Single-cell sequencing of tumour infiltrating T cells efficiently identifies tumour-specific T cell receptors based on the T cell activation score.

Adoptively transferred T cell receptor-engineered T cells are a promising cancer treatment strategy, and the identification of tumour-specific TCRs is essential. Previous studies reported that tumour-reactive T cells and TCRs could be isolated based on the expression of activation markers. However, since T cells with different cell states could not respond uniformly to activation but show a heterogeneous expression profile of activation and effector molecules, isolation of tumour-reactive T cells based on single activation or effector molecules could result in the absence of tumour-reactive T cells; thus, combinations of multiple activation and effector molecules could improve the efficiency of isolating tumour-specific TCRs. We enrolled two patients with lung adenocarcinoma and obtained their tumour infiltrating lymphocytes (TILs) and autologous tumour cells (ATCs). TILs were cocultured with the corresponding ATCs for 12 h and subjected to single-cell RNA sequencing. First, we identified three TCRs with the highest expression levels of IFNG and TNFRSF9 mRNA for each patient, yet only the top one or two recognized the corresponding ATCs in each patient. Next, we defined the activation score based on normalized expression levels of IFNG, IL2, TNF, IL2RA, CD69, TNFRSF9, GZMB, GZMA, GZMK, and PRF1 mRNA for each T cell and then identified three TCRs with the highest activation score for each patient. We found that all three TCRs in each patient could specifically identify corresponding ATCs. In conclusion, we established an efficient approach to isolate tumour-reactive TCRs based on combinations of multiple activation and effector molecules through single-cell RNA sequencing.

TCR extracellular domain genetically linked to CD28, 2B4/41BB and DAP10/CD3ζ -engineered NK cells mediates antitumor effects.

NK cells, especially FDA-approved NK-92 cells, could be used for TCR engineering owing to their specialized cytotoxicity against tumors, safety profile and potential use as an off-the-shelf cellular therapy. The TCR complex requires assembly of TCR- α/ ß chains with CD3 molecules (CD3δ, CD3γ, CD3ε, CD3ζ) to be correctly expressed at the cell membrane, and yet NK cells lack expression of these CD3 subunits besides CD3ζ. Since transmembrane regions of TCR α and ß chains are involved in TCR complex assembly, transmembrane regions of TCR replaced by CD28 transmembrane domain could result in the expression of TCR independent of its companion CD3 subunits. However, since the absence of CD3 signaling components can influence the transmission of TCR signals to NK cells, it is necessary to add the signaling molecules of NK cells followed by CD28 transmembrane domain. Both CD3ζ and DAP10 play an important role in the activation and cytotoxicity of NK cells; moreover, 2B4 and 4-1BB are the main costimulatory molecules in NK cells. Therefore, we designed a chimeric TCR that consisted of the extracellular domains of the TCR α and ß chains specific for NYESO-1 fused to the CD28 transmembrane domain followed by the 41BB and CD3ζ signaling domains as well as the 2B4 and DAP10 signaling domain, respectively. The chimeric TCR genetically engineered NK-92 cells exhibit antigen-specific recognition and lysis of tumor cells both in vitro and in vivo. In addition, TCR-28-2B10/BBζ can be feasibly expressed in primary NK cells and exhibit antigen-reactive recognition and effect function. The overall encouraging data highlight the value of NK-92 cells and primary NK cells engineered to express therapeutic chimeric TCR for adoptive immunotherapies.

Pharmacologic inhibition of IL11/STAT3 signaling increases MHC-I expression and T cell infiltration.

