Search Results (327)

Various AML treatment regimens might trigger different immunological mechanisms against leukemic cells. The role of different immune cell subsets in the mediation of antileukemic processes is not clear. In this study, we longitudinally assessed (leukemia specific) immune subtype compositions in 17 AML patients before stem cell transplantation (SCT) at different timepoints in the course and in different stages of the disease using flow cytometry. Further we correlated immune cell compositions with patients’ response to induction therapy and the median survival (3.8 months in our cohort) of the patients. Finally, we compared immune cell profiles from patients before and after SCT. (1) Patients in CR (compared to dgn and PD) were characterized by higher frequencies of leukemia-derived DC (DCleu), (leukemia-specific—IFNg or TNFα producing or CD107a degranulating) anti-tumor relevant T cells (Tgd, Tβ7), central/effector memory cells (Tcm, Tem), alongside with lower frequencies of (leukemia-specific) regulatory T cells. (2) Patients with higher frequencies of (leukemia-specific) antitumor relevant T cells, (leukemia-specific) memory T cells and NK cells demonstrated a prolonged median survival time and/or responded better to induction (RTI) treatment (3) Comparing patients before and after SCT, only minimal differences were observed. However, patients in CR_preSCT exhibited higher frequencies of DC, Tcm, Tβ7 and leukemia-specific iNKT cells compared to patients in CR_postSCT. (1) Immune monitoring qualifies to quantify (leukemia-specific) immune cells in different stages and under different treatment strategies in the course of AML. (2) Higher frequencies of activating and antitumor relevant leukemia-specific immune cell subtypes found after ‘costimulatory’ (especially KitM induced) treatment’ and in CR. (3) In particular, DC/DCleu, (leukemia-specific) antitumor-relevant T (memory) and NK cells seem to dominate in CR and positively influence RTI and survival. (4) Monitoring of (leukemia-specific) immune cell subtypes contribute to quantify individual AML patients’ antileukemic potential in different stages and treatment groups and also could be used to predict patients’ survival. Full article

Background: Cerebral malaria (CM) is a severe and often fatal complication of Plasmodium falciparum infection that causes devastating brain injury largely through immune-mediated mechanisms. Pathogenic brain-infiltrating CD8⁺ T cells are key drivers of CM pathology, yet the intracellular signals enabling their harmful autoimmune-like activity remain poorly defined. Here, we identify protein kinase C θ (PKCθ), a central antigen receptor-signalling mediator, as a critical contributor to experimental cerebral malaria (ECM). Methods/Results: Using a PKCθ null allele mouse strain on a C57BL/6N background, we demonstrate that PKCθ deficiency significantly improves survival in Plasmodium berghei ANKA (PbA)-infected mice without altering parasite burdens in the blood or brain. Mechanistically, loss of PKCθ skews T cell differentiation towards central memory (Tcm) rather than effector memory (Tem) phenotypes, thereby reducing effector differentiation and sequestration of CD8⁺ T cells in the cerebral microvasculature. This prevents extensive neurovascular damage, preserves neural tissue integrity, and alleviates neurological signs and symptoms. Our findings provide genetic evidence that PKCθ drives CD8⁺ T cell-mediated brain injury in ECM. Conclusions: These results underscore the potential for repurposing clinically PKCθ inhibitors as host-targeted interventions to protect against cerebral injury and improve outcomes in patients with CM. Full article

Peritoneal carcinomatosis (PC) and malignant pleural effusions (MPE) are two common complications of cancers metastatic to the respective body cavities. A PC diagnosis indicates metastasis to the tissue lining the abdominal cavity and is most common in patients with gastrointestinal and gynecological cancers. It is often accompanied by ascites, an accumulation of serous fluid in the abdomen. MPE presents as the accumulation of fluid in the space between the lungs and chest wall. It is a common terminal event in patients diagnosed with breast cancer, lung cancer, lymphoma, and mesothelial cancers, and less commonly, in a wide variety of other epithelial cancers. Due to the aggressive nature of cavitary tumors, the outcome of current treatments for both PC and MPE remains bleak. Although PC and MPE are characteristically affected by different sets of primary tumors (lung/breast/mesothelioma for MPE and gynecologic/gastrointestinal for PC), their environments share common cytokines and cellular components. Owing to the unique cytokine and chemokine content, this environment promotes aggressive tumor behavior and paradoxically both recruits and suppresses central memory and effector memory T cells. The cellular and secretomic complexity of the cavitary tumor environment renders most currently available therapeutics ineffective but also invites approaches that leverage the robust T-cell infiltrate while addressing the causes of local suppression of anti-tumor immunity. Interactions between the heterogeneous components of the tumor environment are an area of active research. We highlight the roles of the immune cell infiltrate, stromal cells, and tumor cells, and the soluble products that they secrete into their environment. A more comprehensive understanding of the cavitary tumor environment can be expected to lead to better immunotherapeutic approaches to these devastating conditions. Full article

