TCF-1 limits intraepithelial lymphocyte antitumor immunity in colorectal carcinoma

Optimization of Immunotherapy Strategies Based on Spatiotemporal Heterogeneity of Tumour-Associated Tissue-Resident Memory T Cells

Tissue-resident memory T cells (TRMs) reside in peripheral tissues and provide rapid immune defence against local infection and tumours. Tumour-associated TRMs share common tissue-resident features and formation mechanisms, representing some unique subsets of tumour-infiltrating lymphocytes (TILs). However, differences in the tumour microenvironment(TME) and tumour evolution stage result in TRMs exhibiting temporal and spatial heterogeneity of phenotype and function not only at different stages, before and after treatment, but also between tumours originating from different tissues, primary and metastatic cancer, and tumour and adjacent normal tissue. The infiltration of TRMs is often associated with immunotherapy response and favourable prognosis; however, due to different definitions, it has been shown that some subtypes of TRMs can also have a negative impact. Therefore, it is crucial to precisely characterise the TRM subpopulations that can influence the therapeutic efficacy and clinical prognosis of various solid tumours. Here, we review the spatiotemporal heterogeneity of tumour-associated TRMs, as well as the differences in their impact on clinical outcomes. We also explore the relationship between TRMs and immune checkpoint blockade (ICB) and TIL therapy, providing insights into potential new targets and strategies for immunotherapy.

Changes in T-lymphocyte subpopulations in patients with colorectal cancer before and after acupoint catgut embedding acupuncture observation

This study aims to explore changes in peripheral blood T-lymphocyte subsets in colorectal cancer (CRC) patients before and after acupoint catgut embedding (ACE) acupuncture observation. Eighty CRC surgical patients who visited from April 2017 to May 2022 were selected as study samples using the convenience sampling method. Patients were randomly divided into a control group (n = 40, receiving conventional chemotherapy) and an observation group (n = 40, receiving 4 weeks of additional ACE acupuncture). The observation group showed higher rates of complete and partial remission compared to the control, though the difference was not statistically significant (P > 0.05). The observation group experienced less reduction in CD3+, CD4+ T lymphocytes, and natural killer cells during chemotherapy. Compared with the control group, the percentage of CD3+ and CD4+ T cells in the observation group significantly increased after the intervention, while CD8+ T-cell levels decreased. The CD4+/CD8+ ratio was at a higher level, and the discrepancy was statistically obvious (P < 0.05). Acupuncture therapy can maintain the normal distribution of peripheral blood T-lymphocyte subpopulations during chemotherapy in patients with CRC, thus better maintaining the immune status of patients.

Microbiota promote enhanced CD39 expression in γδ intraepithelial lymphocytes through the activation of TCR and IL-15 signaling

Intraepithelial lymphocytes expressing the γδ T cell receptor (γδ IEL) provide continuous surveillance of the intestinal epithelium. We report that mice harboring a microbiota-specific hyperproliferative γδ IEL (γδ HYP ) phenotype also upregulate the expression of the ectonucleotidase CD39, a marker of regulatory γδ T cells. Enhanced TCR and IL-15 signaling correlates with a progression from a naïve-like CD39 neg γδ IEL to a more mature, tissue-adapted CD39 hi IEL population. We found that TCRγδ activation drives CD122-mediated CD39 upregulation on γδ HYP IELs and increased mucosal IL-15 further amplifies CD39 expression in these cells. Further investigation revealed that CD39 induction requires sustained exposure to the γδ HYP -associated microbiota. Moreover, CD39 hi γδ IELs exhibit a reduced capacity to produce pro-inflammatory cytokine, which may explain the lack of histopathology in γδ HYP mice. Overall, our study identifies a previously unappreciated mechanism by which an altered microbiota amplifies CD39 expression on γδ HYP IELs, leading to the expansion of γδ IELs with regulatory potential.

Dysregulation of γδ intraepithelial lymphocytes precedes Crohn's disease-like ileitis

Intraepithelial lymphocytes expressing the γδ T cell receptor (γδ IELs) provide immunosurveillance of the intestinal barrier but are reduced in patients with active Crohn's disease (CD). Here, we report an underappreciated role for γδ IELs in maintaining immunological tolerance during the onset and progression of CD-like ileitis using TNFΔARE/+ mice. We found that TNF-induced down-regulation of epithelial hepatocyte nuclear factor 4-gamma/butyrophilin is followed by a loss of ileal Vγ7 IELs and impaired barrier surveillance before the histological onset of disease. A reduction of immunoregulatory CD39+ γδ IELs coincided with the influx of immature, peripheral CD39neg γδ T cells into the epithelium, leading to an expansion of induced IELs, whereas an earlier depletion of γδ IELs correlated with accelerated onset of ileal inflammation. Our findings identify multiple layers of γδ IEL dysregulation before ileitis development, indicating that the loss of steady-state immunoregulatory γδ IELs may contribute to the initiation of ileal CD.

