Haploidentical allogeneic hematopoietic stem cell transplantation (h-HSCT) is increasingly used in patients lacking an HLA-matched donor. In this context, the combination of posttransplant cyclophosphamide (PTCy) and antithymocyte globulin (ATG) effectively prevents graft-versus-host disease, but its impact on the reconstitution of peripheral blood natural killer (NK) cell subsets remains insufficiently characterized. In this study, NK cell subsets were analyzed in depth in 56 adult recipients of unmanipulated h-HSCT with PTCy and ATG. Peripheral blood samples were collected at days +30, +60, and +100 after transplant. NK cell immunophenotype and cytotoxic function were assessed using multiparameter flow cytometry with unsupervised clustering, and degranulation assays against lymphoid and myeloid targets. Data were compared with those from 200 healthy volunteers. In spite of early numerical reconstitution, NK cells exhibited an immature immunophenotype with a low expression of activation markers. Cytotoxic activity against lymphoid targets was preserved, but degranulation against acute myeloid leukemia cell lines was significantly impaired across all NK subsets, including phenotypically mature NK cells. Cytomegalovirus reactivation was associated with an expansion of memory-like NK subsets but did not enhance degranulation. Functional education via killer cell immunoglobulin-like receptors was lost by day +30 and progressively reacquired from day +60 onward, in a pattern primarily influenced by the HLA-C genotype of recipients. These results indicate that, after h-HSCT with PTCy and ATG, NK cell subsets recover in number but fail to achieve early functional competence, particularly against myeloid targets. Strategies aiming at restoring mature NK cell functions warrant prospective investigations, especially in high-risk myeloid malignancies.

Jianpi-huayu Decotion regulates TREM1/DAP12 pathway to improve the immunosuppressive tumor microenvironment and enhance the anti-hepatocellular carcinoma effect of PD-1 inhibitors.

Mathematical modelling of tumor-immune interactions in breast cancer.

Introduction The tumor immune microenvironment (TIME) is highly heterogeneous and strongly influences immunotherapy outcomes and patient prognosis in colorectal cancer (CRC). In this exploratory study, we used three multiplex immunofluorescence (mIF) assays to characterize the spatial immune microenvironment associated with high CD8/PD-L1 infiltration. Methods Three mIF assays quantified the cell densities (cells/mm 2 ) of CD3, CD8, PD-L1, PD-1, CD163, CD56, CD4, Foxp3, Granzyme B (GrzB), CD20, CD11c, CD15, Ki67, and cytokeratin (CK) in the invasive margin (IM) and tumor center (TC) using digital image analysis. Patients were stratified based on CD8/PD-L1 densities and their proximity (cut-off: 20μm) in IM and TC. Immune microenvironment composition was compared between high and low infiltration groups across IM and TC. Results PD-L1 expression was predominantly driven from stromal and immune cells with enrichment at IM versus TC, particularly on CD163 + macrophages. Patients with high CD8/PD-L1 infiltration demonstrated significantly increased densities of CD20 + , CD3 + , PD-1 + , CD8 + PD-1 + , and CD56 + natural killer (NK) cells across tumor tissue, specifically enriched at IM. CD4 + Foxp3 + regulatory cells positively correlate with PD-1 + , CD8 + PD-1 + , and CD56 + cells in IM but not TC. Conclusions This exploratory mIF analysis identifies PD-L1 expression predominantly on stromal and immune cells, enriched in IM, particularly on CD163 + macrophages. High CD8/PD-L1 tumors display spatially organized IM-specific immune niches featuring coordinated effector-regulatory interactions. Comprehensive spatial profiling of IM-enriched populations, including B cells, CD163 + macrophages, regulatory T cells, and NK cells alongside CD8/PD-L1, may refine patient stratification for immunotherapy in CRC.

This study aimed to investigate the impact of intestinal obstruction (IO) caused by colorectal cancer (CRC) on the cancer prognosis and recurrence patterns. We analyzed recurrence patterns in patients with stage II-III CRC and employed a murine model to elucidate the effects of IO on hepatic immunity. We examined the clinical outcomes of CRC patients with IO and utilized a murine IO model to assess alterations in hepatic immunity, focusing on natural killer (NK) cell function. IO was significantly associated with poor prognosis and an increased incidence of liver metastases. In the murine model, IO induced hepatic inflammation and impaired the antitumor activity of liver-resident NK cells, whereas its effects on conventional splenic and pulmonary NK cells were minimal. These findings, consistent between human clinical data and murine experiments, suggest that IO promotes a microenvironment conducive to liver metastasis by compromising hepatic immunity. IO exerts a detrimental effect on hepatic immunity by impairing NK cell-mediated antitumor responses, thereby facilitating liver metastasis in CRC.

