRMs, and such anti-PD-1-mediated reinvigoration of CD8⁺CD103⁺ TRMs could be further enhanced by 4-1BB co-stimulation. Finally, lower levels of Tumor-infiltrating CD8⁺CD103⁺ TRMs are positively correlated with GC progression and poor patients' survival. Our data suggest that restoring CD8⁺CD103⁺ TRM function by combining PD-1 blockade and 4-1BB co-stimulation may be a promising strategy for treating GC.

Downregulation of ACE2 is associated with advanced pathological features and poor prognosis in clear cell renal cell carcinoma

Aims: The aim of this study was to explore the alteration in ACE2 expression and correlation between ACE2 expression and immune infiltration in clear cell renal cell carcinoma (ccRCC). Methods: The authors first analyzed the expression profiles and prognostic value of ACE2 in ccRCC patients using The Cancer Genome Atlas public database. The authors used ESTIMATE and CIBERSORT algorithms to analyze the correlation between ACE2 expression and tumor microenvironment in ccRCC samples. Results: ACE2 was correlated with sex, distant metastasis, clinical stage, tumor T stage and histological grade. Moreover, downregulation of ACE2 was correlated with unfavorable prognosis. In addition, ACE2 expression was associated with different immune cell subtypes. Conclusion: The authors' analyses suggest that ACE2 plays an important role in the development and progression of ccRCC and may serve as a potential prognostic biomarker in ccRCC patients.

Establishment of an Immune Cell Infiltration Score to Help Predict the Prognosis and Chemotherapy Responsiveness of Gastric Cancer Patients

The immune microenvironment plays a critical role in tumor biology. The molecular profiles of immune components and related genes are of tremendous value for the study of primary resistance to immune checkpoint blockers (ICBs) for gastric cancer (GC) and serve as prognostic biomarkers to predict GC survival. Recent studies have revealed that tumor immune cell infiltration (ICI) is an indicator of the survival and responsiveness to chemotherapy in GC patients. Here, we describe the immune cell landscape based on the ESTIMATE and CIBERSORT algorithms to help separate GC into 3 ICI clusters using the unsupervised clustering method. Further in-depth analyses, such as differential expression gene (DEG) analysis and principal component analysis (PCA), help to establish an ICI scoring system. A low ICI score is characterized by an increased tumor mutation burden (TMB). The combination of the ICI score and TMB score better predicts the survival of GC patients. Analyses based on public and our own database revealed that the ICI scoring system could also help predict the survival and chemotherapy responsiveness of GC patients. The present study demonstrated that the ICI score may be an effective prognostic biomarker and predictive indicator for chemotherapy and immunotherapy.

Elevated Expression of PDZD11 Is Associated With Poor Prognosis and Immune Infiltrates in Hepatocellular Carcinoma

Epithelial cells are held together by tight and adherent junctions, which are destroyed by the activation of epithelial-to-mesenchymal transition (EMT). The PLEKHA7-PDZD11 complex has been reported to be important for epithelial cell adhesion and connecting tissues. However, there is no research regarding the expression and role of PDZD11 in liver hepatocellular carcinoma (LIHC) progression. Here, we analyzed PDZD11 mRNA expression and its clinical results in LIHC patient RNA sequencing data based on different open databases. Furthermore, we examined differences in PDZD11 expression in LIHC tissues and cell lines using western blotting and real-time qPCR. These results are the first to report that the mRNA and protein levels of PDZD11 are significantly overexpressed in LIHC. Moreover, high expression of PDZD11 was correlated with poor overall survival in patients with LIHC. Gene regulatory network analysis suggested that PDZD11 is mainly involved in copper ion homeostasis, proteasome, and oxidative phosphorylation pathways. Interestingly, we found that PDZD11 levels were positively correlated with the abundance of immune infiltrates. In particular, higher infiltration levels of CD4⁺ T cells and macrophage subsets significantly affected LIHC patient prognosis. Taken together, these results demonstrate that PDZD11 could be a potential diagnostic and prognostic biomarker in LIHC.

Intratumoral Foxp3+RORγt+ T cell infiltration determines poor prognosis and immunoevasive contexture in gastric cancer patients

BACKGROUND

Foxp3⁺RORγt⁺ T cells possess both characteristics of regulatory T cells and T helper 17 cells and show significant immunoregulatory functions in autoimmune diseases. However, the role and clinical significance of Foxp3⁺RORγt⁺ T cells in gastric cancer remains unclear.

METHODS

We enrolled 452 gastric cancer tissue microarray samples and 60 fresh tumor tissue samples from Zhongshan Hospital. The infiltration of Foxp3⁺RORγt⁺ T cells and immune contexture were examined by immunohistochemistry and flow cytometry. Survival analyses of patient subgroups were conducted by Kaplan-Meier curves, log-rank test and Cox proportional model.

RESULTS

High infiltration of Foxp3⁺RORγt⁺ T cells predicted poor overall survival (P = 0.0222 and 0.0110) and inferior therapeutic response (P = 0.003 for interaction) in gastric cancer. Foxp3⁺RORγt⁺ T cells were associated with impaired effective function of CD8⁺ T cells featured by decreased interferon-γ, granzyme B and CD107a expression. Co-evaluation of Foxp3⁺RORγt⁺ T cells and CD8⁺ T cells could predict survival outcomes and chemotherapeutic responsiveness more precisely.

