Comprehensive snapshots of natural killer cells functions, signaling, molecular mechanisms and clinical utilization

Integrated bioinformatics and functional studies identify CDK9 as a potential prognostic biomarker and therapeutic target in AML

BACKGROUND

Acute myeloid leukemia (AML) is a highly heterogeneous disease characterized by complex genetic and molecular features that contribute to poor prognosis and low cure rates. Therefore, identifying novel therapeutic targets is crucial for improving treatment efficacy and patient survival. This study investigated the potential role of cyclin-dependent kinase 9 (CDK9), a known regulator of gene expression, in AML pathogenesis and prognosis.

METHODS

This study employed multiple bioinformatics approaches, including analysis of CDK9 expression across various cancers using the Tumor Immune Estimation Resource (TIMER2.0) database and further investigation of its expression and prognostic significance in AML using data from the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. Survival analysis and Cox regression analysis were used to assess the association between CDK9 expression and patient prognosis. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) were performed to elucidate the pathways and biological processes influenced by CDK9. Furthermore, the relationship between CDK9 expression and tumor immune infiltration was evaluated, and a protein-protein interaction (PPI) network was constructed. In vitro experiments, including Western blotting, CCK-8 assays, and flow cytometry, were conducted to validate the bioinformatics findings.

RESULTS

Bioinformatics analysis revealed significantly elevated CDK9 expression in AML samples, which correlated with poor patient prognosis. Functional enrichment analysis indicated that CDK9 is involved in key pathways related to cell proliferation, differentiation, and the tumor microenvironment. Moreover, the study observed a strong correlation between CDK9 expression and altered immune cell infiltration, suggesting a potential role in immune evasion. In vitro experiments confirmed that CDK9 overexpression promoted AML cell proliferation and inhibited apoptosis. Additionally, CDK9 showed a strong correlation with epithelial-mesenchymal transition (EMT)-related proteins, suggesting a potential role in AML progression and the EMT process.

CONCLUSIONS

This study demonstrates that CDK9 is a potential prognostic biomarker and therapeutic target in AML. Its involvement in multiple key pathways during AML development and its influence on the tumor immune microenvironment support further exploration of CDK9-targeted therapies to improve AML treatment outcomes.

T cell aging and exhaustion: Mechanisms and clinical implications

T cell senescence and exhaustion represent critical aspects of adaptive immune system dysfunction, with profound implications for health and the development of disease prevention and therapeutic strategies. These processes, though distinct, are interconnected at the molecular level, leading to impaired effector functions and reduced proliferative capacity of T cells. Such impairments increase susceptibility to diseases and diminish the efficacy of vaccines and treatments. Importantly, T cell senescence and exhaustion can dynamically influence each other, particularly in the context of chronic diseases. A deeper understanding of the molecular mechanisms underlying T cell senescence and exhaustion, as well as their interplay, is essential for elucidating the pathogenesis of related diseases and restoring dysfunctional immune responses. This knowledge will pave the way for the development of targeted therapeutic interventions and strategies to enhance immune competence. This review aims to summarize the characteristics, mechanisms, and disease associations of T cell senescence and exhaustion, while also delineating the distinctions and intersections between these two states to enhance our comprehension.

NK cellular derived nanovesicles in tumor immunity

Natural Killer (NK) cells are a vital element of the innate immune system, and NK cell-based therapies have demonstrated efficacy against various malignancies. However, targeting solid tumors has been challenging due to the low infiltration of NK cells into tumors and the effective evasion strategies employed by tumors. Recent studies have shown that NK cell derived nanovesicles (NK-NV) can not only replicate the functions of NK cells but also offer more advantages in clinical applications. They are capable of transporting various cellular components such as proteins, nucleic acids, and lipids across distances, thereby facilitating intercellular communication among various cells within the tumor microenvironment (TME). With the progress in nanomedical technology, these vesicles can be engineered to carry a range of functional elements and therapeutic agents to enhance their antitumoral capabilities. In this review, we summarize the current available literature on NK-NVs, discuss their potential biological functions and the role of non-coding RNAs (ncRNAs), and explore their application in the treatment of solid tumors.

