CD40 Pathway Research Articles

CD155 promotes the progression of colorectal cancer by restraining CD8+ T cells via the PI3K/AKT/NF-κB pathway

BackgroundCD155 is a crucial factor in the regulation of T cell function and contributes to immune escape. CD155 upregulation has been found in several types of cancer. However, the mechanism by which CD155 regulates CD8+ T cell function in colorectal cancer remains unclear. Here we investigated the role and mechanism of CD155 in the regulation of CD8+ T cell function.MethodsWe studied the expression of CD155 in colorectal cancer tissues through western blot, immunohistochemistry, and the TCGA database. We verified the effects of CD155 on the functions of colorectal cancer cells and CD8+ T cells through in vitro experiments. We demonstrated that CD155 affects CD8+ T cell migration and thus promotes tumor growth in a mouse subcutaneous tumor model. We then tested the changes in the PI3K/AKT/NF-κB pathway in CD8+ T cells by flow cytometry.ResultsWe demonstrated that stable CD155 expression was negatively correlated with prognosis in colorectal cancer patients. In vitro experiments confirmed that CD155 does not affect tumor cell proliferation, migration, or invasion. We also revealed that CD155 downregulated the function and migration of CD8+ T cells in vivo and in vitro. Furthermore, CD155 might regulate CD8+ T cells function via the PI3K/AKT/NF-κB pathway.ConclusionThis study revealed that CD155 can promote the progression of colorectal cancer by regulating the PI3K / AKT-NF-κB pathway to promote the depletion of CD8+ T cells and reduce their migration to the tumor microenvironment. CD155 may become an important prognostic biomarker and an effective target for colorectal cancer immunotherapy.

Molecular landscape of CD8+ T cells in pure red cell aplasia.

The aberrant function of lymphocytes is considered a significant contributing factor to pure red cell aplasia (PRCA), but the precise mechanism by which T lymphocytes induce erythroid development stagnation remains unclear. In our study, the CD8+ T lymphocytes were isolated from bone marrow aspirates of acquired PRCA patients and healthy controls. RNA sequencing (RNA-Seq) was performed to analyze gene expression profiles. Additionally, the expression levels of key molecules and transcription factors were assessed at the transcription and protein levels. The RNA-Seq analysis revealed a significant upregulation of genes associated with the PI3K/AKT/mTOR pathway in CD8+ T lymphocytes from patients with PRCA, compared to healthy controls. The mRNA expression of AKT, mTOR and key transcription factors T-bet were significantly upregulated in CD8+ T cells from patients with PRCA. Treatment with rapamycin, an mTOR inhibitor, attenuated the activation of CD8+ T lymphocytes in PRCA patients. Our findings demonstrate the activation of the PI3K/AKT/mTOR signaling pathway in CD8+ T lymphocytes of PRCA patients, suggesting its involvement in PRCA pathogenesis. Targeting this pathway may offer a potential therapeutic strategy for PRCA characterized by CD8+ T cell dysregulation.

VCP downstream metabolite glycerol-3-phosphate (G3P) inhibits CD8+T cells function in the HCC microenvironment

CD8+T cells within the tumor microenvironment (TME) are often functionally impaired, which limits their ability to mount effective anti-tumor responses. However, the molecular mechanisms behind this dysfunction remain incompletely understood. Here, we identified valosin-containing protein (VCP) as a key regulator of CD8+T cells suppression in hepatocellular carcinoma (HCC). Our findings reveal that VCP suppresses the activation, expansion, and cytotoxic capacity of CD8+T cells both in vitro and in vivo, significantly contributing to the immunosuppressive nature of the TME. Mechanistically, VCP stabilizes the expression of glycerol-3-phosphate dehydrogenase 1-like protein (GPD1L), leading to the accumulation of glycerol-3-phosphate (G3P), a downstream metabolite of GPD1L. The accumulated G3P diffuses into the TME and directly interacts with SRC-family tyrosine kinase LCK, a critical component of the T-cell receptor (TCR) signaling pathway in CD8+T cells. This interaction heightens the phosphorylation of Tyr505, a key inhibitory residue, ultimately reducing LCK activity and impairing downstream TCR signaling. Consequently, CD8+T cells lose their functional capacity, diminishing their ability to fight against HCC. Importantly, we demonstrated that targeting VCP in combination with anti-PD1 therapy significantly suppresses HCC tumor growth and restores the anti-tumor function of CD8+T cells, suggesting synergistic therapeutic potential. These findings highlight a previously unrecognized mechanism involving VCP and G3P in suppressing T-cell-mediated immunity in the TME, positioning VCP as a promising upstream target for enhancing immunotherapy in HCC.

