T Cells Research Articles

Systematic Aetiological Assessment of Myocarditis: A Prospective Cohort Study.

Myocarditis is commonly diagnosed in the intensive care cardiology unit (ICCU). No current recommendation nor guideline aids exist for aetiological assessments. From September 2021 to October 2023, 84 patients with acute myocarditis underwent thorough and systematic serum and blood cell panel evaluations to determine the most common causes of myocarditis. Of the 84 patients (median age 34 years, range 22-41 years, 79% male), 16 presented with complicated myocarditis. The systematic aetiological assessment revealed that 36% of patients were positive for lupus anticoagulant, 12% for antinuclear antibodies, 8% for anti-heart antibodies, and 12% for anti-striated muscle antibodies. Viral serology did not yield any significant results. After the aetiological assessment, one patient was diagnosed with an autoimmune inflammatory disorder (Still's disease). T-cell subset analyses indicated that myocarditis severity tended to increase with the T-cell lymphopenia status. A comprehensive, systematic aetiological assessment was of limited value in terms of predicting the clinical or therapeutic outcomes in myocarditis patients presenting to the ICCU.

Large airway T cells in adults with former bronchopulmonary dysplasia

BackgroundBronchopulmonary Dysplasia (BPD) in infants born prematurely is a risk factor for chronic airway obstruction later in life. The distribution of T cell subtypes in the large airways is largely unknown.ObjectiveTo characterize cellular and T cell profiles in the large airways of young adults with a history of BPD.MethodsForty-three young adults born prematurely (preterm (n = 20), BPD (n = 23)) and 45 full-term-born (asthma (n = 23), healthy (n = 22)) underwent lung function measurements, and bronchoscopy with large airway bronchial wash (BW). T-cells subsets in BW were analyzed by immunocytochemistry.ResultsThe proportions of both lymphocytes and CD8 + T cells in BW were significantly higher in BPD (median, 6.6%, and 78.0%) when compared with asthma (3.4% and 67.8%, p = 0.002 and p = 0.040) and healthy (3.8% and 40%, p < 0.001 and p < 0.001). In all adults born prematurely (preterm and BPD), lymphocyte proportion correlated negatively with forced vital capacity (r= -0.324, p = 0.036) and CD8 + T cells correlated with forced expiratory volume in one second, FEV1 (r=-0.448, p = 0.048). Correlation-based network analysis revealed that lung function cluster and BPD-birth cluster were associated with lymphocytes and/or CD4 + and CD8 + T cells. Multivariate regression analysis showed that lymphocyte proportions and BPD severity qualified as independent factors associated with FEV1.ConclusionsThe increased cytotoxic T cells in the large airways in young adults with former BPD, suggest a similar T-cell subset pattern as in the small airways, resembling features of COPD. Our findings strengthen the hypothesis that mechanisms involving adaptive and innate immune responses are involved in the development of airway disease due to preterm birth.

From PsO to PsA: the role of TRM and Tregs in psoriatic disease, a systematic review of the literature.

Psoriasis (PsO) is a chronic skin condition driven by immune mediators like TNFα, INFγ, IL-17, and IL-23. Psoriatic arthritis (PsA) can develop in PsO patients. Although psoriatic lesions may apparently resolve with therapy, subclinical cutaneous inflammation may persist. The role of tissue-resident memory T-cells (TRM), and regulatory T cells (Tregs) that also contribute to chronic inflammation are being explored in this context. This systematic review explores TRM and Tregs in psoriatic disease (PsD) and its progression. A systematic review, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, was performed using Pubmed® and Web of Science™ databases on June 3rd 2023, using patient/population, intervention, comparison, and outcomes (PICO) criteria limited to the English language. A total of 62 reports were identified and included. In PsO, chronic inflammation is driven by cytokines including IL-17 and IL-23, and cellular mediators such as CD8+ and CD4+ T cells. TRM contributes to local inflammation, while Tregs may be dysfunctional in psoriatic skin lesions. Secukinumab and guselkumab, which target IL-17A and the IL-23p19 subunit, respectively, have different effects on CD8+ TRM and Tregs during PsO treatment. Inhibition of IL-23 may provide better long-term results due to its impact on the Treg to CD8+ TRM ratio. IL-23 may contribute to inflammation persisting even after treatment. In PsA, subclinical enthesitis is perceived as an early occurence, and Th17 cells are involved in this pathogenic process. Recent EULAR guidelines highlight the importance of early diagnosis and treatment to intercept PsA. In PsA, CD8+ TRM cells are present in synovial fluid and Tregs are reduced in peripheral blood. The progression from PsO to PsA is marked by a shift in immune profiles, with specific T-cells subsets playing key roles in perpetuating inflammation. Early intervention targeting TRM cells may hold promising, but clinical studies are limited. Ongoing studies such as IVEPSA and PAMPA aim to improve our knowledge regarding PsA interception in high-risk PsO patients, emphasizing the need for further research in this area. Early intervention is crucial for PsO patients at high risk of PsA; T cells, particularly type 17 helper T cells, and CD8+ cells are key in the progression from PsO-to-PsA. Early targeting of TRM in PsD shows promise but more research is needed.

