Lymphocytes provide optimal responses against pathogens with minimal inflammatory pathology. However, the intrinsic mechanisms regulating these responses are unknown. Here, we report that deletion of both transcription factors Egr2 and Egr3 in lymphocytes resulted in a lethal autoimmune syndrome with excessive serum proinflammatory cytokines but also impaired antigen receptor-induced proliferation of B and T cells. Egr2- and Egr3-defective B and T cells had hyperactive signal transducer and activator of transcription-1 (STAT1) and STAT3 while antigen receptor-induced activation of transcription factor AP-1 was severely impaired. We discovered that Egr2 and/or Egr3 directly induced expression of suppressor of cytokine signaling-1 (SOCS1) and SOCS3, inhibitors of STAT1 and STAT3, and also blocked the function of Batf, an AP-1 inhibitor, in B and T cells. Thus, Egr2 and Egr3 regulate B and T cell function in adaptive immune responses and homeostasis by promoting antigen receptor signaling and controlling inflammation.

The transporter associated with antigen processing (TAP) is essential for the transport of antigenic peptides across the membrane of the endoplasmic reticulum. In addition, TAP interacts with major histocompatibility complex class I heavy chain (HC)/β2-microglobulin (β2-m) dimers. We have cloned a cDNA encoding a TAP1/2-associated protein (TAP-A) corresponding in size and biochemical properties to tapasin, which was recently suggested to be involved in class I–TAP interaction (Sadasivan, B., Lehner, P. J., Ortmann, B., Spies, T. & Cresswell, P. (1996)Immunity5, 103–114). The cDNA encodes a 448-residue-long ORF, including a signal peptide. The protein is predicted to be a type I membrane glycoprotein with a cytoplasmic tail containing a double-lysine motif (-KKKAE-COOH) known to maintain membrane proteins in the endoplasmic reticulum. Immunoprecipitation with anti-TAP1 or anti-TAP-A antisera demonstrated a consistent and stoichiometric association of TAP-A with TAP1/2. Class I HC and β2-m also were coprecipitated with these antisera, indicating the presence of a pentameric complex. In pulse–chase experiments, class I HC/β2-m rapidly dissociated from TAP1/2-TAP-A. We propose that TAP is a trimeric complex consisting of TAP1, TAP2, and TAP-A that interacts transiently with class I HC/β2-m. In peptide-binding assays using cross-linkable peptides and intact microsomes, TAP-A bound peptides only in the presence of ATP whereas binding of peptides to TAP1/2 was ATP-independent. This suggests a direct role of TAP-A in peptide loading onto class I HC/β2-m dimer.

Lessons Learned Radiotherapy plus anti–PD‐1 antibody as first‐line therapy is safe and feasible in locally advanced esophageal squamous cell carcinoma. Tumor‐infiltrating and peripheral lymphocytes associated with patient survival. Further studies combining chemoradiotherapy with immunotherapy in locally advanced ESCC, and exploration of predictive biomarkers is warranted. Background We conducted a phase Ib study of radiotherapy plus programmed cell death protein 1 (PD‐1) monoclonal antibody camrelizumab as first‐line treatment for locally advanced esophageal squamous cell carcinoma (ESCC). Methods We planned to enroll 20 patients with newly diagnosed locally advanced ESCC. Patients received 60 Gy radiation (2.0 Gy/fraction, 5 fractions/week), with camrelizumab (200 mg every 2 weeks) starting with radiotherapy and continuing for 32 weeks (i.e., for 16 cycles). The primary endpoints were safety and feasibility. Secondary endpoints were rates of radiologic and pathologic response, overall survival (OS), and progression‐free survival (PFS). Study data were collected by the week during radiotherapy (RT), every month during the maintenance camrelizumab treatment, and every 3 months after treatment. Tumor microenvironment and peripheral blood were monitored at baseline and after 40 Gy radiation for association with efficacy. Results Twenty patients were enrolled and received treatment. One patient (patient 10) was excluded upon discovery of a second tumor in the bladder during treatment, leaving 19 patients for analysis. Toxicity was deemed tolerable. Fourteen (74%) patients had assessed objective response. At a median follow‐up time of 31.0 months (95% confidence interval [CI], 27.0–35.1), median OS and PFS times were 16.7 months (95% CI, 5.9–27.9) and 11.7 months (95% CI, 0–30.3), respectively. OS and PFS rates at 24 months were 31.6% and 35.5%, respectively. Kaplan‐Meier analysis revealed associations between the following factors and OS/PFS: tumor programmed cell death ligand 1 (PD‐L1) expression, PD‐1⁺CD8⁺, PD‐1⁺CD4⁺ T cells, and PD‐L1⁺CD4⁺ T cells; peripheral blood CD4⁺, CD8⁺, CD4⁺ regulatory T cells, and their subsets. Conclusion Radiotherapy plus camrelizumab had manageable toxicity and antitumor efficacy for locally advanced ESCC. Several biomarkers were associated with clinical benefit and deserve further study.