Background: Venetoclax-based combination therapies have provided treatment options for patients with acute myeloid leukemia (AML) who are unfit for intensive chemotherapy. However, venetoclax resistance is common, and for such patients, the prognosis is dismal, and treatment approaches with different mechanisms of action are urgently needed. γδ T cells are a promising candidate owing to their good safety profile and cytotoxic effects in various types of cancers but are mostly unstudied in AML. Methods: Here we used flow cytometry to profile the subtype and memory phenotype of peripheral blood γδ T cells in AML patients and investigate the feasibility of using donor-derived Vγ9Vδ2 T cells to treat AML as both a single agent and in combination with venetoclax. Additionally, we used bioluminescence imaging to examine the effect of donor-derived Vγ9Vδ2 T cells on AML xenograft models alone and in combination with venetoclax. Results: We observed that Vδ2 T cells were less abundant and the TEMRA (terminally differentiated effector memory) phenotype was more prevalent as compared with that of healthy donors, suggesting that replenishing patients with Vδ2 T cells may be an effective treatment option. We found that donor-derived Vγ9Vδ2 T cells that Vγ9Vδ2 T cells efficiently induced apoptosis in AML cells from eight cell lines and three primary cultures in an effector-to-target cell ratio-dependent manner. Moreover, Vγ9Vδ2 T cells showed potent cytotoxicity against the venetoclax-resistant OCI-AML3 cell line and remained potent in the presence of venetoclax. Treatment with Vγ9Vδ2 T cells significantly extended survival in two AML xenograft models established with the aggressive Molm-13 and the venetoclax-resistant OCI-AML3 cell lines. An additive effect of venetoclax and Vγ9Vδ2 T cells was observed in the latter model. Conclusions: Overall, these findings suggest Vγ9Vδ2 T cells as a promising “off-the-shelf” immunotherapy approach for AML patients, especially for patients with venetoclax-resistant disease. Full article

Objective: This study aims to explore the mechanism of regulated cell death-related genes in the development of endometrial carcinoma. Methods: Endometrial carcinoma-related datasets were yielded via the Cancer Genome Atlas and Gene Expression Omnibus databases, and regulated cell death-related genes were extracted from the literature. Differential expression analysis, weighted gene co-expression network analysis, and protein interaction analysis were performed to identify critical regulated cell death-related genes. Gene set enrichment analysis was used to identify the functional pathways involved in these critical genes. Afterward, the best clustering approach for tumor samples was yielded via consensus clustering analysis, and nomogram prediction models were built. Shiny Methylation Analysis Resource Tool was used to compare the expression levels of CpG methylation probes for critical genes between tumor and normal samples. Spearman correlation analysis was conducted to investigate the relationship between critical genes and various immune features. Eventually, immuno-infiltrative analysis was implemented, and potential therapeutic agents were screened targeting critical genes. The data were analyzed and visualized by R software using different packages. In addition, the expressions of critical genes were validated by quantitative real-time polymerase chain reaction and immunochemistry. Results: Four critical genes, namely GBP2, SLC11A1, P2RX7, and HCLS1, were identified, and they were involved in various functional pathways such as leukocyte-mediated cytotoxicity. There were substantial differences in CpG methylation in GBP2, SLC11A1, and HCLS1 between tumor and normal samples. As for immune features, all critical genes were positively connected with immunosuppressive factors such as TIGIT and most HLA molecules in endometrial carcinoma. The critical genes high/low expression groups of tumor samples showed different immune responses towards PD-1, PD-L1, and CTLA-4 immunotherapy. The infiltration of 24 immune cells, such as effector memory CD8⁺ T cells, was notably different between tumor and normal samples. Based on sensitivity analysis of chemotherapeutic agents, we found the highest positive correlation between SLC11A1 and “BI.2536” and the strongest passive correlation of HCLS1 and GBP2 with “Ribociclib”, as well as P2RX7 with “BMS.754807”. Quantitative real-time polymerase chain reaction suggested that the expression trends of GBP2, P2RX7, and HCLS1 were consistent with the results of bioinformatic analysis. Conclusions: Regulated cell death-related genes (GBP2, SLC11A1, P2RX7, and HCLS1) may play a role in endometrial carcinoma development, which can provide new ideas for the treatment and prognosis prediction of this disease. Full article