High FLT3 expression increases immune-cell infiltration in the tumor microenvironment and correlates with prolonged disease-free survival in patients with non-small cell lung cancer.

Most of the currently used cancer immunotherapies inhibit the programmed cell death protein 1 (PD1)-programmed cell death 1 ligand 1 (PDL1) axis of T-cells. However, dendritic cells (DCs) controlled by natural killer (NK) cells via the FMS-related tyrosine kinase 3 (FLT3) axis are necessary for activation of T-cells. The aim of the study was to evaluate FLT3 as a prognostic factor and determine its role in immune infiltration (with emphasis on NK cells and DCs). Using The Cancer Genome Atlas (TCGA) database, we performed bioinformatic analysis of the gene expression datasets of 501 lung squamous cell carcinoma (LUSC) and 515 lung adenocarcinoma (LUAD) patient who had corresponding clinical data [analysis was performed in R (version 4.2.0)]. Disease-free survival (DFS) differed between the FLT3-low and FLT3-high expression groups, respectively, in LUSC (61.0 vs 71.3 months P = 0.075) and LUAD (32.7 vs 47.5 months P = 0.045). A tumor microenvironment (TME) with high immune infiltration and rich in T-cell exhaustion markers was observed in the FLT3-high group. We showed overexpression of NK cell and DC gene signatures in the FLT3-high expression group as well as overexpression of key effector genes of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes protein (STING) pathway, which is crucial in response to radiotherapy. High expression of FLT3 in the TME was associated with immune cell infiltration (especially of NK cells and DCs), increased expression of T-cell exhaustion markers and expression of effector genes of the cGAS-STING pathway, which may consequently increase susceptibility to immunotherapy and radiotherapy. High FLT3 expression correlated with prolonged DFS in the LUSC and LUAD cohorts.

Novel Approach for Pancreas Transcriptomics Reveals the Cellular Landscape in Homeostasis and Acute Pancreatitis

Acinar cells produce digestive enzymes that impede transcriptomic characterization of the exocrine pancreas. Thus, single-cell RNA-sequencing studies of the pancreas underrepresent acinar cells relative to histological expectations, and a robust approach to capture pancreatic cell responses in disease states is needed. We sought to innovate a method that overcomes these challenges to accelerate study of the pancreas in health and disease. We leverage FixNCut, a single-cell RNA-sequencing approach in which tissue is reversibly fixed with dithiobis(succinimidyl propionate) before dissociation and single-cell preparation. We apply FixNCut to an established mouse model of acute pancreatitis, validate findings using GeoMx whole transcriptome atlas profiling, and integrate our data with prior studies to compare our method in both mouse and human pancreas datasets. FixNCut achieves unprecedented definition of challenging pancreatic cells, including acinar and immune populations in homeostasis and acute pancreatitis, and identifies changes in all major cell types during injury and recovery. We define the acinar transcriptome during homeostasis and acinar-to-ductal metaplasia and establish a unique gene set to measure deviation from normal acinar identity. We characterize pancreatic immune cells, and analysis of T-cell subsets reveals a polarization of the homeostatic pancreas toward type-2 immunity. We report immune responses during acute pancreatitis and recovery, including early neutrophil infiltration, expansion of dendritic cell subsets, and a substantial shift in the transcriptome of macrophages due to both resident macrophage activation and monocyte infiltration. FixNCut preserves pancreatic transcriptomes to uncover novel cell states during homeostasis and following pancreatitis, establishing a broadly applicable approach and reference atlas for study of pancreas biology and disease.

