Signaling via a CD27-TRAF2-SHP-1 axis during naive T cell activation promotes memory-associated gene regulatory networks

CD27 costimulation supports metabolic fitness of CD4+ T cells by enhancing de novo nucleotide and protein synthesis

T cells undergo many metabolic changes throughout the different phases of their response in lymphoid and nonlymphoid tissues. Cell metabolism meets demands for energy and biosynthesis, particularly during cell division and effector differentiation. As costimulatory receptors, CD28 and various TNF receptor (TNFR) family members shape T-cell clonal expansion, survival and effector functions and are important clinical targets. While CD28 is acknowledged as a metabolic regulator, little is known about how TNFRs shape T-cell metabolism. We here identify TNFR family member CD27 as a metabolic regulator in activated human CD4+ T cells. In the context of CD3 signaling and CD28 costimulation, CD27 proved to regulate specific metabolic functions, as determined by metabolomics and metabolic tracer experiments. CD27 costimulation supported upregulation of glycolysis, the pentose phosphate pathway and the TCA cycle, increasing the use of glucose-derived carbon and glutamine-derived nitrogen as building blocks for de novo nucleotide synthesis. It also promoted uptake of amino acids (AAs) and modulated pathways of AA metabolism. Accordingly, CD27 costimulation boosted protein translation in CD3- and CD3/CD28-activated CD4+ T cells, which proceeded via enhanced mTOR pathway activation. Remarkably, CD27, OX40 and 4-1BB all enhanced CD3-induced mTOR signaling, but only CD27 could overrule inhibitory PD-1 signaling. CD27 costimulation increased IL-2, IFNγ and TNFα production by CD3-activated CD4+ T cells, also in presence of PD-1 signaling. Next to previously defined beneficial effects of CD27 on activated T-cell survival and CTL differentiation and Th1 effector differentiation, these data support its essential contribution to T-cell metabolism and its relevance as a therapeutic target.

TNF/TNFR Superfamily Members in Costimulation of T Cell Responses-Revisited

Prosurvival tumor necrosis factor receptor (TNFR) superfamily (TNFRSF) members on T cells, including 4-1BB, CD27, GITR, and OX40, support T cell accumulation during clonal expansion, contributing to T cell memory. During viral infection, tumor necrosis factor superfamily (TNFSF) members on inflammatory monocyte-derived antigen-presenting cells (APCs) provide a postpriming signal (signal 4) for T cell accumulation, particularly in the tissues. Patients with loss-of-function mutations in TNFR/TNFSF members reveal a critical role for 4-1BB and CD27 in CD8 T cell control of Epstein-Barr virus and other childhood infections and of OX40 in CD4 T cell responses. Here, on the 20th anniversary of a previous Annual Review of Immunology article about TNFRSF signaling in T cells, we discuss the effects of endogenous TNFRSF signals in T cells upon recognition of TNFSF members on APCs; the role of TNFRSF members, including TNFR2, on regulatory T cells; and recent advances in the incorporation of TNFRSF signaling in T cells into immunotherapeutic strategies for cancer.

The role of TRAF2 in pan-cancer revealed by integrating informatics and experimental validation

Background

Tumor necrosis factor (TNF) receptor associated factor-2 (TRAF2) is an E3 ubiquitin ligase and scaffolding protein that contribute to the progression of various malignant tumors. However, the role of TRAF2 expression in epigenetic, cancer prognosis, and immune responses in tumor microenvironment is unclear.

Methods

We used The Human Protein Atlas (HPA) database, TIMER 2.0 database, and TCGA database to evaluate TRAF2 expression in human normal and tumor tissues. Correlation of TRAF2 expression with mutations and epigenetic in tumors was evaluated using the cBioPortal platform and the GSCA database. To assess the prognostic value of TRAF2, we performed Kaplan-Meier plots and Cox regression analysis. LinkedOmics database was used for PANTHER Pathways enrichment analysis. The relationship between TRAF2 expression and immune checkpoint genes, as well as immune cell infiltration, was examined using TIMER 2.0 and the R language. Single-cell sequencing data and multiple immunofluorescence staining were used to observe the co-expression of TRAF2 on hepatocellular carcinoma cells and immune cells. Furthermore, using siRNA-mediated knockdown, we explored the potential role of TRAF2 in liver cancer cell biology.