Chimeric Peptide Functionalized Immunostimulant to Orchestrate Photodynamic Immunotherapeutic Effect by PD-L1 Deglycosylation and CD47 Inhibition.

Breast cancer utilizes diverse immunosuppressive mechanisms to evade immune surveillance, thereby impairing immunotherapeutic effects. In this work, a chimeric peptide functionalized immunostimulant (designated as aGlyR) is fabricated to boost photodynamic immunotherapy through PD-L1 deglycosylation and CD47 inhibition. The photosensitizer protoporphyrin IX (PpIX) is conjugated to a PD-L1 deglycosylation peptide via a hydrophilic PEG8 linker, yielding the chimeric peptide Fmoc-K(PpIX)-PEG8-GFTATPPAPDSPQEP. This chimeric peptide could self-assemble into nanomicelles capable of encapsulating the CD47 inhibitor RRx-001, generating the multifunctional photodynamic immunostimulant aGlyR. In vitro and in vivo results indicate that the photodynamic therapy (PDT) of aGlyR could disrupt breast cancer cells and trigger immunogenic cell death (ICD), leading to the release of tumor-associated antigens (TAAs) and the activation of immunological cascades. Additionally, the chimeric peptide component of aGlyR results in the deglycosylation and degradation of PD-L1, which restores T cell-mediated immune activity. Concurrently, the release of RRx-001 blocks the CD47 pathway, disrupting the antiphagocytic signaling of breast cancer cells and activating innate immune responses. This synergistic immunomodulatory approach effectively reverses the complex immunosuppressive factors, significantly enhancing the immunotherapeutic effects of conventional treatments.

Cervical Cancer Cells Use the CD95 and IL-2 Pathways to Promote Their Proliferation and Survival.

Cervical cancer is a global health problem; therapies focused on eliminating tumour cells and strengthening different immunotherapies are in development. However, it has been observed that cervical tumour cells can evade cell death mechanisms and generate immune system molecules to promote their proliferation and metastasis. In this context, we analysed the role of the IL-2 and CD95 pathways, essential molecules in activating the immune system and eliminating tumour cells. However, it is important to analyse their role in cervical tumour cells because these cells could be using these pathways to proliferate. In this study, we found that SiHa and HeLa cells respond to treatment, with 10 IU/mL of IL-2 inducing their proliferation and 100 IU/mL of IL-2 decreasing their proliferation. We also observed that they express a high percentage of the CD95 receptor and its ligand (CD95L) and that treatment with CD95 agonist antibodies at low doses increases cell proliferation. Furthermore, simultaneous treatment with high doses of IL-2 plus CD95 agonist antibody positively regulates LC3B accumulation. We did not observe apoptosis under any of the treatments carried out. In conclusion, cervical tumour cells can use the IL-2 and CD95 pathways to induce their proliferation and potentially activate cytoprotective mechanisms for survival.

CD40 ligation-induced ERK activation leads to enhanced radiosensitivity in cervical carcinoma cells via promoting autophagy.

CD40, a member of the tumor necrosis factor (TNF) receptor superfamily, plays an important role not only in the immune system but also in tumor progression. CD40 ligation reportedly promotes autophagy in immune cells. However, the effects of CD40 ligation on autophagy and its mechanism in solid tumor cells are still unclear. In this study, we find that CD40 ligation promotes autophagosome formation and consequently promotes autophagic flux in cervical cancer cells. Mechanistically, this effect relies on ERK contributing to CD40 ligation-induced ATG13 upregulation by p53. Furthermore, we demonstrate that CD40 ligation-induced autophagy increases the radiosensitivity of cervical cancer cells. Taken together, our results provide new evidence for the involvement of the CD40 pathway in autophagy and radiotherapy in cervical cancer cells.