Relative deficiency in interferon-γ-secreting CD4+ T cells is strongly associated with poorer COVID-19 vaccination responses in older adults.

Although the two-dose mRNA vaccination regime provides protection against SARS-CoV-2, older adults have been shown to exhibit poorer vaccination responses. In addition, the role of vaccine-induced T-cell responses is not well characterised. We aim to assess the impact of age on immune responses after two doses of the BNT162b2 mRNA vaccine, focussing on antigen-specific T-cells. A prospective 3-month study was conducted on 15 young (median age 31 years, interquartile range (IQR) 25-35 years) and 14 older adults (median age 72 years, IQR 70-73 years). We assessed functional, neutralising antibody responses against SARS-CoV-2 variants using ACE-2 inhibition assays, and changes in B and T-cell subsets by high-dimensional flow cytometry. Antigen-specific T-cell responses were also quantified by intracellular cytokine staining and flow cytometry. Older adults had attenuated T-helper (Th) response to vaccination, which was associated with weaker antibody responses and decreased SARS-CoV-2 neutralisation. Antigen-specific interferon-γ (IFNγ)-secreting CD4+ T-cells to wild-type and Omicron antigens increased in young adults, which was strongly positively correlated with their neutralising antibody responses. Conversely, this relationship was negative in older adults. Hence, older adults' relative IFNγ-secreting CD4+ T cell deficiency might explain their poorer COVID-19 vaccination responses. Further exploration into the aetiology is needed and would be integral in developing novel vaccination strategies and improving infection outcomes in older adults.

Effects of High-Dose Vitamin C on Liver Function, Systemic Inflammatory and Immune Responses in Patients with Severe Acute Pancreatitis

The objective of this study was to explore the impact of high-dose vitamin C on severe acute pancreatitis patients. This study involved 76 hospital patients from November 2022 to November 2023, divided into two groups: a high-dose group (44 patients) receiving 10 g of vitamin C daily and a routine-dose group (32 patients) receiving 1 g daily. The study evaluated treatment effects, liver function, inflammation levels, and blood T-lymphocyte subsets and complications. At 14 days, the high-dose group showed better overall treatment effects, lower levels of liver enzymes and inflammatory markers, and higher levels of T lymphocytes, with no significant difference in complications compared to the routine-dose group. The findings suggest that high-dose vitamin C effectively improves liver function, reduces inflammation, and boosts immunity in severe acute pancreatitis patients.

Tumor-secreted FGF21 acts as an immune suppressor by rewiring cholesterol metabolism of CD8+T cells

Tumors employ diverse strategies for immune evasion. Unraveling the mechanisms by which tumors suppress anti-tumor immunity facilitates the development of immunotherapies. Here, we have identified tumor-secreted fibroblast growth factor 21 (FGF21) as a pivotal immune suppressor. FGF21 is upregulated in multiple types of tumors and promotes tumor progression. Tumor-secreted FGF21 significantly disrupts anti-tumor immunity by rewiring cholesterol metabolism of CD8+Tcells. Mechanistically, FGF21 sustains the hyperactivation of AKT-mTORC1-sterol regulatory-element-binding protein 1 (SREBP1) signal axis in the activated CD8+T cells, resulting in the augment of cholesterol biosynthesis and Tcell exhaustion. FGF21 knockdown or blockade using a neutralizing antibody normalizes AKT-mTORC1 signaling and reduces excessive cholesterol accumulation in CD8+T cells, thus restoring CD8+T cytotoxic function and robustly suppressing tumor growth. Our findings reveal FGF21 as a "secreted immune checkpoint" that hampers anti-tumor immunity, suggesting that inhibiting FGF21 could be a valuable strategy to enhance the cancer immunotherapy efficacy.

Deep Immunophenotyping of Circulating T and B Cells in Relapsing Adult-Onset Still's Disease.

Adult-onset Still's disease (AOSD) is a complex systemic inflammatory disorder, categorized as an 'IL-1 driven' inflammasomapathy. Despite this, the interaction between T and B cells remains poorly understood. We conducted a study, enrolling 7 patients with relapsing AOSD and 15 healthy control subjects, utilizing deep flow cytometry analysis to examine peripheral blood T- and B-cell subsets. T-cell and B-cell subsets were significantly altered in patients with AOSD. Within CD4+ T cells, Th2 cells were decreased. Additionally, Th17 cell and follicular Th cell subsets were altered within CD45RA-CD62L+ and CD45RA-CD62L- Th cells in patients with AOSD compared to healthy controls. We identified changes in CD8+ T cell maturation and 'polarization' in AOSD patients, with an elevated presence of the TEMRA CD8+ T cell subset. Furthermore, the percentage of Tc1 cells was decreased, while the frequency of CCR6-CXCR3- Tc2 cells was elevated. Finally, we determined that the frequency of CD5+CD27- B cells was dramatically decreased in patients with AOSD compared to healthy controls. Further investigations on a large group of patients with AOSD are required to evaluate these adaptive immunity cells in the disease pathogenesis.