Antiretroviral Therapy at Conception Leads to Lower Peripheral CD49a+ NK Cells and Higher SERPINB2

Problem: Antiretroviral therapy (ART) during pregnancy is essential to prevent vertical HIV transmission and preserve the health of the mother and child. However, ART in pregnancy has been associated with adverse birth outcomes linked to poor placental development. Immune dysregulation of placental development is an important factor in the development of preeclampsia (PE), a common hypertension disorder of pregnancy. Some studies found an association between ART use at conception or during the first trimester and PE. However, little is known regarding the impact of timing of ART initiation on the immune environment in pregnancy. Methods: To investigate the immune environment in pregnant persons with HIV (PPWH) on ART at conception (N = 40) compared to PPWH that started ART in the second trimester (N = 40) we analyzed specimens from the International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) Perinatal Core Protocol, P1025, concluded in 2013. Results: No difference was found in soluble factors in circulation including PlGF and sFLt-1, associated with PE. However, upon analysis of PBMC by high dimension flow cytometry, we detected a lower frequency of circulating CD49a+ NK cells, associated with uterine tissue and pregnancy, in PPWH on ART at conception compared with PPWH who started ART in the second trimester. Moreover, PBMC from PPWH on ART at conception expressed higher levels of SERPINB2 in transcriptomics analyses. Conclusions: Our findings shed new insights into the potential impact of ART at conception and suggest the persistence of a dysregulated inflammatory environment compared to PPWH starting ART after the conclusion of placental development.

Tumor-Associated Macrophages: Polarization, Immunoregulation, and Immunotherapy

Tumor-associated macrophages' (TAMs) origin, polarization, and dynamic interaction in the tumor microenvironment (TME) influence cancer development. They are essential for homeostasis, monitoring, and immune protection. Cells from bone marrow or embryonic progenitors dynamically polarize into pro- or anti-tumor M2 or M1 phenotypes based on cytokines and metabolic signals. Recent advances in TAM heterogeneity, polarization, characterization, immunological responses, and therapy are described here. The manuscript details TAM functions and their role in resistance to PD-1/PD-L1 blockade. Similarly, TAM-targeted approaches, such as CSF-1R inhibition or PI3Kγ-driven reprogramming, are discussed to address anti-tumor immunity suppression. Furthermore, innovative biomarkers and combination therapy may enhance TAM-centric cancer therapies. It also stresses the relevance of this distinct immune cell in human health and disease, which could impact future research and therapies.

Targeting ATF5, CEBPB, and CEBPD with Cell-Penetrating Dpep Sensitizes Tumor Cells to NK-92MI Cell Cytotoxicity

Natural killer (NK) cells are an important innate defense against malignancies, and exogenous sources of NK cells have been developed as anti-cancer agents. Nevertheless, the apparent limitations of NK cells in clearing cancers have suggested that their efficacy might be augmented by combination with other treatments. We have developed cell-penetrating peptides that target the transcription factors ATF5, CEBPB, and CEBPD and that promote apoptotic cancer cell death both in vitro and in vivo without apparent toxicity to non-transformed cells. We report here that one such peptide, Dpep, significantly sensitizes a variety of tumor cell types to the cytotoxic activity of the NK cell line, NK-92MI. Such sensitization requires pre-exposure of tumor cells to Dpep and does not appear due to effects of Dpep on NK cells themselves. Our findings suggest that Dpep acts in this context to lower the apoptotic threshold of tumor cells to NK cell toxicity. Additionally, while Dpep pre-treatment does not prevent tumor cells from causing NK cell "inactivation", it sensitizes cancer cells to repeated rounds of exposure to fresh NK cells. These findings thus indicate that Dpep pre-treatment is an effective strategy to sensitize cancer cells to the cytotoxic actions of NK cells.

Addressing graft-versus-host disease in allogeneic cell-based immunotherapy for cancer

Allogeneic cell-based immunotherapies, particularly CAR-T cell therapy, represent a significant advancement in cancer treatment, offering scalable and consistent alternatives to autologous therapies. However, their widespread use is limited by the risk of graft-versus-host disease (GvHD). This review provides a comprehensive overview of GvHD in the context of allogeneic cell-based cancer immunotherapy and evaluates current strategies to mitigate its effects. Key strategies include genetic engineering approaches such as T cell receptor (TCR) knockout (KO) and T cell receptor alpha constant (TRAC) CAR knock-in. Alternative immune cell types like natural killer (NK) cells and natural killer T (NKT) cells offer potential solutions due to their lower alloreactivity. Additionally, stem cell technology, utilizing induced pluripotent stem cells (iPSCs), enables standardized and scalable production of engineered CAR-T cells. Clinical trials evaluating these strategies, such as UCART19 and CTX110, demonstrate promising results in preventing GvHD while maintaining anti-tumor efficacy. The review also addresses manufacturing considerations for allogeneic cell products and the challenges in translating preclinical findings into clinical success. By addressing these challenges, allogeneic cell-based immunotherapy continues to advance, paving the way for more accessible, scalable, and effective cancer treatments.