BACKGROUND: Recent studies have discovered an emerging role of IL11 in various colitis-associated cancers, suggesting that IL11 mainly promotes tumor cell survival and proliferation in regulating tumorigenesis. Herein we aimed to reveal a novel function of IL-11 through STAT3 signaling in regulating tumor immune evasion. METHODS: AOM/DSS model in Il11-/- and Apcmin/+/Il11-/- mice were used to detect tumor growth and CD8+ T infiltration. STAT1/3 phosphorylation and MHC-I, CXCL9, H2-K1 and H2-D1 expression were detected in MC38 cells and intestine organoids treated with/without recombinant IL11 to explore effect of IL11/STAT3 signaling, with IL11 mutein used to competitively inhibit IL11 and rescue inhibited STAT1 activation. Correlation between IL11 and CD8+ T infiltration was analyzed using TIMER2.0 website. IL11 expression and survival prognosis was analyzed in clinical data of patient cohort from Nanfang Hospital. RESULTS: IL11 is highly expressed in CRC and indicates unfavorable prognosis. IL11 knockout increased CD8+ T cell infiltration and reduced intestinal and colon formation. Tumors were significantly suppressed while MHC-I and CXCL9 expression for CD8+ T infiltration were remarkably increased in the tumor tissues of Apcmin/+/Il11-/- mice or Il11-/- mice induced by AOM/DSS. IL11/STAT3 signaling downregulated MHC-I and CXCL9 by inhibiting IFNγ-induced STAT1 phosphorylation. IL11 mutein competitively inhibit IL11 to upregulate CXCL9 and MHC-I in tumor and attenuated tumor growth. CONCLUSIONS: This study ascribes for a new immunomodulatory role for IL11 during tumor development that is amenable to anti-cytokine based therapy of colon cancer.

Blockade of IL-6 inhibits tumor immune evasion and improves anti-PD-1 immunotherapy.

Long-standing inflammatory bowel disease predisposes to the development of colorectal cancer (CRC). Interleukin (IL) -6, a pivotal link between chronic inflammation and tumor progression, has recently been recognized as a potential therapeutic target. The effect of IL-6 on proliferation and metastasis of CRC by activating the STAT3 pathway has been widely demonstrated in recent years, but few on mediating tumor immune evasion. In this study, we found that IL-6 was remarkably overexpressed in CRC and its elevation was associated with a poor prognosis. We studied CRC tumorigenesis in vivo by inoculating MC38 tumors and induced-CRC model via AOM/DSS (azoxymethane/dextransulfate sodium) in IL-6 deficient (IL-6-/-) and wild-type (WT) mice and found that IL-6-/- mice were less susceptible to develop tumors, compared to WT mice. We detected CD8+ T cells via immunofluorescence and found they exhibit high expression in tumor of IL-6-/- mice. High level of IL-6 was found in colitis model, with down-regulation of MHC-I molecules. In in vitro experiments, we found that IL-6 may act as a negative regulator in IFNγ-STAT1-MHC-I signaling. In addition, vivo trials also confirmed that MHC-I mRNA level was negatively related to the existence of IL-6. Furthermore, the blockade of IL-6 also activated CD8+T-cell accumulation and led to the high PD-L1 expression in CRC, which can sensitize animals to anti-PD-1 therapy. Our study provides a research basis for the significant role of IL-6 in tumor evasion and highlights a novel target to improve the efficacy of immunotherapy.

Pre-depletion of TRBC1+ T cells promotes the therapeutic efficacy of anti-TRBC1 CAR-T for T-cell malignancies.

Targeting T cell receptor ß-chain constant region 1 (TRBC1) CAR-T could specifically kill TRBC1+ T-cell malignancies. However, over-expressed CARs on anti-TRBC1 CAR transduced TRBC1+ T cells (CAR-C1) bound to autologous TRBC1, masking TRBC1 from identification by other anti-TRBC1 CAR-T, and moreover only the remaining unoccupied CARs recognized TRBC1+ cells, considerably reducing therapeutic potency of CAR-C1. In addition, co-culture of anti-TRBC1 CAR-T and TRBC1+ cells could promote exhaustion and terminal differentiation of CAR-T. These findings provide a rationale for pre-depleting TRBC1+ T cells before anti-TRBC1 CAR-T manufacturing.

Oral microbiome and risk of malignant esophageal lesions in a high-risk area of China: A nested case-control study.