PI3K/AKT/mTOR and PD‑1/CTLA‑4/CD28 pathways as key targets of cancer immunotherapy (Review).

T cells play an important role in cancer, and energy metabolism can determine both the proliferation and differentiation of T cells. The inhibition of immune checkpoint molecules programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) are a promising cancer treatment. In recent years, research on CD28 has increased. Although numerous reports involve CD28 and its downstream PI3K/AKT/mTOR signaling mechanisms in T cell metabolism, they have not yet been elucidated. A literature search strategy was used for the databases PubMed, Scopus, Web of Science and Cochrane Library to ensure broad coverage of medical and scientific literature, using a combination of keywords including, but not limited to, 'lung cancer' and 'immunotherapy'. Therefore, the present study reviewed the interaction and clinical application of the PD-1/CTLA-4/CD28 and PI3K/AKT/mTOR pathways in T cells, aiming to provide a theoretical basis for immunotherapy in clinical cancer patients.

Dedicator of cytokinesis 8 (DOCK8) mutation impairs the differentiation of helper T cells by regulating the glycolytic pathway of CD4+ T cells.

Dedicator of cytokinesis 8 (DOCK8) deficiency is a primary immunodeficiency disease caused by mutations in exon 45 of the DOCK8 gene. The clinical signs primarily consist of increased serum IgE levels, eczema, repeated skin infections, allergies, and upper respiratory tract infections. Using CRISPR/Cas9 technology, we generated a DOCK8 exon 45 mutation in mice, mirroring the mutation found in patients. The results indicated that DOCK8 mutation impairs peripheral T cell homeostasis, disrupts regulatory T cells (Tregs) development, increases ICOS expression in Tregs within peripheral lymph nodes (pLn), and promotes Th17 cell differentiation within the spleen and pLn. Upon virus infection, DOCK8 mutation CD4+ T cells have a Th2 effector fate. RNA-bulk sequencing data revealed alternations in the mTOR pathway of DOCK8 mutant CD4+ T cells. We observed that DOCK8 mutation upregulates the glycolysis levels in CD4+ T cells, which is related to the Akt/mTOR/S6/HIF-1α pathway. In summary, our research elucidates that DOCK8 regulates the differentiation of helper T cells by modulating the glycolytic pathway in CD4+ T cells, thereby advancing the comprehension and offering potential treatment of diseases in DOCK8-deficient patients.

225.9: Delayed immune tolerance for cardiac allografts in nonhuman primates by targeting CD154, CD2, and CD28 costimulation pathways.

225.9: Delayed immune tolerance for cardiac allografts in nonhuman primates by targeting CD154, CD2, and CD28 costimulation pathways.

TGFβ signaling pathway is altered by HLA-B27 expression, resulting in pathogenic consequences relevant for spondyloarthritis