Reprogramming the breast tumor immune microenvironment: cold-to-hot transition for enhanced immunotherapy

This review discusses reprogramming the breast tumor immune microenvironment from an immunosuppressive cold state to an immunologically active hot state. A complex interplay is revealed, in which the accumulation of metabolic byproducts-such as lactate, reactive oxygen species (ROS), and ammonia-is shown to impair T-cell function and promote tumor immune escape. It is demonstrated that the tumor microenvironment (TME) is dominated by immunosuppressive cytokines, including interleukin-10 (IL-10), transforming growth factorβ (TGFβ), and IL-35. Notably, IL-35 is produced by regulatory T cells and breast cancer cells. The conversion of conventional T cells into IL-35-producing induced regulatory T cells, along with the inhibition of pro-inflammatory cytokine secretion, contributes to the suppression of anti-tumor immunity. It is further demonstrated that key immune checkpoint molecules-such as PD-1, PDL1, CTLA-4, TIM-3, LAG-3, and TIGIT-are upregulated within the TME, leading to Tcell exhaustion and diminished immune responses. The blockade of these checkpoints is shown to restore T-cell functionality and is proposed as a strategy to convert cold tumors into hot ones with robust effector cell infiltration. The therapeutic potential of chimeric antigen receptor (CAR)T cell therapy is also explored, and targeting specific tumor-associated antigens, such as glycoproteins and receptor tyrosine kinases, is highlighted. It is suggested that CART cell efficacy can be enhanced by combining these cells with immune checkpoint inhibitors and other immunomodulatory agents, thereby overcoming the barriers imposed by the immunosuppressive TME. Moreover, the role of the microbiome in regulating estrogen metabolism and systemic inflammation is reviewed. Alterations in the gut microbiota are shown to affect the TME, and microbiome-based interventions are proposed as an additional means to facilitate the cold-to-hot transition. It is concluded that by targeting the metabolic and immunological pathways that underpin immune suppression-through combination strategies involving checkpoint blockade, CART cell therapies, and microbiome modulation-the conversion of the breast TME from cold to hot can be achieved. This reprogramming is anticipated to enhance immune cell infiltration and function, thereby improving the overall efficacy of immunotherapies and leading to better clinical outcomes for breast cancer patients.

Global research trends and focus on immunotherapy for endometrial cancer: a comprehensive bibliometric insight and visualization analysis (2012-2024)

Background

This study conducted a novel systematic bibliometric and visualization analysis of global literature on immunotherapy for endometrial cancer (EC) to explore dynamic trends, research hotspots, and emerging topics, providing valuable references for future research.

Methods

Articles and reviews on EC immunotherapy published between 2012 and August 2024 were retrieved from the Web of Science Core Collection (WoSCC). Bibliometric tools, CiteSpace and VOSviewer, were used to analyze clustering patterns and research dynamics.

Results

A total of 861 articles were contributed by 5,331 authors from 1,392 institutions across 58 countries or regions, involving 1,823 keywords. China demonstrated outstanding performance in this field, contributing over 40% of the total publications and ranking first in publication volume. However, the total citation counts for publications from China lags that of the United States, highlighting the latter's leading position and areas for further improvement in China's research efforts. The University of Texas Medical Anderson Cancer Center and Nanjing Medical University were the two institutions with the highest number of publications. In terms of authorship, research teams led by Bosse, Tjalling, and Creutzberg, Carien L made significant contributions to advancing the field. Among individual publications, the work by Talhouk et al. achieved the highest average annual citation count of 70.88, demonstrating its profound impact. In terms of journals, Gynecologic Oncology emerged as a pivotal academic platform, publishing numerous articles and achieving the highest co-citation frequency. Additionally, Frontiers in Oncology, Frontiers in Immunology, and Frontiers in Genetics have become some of the most active and rapidly developing journals in recent years. Research hotspots are concentrated on themes such as the "Tumor Immune Microenvironment", "Immune Checkpoint Inhibitors", and "Targeted Therapy". Recent trends and frontier research focus on the combined application of immune checkpoint inhibitors with other therapies, research on the application of nanotechnology in immunotherapy, and the integration of artificial intelligence to enhance precision medicine. Additionally, efforts are increasingly directed toward advancing various immunotherapy strategies from basic research to clinical applications.