OBJECTIVE: We aimed to prospectively evaluate the association of oral microbiome with malignant esophageal lesions and its predictive potential as a biomarker of risk. METHODS: We conducted a case-control study nested within a population-based cohort with up to 8 visits of oral swab collection for each subject over an 11-year period in a high-risk area for esophageal cancer in China. The oral microbiome was evaluated with 16S ribosomal RNA (rRNA) gene sequencing in 428 pre-diagnostic oral specimens from 84 cases with esophageal lesions of severe squamous dysplasia and above (SDA) and 168 matched healthy controls. DESeq analysis was performed to identify taxa of differential abundance. Differential oral species together with subject characteristics were evaluated for their potential in predicting SDA risk by constructing conditional logistic regression models. RESULTS: A total of 125 taxa including 37 named species showed significantly different abundance between SDA cases and controls (all P<0.05 & false discovery rate-adjusted Q<0.10). A multivariate logistic model including 11 SDA lesion-related species and family history of esophageal cancer provided an area under the receiver operating characteristic curve (AUC) of 0.89 (95% CI, 0.84-0.93). Cross-validation and sensitivity analysis, excluding cases diagnosed within 1 year of collection of the baseline specimen and their matched controls, or restriction to screen-endoscopic-detected or clinically diagnosed case-control triads, or using only bacterial data measured at the baseline, yielded AUCs>0.84. CONCLUSIONS: The oral microbiome may play an etiological and predictive role in esophageal cancer, and it holds promise as a non-invasive early warning biomarker for risk stratification for esophageal cancer screening programs.

Efficacy of endoscopic screening for esophageal cancer in China (ESECC): design and preliminary results of a population-based randomised controlled trial.

OBJECTIVE: Description of the design and preliminary results of baseline recruitment and screening in the endoscopic screening for esophageal cancer in China (ESECC), the first randomised controlled trial (RCT) assessing efficacy and cost-effectiveness of endoscopic screening for esophageal squamous cell carcinoma (ESCC). DESIGN: ESECC trial is a cluster RCT, and 668 villages in rural Hua County, Henan Province, a high-incidence area of ESCC in China, were randomised into two arms at a ratio of 1:1. Screening arm participants were screened by Lugol chromoendoscopy; no screening was performed in the control arm. ESCC-specific and all-cause mortality, incidence of advanced ESCC and cost-effectiveness of screening will be evaluated in the next 10-year follow-up. Here, we report the performance of baseline recruitment and randomisation, prevalence of upper GI lesions and risk factors for ESCC. RESULTS: A total of 17 151 and 16 797 participants were enrolled in screening and control arms from January 2012 to September 2016. The truncated prevalence (aged 45-69 years) of oesophageal and overall upper GI high-grade lesions was 744.0/100 000 and 902.0/100 000. 69.9% of the 113 patients with high-grade oesophageal lesions were of early stage. Risk factors for severe oesophageal dysplasia and more severe lesions in this population included higher age, family history of ESCC, lower body mass index, eating rapidly and frequent ingestion of leftovers. CONCLUSION: This ESECC trial met the predesigned recruitment and randomisation requirements. Age, family history, undernutrition and unhealthy dietary habits increased the risk for high-grade oesophageal lesions in this high-risk population. TRAIL REGISTRATION NUMBER: NCT01688908; Pre-results.

TCR repertoire intratumor heterogeneity of CD4+ and CD8+ T cells in centers and margins of localized lung adenocarcinomas.

Intratumor heterogeneity (ITH) of T cell receptor (TCR) repertoire in different T-cell subsets and locations in lung adenocarcinomas was unclear. Here, we investigated percentages and TCR repertoire of freshly isolated CD4+ and CD8+ tumor infiltrating lymphocytes (TILs) in tumor centers and margins by flow cytometry on 80 tumor samples from 20 patients and high-throughput TCR sequencing on 27 and 25 samples of CD4+ and CD8+ TILs from seven patients. Our results demonstrated that amount and TCR repertoire diversity of CD4+ TILs were significantly higher than those of CD8+ TILs and moreover substantial ITH regarding amount and TCR repertoire of CD4+ and CD8+ TILs were observed. Additionally, ITH of CD4/CD8 T-cell ratio and CD8+ TIL repertoire across center regions was lower than that across margin regions. The amount and TCR repertoire ITH of CD4+ and CD8+ TILs and mean clonality of CD8+ TILs in tumor centers were associated with relapse. Our study provides insights into amount and TCR repertoire ITH of CD4+ and CD8+ TILs in tumor centers and margins as well as corresponding association with prognosis in lung adenocarcinoma patients, suggesting potential clinical significance of TCR repertoire.