Clinical efficacy of recombinant human basic fibroblast growth factor combined with ranitidine in the treatment of recurrent oral ulcer and its effect on serum TNF, IL-2 and T-lymphocyte subsets.

To evaluate the clinical efficacy of recombinant human basic fibroblast growth factor (rh-bFGF) combined with ranitidine in the treatment of recurrent oral ulcer and its effects on serum TNF, IL-2 and T-lymphocyte subsets. This was a retrospective study. Eighty patients with oral ulcers admitted to First Medical Center, Chinese PLA General Hospital from July 2021 to June 2022 were randomly divided into the control group and the experimental group (n=40). Patients in the control group were given topical treatment with rh-bFGF gel, while those in the experimental group were given oral treatment combined with ranitidine based on the control group, and both groups were treated continuously for 14 days. The therapeutic effect, pain relief time, ulcer healing time, as well as the differences in the levels of inflammatory factors and T-lymphocyte subsets were compared and analyzed between the two groups. The overall response rate of the experimental group was 92.5%, while that of the control group was 75%, with a statistically significant difference(P=0.03). After treatment, inflammatory factors indexes in the experimental group were significantly lower than those in the control group, with statistically significant differences (P=0.00). The indexes of T-lymphocyte subsets in the experimental group were significantly higher than those in the control group after treatment, with statistically significant differences (P=0.00). Recombinant human basic fibroblast growth factor combined with ranitidine is effective in the treatment of recurrent oral ulcers, boasting various benefits such as effectively promoting ulcer healing, reducing pain and inflammatory response, and enhancing immune function.

Effect of Incomplete Cryoablation and Matrix Metalloproteinase Inhibition on Intratumoral CD8+ T-Cell Infiltration in Murine Hepatocellular Carcinoma.

Background Image-guided tumor ablation is the first-line therapy for early-stage hepatocellular carcinoma (HCC), with ongoing investigations into its combination with immunotherapies. Matrix metalloproteinase (MMP) inhibition demonstrates immunomodulatory potential and reduces HCC tumor growth when combined with ablative treatment. Purpose To evaluate the effect of incomplete cryoablation with or without MMP inhibition on the local immune response in residual tumors in a murine HCC model. Materials and Methods Sixty 8- to 10-week-old female BALB/c mice underwent HCC induction with use of orthotopic implantation of syngeneic Tib-75 cells. After 7 days, mice with a single lesion were randomized into treatment groups: (a) no treatment, (b) MMP inhibitor, (c) incomplete cryoablation, and (d) incomplete cryoablation and MMP inhibitor. Macrophage and T-cell subsets were assessed in tissue samples with use of immunohistochemistry and immunofluorescence (cell averages calculated using five 1-μm2 fields of view [FOVs]). C-X-C motif chemokine receptor type 3 (CXCR3)- and interferon γ (IFNγ)-positive T cells were assessed using flow cytometry. Groups were compared using unpaired Student t tests, one-way analysis of variance with Tukey correction, and the Kruskal-Wallis test with Dunn correction. Results Mice treated with incomplete cryoablation (n = 6) showed greater infiltration of CD206+ tumor-associated macrophages (mean, 1.52 cells per FOV vs 0.64 cells per FOV; P = .03) and MMP9-expressing cells (mean, 0.89 cells per FOV vs 0.11 cells per FOV; P = .03) compared with untreated controls (n = 6). Incomplete cryoablation with MMP inhibition (n = 6) versus without (n = 6) led to greater CD8+ T-cell (mean, 15.8% vs 8.29%; P = .04), CXCR3+CD8+ T-cell (mean, 11.64% vs 8.47%; P = .004), and IFNγ+CD8+ T-cell infiltration (mean, 11.58% vs 5.18%; P = .02). Conclusion In a mouse model of HCC, incomplete cryoablation and systemic MMP inhibition showed increased cytotoxic CD8+ T-cell infiltration into the residual tumor compared with either treatment alone. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Gemmete in this issue.