Results

Our findings indicate that TRAF2 is frequently mutated and significantly overexpressed in various types of cancers, and this overexpression is linked to a poor prognosis. The epigenetic alterations in TRAF2 was significant across various types of cancers. TRAF2 is associated with the levels of various immune checkpoint genes and multiple tumor-infiltrating immune cells, suggesting its potential involvement in tumor microenvironment. Of note, enrichment analysis revealed a significant correlation between TRAF2 and T cell activation, and single-cell sequencing indicated that TRAF2 was overexpressed in malignant cells and T cells. In vivo results demonstrated that TRAF2 was closely associated with T lymphocytes in hepatocellular carcinoma. The results of our in vitro experimental studies confirmed that the loss of TRAF2 function inhibits the malignant behavior of HepG2 cells in hepatocellular carcinoma.

Conclusion

TRAF2 represents a potential prognostic biomarker and therapeutic target for cancer immunotherapy, particularly in patients with hepatocellular carcinoma.

Biomimetic Nanomaterials Based on Peptide In Situ Self-Assembly for Immunotherapy Applications

Cancer remains the leading cause of patient death worldwide and its incidence continues to rise. Immunotherapy is rapidly developing due to its significant differences in the mechanism of action from conventional radiotherapy and targeted antitumor drugs. In the past decades, many biomaterials have been designed and prepared to construct therapeutic platforms that modulate the immune system against cancer. Immunotherapeutic platforms utilizing biomaterials can markedly enhance therapeutic efficacy by optimizing the delivery of therapeutic agents, minimizing drug loss during circulation, and amplifying immunomodulatory effects. The intricate physiological barriers of tumors, coupled with adverse immune environments such as inadequate infiltration, off-target effects, and immunosuppression, have emerged as significant obstacles impeding the effectiveness of oncology drug therapy. However, most of the current studies are devoted to the development of complex immunomodulators that exert immunomodulatory functions by loading drugs or adjuvants, ignoring the complex physiological barriers and adverse immune environments of tumors. Compared with conventional biomaterials, biomimetic nanomaterials based on peptide in situ self-assembly with excellent functional characteristics of biocompatibility, biodegradability, and bioactivity have emerged as a novel and effective tool for cancer immunotherapy. This article presents a comprehensive review of the latest research findings on biomimetic nanomaterials based on peptide in situ self-assembly in tumor immunotherapy. Initially, we categorize the structural types of biomimetic peptide nanomaterials and elucidate their intrinsic driving forces. Subsequently, we delve into the in situ self-assembly strategies of these peptide biomimetic nanomaterials, highlighting their advantages in immunotherapy. Furthermore, we detail the applications of these biomimetic nanomaterials in antigen presentation and modulation of the immune microenvironment. In conclusion, we encapsulate the challenges and prospective developments of biomimetic nanomaterials based on peptide in situ self-assembly for clinical translation in immunotherapy.

Immune suppression by human thymus-derived effector Tregs relies on glucose/lactate-fueled fatty acid synthesis

Regulatory T cells (Tregs) suppress pro-inflammatory conventional T cell (Tconv) responses. As lipids impact cell signaling and function, we compare the lipid composition of CD4+ thymus-derived (t)Tregs and Tconvs. Lipidomics reveal constitutive enrichment of neutral lipids in Tconvs and phospholipids in tTregs. TNFR2-co-stimulated effector tTregs and Tconvs are both glycolytic, but only in tTregs are glycolysis and the tricarboxylic acid (TCA) cycle linked to a boost in fatty acid (FA) synthesis (FAS), supported by relevant gene expression. FA chains in tTregs are longer and more unsaturated than in Tconvs. In contrast to Tconvs, tTregs effectively use either lactate or glucose for FAS and rely on this process for proliferation. FASN and SCD1, enzymes responsible for FAS and FA desaturation, prove essential for the ability of tTregs to suppress Tconvs. These data illuminate how effector tTregs can thrive in inflamed or cancerous tissues with limiting glucose but abundant lactate levels.

CAR-T cell manufacturing landscape-Lessons from the past decade and considerations for early clinical development

CAR-T cell therapies have consolidated their position over the last decade as an effective alternative to conventional chemotherapies for the treatment of a number of hematological malignancies. With an exponential increase in the number of commercial therapies and hundreds of phase 1 trials exploring CAR-T cell efficacy in different settings (including autoimmunity and solid tumors), demand for manufacturing capabilities in recent years has considerably increased. In this review, we explore the current landscape of CAR-T cell manufacturing and discuss some of the challenges limiting production capacity worldwide. We describe the latest technical developments in GMP production platform design to facilitate the delivery of a range of increasingly complex CAR-T cell products, and the challenges associated with translation of new scientific developments into clinical products for patients. We explore all aspects of the manufacturing process, namely early development, manufacturing technology, quality control, and the requirements for industrial scaling. Finally, we discuss the challenges faced as a small academic team, responsible for the delivery of a high number of innovative products to patients. We describe our experience in the setup of an effective bench-to-clinic pipeline, with a streamlined workflow, for implementation of a diverse portfolio of phase 1 trials.