A novel PAK1/TCF1 regulatory axis promotes non-small cell lung cancer progression

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death, necessitating the identification of novel therapeutic targets. P21-activated kinases-1 (PAK1) plays a crucial role in oncogenesis, including NSCLC. Recent findings have elucidated T cell factor 1 (TCF1) as an anti-tumour factor, influencing T cell biology. However, the precise mechanism by which PAK1 promotes NSCLC progression via TCF1 regulation remains unclear.

METHODS

We collected 23 pairs of NSCLC tissue samples and obtained NSCLC RNA sequencing data and corresponding clinicopathologic information from The Cancer Genome Atlas (TCGA). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) assessed PAK1 and TCF1 expression in NSCLC tissues and cells. Gain and loss-of-function experiments evaluated PAK1 and TCF1 effects on cell proliferation, invasion, migration, and apoptosis in vitro. Mechanistically, western blot (WB) and immunoprecipitation analysis evaluated the interaction between PAK1 and TCF1 in NSCLC. Finally, we assessed the clinical prognostic, disease progression, and immunotherapy response of PAK1 and TCF1 and their correlation with immune cell infiltration, immune checkpoint inhibitors (PD1, PDL1).

RESULTS

PAK1 expression was elevated in NSCLC tissues and cells, while TCF1 was significantly downregulated. PAK1 expression showed a significant inverse correlation with TCF1 mRNA in NSCLC. Silencing PAK1 (using shRNAs) and inhibiting PAK1 with the small molecule IPA-3 suppressed NSCLC cell malignancy in a dose-dependent manner, upregulating TCF1 expression, and vice versa. TCF1 amplification with the small molecule (TWS119) inhibited NSCLC cell proliferation, migration, and invasion in a dose-dependent manner without affecting PAK1 expression. Immunoprecipitation analysis confirmed PAK1 and TCF1 interaction in NSCLC. Joint survival analysis indicated that high PAK1 and low TCF1 expression were associated with unfavourable survival in patients with NSCLC. Lastly, the TCF1 was significantly correlated with immune cell infiltration [CD8+ T cell, and tumor infiltrating lymphocytes (TILs)], immune checkpoint inhibitors (PD1, PDL1), and can accurately predict the immunotherapeutic response.

CONCLUSION

This study demonstrates, for the first time, that PAK1 negatively regulates TCF1, contributing to NSCLC pathogenesis. The PAK1/TCF1 regulatory axis emerges as a critical determinant of carcinogenesis and a promising therapeutic target for NSCLC.

Nomogram Prediction of Response to Neoadjuvant Chemotherapy Plus Pembrolizumab in Locally Advanced Hypopharyngeal Squamous Cell Carcinoma

IMPORTANCE

The objective response (ORR) rate in patients with locally advanced hypopharyngeal squamous cell-carcinoma (LA-HPSCC) following neoadjuvant chemotherapy (NACT) of albumin-bound paclitaxel plus carboplatin is low. At present, it is unclear whether the addition of pembrolizumab could increase the ORR or not.

OBJECTIVE

To investigate whether the addition of pembrolizumab could increase the ORR, and to develop a nomogram to predict the response of pembrolizumab addition.

DESIGN

Retrospective cohort study.

SETTING

This study was conducted at a single institution.

PARTICIPANTS

This study included 129 patients who conformed to the inclusion criteria.

INTERVENTION OR EXPOSURES

NACT with or without pembrolizumab for patients with LA-HPSCC.

MAIN OUTCOME MEASURES

The ORR was analyzed according to the RECIST 1.1 criteria and a nomogram was developed based on least absolute shrinkage and selection operator and multivariable Cox regression analysis. Predictive accuracy and discriminative ability of the nomogram were evaluated by receiver operating characteristics, precision recall, calibration curves, and decision curve analysis.

RESULTS

Eighty-two patients received NACT and 47 also received pembrolizumab. ORR was higher in patients receiving additional pembrolizumab (66.0% vs 47.6%, χ2 = 4.074, P = .044). The nomogram identified pretreatment levels of lymphocytes and red blood cells as independent predictors of a high ORR, while basophil levels were an independent predictor of a low ORR. Calibration curve showed that the nomogram-based predictions corresponded well with actual observations. C-index of the nomogram was 0.925 (0.848-1.002) and the area under curve was 0.925. Decision curve analysis affirmed that the nomogram had important clinical value.