Abstract B022: Targeting epithelial-mesenchymal plasticity and CD73 to enhance responses of breast cancers to immune checkpoint blockade therapies

Abstract Immune checkpoint blockade (ICB) therapy has generated dramatic responses in certain types of human tumors however, the response of breast cancers has been largely limited. Epithelial-mesenchymal plasticity (EMP) enables carcinoma cells to metastasize, gain tumor-initiating ability and mount resistance to chemotherapies. In addition, we have demonstrated that this plasticity program also contributes to the establishment of an immunosuppressive tumor microenvironment and confers resistance to ICB therapy (Dongre and Weinberg 2019). By establishing novel, preclinical models of more-epithelial or more-mesenchymal breast tumors, we observed that epithelial tumors recruit CD8+ T-cells to their microenvironment and are sensitive to anti-CTLA4 ICB. In contrast, mesenchymal tumors recruit Tregs and M2-like macrophages and are resistant to the same treatment (Dongre et al., 2017). Strikingly, abrogation of CD73 from more-mesenchymal cells completely sensitizes otherwise refractory tumors to anti-CTLA4 ICB (Dongre et al., 2021). These findings demonstrated for the first time that more-mesenchymal breast cancer cells can be completely sensitized to anti-tumor immunity by interrupting certain cell-intrinsic signaling channels. However, the underlying mechanisms of such sensitization remain elusive. Additionally, the regulatory networks that control the expression of CD73 itself in more-mesenchymal but not epithelial breast cancer cells are not well defined. To determine the subset of T-cells that is functionally important in sensitizing mesenchymal tumors lacking CD73, we depleted either conventional CD4+ T-cells or CD8+ cytotoxic T-cells in combinatoin with ICB. While responding mice recruited both T-cells to their tumors, only CD4+ T-cells (and not CD8+ T-cells) were functionally important in driving sensitization. Along these lines, more-mesenchymal cancer cells lacking CD73 failed to respond to anti-CTLA4 ICB when propagated in genetically engineered mice lacking CD4+ T-cells relative to wild type controls. Importantly, depletion of CD4+ T-cells also prevented the recruitment of peripheral CD8+ T-cells to responding tumors, thereby driving resistance to ICB. In addition, we observed that human triple negative breast cancer cell lines expressed the highest amount of CD73 relative to hormone receptor-positive cell lines. Most importantly, activating EMP in human breast cancer cells by doxycycline-controlled expression of various transcription factors, induced the expression of CD73. Taken together, our work demonstrates that (i) the phenotypic plasticity of breast cancer cells can predict responses to ICB (ii) targeting CD73 can completely sensitize more-mesenchymal tumors to anti-CTLA4 ICB in a CD4+ T-cell dependent fashion and; (iii) altering the cellular plasticity of cancer cells can regulate CD73 expression. Given the highly refractory nature of more-mesenchymal cancer cells, our findings hold tremendous potential in aiding translational efforts to target cancer plasticity to enhance responses of breast cancers to ICB therapy. Citation Format: Anushka Dongre. Targeting epithelial-mesenchymal plasticity and CD73 to enhance responses of breast cancers to immune checkpoint blockade therapies [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B022.

Molecular phenotypes behind patient stratification based on TP53 and HPV status and potential for treatment personalization with first single-cell RNA sequencing atlas of penile cancer.