BackgroundAssociation of HLA-B27 with spondyloarthritis (SpA) has been known for 50 years, but still remains unexplained. We recently showed that HLA-B27 expressed in wing imaginal disc from HLA-B27/human-β2 microglobulin (hβ2m) transgenic Drosophila deregulated bone morphogenetic protein (BMP) pathway by interacting physically with type I BMP receptor (BMPR1) Saxophone (Sax), leading to crossveinless phenotype.MethodsGenetic interaction was studied between activin/transforming growth factor β (TGFβ) pathway and HLA-B27/hβ2m in transgenic Drosophila wings. The HLA-B27-bound peptidome was characterized in wing imaginal discs. In mesenteric lymph node (mLN) T cells from HLA-B27/hβ2m rat (B27 rat), physical interaction between HLA-B27 and activin receptor-like kinase-2 (ALK2), ALK3 and ALK5 BMPR1s, phosphorylation of small mothers against decapentaplegic (SMADs) and proteins of the non-canonical BMP/TGFβ pathways induced by its ligands, and the transcript level of target genes of the TGFβ pathway, were evaluated.ResultsIn HLA-B27/hβ2m transgenic Drosophila, inappropriate signalling through the activin/TGFβ pathway, involving Baboon (Babo), the type I activin/TGFβ receptor, contributed to the crossveinless phenotype, in addition to deregulated BMP pathway. We identified peptides bound to HLA-B27 with the canonical binding motif in HLA-B27/hβ2m transgenic Drosophila wing imaginal disc. We demonstrated specific physical interaction, between HLA-B27/hβ2m and mammalian orthologs of Sax and Babo, i.e. ALK2 and ALK5 (i.e. TGFβ receptor I), in the mLN cells from B27 rat. The magnitude of phosphorylation of SMAD2/3 in response to TGFβ1 was increased in T cells from B27 rats, showing evidence for deregulated TGFβ pathway. Accordingly, expression of several target genes of the pathway was increased in T cells from B27 rats, in basal conditions and/or after TGFβ exposure, including Foxp3, Rorc, Runx1 and Maf. Interestingly, Tgfb1 expression was reduced in naive T cells from B27 rats, even premorbid, an observation consistent with a pro-inflammatory pattern.ConclusionsThis study shows that HLA-B27 alters the TGFβ pathways in Drosophila and B27 rat. Given the importance of this pathway in CD4 + T cells differentiation and regulation, its disturbance could contribute to the abnormal expansion of pro-inflammatory T helper 17 cells and altered regulatory T cell phenotype observed in B27 rats.

Single-Cell Transcriptomic Profiling Unveils Dynamic Immune Cell Responses during Haemonchus contortus Infection.

Haemonchus contortus is a parasite widely distributed in tropical, subtropical, and warm temperate regions, causing significant economic losses in the livestock industry worldwide. However, little is known about the genetics of H. contortus resistance in livestock. In this study, we monitor the dynamic immune cell responses in diverse peripheral blood mononuclear cells (PBMCs) during H. contortus infection in goats through single-cell RNA sequencing (scRNA-Seq) analysis. A total of four Boer goats, two goats with oral infection with the L3 larvae of H. contortus and two healthy goats as controls, were used in the animal test. The infection model in goats was established and validated by the fecal egg count (FEC) test and qPCR analysis of the gene expression of IL-5 and IL-6. Using scRNA-Seq, we identified seven cell types, including T cells, monocytes, natural killer cells, B cells, and dendritic cells with distinct gene expression signatures. After identifying cell subpopulations of differentially expressed genes (DEGs) in the case and control groups, we observed the upregulation of multiple inflammation-associated genes, including NFKBIA and NFKBID. Kyoto Encyclopedia of the Genome (KEGG) enrichment analysis revealed significant enrichment of NOD-like receptor pathways and Th1/Th2 cell differentiation signaling pathways in CD4 T cells DEGs. Furthermore, the analysis of ligand-receptor interaction networks showed a more active state of cellular communication in the PBMCs from the case group, and the inflammatory response associated MIF-(CD74 + CXCR4) ligand receptor complex was significantly more activated in the case group, suggesting a potential inflammatory response. Our study preliminarily revealed transcriptomic profiling characterizing the cell type specific mechanisms in host PBMCs at the single-cell level during H. contortus infection.