Conclusions

This comprehensive analysis reveals rapid advancements and significant potential in EC immunotherapy. Strengthening international collaboration and addressing barriers in the translation of research to clinical practice will drive further progress in this promising field.

The Role of Inflammation in Cancer: Mechanisms of Tumor Initiation, Progression, and Metastasis

Inflammation is an essential component of the immune response that protects the host against pathogens and facilitates tissue repair. Chronic inflammation is a critical factor in cancer development and progression. It affects every stage of tumor development, from initiation and promotion to invasion and metastasis. Tumors often create an inflammatory microenvironment that induces angiogenesis, immune suppression, and malignant growth. Immune cells within the tumor microenvironment interact actively with cancer cells, which drives progression through complex molecular mechanisms. Chronic inflammation is triggered by factors such as infections, obesity, and environmental toxins and is strongly linked to increased cancer risk. However, acute inflammatory responses can sometimes boost antitumor immunity; thus, inflammation presents both challenges and opportunities for therapeutic intervention. This review examines how inflammation contributes to tumor biology, emphasizing its dual role as a critical factor in tumorigenesis and as a potential therapeutic target.

Neoleukin-2/15-armored CAR-NK cells sustain superior therapeutic efficacy in solid tumors via c-Myc/NRF1 activation

Adoptive transfer of chimeric antigen receptor (CAR)-modified natural killer (NK) cells represents a transformative approach that has significantly advanced clinical outcomes in patients with malignant hematological conditions. However, the efficacy of CAR-NK cells in treating solid tumors is limited by their exhaustion, impaired infiltration and poor persistence in the immunosuppressive tumor microenvironment (TME). As NK cell functional states are associated with IL-2 cascade, we engineered mesothelin-specific CAR-NK cells that secrete neoleukin-2/15 (Neo-2/15), an IL-2Rβγ agonist, to resist immunosuppressive polarization within TME. The adoptively transferred Neo-2/15-armored CAR-NK cells exhibited enhanced cytotoxicity, less exhaustion and longer persistence within TME, thereby having superior antitumor activity against pancreatic cancer and ovarian cancer. Mechanistically, Neo-2/15 provided sustained and enhanced downstream IL-2 receptor signaling, which promotes the expression of c-Myc and nuclear respiratory factor 1 (NRF1) in CAR-NK cells. This upregulation was crucial for maintaining mitochondrial adaptability and metabolic resilience, ultimately leading to increased cytotoxicity and pronounced persistence of CAR-NK cells within the TME. The resistance against TME immunosuppressive polarization necessitated the upregulation of NRF1, which is essential to the augmentative effects elicited by Neo-2/15. Overexpression of NRF1 significantly bolsters the antitumor efficacy of CAR-NK cells both in vitro and in vivo, with increased ATP production. Collectively, Neo-2/15-expressing CAR-NK cells exerts superior antitumor effects by exhaustion-resistance and longer survival in solid tumors.

Biomimetic Diselenide-Sonosensitizer Nanoplatform for Enhanced Sonodynamic Therapy and In Situ Remodeling Immunosuppressive Microenvironment via Activating Innate and Adaptive Immunotherapy

Sonodynamic therapy (SDT), which is non-invasive and controllable has the potential to treat triple-negative breast cancer (TNBC). However, the hypoxia and immunosuppressive tumor microenvironment (TME) often block the production of reactive oxygen species and the induction of SDT-activated immunogenic cell death, thus limiting the activation of adaptive immune responses. To alleviate these challenges, we proposed the development of a multifunctional biomimetic nanoplatform (mTSeIR), which was designed with diselenide-conjugated sonosensitizers and tirapazamine (TPZ), encapsulated within M1 macrophage membrane. This nanoplatform utilized hypoxia-induced chemotherapy to improve the efficacy of SDT, to further enhance adaptive immunotherapy by activating innate immunity and remodeling the immunosuppressive TME. Firstly, the prodrug TPZ was activated due to the increased oxygen consumption associated with SDT. Subsequently, the mTSeIR enhanced repolarization of M2 macrophages to the M1 phenotype. The diselenide component in mTSeIR effectively activated the natural killer cell-mediated antitumor innate immune response. Ultimately, in vivo studies indicated that mTSeIR+US with good biosafety achieved over 98% tumor inhibition and enhanced adaptive immunotherapy. This research presents an efficient approach that addressed the limitations of SDT and achieves simultaneous activation of both innate and adaptive immunotherapy, resulting in significant antitumor and anti-metastatic efficacy in TNBC.