8 Background: TP53 mutations and Human papillomavirus (HPV) have been suggested to impact penile squamous cell carcinoma (pSCC) prognosis and may predict treatment outcomes. Insights in differences in tumor micro-environment at single cell resolution may benefit personalized therapeutic development and are currently unavailable. Methods: We performed single cell RNA sequencing and targeted next generation sequencing (for TP53 loss-of-function mutations; p53LOF) on primary HPV-associated and HPV-independent (HPV+/-) pSCC lesions or healthy control samples of the coronal sulcus skin. Cell clusters were annotated based on known marker genes. Gene Set Enrichment Analysis (GSEA) and slingshot trajectory analysis was performed using R/Seurat package. Results: Twenty-two samples were analyzed: 4 tumors harbored p53LOF mutations (1 HPV+ p53LOF, 3 HPV- p53LOF), 6 HPV- p53WT, 6 HPV+ p53WT and 6 healthy controls. A total of 84.394 cells was annotated and we identified 68 distinct cell subtypes in pSCC. In epithelial cells, two distinct pseudotime trajectories stemming from the basal cells were identified characterized by either signals of partial epithelial-mesenchymal transition (pEMT; TGFB, ZEB2, SNAI2) or cornification ( ELF3, KRT19, PPL). Whilst the pEMT trajectory was enriched in p53LOF samples, cornification was enriched in HPV+ p53WT. HPV- p53WT samples displayed increase in metabolic changes and stemness hallmarks ( SOX2, HEY1, ZEB1). GSEA confirmed these findings and showed upregulation of pEMT gene sets in p53LOF; fatty acid metabolism and xenobiotic metabolism in HPV- p53WT, and cornification in HPV+ p53WT. We observed an immune suppressive environment in p53LOF patients with higher regulatory T-cell abundancy, and this correlated with abundancy in the epithelial pEMT clusters. Pseudo-bulk analysis on all T-cell subsets demonstrated a higher expression of inhibitory immune checkpoints ( PD-1, CTLA4, TIM3 and LAG3) in p53LOF and HPV- p53WT while HPV+ p53WT patients displayed higher abundancy of immunomodulatory and cytotoxic natural killer (NK) cells. Conclusions: We established the first comprehensive pSCC transcriptomic atlas at single cell resolution and illustrate differences in molecular phenotypes of pSCC according to TP53 mutation- and HPV status. p53LOF tumors are characterized by pEMT, which is a known driver of invasiveness, therapy resistance and metastasis. HPV- p53WT display hallmarks of stemness, which is related to and may explain chemotherapy-resistance often observed in these patients. p53LOF and HPV- p53WT display immune-evasion and exhaustion, while HPV+ p53WT are characterized by abundant cytotoxic innate-like lymphocytes. These observations provide deeper insights into cancer biology that will help advancing pSCC diagnosis and therapy.

A versatile CRISPR-Cas13d platform for multiplexed transcriptomic regulation and metabolic engineering in primary human T cells

CRISPR technologies have begun to revolutionize Tcell therapies; however, conventional CRISPR-Cas9 genome-editing tools are limited in their safety, efficacy, and scope. To address these challenges, we developed multiplexed effector guide arrays (MEGA), a platform for programmable and scalable regulation of the Tcell transcriptome using the RNA-guided, RNA-targeting activity of CRISPR-Cas13d. MEGA enables quantitative, reversible, and massively multiplexed gene knockdown in primary human Tcells without targeting or cutting genomic DNA. Applying MEGA to a model of CAR Tcell exhaustion, we robustly suppressed inhibitory receptor upregulation and uncovered paired regulators of Tcell function through combinatorial CRISPR screening. We additionally implemented druggable regulation of MEGA to control CAR activation in a receptor-independent manner. Lastly, MEGA enabled multiplexed disruption of immunoregulatory metabolic pathwaysto enhance CAR Tcell fitness and anti-tumor activity invitro and invivo. MEGA offers a versatile synthetic toolkit for applications in cancer immunotherapy and beyond.

Desmoplasia Is Associated with Decreased Cytotoxic and Helper T Cells and Increased T-Cell Exhaustion in Cutaneous Squamous Cell Carcinoma

Desmoplasia Is Associated with Decreased Cytotoxic and Helper T Cells and Increased T-Cell Exhaustion in Cutaneous Squamous Cell Carcinoma

Specific T-cell subsets have a role in anti-viral immunity and pathogenesis but not viral dynamics or onwards vector transmission of an important livestock arbovirus.