Role of MNK/eIF4E pathway in CD4+ Th2 cytokine-induced lung fibrosis in chronic allergic asthma

Abstract Despite therapeutic advances in allergic asthma, the persistent challenge of airway remodeling still exists, necessitating further exploration. We aimed to investigate the influence of CD4+ Th2 cytokines on fibrosis associated with airway remodeling, with a focus on mesenchymal cell (MC) transformation. Using both human and mouse lung MCs, we investigated the pivotal role of MNK/eIF4E pathway in regulating fibrous protein expression driven by CD4+ Th2 cytokines. To assess this, we employed western blot and flow cytometry studies, while Luminex assays measured cytokine and chemokine secretion from activated lung MCs responding to Th2 cytokines. Treatment with Th2 cytokines significantly increased ATX expression in lung MCs, a response mitigated by the specific MNK1/2 inhibitor (eFT-508). Furthermore, this inhibitor not only abolished the phosphorylation of eIF4E but also reduced collagen levels within activated MCs induced by Th2 cytokines. Luminex assay results demonstrated a significant decrease in IL-6, CCL-2, and GM-CSF in the activated MCs upon inhibiting the MNK1/2 pathway. Additionally, eFT-508 exhibited a marked reduction in lymphocyte migration, utilizing the Boyden chamber transwell assay. Our study reveals that targeting the MNK/eIF4E pathway holds promise in mitigating airway remodeling associated with MCs fibrosis and provides valuable molecular insights for future therapeutic interventions related to fibrosis in the airway remodeling of allergic asthma.

Disruption of IFNγ, GZMB, PRF1, or LYST Results in Reduced Suppressive Function in Human CD8+ T Cells.

An imbalance between proinflammatory and regulatory processes underlies autoimmune disease pathogenesis. We have shown that acute relapses of multiple sclerosis are characterized by a deficit in the immune suppressive ability of CD8+ T cells. These cells play an important immune regulatory role, mediated in part through cytotoxicity (perforin [PRF]/granzyme [GZM]) and IFNγ secretion. In this study, we further investigated the importance of IFNγ-, GZMB-, PRF1-, and LYST-associated pathways in CD8+ T cell-mediated suppression. Using the CRISPR-Cas9 ribonucleoprotein transfection system, we first optimized efficient gene knockout while maintaining high viability in primary bulk human CD8+ T cells. Knockout was confirmed through quantitative real-time PCR assays in all cases, combined with flow cytometry where appropriate, as well as confirmation of insertions and/or deletions at genomic target sites. We observed that the knockout of IFNγ, GZMB, PRF1, or LYST, but not the knockout of IL4 or IL5, resulted in significantly diminished invitro suppressive ability in these cells. Collectively, these results reveal a pivotal role for these pathways in CD8+ T cell-mediated immune suppression and provide important insights into the biology of human CD8+ T cell-mediated suppression that could be targeted for immunotherapeutic intervention.

Prognostic value of CD8+T cells related genes and exhaustion regulation of Notch signaling pathway in hepatocellular carcinoma.

Immunotherapy has emerged as the primary treatment modality for patients with advanced Hepatocellular carcinoma (HCC). However, its clinical efficacy remains limited, benefiting only a subset of patients, while most exhibit immune tolerance and face a grim prognosis. The infiltration of immune cells plays a pivotal role in tumor initiation and progression. In this study, we conducted an analysis of immune cell infiltration patterns in HCC patients and observed a substantial proportion of CD8+T cells. Leveraging the weighted gene co-expression network analysis (WGCNA), we identified 235 genes associated with CD8+T cell and constructed a risk prediction model. In this model, HCC patients were stratified into a high-risk and low-risk group. Patients in the high-risk group exhibited a lower survival rate, predominantly presented with intermediate to advanced stages of cancer, displayed compromised immune function, showed limited responsiveness to immunotherapy, and demonstrated elevated expression levels of the Notch signaling pathway. Further examination of clinical samples demonstrated an upregulation of the Notch1+CD8+T cell exhaustion phenotype accompanied by impaired cytotoxicity and cytokine secretion functions that worsened with increasing Notch activation levels. Our study not only presents a prognostic model but also highlights the crucial involvement of the Notch pathway in CD8+T cell exhaustion-a potential target for future immunotherapeutic interventions.