T cell receptor ß-chain repertoire analysis of tumor-infiltrating lymphocytes in pancreatic cancer.

Pancreatic cancer is lethal due to lack of perceptible symptoms and effective treatment methods. Immunotherapy may provide promising therapeutic choices for malignant tumors like pancreatic cancer. Tumor-infiltrating lymphocytes (TIL) in tumor mesenchyme could recognize peptide antigens presented on the surface of tumor cells. The present study aimed to test the relationship between the T cell receptor (TCR) ß repertoire of the tumor and peripheral blood, and also to investigate the intra-tumor spatial heterogeneity of the TCR ß repertoire in pancreatic cancer. To the best of our knowledge, this is the first study to evaluate the clonal composition of TCR ß repertoire in TIL across the spatial extent of pancreatic cancer. In this study, we studied 5 patients who were diagnosed with primary pancreatic cancer. Ultra-deep sequencing was used to assess the rearrangement of the TCR ß-chain (TCR ß) gene. HE staining and immunohistochemistry of CD3, CD4, CD8 and HLA class I were used to show histopathology and immune conditions macroscopically. TIL repertoire showed that different regions of the same tumor showed a greater number of repertoire overlaps between each other than between peripheral blood, which suggested that T cell clones in pancreatic cancer might be quite different from those in peripheral blood. In contrast, intra-tumoral TCR ß repertoires were spatially homogeneous between different regions of a single tumor tissue. Based on these results, we speculated that the cellular adaptive immune response in pancreatic cancer was spatially homogeneous; this may pave the way for immunotherapy for the treatment of pancreatic cancer patients.

Effectiveness of Intensive Endoscopic Screening for Esophageal Cancer in China: A Community-Based Study.

Evidence is required to evaluate the effectiveness of population-level endoscopic screening for esophageal cancer (EC). In this study, 5,632 permanent residents aged 25-65 years from 6 villages in Hua County, Henan Province, China, were defined as the screening cohort and were offered intensive endoscopic screening. Residents of all 914 remaining villages in Hua County were included as the control cohort, and age-sex standardization was used to calculate the expected numbers of EC and upper gastrointestinal (GI) tract cancer cases and deaths in the screening cohort. The effectiveness of screening was assessed by comparing observed numbers of cases and deaths with expected numbers after 9-year follow-up of these screened subjects (2007-2016). In the screening cohort, 23 upper GI cancers (including 16 ECs) and 10 upper GI cancer deaths (including 5 EC deaths) were identified, and 47% (standardized incidence ratio = 0.53, 95% confidence interval (CI): 0.33, 0.87) and 66% (standardized mortality ratio = 0.34, 95% CI: 0.14, 0.81) reductions in cumulative EC incidence and mortality were found. For upper GI cancers, incidence and mortality were lowered by 43% (standardized incidence ratio = 0.57, 95% CI: 0.38, 0.86) and 53% (standardized mortality ratio = 0.47, 95% CI: 0.25, 0.88), respectively. This study showed that upper GI tract endoscopy is an effective population-level screening test for EC in high-risk regions.

Clonal distribution and intratumour heterogeneity of the B-cell repertoire in oesophageal squamous cell carcinoma.