Bluetongue virus (BTV) is an arthropod-borne Orbivirus that is almost solely transmitted by Culicoides biting midges and causes a globally important haemorrhagic disease, bluetongue (BT), in susceptible ruminants. Infection with BTV is characterised by immunosuppression and substantial lymphopenia at peak viraemia in the host. In this study, the role of cell-mediated immunity and specific T-cell subsets in BTV pathogenesis, clinical outcome, viral dynamics, immune protection, and onwards transmission to a susceptible Culicoides vector is defined in unprecedented detail for the first time, using an in vivo arboviral infection model system that closely mirrors natural infection and transmission of BTV. Individual circulating CD4+, CD8+, or WC1+ γδ T-cell subsets in sheep were depleted through the administration of specific monoclonal antibodies. The absence of cytotoxic CD8+ T cells was consistently associated with less severe clinical signs of BT, whilst the absence of CD4+ and WC1+ γδ T cells both resulted in an increased clinical severity. The absence of CD4+ T cells also impaired both a timely protective neutralising antibody response and the production of IgG antibodies targeting BTV non-structural protein, NS2, highlighting that the CD4+ T-cell subset is important for a timely protective immune response. T cells did not influence viral replication characteristics, including onset/dynamics of viraemia, shedding, or onwards transmission of BTV to Culicoides. We also highlight differences in T-cell dependency for the generation of immunoglobulin subclasses targeting BTV NS2 and the structural protein, VP7. This study identifies a diverse repertoire of T-cell functions during BTV infection in sheep, particularly in inducing specific anti-viral immune responses and disease manifestation, and will support more effective vaccination strategies.

RWTC-MBTA Vaccine Induces Potent Adaptive Immune Responses Against Glioblastomas via Dynamic Activation of Dendritic Cells.

Despite strides in immunotherapy, glioblastoma multiforme (GBM) remains challenging due to low inherent immunogenicity and suppressive tumor microenvironment. Converting "cold" GBMs to "hot" is crucial for immune activation and improved outcomes. This study comprehensively characterized a therapeutic vaccination strategy for preclinical GBM models. The vaccine consists of Mannan-BAM-anchored irradiated whole tumor cells, Toll-like receptor ligands [lipoteichoic acid (LTA), polyinosinic-polycytidylic acid (Poly (I:C)), and resiquimod (R-848)], and anti-CD40 agonistic antibody (rWTC-MBTA). Intracranial GBM models (GL261, SB28 cells) are used to evaluate the vaccine efficacy. A substantial number of vaccinated mice exhibited complete regression of GBM tumors in a T-cell-dependent manner, with no significant toxicity. Long-term tumor-specific immune memory is confirmed upon tumor rechallenge. In the vaccine-draining lymph nodes of the SB28 model, rWTC-MBTA vaccination triggered a major rise in conventional dendritic cell type 1 (cDC1) 12h post-treatment, followed by an increase in conventional dendritic cell type 2 (cDC2), monocyte-derived dendritic cell (moDC), and plasmacytoid dendritic cell (pDC) on Day 5 and Day 13. Enhanced cytotoxicity of CD4+ and CD8+ T cells in vaccinated mice is verified in co-culture with tumor cells. Analyses of immunosuppressive signals (T-cell exhaustion, myeloid-derived suppressor cells (MDSC), M2 macrophages) in the GBM microenvironment suggest potential combinations with other immunotherapies for enhanced efficacy. In conclusion, the authors findings demonstrate that rWTC-MBTA induces potent and long-term adaptive immune responses against GBM.

Id2 epigenetically controls CD8+ T-cell exhaustion by disrupting the assembly of the Tcf3-LSD1 complex

CD8+ T-cell exhaustion is a state of dysfunction that promotes tumor progression and is marked by the generation of Slamf6+ progenitor exhausted (Texprog) and Tim-3+ terminally exhausted (Texterm) subpopulations. Inhibitor of DNA binding protein 2 (Id2) has been shown to play important roles in T-cell development and CD8+ T-cell immunity. However, the role of Id2 in CD8+ T-cell exhaustion is unclear. Here, we found that Id2 transcriptionally and epigenetically regulates the generation of Texprog cells and their conversion to Texterm cells. Genetic deletion of Id2 dampens CD8+ T-cell-mediated immune responses and the maintenance of stem-like CD8+ T-cell subpopulations, suppresses PD-1 blockade and increases tumor susceptibility. Mechanistically, through its HLH domain, Id2 binds and disrupts the assembly of the Tcf3-Tal1 transcriptional regulatory complex, and thus modulates chromatin accessibility at the Slamf6 promoter by preventing the interaction of Tcf3 with the histone lysine demethylase LSD1. Therefore, Id2 increases the abundance of the permissive H3K4me2 mark on the Tcf3-occupied E-boxes in the Slamf6 promoter, modulates chromatin accessibility at the Slamf6 promoter and epigenetically regulates the generation of Slamf6+ Texprog cells. An LSD1 inhibitor GSK2879552 can rescue the Id2 knockout phenotype in tumor-bearing mice. Inhibition of LSD1 increases the abundance of Slamf6+Tim-3− Texprog cells in tumors and the expression level of Tcf1 in Id2-deleted CD8+ T cells. This study demonstrates that Id2-mediated transcriptional and epigenetic modification drives hierarchical CD8+ T-cell exhaustion, and the mechanistic insights gained may have implications for therapeutic intervention with tumor immune evasion.