Abstract 4991: Radiotherapy-induced immunological and therapeutic response depends on stem-like TCF-1+PD-1+CD8+ T-cells

Abstract Radiotherapy is a frequently used treatment for cancer. Recent data, including ours, showed that radiotherapy promotes an inflammatory response in the tumor that supports tumor-specific immunity, and in fact, the efficacy of radiotherapy in pre-clinical models depends on CD8+ T-cells. According to our preliminary data, the response to radiotherapy is independent of de novo recruited CD8+ T-cells, suggesting that radiation drives differentiation and proliferation of preexisting intratumoral CD8+ T-cells. Intratumoral CD8+ T-cells are heterogeneous concerning phenotype and function. Under conditions of chronic stimulation by antigen, a subset of CD8+ T-cells expressing PD-1 and the transcription factor TCF-1 was described. These so-called stem-like CD8+ T-cells, which give rise to effector cells, were shown to be essential for the clinical response to PD-1 blockade. How radiotherapy influences the different CD8+ T-cell subsets in the tumor microenvironment has not been comprehensively investigated. We propose that the efficacy of radiotherapy depends on the presence of stem-like CD8+ T-cells, presumably by giving rise to effector cells. To address this, we selectively depleted TCF-1+ cells from tumor-bearing mice immediately before radiotherapy. Subsequently, we correlated tumor regression with the immunological response using single-cell analyses of intratumoral CD8+ T-cells. In the absence of TCF-1+ cells, we found a reduced efficacy and reduced number of intratumoral effector cells after radiotherapy. We currently analyze our single-cell RNA-sequencing data and expect to discover novel radiotherapy-induced pathways in CD8+ T-cells that contribute to therapeutic efficacy. Citation Format: Hakan Köksal, Michael Herbst, Nicola Marti, Maries van den Broek. Radiotherapy-induced immunological and therapeutic response depends on stem-like TCF-1+PD-1+CD8+ T-cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4991.

JAK/STAT signaling pathway affects CCR5 expression in human CD4+ T cells.

CCR5 serves as R5-tropic HIV co-receptor. Knocking out CCR5 in HIV patients, which has occurred <10 times, is believed important for cure. JAK/STAT inhibitors tofacitinib and ruxolitinib inhibit CCR5 expression in HIV+ viremic patients. We investigated the association of JAK/STAT signaling pathway with CCR5/CCR2 expression in human primary CD4+ T cells and confirmed its importance. Six of nine JAK/STAT inhibitors that reduced CCR5/CCR2 expression were identified. Inhibitor-treated CD4+ T cells were relatively resistant, specifically to R5-tropic HIV infection. Furthermore, single JAK2, STAT3, STAT5A, and STAT5B knockout and different combinations of JAK/STAT knockout significantly reduced CCR2/CCR5 expression of both RNA and protein levels, indicating that CCR5/CCR2 expression was positively regulated by JAK-STAT pathway in CD4+ T cells. Serum and glucocorticoid-regulated kinase 1 (SGK1) knockout affected CCR2/CCR5 gene expression, suggesting that SGK1 is involved in CCR2/CCR5 regulation. If cell surface CCR5 levels can be specifically and markedly down-regulated without adverse effects, that may have a major impact on the HIV cure agenda.

Synthetic dual co-stimulation increases the potency of HIT and TCR-targeted cell therapies.

Chimeric antigen receptor T cells have dramatically improved the treatment of hematologic malignancies. T cell antigen receptor (TCR)-based cell therapies are yet to achieve comparable outcomes. Importantly, chimeric antigen receptors not only target selected antigens but also reprogram T cell functions through the co-stimulatory pathways that they engage upon antigen recognition. We show here that a fusion receptor comprising the CD80 ectodomain and the 4-1BB cytoplasmic domain, termed 80BB, acts as both a ligand and a receptor to engage the CD28 and 4-1BB pathways, thereby increasing the antitumor potency of human leukocyte antigen-independent TCR (HIT) receptor- or TCR-engineered T cells and tumor-infiltrating lymphocytes. Furthermore, 80BB serves as a switch receptor that provides agonistic 4-1BB co-stimulation upon its ligation by the inhibitory CTLA4 molecule. By combining multiple co-stimulatory features in a single antigen-agnostic synthetic receptor, 80BB is a promising tool to sustain CD3-dependent T cell responses in a wide range of targeted immunotherapies.