Recent successes in tumour immunotherapies have highlighted the importance of tumour immunity. However, most previous studies to date have focused on T-cell immune response, although B cells are key players in the core immune network and are associated with T-cell immune response. Based on our previous study delineating T-cell receptor (TCR) repertoire in seven patients with oesophageal squamous cell carcinoma (ESCC), this study profiled the B-cell receptor (BCR) repertoire of multiple tumour regions, adjacent normal tissue, and blood from the same seven patients to reveal the characteristics of B-cell immunity and the relationship to TCR repertoire in ESCC patients. We found that intratumour BCR repertoire was significantly more oligoclonal than matched adjacent normal tissue or peripheral blood and, moreover, clonal amplification of B cells in multiple tumour regions was significantly heterogeneous, although clonal amplification of the TCR repertoire across different tissue compartments and regions of the same tumour was similar. However, both BCR and TCR repertoires in the tumour microenvironment were distinct from those in adjacent normal tissues and blood, and thus represented a group of B and T cells that were spatially confined to the tumour microenvironment and could react to tumour antigens. Additionally, B- and T-cell clones varying between different tumour regions showed intratumour heterogeneity of B- and T-cell immune response. Thus, multiple tumour biopsies could be essential to comprehensively delineate the adaptive immune response to an individual ESCC. These findings expand our understanding of adaptive anti-tumour immunity and shed more light on ESCC immunotherapy. This study provides insights into the intratumour heterogeneity of the BCR repertoire as well as the difference and relationship between the BCR and TCR repertoire in ESCC, expanding our understanding of adaptive anti-tumour immunity and ESCC immunotherapy. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Immediate and substantial evolution of T-cell repertoire in peripheral blood and tumor microenvironment of patients with esophageal squamous cell carcinoma treated with preoperative chemotherapy.

Preoperative chemotherapy could decrease tumor size and improve overall survival for esophageal squamous cell carcinoma (ESCC), and moreover, rational combination of chemotherapy and immunotherapy could increase likelihood of inducing an effective antitumor immune response. However, the immunologic impact of chemotherapeutic drugs originally chosen for cancer treatment due to the direct toxicity is poorly understood. We assess the effect of a combination of clinically approved chemotherapeutic drugs [paclitaxel-nedaplatin (PTX-NDP)] on T-cell receptor (TCR) repertoires of peripheral T cells and tumor-infiltrating lymphocytes (TILs) from five patients with primary ESCC. We found that PTX-NDP therapy induced immediate and substantial changes in clonotype frequencies of peripheral T cells and TILs, and moreover, compared with clonal amplification, clonal contraction was more likely to occur in more abundant clones in patients with ESCC. Significant increases in TCR diversity were observed in peripheral T cells but not in TILs after PTX-NDP therapy. Reconstruction of posttreatment TILs was not merely a result of local expansion or contraction of pretreatment TILs, but also-at least in part-a consequence of the migration of peripheral T cells into the chronically inflamed tumor microenvironment. Our findings uncover further insight into T-cell immune response modulated with chemotherapy, providing for theoretical bases for rational combination strategy of chemotherapy and immunotherapy.

Mutation analysis of the EBV-lymphoblastoid cell line cautions their use as antigen-presenting cells.

Lymphoblastoid cell lines (LCLs) have been widely used as professional antigen-presenting cells (APCs). However, neoantigen-loaded LCLs could induce nonspecific T-cell response, which could be due to expression of both Epstein-Barr virus (EBV) antigens and nonsynonymous mutations arising in LCLs. Since the number of passages could influence mutational characteristics of LCLs, and moreover extensive proliferation of LCLs in vitro is necessary to activate T cells for immunotherapy, we comprehensively profiled mutational characteristics by comparing eight sets of B cells and matched high-passage LCLs using whole-exome sequencing in order to assess the effect of nonsynonymous mutations arising in LCLs on nonspecific T-cell response. We found 315 nongermline mutations (approximately 40mut/subject) randomly distributed across all chromosomes including 18 mutations in immunoglobulin V and J genes in eight LCLs, of which 137 candidate neoantigens (approximately 17mut/subject) were identified. The underlying mutational processes linked to EBV-transformed LCLs could be attributed to activation induced cytidine deaminase gene expression which contributes to cytosine mutation clusters in LCLs through cytosine deamination. Pathways significantly enriched by nonsilent mutations of each LCL were totally different among all LCLs. In conclusion, high-passage LCLs may not be suitable to serve as APCs due to random nonsilent mutations, particularly for presentation of neoantigens of low immunogenicity, although further experimental proofs are needed.