Cytokine modulation and immunoregulation of uterine NK cells in pregnancy disorders

Uterine natural killer (uNK) cells play a pivotal role in promoting placental development and supporting maternal-fetal immune tolerance, primarily through cytokine regulation and growth factor production. While the importance of uNK cells in pregnancy is well-established, the mechanisms of their interactions with trophoblasts and contributions to various pregnancy complications remain incompletely understood. This review highlights recent advancements in understanding uNK cell functions, with a focus on cytokine production, growth factor secretion, and receptor-ligand interactions, particularly involving killer immunoglobulin-like receptors (KIR) and human leukocyte antigen-C (HLA-C). We explore how uNK cell dysfunction contributes to pregnancy complications, including preeclampsia, recurrent pregnancy loss, and placenta accreta spectrum (PAS) disorders, emphasizing their roles in immune tolerance and placental health. By detailing the distinct cytokine signaling pathways and functional subtypes of uNK cells, this review provides insights into their regulatory mechanisms essential for pregnancy maintenance. Additionally, we discuss emerging therapeutic strategies targeting uNK-trophoblast interactions and propose future research directions, including the development of non-invasive biomarkers and personalized interventions. This comprehensive review addresses critical knowledge gaps, aiming to advance research in reproductive immunology and guide therapeutic innovations in maternal health.

Attenuated adenosine mediated immune-dampening increases natural killer cell activity in early age-related macular degeneration

Non-exudative age-related macular degeneration (AMD) involves retinal pigment epithelium (RPE) dysfunction and has been linked to altered intraocular immunity. Our investigation focuses on immune cell subsets and inflammation-associated factors in the eyes with early and intermediate AMD. We observed elevated levels of activated natural killer (NK) cells and interferon-γ, concurrent with reduced myeloid-derived suppressor cells (MDSCs) and adenosine in AMD eyes. Aqueous humor from AMD patients had diminished ability to dampen NK cell activation, an effect rescued by adenosine supplementation. The Cryba1 cKO mouse model recapitulated these immune alterations, and single-cell RNA-sequencing identified NK cell-related genes and NK cell-RPE interactions. Co-culture of activated NK cells with RPE cells induced barrier dysfunction and Gasdermin-E driven pyroptosis providing a functional link relevant to AMD. These findings suggest a double-hit model where elevated immune activation and loss of immune dampening mechanisms drive AMD progression. Resetting the intraocular immune balance may be a promising therapeutic strategy for managing early and intermediate AMD.

Comprehensive Sepsis Risk Prediction in Leukemia Using a Random Forest Model and Restricted Cubic Spline Analysis

Background

Sepsis is a severe complication in leukemia patients, contributing to high mortality rates. Identifying early predictors of sepsis is crucial for timely intervention. This study aimed to develop and validate a predictive model for sepsis risk in leukemia patients using machine learning techniques.

Methods

This retrospective study included 4310 leukemia patients admitted to the Affiliated Hospital of Guangdong Medical University from 2005 to 2024, using 70% for training and 30% for validation. Feature selection was performed using univariate logistic regression, LASSO, and the Boruta algorithm, followed by multivariate logistic regression analysis. Seven machine learning models were constructed and evaluated using receiver operating characteristic (ROC) curves and decision curve analysis (DCA). Shapley additive explanations (SHAP) were applied to interpret the results, and restricted cubic spline (RCS) regression explored the nonlinear relationships between variables and sepsis risk. Furthermore, we examined the interactions among predictors to better understand their potential interrelationships.

Results

The random forest (RF) model outperformed all others, achieving an AUC of 0.765 in the training cohort and 0.700 in the validation cohort. Key predictors of sepsis identified by SHAP analysis included C-reactive protein (CRP), procalcitonin (PCT), neutrophil count (Neut), lymphocyte count (Lymph), thrombin time (TT), red blood cell count (RBC), total bile acid (TBA), and systolic blood pressure (SBP). RCS analysis revealed significant non-linear associations between CPR, PCT, Neut, Lymph, TT, RBC and SBP with sepsis risk. Pairwise correlation analysis further revealed interactions among these variables.

Conclusion

The RF model exhibited robust predictive power for sepsis in leukemia patients, providing clinicians with a valuable tool for early risk assessment and the optimization of treatment strategies.