Melanoma Derived Exosomes Amplify Radiotherapy Induced Abscopal Effect via IRF7/I-IFN Axis in Macrophages.

Radiotherapy (RT) can induce tumor regression outside the irradiation field, known as the abscopal effect. However, the detailed underlying mechanisms remain largely unknown. A tumor-bearing mouse model is successfully constructed by inducing both subcutaneous tumors and lung metastases. Single-cell RNA sequencing, immunofluorescence, and flow cytometry are performed to explore the regulation of tumor microenvironment (TME) by RT. A series of in vitro assays, including luciferase reporter, RNA Pulldown, and fluorescent in situ hybridization (FISH) assays, are performed to evaluate the detailed mechanism of the abscopal effect. In addition, in vivo assays are performed to investigate combination therapy strategies for enhancing the abscopal effect. The results showed that RT significantly inhibited localized tumor and lung metastasis progression and improved the TME. Mechanistically, RT promoted the release of tumor-derived exosomes carrying circPIK3R3, which is taken up by macrophages. circPIK3R3 promoted Type I interferon (I-IFN) secretion and M1 polarization via the miR-872-3p/IRF7 axis. Secreted I-IFN activated the JAK/STAT signaling pathway in CD8+ T cells, and promoted IFN-γ and GZMB secretion. Together, the study shows that tumor-derived exosomes promote I-IFN secretion via the circPIK3R3/miR-872-3p/IRF7 axis in macrophages and enhance the anti-tumor immune response of CD8+ T cells.

The CUL5 E3 ligase complex negatively regulates central signaling pathways in CD8+ T cells

CD8+ T cells play an important role in anti-tumor immunity. Better understanding of their regulation could advance cancer immunotherapies. Here we identify, via stepwise CRISPR-based screening, that CUL5 is a negative regulator of the core signaling pathways of CD8+ T cells. Knocking out CUL5 in mouse CD8+ T cells significantly improves their tumor growth inhibiting ability, with significant proteomic alterations that broadly enhance TCR and cytokine signaling and their effector functions. Chemical inhibition of neddylation required by CUL5 activation, also enhances CD8 effector activities with CUL5 validated as a major target. Mechanistically, CUL5, which is upregulated by TCR stimulation, interacts with the SOCS-box-containing protein PCMTD2 and inhibits TCR and IL2 signaling. Additionally, CTLA4 is markedly upregulated by CUL5 knockout, and its inactivation further enhances the anti-tumor effect of CUL5 KO. These results together reveal a negative regulatory mechanism for CD8+ T cells and have strong translational implications in cancer immunotherapy.

Integrating Network Pharmacology and Experimental Validation to Elucidate the Mechanism of Jiegeng Decoction in Improving Allergic Asthma.

Allergic asthma is a prevalent form of asthma that is characterized primarily by airway inflammation. Jiegeng decoction (JGT) is a traditional Chinese herbal formula known for its anti-inflammatory properties and has been used to treat respiratory diseases for centuries. This study aimed to investigate the biological effects and mechanisms of action of JGT in improving allergic asthma. An experimental allergic asthma mouse model was established using ovalbumin. The results showed that JGT significantly improved inflammation cell infiltration in the lung tissue of allergic asthmatic mice and the inflammatory environment of Th2 cells in the bronchoalveolar lavage fluid while also reducing serum IgE levels. Subsequently, 38 components of JGT were identified through liquid chromatography-mass spectrometry. Network pharmacology revealed that regulating inflammation and immune responses is the primary biological process by which JGT improves allergic asthma, with Th2 cell differentiation and the JAK-STAT signaling pathway being the key mechanisms of action. Finally, qPCR, flow cytometry, and Western blotting were used to validate that JGT inhibited Th2 cell differentiation by blocking the JAK1-STAT6 signaling pathway in CD4+ T cells, ultimately improving allergic asthma. This study provides a novel perspective on the therapeutic potential of JGT in the treatment of allergic asthma.