Differential DNA methylation profiles of human B lymphocytes and Epstein-Barr virus-immortalized B lymphocytes.

OBJECTIVE: This study aimed to comprehensively assess Epstein-Barr virus (EBV)-induced methylation alterations of B cell across whole genome. METHODS: We compared DNA methylation patterns of primary B cells and corresponding lymphoblastoid cell lines (LCLs) from eight participants. The genome-wide DNA methylation profiles were compared at over 850,000 genome-wide methylation sites. RESULTS: DNA methylation analysis revealed 87,732 differentially methylated CpG sites, representing approximately 12.41% of all sites in LCLs compared to primary B cells. The hypermethylated and hypomethylated CpG sites were about 22.75% or 77.25%, respectively. Only 0.8% of hypomethylated sites and 4.5% of hypermethylated sites were located in CpG islands, whereas 8.0% of hypomethylated sites and 16.3% of hypermethylated sites were located in shore (N_shore and S_shore). Using principal component analysis of the DNA methylation profiles, primary B cells and LCLs could be accurately predicted. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differently methylated genes revealed that most of the top GO biological processes were related to cell activation and immune response, and some top enrichment pathways were related with activation and malignant transformation of human B cells. CONCLUSIONS: Our study demonstrated genome-wide DNA methylation variations between primary B cells and corresponding LCLs, which might yield new insight on the methylation mechanism of EBV-induced immortalization.

T cell receptor ß-chain repertoire analysis reveals the association between neoantigens and tumour-infiltrating lymphocytes in multifocal papillary thyroid carcinoma.

To explore whether a few nonsynonymous somatic mutations could induce activation and proliferation of neoantigen-specific tumour-infiltrating lymphocytes (TILs) in tumours with low mutation rates, we analysed a patient with multifocal papillary thyroid carcinoma (seven noncontiguous cancer foci) to investigate the relationship between neoantigens and TILs. These seven foci had a few or no nonsynonymous somatic mutations; moreover, multiple loci had similar or different spectra of mutations. We used high-throughput sequencing of the rearranged genes in T cell receptor ß-chain (TCRß) to reveal the basic characteristics of T cells in seven tumour foci and matched adjacent normal tissue. We found that in multifocal papillary thyroid carcinoma the number of nonsynonymous somatic mutations was positively associated with oligoclonal TCRß repertoire, and tumour foci with similar spectra of mutations had higher overlap of TCRß repertoire. In conclusion, the number of nonsynonymous somatic mutations is small in tumours with low mutation rates but these mutations still play an important role in activating neoantigen-specific TILs.

A Model To Identify Individuals at High Risk for Esophageal Squamous Cell Carcinoma and Precancerous Lesions in Regions of High Prevalence in China.