Patients with locally advanced esophageal squamous cell carcinoma (ESCC) show poor survival after concurrent chemoradiotherapy. This study investigated the safety and feasibility of combining concurrent chemoradiotherapy with the anti-PD-1 antibody camrelizumab as first-line treatment for these patients. In this phase 1b study (ClinicalTrials.gov NCT03671265), patients received concurrent chemotherapy (cisplatin [25 mg/m²] plus docetaxel [25 mg/m²] for 4 weeks) and radiotherapy (2.0 Gy/fraction, total 60 Gy) with camrelizumab (200 mg every 2 weeks for 32 weeks). Primary endpoints were safety and tolerability, and health-related quality of life. Secondary endpoints were radiological and pathological response rates, overall survival (OS), and progression-free survival (PFS). Candidate biomarkers in tumor and peripheral blood were monitored at baseline and after 40 Gy radiation. Twenty patients were enrolled. The most common treatment-related grade 3 adverse events included radiation esophagitis (20%) and esophageal fistula (10%). Serious treatment-related adverse events occurred in eight (40%) patients. No treatment-related deaths were reported. Health-related quality of life did not deteriorate. Thirteen (65%) patients had an objective response after 40 Gy radiation. At a median follow-up of 23.7 months (95% CI 21.9–24.5), OS and PFS time ranged from 8.2–28.5 and 4.0–28.5 months, respectively. The 12-month and 24-month OS rate was 85.0% and 69.6%; PFS rate was 80.0% and 65.0%. Tumor PD-L1 expression and CD11c⁺ dendritic cells and peripheral-blood IL-27, IL-15, Eotaxin-3, and IL-22 were associated with OS. First-line concurrent chemoradiotherapy plus camrelizumab had a manageable safety profile and promising antitumour efficacy for ESCC, and deserves further study.

Objective: Gastric cancer (GC) is the fourth most common cause of cancer-related deaths in the world. In the current study, we aim to identify the hub genes and uncover the molecular mechanisms of GC. Methods: The expression profiles of the genes and the miRNAs were extracted from the Gene Expression Omnibus database. The identification of the differentially expressed genes (DEGs), including miRNAs, was performed by the GEO2R. Database for Annotation, Visualization and Integrated Discovery was used to perform GO and KEGG pathway enrichment analysis. The protein–protein interaction (PPI) network and miRNA-gene network were constructed using Cytoscape software. The hub genes were identified by the Molecular Complex Detection (MCODE) plugin, the CytoHubba plugin and miRNA-gene network. Then, the identified genes were verified by Kaplan–Meier plotter database and quantitative real-time PCR (qRT-PCR) in GC tissue samples. Results: A total of three mRNA expression profiles (GSE13911, GSE79973 and GSE19826) were downloaded from the Gene Expression Omnibus (GEO) database, including 69, 20 and 27cases separately. A total of 120 overlapped upregulated genes and 246 downregulated genes were identified. The majority of the DEGs were enriched in extracellular matrix organization, collagen catabolic process, collagen fibril organization and cell adhesion. In addition, three KEGG pathways were significantly enriched, including ECM-receptor interaction, protein digestion and absorption, and the focal adhesion pathways. In the PPI network, five significant modules were detected, while the genes in the modules were mainly involved in the ECM-receptor interaction and focal adhesion pathways. By combining the results of MCODE, CytoHubba and miRNA-gene network, a total of six hub genes including COL1A2, COL1A1, COL4A1, COL5A2, THBS2 and ITGA5 were chosen. The Kaplan–Meier plotter database confirmed that higher expression levels of these genes were related to lower overall survival, except for COL5A2. Experimental validation showed that the rest of the five genes had the same expression trend as predicted. Conclusion: In conclusion, COL1A2, COL1A1, COL4A1, THBS2 and ITGA5 may be potential biomarkers and therapeutic targets for GC. Moreover, ECM-receptor interaction and focal adhesion pathways play significant roles in the progression of GC.

Maintaining tolerance of T cells to self-antigens is essential to avoid autoimmune disease. How self-reactive T cells are kept functionally inactive is, however, unknown. In this study, we show that early growth response gene 2 (Egr-2), a zinc-finger transcription factor, is expressed in CD44^high T cells and controls their proliferation and activation. In the absence of Egr-2, CD44^high, but not CD44^low T cells, are hyperreactive and hyperproliferative in vivo. The accumulation of activated CD4⁺CD44^high T cells leads to the development of a late onset lupuslike autoimmune disease characterized by the accumulation of interferon (IFN)-γ and interleukin (IL)-17–producing CD4⁺ T cells, loss of tolerance to nuclear antigens, massive infiltration of T cells into multiple organs and glomerulonephritis. We found that the expression of cyclin-dependent kinase inhibitor p21cip1 was impaired in Egr-2–deficient T cells, whereas the expression of IFN-γ and IL-17 in response to T cell receptor ligation was significantly increased, suggesting that Egr-2 activates the expression of genes involved in the negative regulation of T cell proliferation and inflammation. These results demonstrate that Egr-2 is an intrinsic regulator of effector T cells and controls the expansion of self-reactive T cells and development of autoimmune disease.