Recently, senescent T cells in the peripheral blood have been detected using senescence-associated β-galactosidase (SA-βGal) activity and have been used as an endpoint in clinical trials. However, the epidemiological association between the abundance of SA-βGal-stained senescent CD8+ T cells and chronological age has not been fully elucidated. To examine the correlation between the proportion of SA-βGal^high CD8+ T cells and age, we analyzed previously collected clinical trial data. We conducted a cross-sectional analysis of 632 Japanese adults aged 40–59 years who participated in the screening phase of a clinical trial. To characterize senescent CD8+ T cells, we measured the proportion of SA-βGal^high in total CD8+ T cells and each subset—naïve, central memory (TCM), effector memory (TEM), and terminally differentiated effector memory (TEMRA). We then calculated the correlation coefficients between the proportion of SA-βGal^high CD8+ T cells and age. The proportion of SA-βGal^high cells in total CD8+ T cells, naïve, TCM, TEM, and TEMRA CD8+ T cells increased significantly with age. In Japanese adults, the proportion of SA-βGal^high in CD8+ T cells may serve as a useful biomarker of immune senescence. Full article

Tissue-resident memory T (TRM) cells have emerged as critical sentinels in the control of cancer metastasis, yet their precise roles across different tumor types and tissues remain underappreciated. Here, we review current insights into the mechanisms governing TRM cell seeding and retention in pre-metastatic niches, their effector functions in eliminating disseminated tumor cells, and their dynamic crosstalk with local stromal and myeloid populations. Here, we highlight evidence for organ-specific variability in TRM cell-mediated immunity, discuss strategies for therapeutically harnessing these cells—ranging from vaccination and checkpoint modulation to chemokine axis manipulation—and explore their promise as prognostic biomarkers. Finally, we outline key knowledge gaps and future directions aimed at translating TRM cell biology into targeted interventions to prevent and treat metastatic disease. Full article

Background/Objectives: Effective prophylaxis for Mycobacterium tuberculosis (Mtb) requires greater understanding of immune correlates of protection. With renewed interest in BCG as an Mtb vaccine, particularly via the intravenous (IV) route, our objective was to characterize both innate and adaptive immune correlates of vaccine-induced pulmonary immunity as potential biomarkers for protective efficacy in a murine model of Mtb infection. Methods: Mice were given BCG via different routes and some boosted with recombinant virus constructs encoding Mtb Ag85B. Responding innate lymphoid cell (ILC) populations, T cells and B cells were analyzed by fluorescence activated cell sorting (FACS) for surface markers and by intracellular cytokine staining or antibody ELISPOT. Some immunized mice were challenged with aerosolized Mtb and monitored for bacterial growth in the lungs and spleen. Results: BCG given IV, but not intranasally or subcutaneously, resulted in marked increases in IFNγ expression at 72 h by pulmonary CD49⁺ NK cells, CD69⁺ ILC1, and two ILC3 populations, NCR-ILC3 and LTi cells, the latter also producing IL-22. Pulmonary ILC2 populations in these mice had significantly increased IL-13 expression at 24 h compared to the other routes. Interestingly, high levels of NK cells and ILC1 expressing IFNγ and/or TNFα were sustained at 8 wk, with sustained expression of IL-17A by pulmonary NCR-ILC3 and pronounced tissue-resident and effector memory CD4⁺ and CD8⁺ T cell responses. Intranasal boosting with Ad-Ag85B enhanced these T cell responses and generated Mtb-specific pulmonary IgA and IgG B cells, correlating with significantly reduced bacterial loads following Mtb challenge. Conclusions: BCG given IV primed for both early and persistent pulmonary ILC1/ILC3 responses of a predominantly Th1/Th17-type profile along with local Mtb-specific memory T cell and B cell populations, correlating with enhanced protective efficacy. These are worthy of further study as compartmentalized biomarkers for effective vaccine-induced local immunity against Mtb. Full article