CONCLUSIONS

We found that Foxp3⁺RORγt⁺ T cells could potentially attenuate effective functions of CD8⁺ T cells and led to adverse survival outcomes and inferior chemotherapeutic responsiveness. Moreover, the novel co-evaluation system might be useful for prognosis prediction for appropriate treatment in gastric cancer.

NOVELTY AND IMPACT STATEMENTS

Clinical significance of Foxp3⁺RORγts⁺ T cells has not been studied in gastric cancer. Herein, we investigated the prognostic value of Foxp3+RORγt+ T cells in 452 patients. We demonstrated that intratumoral Foxp3⁺RORγt⁺ T cell infiltration was a prognostic biomarker for overall survival and the identification of patients might benefit from post-gastrectomy 5-fluorouracil. These findings allow a more precise stratification upon the co-evaluation with CD8⁺ T cells to better clinical management for patients who would benefit from 5-fluorouracil.

Endometrial Cancer Suppresses CD8+ T Cell-Mediated Cytotoxicity in Postmenopausal Women

Endometrial cancer is the most common gynecological cancer. To investigate how it suppresses host immune function, we isolated CD8+ T cells from endometrial endometroid carcinomas and adjacent non-cancerous endometrium and determined if the tumor environment regulates cytotoxic capacity. Endometrial carcinomas had increased numbers of CD8+ T cells compared to adjacent non-cancerous endometrium. Tumor CD8+ T cells expressed significantly less granzyme A (GZA), B (GZB), and PD-1 than those in adjacent non-cancerous tissues and also had significantly lower cytotoxic killing of allogeneic target cells. CD103-CD8+ T cells, but not CD103+CD8+ T cells, from both adjacent and tumor tissue were primarily responsible for killing of allogeneic target cells. Secretions recovered from endometrial carcinoma tissues suppressed CD8+ cytotoxic killing and lowered perforin, GZB and PD-1 expression relative to non-tumor CD8+ T cells. Furthermore, tumor secretions contained significantly higher levels of immunosuppressive cytokines including TGFβ than non-tumor tissues. Thus, the tumor microenvironment suppresses cytotoxic killing by CD8+ T cells via the secretion of immunosuppressive cytokines leading to decreased expression of intracellular cytolytic molecules. These studies demonstrate the complexity of CD8+ T cell regulation within the endometrial tumor microenvironment and provide a foundation of information essential for the development of therapeutic strategies for gynecological cancers.

Intratumoral CD103+ CD8+ T cells predict response to PD-L1 blockade

BACKGROUND

CD8+ tissue-resident memory T (T_RM) cells, marked by CD103 (ITGAE) expression, are thought to actively suppress cancer progression, leading to the hypothesis that their presence in tumors may predict response to immunotherapy.

METHODS

Here, we test this by combining high-dimensional single-cell modalities with bulk tumor transcriptomics from 1868 patients enrolled in lung and bladder cancer clinical trials of atezolizumab (anti-programmed cell death ligand 1 (PD-L1)).

RESULTS

ITGAE was identified as the most significantly upregulated gene in inflamed tumors. Tumor CD103+ CD8+ T_RM cells exhibited a complex phenotype defined by the expression of checkpoint regulators, cytotoxic proteins, and increased clonal expansion.

CONCLUSIONS

Our analyses indeed demonstrate that the presence of CD103+ CD8+ T_RM cells, quantified by tracking intratumoral CD103 expression, can predict treatment outcome, suggesting that patients who respond to PD-1/PD-L1 blockade are those who exhibit an ongoing antitumor T-cell response.

Tertiary lymphoid structures show infiltration of effective tumor-resident T cells in gastric cancer

Several studies have reported that tissue‐resident memory T cells (TRM cells) or tertiary lymphoid structures (TLSs) are associated with a good prognosis. The aim of this study was to clarify the association of TRM cells and TLSs in the tumor immune microenvironment in gastric cancer (GC). We performed immunohistochemical and immunofluorescence staining to detect the presence of CD103⁺ T cells and to assess the association between CD103⁺ T cells and TLSs. CD103⁺ T cells were observed in the tumor epithelium accompanied by CD8⁺ T cells and were associated with a better prognosis in GC. Furthermore, CD103⁺ T cells were located around TLSs, and patients with CD103^high had more rich TLSs. Patients who had both CD103^high cells and who were TLS‐rich had a better prognosis than patients with CD103^low cells and who were TLS‐poor. Moreover, for patients who received PD‐1 blockade therapy, CD103^high and TLS‐rich predicted a good response. Flow cytometry was performed to confirm the characteristics of CD103⁺CD8⁺ T cells and showed that CD103⁺CD8⁺ T cells in GC expressed higher levels of PD‐1, granzyme B, and interferon‐γ than CD103⁻CD8⁺ T cells. Our results suggested that CD103⁺CD8⁺ cells in GC are correlated with TLSs, resulting in enhanced antitumor immunity in GC.