BACKGROUND & AIMS: We aimed to develop a population-based model to identify individuals at high risk for esophageal squamous cell carcinoma (ESCC) in regions of China with a high prevalence of this cancer. METHODS: We collected findings from 15,073 permanent residents (45-69 years old) of 334 randomly selected villages in Hua County, Henan Province, China who underwent endoscopic screening (with iodine staining) for ESCC from January 2012 through September 2015. The entire esophagus and stomach were examined; biopsies were collected from all focal lesions (or from standard sites in the esophagus if no abnormalities were found) and analyzed histologically. Squamous dysplasia, carcinoma in situ, and ESCC were independently confirmed by 2 pathologists. Before endoscopy, subjects completed a questionnaire on ESCC risk factors. Variables were evaluated with unconditional univariate logistic regression analysis; variables found to be significantly associated with ESCC were then analyzed by multivariate logistic regression modeling. We used the Akaike information criterion to develop our final model structure and the coding form of variables with multiple measures. We developed 2 groups of models, separately defining severe dysplasia and above (SDA) (lesions including severe dysplasia and higher-grade lesions) and moderate dysplasia and above (lesions including moderate dysplasia and higher-grade lesions) as outcome events. Age-stratified and whole-age models were developed; their discriminative ability in the full multivariate model and the simple age model was compared. We performed area under the receiver operating characteristic curve (AUC) and the DeLong test to evaluate model performance. RESULTS: Our age-stratified prediction models identified individuals 60 years of age or younger with SDA with an AUC value of 0.795 (95% confidence interval, 0.736-0.854) and individuals older than 60 years with SDA with an AUC value of 0.681 (95% confidence interval, 0.618-0.743). Factors associated with SDA in individuals 60 years or younger included age closer to 60 years, use of coal or wood as a main source of cooking fuel, body mass index of 22 kg/m2 or less, unexplained epigastric pain, and rapid ingestion of meals. In subjects older than 60 years, SDA associated with age, family history of ESCC, cigarette smoking, body mass index of 22 kg/m2 or less, pesticide exposure, irregular eating habits, intake of high temperature foods, rapid ingestion of meals, and ingestion of leftover food in summer months. Use of our model in screening could have allowed 27% of subjects 60 years or younger and 9% of subjects older than 60 years to avoid endoscopy without missing SDAs. This means that approximately 2500 of endoscopies in total (16.6%) could have been avoided. CONCLUSIONS: We developed a low-cost, easy-to-use model to identify individuals at risk for severe dysplasia or cancer of the esophagus living in a region of China with a high risk of ESCC. This model might be used to select individuals and groups of persons who should undergo endoscopy analysis for esophageal cancer.

T cell receptor ß-chain repertoire analysis reveals intratumour heterogeneity of tumour-infiltrating lymphocytes in oesophageal squamous cell carcinoma.

Oesophageal squamous cell carcinoma (ESCC) has a generally poor prognosis, due to the lack of effective treatment methods. Immunotherapeutic approaches based on tumour-infiltrating lymphocytes (TILs) have demonstrated that durable responses are produced in some patients with solid tumours, which suggests the potential feasibility of clinical application of immunotherapy for ESCC. However, many of the basic characteristics of TILs in ESCC are poorly understood, including clonality, specificity and spatial heterogeneity of the response of TILs, which depends on the interaction between antigens and T cell receptors (TCRs). We used ultra-deep sequencing of rearranged genes in TCR ß-chain (TCRß) to profile the basic characteristics of T cells in tumour tissues (four to six regions from each tumour) as well as matched adjacent normal tissue and peripheral blood from seven patients diagnosed with primary ESCC. We found that T cell clones within ESCCs were quite different from those of the peripheral blood and even the adjacent normal tissues in general. Although there was a relatively higher degree of overlap of intratumoural TCRß repertoires than those between the tumour and other tissues, intratumoural TCRß repertoires were spatially heterogeneous. Due to the restricted sampling, high-throughput TCRß sequencing could characterize the diversity and composition of a limited (compartment-dependent) fraction of the respective T cell clones in any individual ESCC, expanding our understanding of immune behaviour and immune response and shedding more light on ESCC immunotherapy. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Clonal Distribution and Intratumor Heterogeneity of the TCR Repertoire in Papillary Thyroid Cancer With or Without Coexistent Hashimoto's Thyroiditis.