Recent multiomics advancements have improved our understanding of immune dysregulation in dilated cardiomyopathy (DCM). However, specific immune cell subsets and their regulatory genes are still ambiguous. This study aimed to explore immune cell imbalances and regulatory genes in DCM, discover diagnostic biomarkers, and identify potential therapeutic targets. Immune cell infiltration in DCM patients was quantified via deconvolution algorithms and single-cell RNA sequencing. Flow cytometry validation in 40 DCM patients and 40 healthy controls confirmed a notable increase in CD4⁺ effector memory T cells (CD4⁺ TEM cells) in DCM patients. Differential expression analysis of the GSE101585 dataset revealed 1783 genes. Weighted gene coexpression network analysis (WGCNA) identified a core immune-regulatory gene set, and protein–protein interaction (PPI) analysis highlighted 36 hub genes. Machine learning cross-validation identified four diagnostic biomarkers (LRRTM4, PTPN22, FAM175B, and PROM2) whose transcriptional changes had been validated by qPCR. Among these genes, PTPN22 was strongly correlated with CD4⁺ TEM cell abundance. Additionally, DSigDB analysis predicted 87 potential therapeutic drugs, with PTPN22 being the target of the most drugs. This study reveals a CD4⁺ T cell subset-centered immunoregulatory network in DCM, identifying novel diagnostic biomarkers and druggable targets to guide precision immunomodulatory strategies for DCM management. Full article

Hepatic viruses, such as hepatitis B and C (HBV and HCV), evade immune defenses and drive liver cirrhosis and cancer. They remain a major global health burden, requiring deeper research into immune responses; specifically, adaptive immunity. This study aims to analyze T cellular subsets in chronic HBV and HCV infection and investigate their potential role in the immunopathogenesis of these conditions. Methods: For our study, we collected 123 blood samples taken from patients infected with HCV (n = 36) and HBV (n = 34) and healthy volunteers (n = 53). With the use of flow cytometry, we assessed levels of CD4+ and CD8+ minor T cell subpopulations (naïve, central, and effector memory cells (CM and EM), terminally differentiated EM (TEMRA), Th1, Th2, Th17, Tfh, Tc1, Tc2, Tc17, Tc17.1). Results: Despite similar total CD4+ T cell frequencies across chronic HCV, HBV, and healthy groups, patients with hepatitis showed elevated TEMRA, EM, and CM subsets alongside depleted naïve Th cells and specific CM subpopulations compared to controls. Patients with chronic HCV and HBV showed elevated CD8+ T cell frequencies versus controls, with disease-specific shifts: reduced EM CTLs but increased TEMRA CTLs, Tc1/Tc17.1 depletion (notably Tc17.1 in HCV), and higher Tc2 levels. Conclusions: Viral clearance in HBV and HCV requires a delicate balance between immunity and viral activity. Despite similar T cell frequencies (CD3+/CD4+/CD8+), minor subsets revealed distinct patterns differentiating HCV, HBV, and healthy controls. Full article