Intratumoral CD103+CD4+ T cell infiltration defines immunoevasive contexture and poor clinical outcomes in gastric cancer patients

Our previous study has identified intratumoral CD103⁺CD8⁺ T cells as a favorable prognostic factor in gastric cancer. However, the significance of CD103⁺CD4⁺ T cells in gastric cancer hasn’t yet been elucidated. Here, we aimed to investigate the clinical significance and phenotype characteristics of intratumoral CD103⁺CD4⁺ T cells in gastric cancer. In our study, 469 formalin-fixed and paraffin-embedded samples and 24 fresh tissue specimens of patients with gastric cancer from Zhongshan Hospital were included. We manifested that intratumoral CD103⁺CD4⁺ T cells in gastric cancer predicted poor overall survival and inferior responsiveness to fluorouracil-based ACT. The density and phenotypic characteristics of CD103⁺CD4⁺ T cells in gastric cancer were detected by immunohistochemistry and flow cytometry, which showed that CD103⁺CD4⁺ T cells exhibited an immunosuppressive phenotype and higher retention capacity in tumor tissues. Furthermore, increased CD103⁺CD4⁺ T cells contributed to CD8⁺T cell dysfunction with decreased granzyme B (GZMB), interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α) and perforin (PRF-1) expression in gastric cancer. Overall, this study revealed that intratumoral CD103⁺CD4⁺T cell infiltration defined immunoevasive contexture and predicted poor prognosis and inferior responsiveness to fluorouracil-based ACT. Therefore, we recommended that CD103⁺CD4⁺ T cells might be a potential immunotherapeutic target for gastric cancer.

Tumor-infiltrating podoplanin+ cells in gastric cancer: clinical outcomes and association with immune contexture

Podoplanin (PDPN) has been proved to have significant immunoregulatory effects in several types of malignancies and is considered to be a novel immune checkpoint molecule. However, the clinical significance of PDPN and its potential influence on immune contexture in gastric cancer remain obscure. Here, we aimed to investigate the clinical outcomes and immunoregulatory role of tumor-infiltrating PDPN⁺ cells (tPDPNs) in gastric cancer. A total of 454 tumor tissue microarray specimens and 68 fresh tumor tissues of gastric cancer patients from Zhongshan Hospital, and transcriptional data of 293 gastric cancer patients from The Cancer Genome Atlas were included. We demonstrated that tPDPNs high subgroup experienced worse overall survival and disease-free survival, and indicated inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy (ACT) in gastric cancer. The abundance of tPDPNs was correlated with an immunoevasive contexture characterized by pro-tumor macrophage and dysfunctional CD8⁺ T cell infiltration. Moreover, dysfunctional CD8⁺ T cells in tPDPNs high subgroup exhibited decreased interferon-γ, granzyme B and perforin-1 expression yet elevated programmed cell death-1 (PD-1) and T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) expression. Stratification of gastric cancer patients into different risk groups based on tPDPNs and CD8⁺ T cells showed distinct prognosis, responsiveness to ACT and molecular characteristics. This study revealed that the abundance of tPDPNs could identify an immunoevasive contexture and might be applied as an independent predictor for poor prognosis and suboptimal ACT responsiveness. Thus, we recommended tPDPNs as a promising therapeutic target in gastric cancer.

Characteristics of TCR Repertoire Associated With Successful Immune Checkpoint Therapy Responses

Immunotherapies have revolutionized cancer treatment. In particular, immune checkpoint therapy (ICT) leads to durable responses in some patients with some cancers. However, the majority of treated patients do not respond. Understanding immune mechanisms that underlie responsiveness to ICT will help identify predictive biomarkers of response and develop treatments to convert non-responding patients to responding ones. ICT primarily acts at the level of adaptive immunity. The specificity of adaptive immune cells, such as T and B cells, is determined by antigen-specific receptors. T cell repertoires can be comprehensively profiled by high-throughput sequencing at the bulk and single-cell level. T cell receptor (TCR) sequencing allows for sensitive tracking of dynamic changes in antigen-specific T cells at the clonal level, giving unprecedented insight into the mechanisms by which ICT alters T cell responses. Here, we review how the repertoire influences response to ICT and conversely how ICT affects repertoire diversity. We will also explore how changes to the repertoire in different anatomical locations can better correlate and perhaps predict treatment outcome. We discuss the advantages and limitations of current metrics used to characterize and represent TCR repertoire diversity. Discovery of predictive biomarkers could lie in novel analysis approaches, such as network analysis of amino acids similarities between TCR sequences. Single-cell sequencing is a breakthrough technology that can link phenotype with specificity, identifying T cell clones that are crucial for successful ICT. The field of immuno-sequencing is rapidly developing and cross-disciplinary efforts are required to maximize the analysis, application, and validation of sequencing data. Unravelling the dynamic behavior of the TCR repertoire during ICT will be highly valuable for tracking and understanding anti-tumor immunity, biomarker discovery, and ultimately for the development of novel strategies to improve patient outcomes.