The intratumor heterogeneity (ITH) of the amount and TCR repertoires of tumor infiltrating lymphocytes (TILs) in PTC with and without coexistent Hashimoto's thyroiditis (HT) are unclear. Here, we investigated the amount of T cells in tumor and corresponding normal tissues by immunohistochemical staining on 80 tumor samples and 40 normal samples from 40 patients. The immune repertoire of T cells was identified on 24 tumor samples and 12 normal samples from 12 patients using TCR high-throughput sequencing. The results demonstrated that the numbers of CD3+, CD4+ and CD8+ T cells in PTC without coexistent HT (PTC-WO) were significantly lower than those in PTC with existing HT (PTC-W). In PTC-W, the density of CD4+ TILs were generally higher when compared with CD8+ TILs. Furthermore, we found that the numbers of CD3+ T cells and their CD4+, CD8+ subtypes in tumor samples were generally higher than those in normal tissue in PTC-WO and moreover, the number of CD3+ T cells was negatively associated with TCR clonality in PTC-WO. In addition, although ITH of the TCR repertoire truly existed in PTC-W and PTC-WO, the TCR repertoires between distinct regions of the non-adjacent tumor foci were presented with a higher degree of similarity than those between tumor and matched normal tissue in PTC-WO, yet the similarity of intratumor repertoires was not significantly higher than those between tumor and corresponding normal samples in PTC-W. This research comprehensively delineated the quantity and TCR repertoire ITH of T cells in PTC-W and PTC-WO, suggesting that TILs might be reactive to tumor antigens in PTC-WO. Moreover, multiregion biopsies should be performed to precisely identify the immune background in PTC-W and PTC-WO.

Autophagic flux restoration of senescent T cells improves antitumor activity of TCR-engineered T cells.

Objectives: Although adoptive cell therapy with T-cell receptor-engineered T cells (TCR-Ts) has mediated effective antitumor responses in several cancers, senescence of T cells could impair the therapeutic effect of TCR-Ts. Thus, it is essential to elucidate the characteristics of senescent TCR-Ts and how to subsequently improve their antitumor effect. Here, we focused on the influence of autophagy on TCR-Ts, since autophagy is tightly associated with the regulation of T-cell activation, proliferation and differentiation. Methods: We first evaluated autophagy level of senescent TCR-Ts, and then the senescent TCR-Ts were expanded in vitro for 7 days with and without spermidine treatment, respectively. Furthermore, the proliferative potential, phenotypical characteristics and functionality of the propagated senescent TCR-Ts were analysed in vitro and in vivo after 7-day ex vivo expansion. Results: We found that autophagic flux of senescent TCR-T cells was significantly impaired. The restoration of autophagic flux via spermidine treatment reduced the expression of inhibitory immunoreceptors (PD-1, TIM-3 or LAG-3), enhanced proliferation and effector functions and subsequently demonstrated the superior in vitro and in vivo antitumor activity of TCR-Ts. Conclusion: These data suggest that spermidine treatment presents an opportunity to improve the antitumor effect of TCR-Ts for the treatment of solid tumors.

Autophagic flux restoration enhances the antitumor efficacy of tumor infiltrating lymphocytes.

BACKGROUND: Although adoptive cell therapy with tumor infiltrating lymphocytes (TILs) has mediated effective antitumor responses in several cancers, dysfunction and exhaustion of TILs significantly impair the therapeutic effect of TILs. Thus, it is essential to elucidate the exhausted characteristics of TILs and improve the antitumor effect of TILs by reversing their exhaustion. Here, we focused on the influence of autophagy on TILs in terms of T-cell activation, proliferation, and differentiation in vitro and in vivo. METHODS: We first evaluated autophagy level of TILs and influence of spermidine treatment on autophagy levels of TILs. Furthermore, we assessed the proliferative potential, phenotypical characteristics, T cell receptor (TCR) repertoire and antitumor activity of TILs with and without spermidine treatment. RESULTS: We found that autophagic flux of TILs, especially exhausted TILs that express inhibitory immunoreceptors and have impaired proliferative capacity and decreased production of cytotoxic effector molecules, was significantly impaired. The restoration of autophagic flux via spermidine treatment resulted in increased diversity of the TCR repertoire, reduced expression of inhibitory immunoreceptors (PD1, TIM3, or LAG3), enhanced proliferation and effector functions, which subsequently demonstrated the superior in vitro and in vivo antitumor activity of TILs. Our findings unveil that spermidine, as an autophagy inducer, reverses dysfunction and exhaustion of TILs and subsequently improves the antitumor activity of TILs. CONCLUSIONS: These data suggest that spermidine treatment presents an opportunity to improve adoptive TIL therapy for the treatment of solid tumors.