Background/Objectives: Glucan particles (GPs), derived from Saccharomyces cerevisiae yeast, possess unique biomedical properties. Nevertheless, it is imperative that a comprehensive risk assessment is conducted during pre-clinical development. GPs are primarily constituted of a naturally occurring polymer known as β-glucan. This study characterized GPs, focusing on physicochemical attributes, biocompatibility, and immunomodulatory potential. Methods: GPs were characterized for size, morphology, surface charge, and protein encapsulation efficiency using dynamic light scattering (DLS), electron microscopy, and encapsulation assays. Biocompatibility was assessed through cytotoxicity assays (MTT), hemolysis tests, and measurement of reactive oxygen (ROS) and nitric oxide (NO) production in immune cells. Immunomodulatory potential was evaluated by cytokine and chemokine secretion analysis in peripheral blood mononuclear cells (PBMCs) and monocyte-derived dendritic cells (moDCs) and through in vivo immunization studies in a murine model, focusing on cellular immune responses. Results: GPs demonstrated stable physicochemical properties and efficient protein encapsulation, highlighting their suitability as vaccine delivery systems. They exhibited biocompatibility by not inducing cytotoxicity, hemolysis, or excessive ROS and NO production. In PBMCs, GPs stimulated cytokine secretion, suggesting their adjuvant potential. GPs were efficiently internalized by monocytes and led to specific chemokine secretion in stimulated moDCs. In a murine model, GPs induced distinctive cellular immune responses, including TNF-α and IFN-γ production and effector memory T cell activation. Conclusions: These findings emphasize GPs’ biocompatibility and immunomodulatory effects, highlighting their potential in immunotherapy and vaccine development, particularly for targeting infectious agents like hepatitis B virus. Full article

Despite targeting mainly the respiratory tract, SARS-CoV-2 disrupts T cell homeostasis in ways that may explain both acute lethality and long-term immunological consequences. In this study, we aimed to evaluate the T-cell-mediated chain of immunity and formation of TCR via TREC assessment in COVID-19 and long COVID (LC). For this study, we collected 231 blood samples taken from patients with acute COVID-19 (n = 71), convalescents (n = 51), people diagnosed with LC (n = 63), and healthy volunteers (n = 46). With flow cytometry, we assessed levels of CD4+ and CD8+ minor T cell subpopulations (i.e., naïve, central and effector memory cells (CM and EM), Th1, Th2, Th17, Tfh, Tc1, Tc2, Tc17, Tc17.1, and subpopulations of effector cells (pE1, pE2, effector cells)). Additionally, we measured TREC levels. We found distinct changes in immune cell distribution—whilst distribution of major subpopulations of T cells was similar between cohorts, we noted that COVID-19 was associated with a decrease in naïve Th and CTLs, an increase in Th2/Tc2 lymphocyte polarization, an increase in CM cells, and a decrease in effector memory cells 1,3, and TEMRA cells. LC was associated with naïve CTL increase, polarization towards Th2 population, and a decrease in Tc1, Tc2, Em2, 3, 4 cells. We also noted TREC correlating with naïve cells subpopulations. Our findings suggest ongoing immune dysregulation, possibly driven by persistent antigen exposure or tissue migration of effector cells. The positive correlation between TREC levels and naïve T cells in LC patients points to residual thymic activity. The observed Th2/Th17 bias supports the hypothesis that LC involves autoimmune mechanisms, potentially driven by molecular mimicry or loss of immune tolerance. Full article

CD8+ T lymphocytes (CTLs) act as serial killers of infected or malignant cells by releasing large amounts of interferon-gamma (IFNγ) and granzymes. Although IFNγ is a pleiotropic cytokine with diverse immunomodulatory functions, its precise spatiotemporal regulation and role in CTL-mediated cytotoxicity remain incompletely understood. Using wild-type and granzyme B-mTFP knock-in mice, we employed a combination of in vitro approaches, including T cell isolation and culture, plate-bound anti-CD3e stimulation, degranulation assays, flow cytometry, immunofluorescence, and structured illumination microscopy, to investigate IFNγ dynamics in CTLs. IFNγ expression in CTLs was rapid, transient, and strictly dependent on T cell receptor (TCR) activation. We identified two functionally distinct IFNγ-producing subsets: IFNγ^high (IFNγ^hi) and IFNγ^low (IFNγ^lo) CTLs. IFNγ^hi CTLs exhibited an effector/effector memory phenotype, significantly elevated CD107a surface expression (a marker of lytic granule exocytosis), and higher colocalization with cis-Golgi and granzyme B compared to IFNγ^lo CTLs. Furthermore, CRTAM, an early activation marker, correlated with IFNγ expression in naive CTLs. Our findings establish a link between elevated IFNγ production and enhanced CTL cytotoxicity, implicating CRTAM as a potential regulator of early CTL activation and IFNγ induction. These insights provide a foundation for optimizing T cell-based immunotherapies against infections and cancers. Full article