CONCLUSIONS AND RELEVANCE

Pembrolizumab could improve the ORR in LA-HPSCC patients treated with NACT. Furthermore, a risk-prediction nomogram incorporating readily assessable routine pretreatment blood parameters can accurately estimate the response to NACT with pembrolizumab, leading to precise treatment and minimizing the waste of medical resources.

Nurturing the phenotype: Environmental signals and transcriptional regulation of intestinal γδ T cells

The intestinal epithelium harbours a unique lymphocyte population, the intraepithelial lymphocytes (IELs). A large fraction of IELs is represented by γδ T cells. Their role in epithelial homeostasis and immune response is well documented, but a conclusive view of their developmental pathway is still missing. In this review, we discuss the existing literature as well as recent advances regarding the tissue adaptation of γδ IELs, both for the characteristic cytotoxic subset and the newly described noncytotoxic subset. We particularly highlight the environmental cues and the transcriptional regulation that equip γδ T cells with their IEL phenotype.

From backstage to the spotlight: γδT cells in cancer

γδT cells represent a group of immune cells that are understudied but whose utility has been recognized for cancer immunotherapy purposes. Recent studies have highlighted a critical role for these cells in tumor initiation, growth, and metastasis and revealed an increasingly complex biology of γδT cell subsets that is context and tissue specific. We discuss here how γδT cell subsets are regulated, their interaction with cancer and other immune cells, and the implications from these latest discoveries for people with cancer.

T cell factor 1 (TCF-1) defines T cell differentiation in colorectal cancer

The presence of precursor to exhausted (Tpex) CD8+ T cells is important to maintain robust immunity following treatment with immune checkpoint inhibition (ICI). Impressive responses to ICI are emerging in patients with stage II-III mismatch repair (MMR)-deficient (dMMR) colorectal cancer (CRC). We found 64% of dMMR and 15% of mismatch repair-proficient (pMMR) stage III CRCs had a high frequency of tumor infiltrating lymphocytes (TIL-hi). Furthermore, expression of TCF-1 (Tcf7) by CD8+ T cells predicted improved patient prognosis and Tpex cells (CD3+CD8+TCF-1+PD-1+) were abundant within lymphoid aggregates of stage III CRCs. In contrast, CD3+CD8+TCF-1-PD-1+ cells were more abundant at the invasive front and tumor core, while γδ T cells were equally abundant in all tumor areas. Interestingly, no differences in the frequency of Tpex cells were observed between TIL-hi dMMR and TIL-hi pMMR CRCs. Therefore, Tpex cell function and ICI response rates in TIL-hi CRC warrants further investigation.

The burgeoning spatial multi-omics in human gastrointestinal cancers

The development and progression of diseases in multicellular organisms unfold within the intricate three-dimensional body environment. Thus, to comprehensively understand the molecular mechanisms governing individual development and disease progression, precise acquisition of biological data, including genome, transcriptome, proteome, metabolome, and epigenome, with single-cell resolution and spatial information within the body's three-dimensional context, is essential. This foundational information serves as the basis for deciphering cellular and molecular mechanisms. Although single-cell multi-omics technology can provide biological information such as genome, transcriptome, proteome, metabolome, and epigenome with single-cell resolution, the sample preparation process leads to the loss of spatial information. Spatial multi-omics technology, however, facilitates the characterization of biological data, such as genome, transcriptome, proteome, metabolome, and epigenome in tissue samples, while retaining their spatial context. Consequently, these techniques significantly enhance our understanding of individual development and disease pathology. Currently, spatial multi-omics technology has played a vital role in elucidating various processes in tumor biology, including tumor occurrence, development, and metastasis, particularly in the realms of tumor immunity and the heterogeneity of the tumor microenvironment. Therefore, this article provides a comprehensive overview of spatial transcriptomics, spatial proteomics, and spatial metabolomics-related technologies and their application in research concerning esophageal cancer, gastric cancer, and colorectal cancer. The objective is to foster the research and implementation of spatial multi-omics technology in digestive tumor diseases. This review will provide new technical insights for molecular biology researchers.

Orthotopic MC-38 Allograft as a Robust Preclinical Model of Colorectal Carcinoma

Colorectal cancer (CRC) is a significant global health concern, requiring effective preclinical models for studying its development and testing therapies. Mouse models have been used, including spontaneous tumors, carcinogen exposure, and tumor cell implantation as xenografts or at orthotopic sites. Here, we describe an orthotopic preclinical model of CRC, which provides a valuable tool for studying tumor growth and the tumor microenvironment, offering a more accurate representation of human CRC compared to xenograft models.