Construction of disulfidptosis-based immune response prediction model with artificial intelligence and validation of the pivotal grouping oncogene c-MET in regulating T cell exhaustion.

Given the lack of research on disulfidptosis, our study aimed to dissect its role in pan-cancer and explore the crosstalk between disulfidptosis and cancer immunity. Based on TCGA, ICGC, CGGA, GSE30219, GSE31210, GSE37745, GSE50081, GSE22138, GSE41613, univariate Cox regression, LASSO regression, and multivariate Cox regression were used to construct the rough gene signature based on disulfidptosis for each type of cancer. SsGSEA and Cibersort, followed by correlation analysis, were harnessed to explore the linkage between disulfidptosis and cancer immunity. Weighted correlation network analysis (WGCNA) and Machine learning were utilized to make a refined prognosis model for pan-cancer. In particular, a customized, enhanced prognosis model was made for glioma. The siRNA transfection, FACS, ELISA, etc., were employed to validate the function of c-MET. The expression comparison of the disulfidptosis-related genes (DRGs) between tumor and nontumor tissues implied a significant difference in most cancers. The correlation between disulfidptosis and immune cell infiltration, including T cell exhaustion (Tex), was evident, especially in glioma. The 7-gene signature was constructed as the rough model for the glioma prognosis. A pan-cancer suitable DSP clustering was made and validated to predict the prognosis. Furthermore, two DSP groups were defined by machine learning to predict the survival and immune therapy response in glioma, which was validated in CGGA. PD-L1 and other immune pathways were highly enriched in the core blue gene module from WGCNA. Among them, c-MET was validated as a tumor driver gene and JAK3-STAT3-PD-L1/PD1 regulator in glioma and T cells. Specifically, the down-regulation of c-MET decreased the proportion of PD1+ CD8+ T cells. To summarize, we dissected the roles of DRGs in the prognosis and their relationship with immunity in pan-cancer. A general prognosis model based on machine learning was constructed for pan-cancer and validated by external datasets with a consistent result. In particular, a survival-predicting model was made specifically for patients with glioma to predict its survival and immune response to ICIs. C-MET was screened and validated for its tumor driver gene and immune regulation function (inducing t-cell exhaustion) in glioma.

Anti-cathepsin D immunotherapy triggers both innate and adaptive anti-tumour immunity in breast cancer.

Triple-negative breast cancer (TNBC) has poorer outcomes than other breast cancers (BC), including HER2+ BC. Cathepsin D (CathD) is a poor prognosis marker overproduced by BC cells, hypersecreted in the tumour microenvironment with tumour-promoting activity. Here, we characterized the immunomodulatory activity of the anti-CathD antibody F1 and its improved Fab-aglycosylated version (F1M1) in immunocompetent mouse models of TNBC (C57BL/6 mice harbouring E0771 cell grafts) and HER2-amplified BC (BALB/c mice harbouring TUBO cell grafts). CathD expression was evaluated by western blotting and immunofluorescence, and antibody binding to CathD by ELISA. Antibody anti-tumour efficacy was investigated in mouse models. Immune cell recruitment and activation were assessed by immunohistochemistry, immunophenotyping, and RT-qPCR. F1 and F1M1 antibodies remodelled the tumour immune landscape. Both antibodies promoted innate antitumour immunity by preventing the recruitment of immunosuppressive M2-polarized tumour-associated macrophages (TAMs) and by activating natural killer cells in the tumour microenvironment of both models. This translated into a reduction of T-cell exhaustion markers in the tumour microenvironment that could be locally supported by enhanced activation of anti-tumour antigen-presenting cell (M1-polarized TAMs and cDC1 cells) functions. Both antibodies inhibited tumour growth in the highly-immunogenic E0771 model, but only marginally in the immune-excluded TUBO model, indicating that anti-CathD immunotherapy is more relevant for BC with a high immune cell infiltrate, as often observed in TNBC. Anti-CathD antibody-based therapy triggers the anti-tumour innate and adaptive immunity in preclinical models of BC and is a promising immunotherapy for immunogenic TNBC.