Mycoplasma pneumoniae, a cell wall-deficient pathogen, primarily affects children and adolescents, causing Mycoplasma pneumoniae pneumonia (MPP). Following the relaxation of non-pharmaceutical interventions (NPIs) post COVID-19, there has been a global increase in MPP cases and macrolide-resistant strains. Vaccination against M. pneumoniae is being explored as a promising approach to reduce infections, limit antibiotic misuse, and prevent the emergence of drug-resistant variants. We developed an mRNA vaccine, mRNA-SP+P1, incorporating a eukaryotic signal peptide (tissue-type plasminogen activator signal peptide) fused to the C-terminal region of the P1 protein. Targeting amino acids 1288 to 1518 of the P1 protein, the vaccine was administered intramuscularly to BALB/c mice in a three-dose regimen. To evaluate immunogenicity, we quantified anti-P1 IgG antibody titers using enzyme-linked immunosorbent assays (ELISAs) and assessed cellular immune responses by analyzing effector memory T cell populations using flow cytometry. We also tested the functional activity of vaccine-induced sera for their ability to inhibit adhesion of the ATCC M129 strain to KMB17 cells. The vaccine’s protective efficacy was assessed against the ATCC M129 strain and its cross-protection against the ST3-resistant strain. Transcriptomic analysis was conducted to investigate gene expression changes in peripheral blood, aiming to uncover mechanisms of immune modulation. The mRNA-SP+P1 vaccine induces P1 protein-specific IgG antibodies and an effector memory T-cell response in BALB/c mice. Adhesion inhibition assays demonstrated that serum from vaccinated mice attenuatesthe adhesion ability of ATCC M129 to KMB17 cells. Furthermore, three doses of the vaccine confer significant and long-lasting, though partial, protection against the ATCC M129 strain and partial cross-protection against the ST3 drug-resistant strain. Transcriptome analysis revealed significant gene expression changes in peripheral blood, confirming the vaccine’s capacity to elicit an immune response from the molecular level. Our results indicate that the mRNA-SP+P1 vaccine appears to be an effective vaccine candidate against the prevalence of Mycoplasma pneumoniae. Full article

Background/Objectives: Immune checkpoint inhibitors (ICIs) have revolutionized advanced melanoma treatment, yet many patients fail to achieve sustained clinical benefit. Several biomarkers, including tumor microenvironment (TME) signature, PD-1/PD-L1 expression, and IFN-γ signaling, have been proposed. However, robust predictive markers remain elusive. This study aimed to identify molecular markers of response by analyzing tumor and peripheral immune signatures. Methods: This study analyzed 21 advanced melanoma patients treated with ICIs. Formalin-fixed, paraffin-embedded tumors underwent RNA-sequencing targeting 1392 immuno-oncology probes. Genes significantly associated with progression-free survival (PFS) by log-rank test underwent hierarchical clustering analysis (HCA). Differential expression and xCell analyses were then performed on the resulting clusters. Cox multivariate analysis was applied to identify independent PFS predictors. Pre-treatment peripheral blood mononuclear cells were analyzed by mass cytometry, followed by FlowSOM and UMAP clustering. Results: Fifty-five genes significantly associated with PFS identified two molecular clusters via HCA. Cluster A demonstrated prolonged PFS (59.4 vs. 2.4 months, p = 0.0004), while Cluster B was characterized by downregulated IFN-γ signaling, antigen presentation pathways, and reduced immune score. Multivariate Cox analysis confirmed molecular cluster as an independent PFS predictor (p < 0.001). Mass cytometry revealed higher frequencies of circulating PD-1+ CD4+ effector memory (EM) T subpopulations among responders. Conclusions: This study highlights the potential role of molecular and immune profiling in predicting ICI response in advanced melanoma. The identification of distinct molecular clusters underscores significant TME heterogeneity, with immune-cold tumor clusters associated with poorer outcomes. Furthermore, circulating PD-1+ T subpopulations emerged as potential markers of ICI response, suggesting their value in improving patient stratification. Full article