IgG4 monoclonal anti-CD47 for cancer immunotherapy resulted in anemia necessitating red cell (RBC) transfusions. Although the antibody readily binds to CD47 on RBCs, the mechanism underlying the anemia associated with IgG4 is poorly understood. We investigated samples from patients receiving Hu5F9-G4 (magrolimab) with positive reactivity in compatibility tests using a monocyte-monolayer assay (MMA). For RBC opsonization, patient plasma was diluted to avoid direct agglutination and to give a 4+ indirect antiglobulin test (IAT) and >103 mean fluorescent intensity (MFI) by flow cytometry. Fcγ receptor blocking used F(ab')2 antibodies. Antibody-dependent cellular cytotoxicity (ADCC) used purified natural killer (NK) cells. Recombinant IgG4 anti-K and polyclonal anti-D were tested by MMA concurrent with blocking of CD47 with a deglycosylated antibody. Five of six samples showed significant erythrophagocytosis (phagocytosis index [PI] = 20-60; PI > 5 clinically significant) with the exception having 30-fold lower MFI. Phagocytosis was not increased in the presence of complement. Fcγ receptor blocking showed FcγRI and FcγRIIa were involved but not FcγRIIIa, supported by negative results when tested for NK ADCC. IgG4 anti-K also showed significant erythrophagocytosis (PI = 30). Blocking of CD47 increased phagocytosis, 1.7 to 3.9-fold, respectively, of RBCs opsonized with IgG4 anti-K or polyclonal anti-D. IgG4 RBC antibodies, generally not considered clinically significant for transfusion, can result in erythrophagocytosis providing an explanation for anemia related to anti-CD47 mediated by FcγRI and FcγRIIa. Enhanced phagocytosis of alloantibody-coated RBCs with concurrent blocking CD47 suggests potential for enhanced complications for patients who develop RBC alloantibodies while receiving cancer therapies targeting CD47.

CD19-specific CAR T cells engineered to secrete a constitutively active form of the pro-inflammatory cytokine, interleukin (IL)-18 have demonstrated impressive efficacy in a recent clinical trial involving subjects who had failed prior CAR T cell therapy. Corroborating these clinical data, preclinical studies of IL-18-armored CAR and T cell receptor-engineered T cells have demonstrated enhanced anti-tumor activity in several xenograft and syngeneic mouse cancer models. Interleukin-18 improves tumor clearance via direct effects on CAR T cells and indirect actions on cells on a variety of host immune cells, including natural killer, macrophage and dendritic cells. Compared to unarmored CAR T cells, IL-18-secreting CAR T cells are less exhausted, expand more efficiently and produce greater quantities of interferon (IFN)-γ. However, upregulated circulating IL-18 and its downstream mediator, IFN-γ, are also associated with systemic toxicities which have proven to be severe on occasions. In light of this, several groups have developed strategies that set out to restrict IL-18 release or biological activity to the tumor microenvironment. Among these, CAR T cells armored with NFAT-inducible IL-18 are now undergoing clinical testing. The evaluation of inducible or tumor-selective IL-18 deployment will show whether it is possible to minimize IL-18 related systemic toxicities while preserving localized amplification of anti-tumor activity.

Treatment with latency-reversing agents (LRAs) alone has been ineffective in reducing HIV-1 reservoirs in people living with HIV-1 (PLWH) who are on antiretroviral therapy (ART), due to inefficiencies in reservoir reactivation and adaptive immune responses. However, NK cells activated with cytokines may be able to target HIV-1 reservoirs more effectively. To explore the therapeutic potential of NK cells, we expanded blood NK cells from multiple donors ex vivo into CD56bright CD16+ "eNK" cells using artificial antigen-presenting cells (aAPCs) expressing membrane-bound IL21. eNK cells express multiple activating receptors and are highly cytotoxic against specific target cells. They can also kill HIV-infected CD4+ T cells via antibody-dependent cell-mediated cytotoxicity (ADCC) using broadly neutralizing antibodies (bNAbs) against HIV-1 Env gp120/gp41. Notably, eNK cells from PLWH on ART efficiently killed autologous HIV-1+ T cells reactivated by a combination of vorinostat (SAHA) and IL-15 or an IL-15 superagonist (N-803), as evidenced by declines in proviral load, inducible HIV-1 mRNA, and virus release. Adoptive immunotherapy with eNK cells combined with LRA treatment thus presents a promising strategy to reduce the latent HIV-1 reservoir in PLWH.IMPORTANCEAntiretroviral therapy (ART) lowers HIV levels in the blood to nearly undetectable amounts, but stopping therapy almost always leads to HIV rebounding in the bloodstream. DNA and RNA tests show that most people living with HIV (PLWH) on ART retain long-lasting HIV reservoirs that remain hidden from the immune system when no HIV is being produced. Eradicating HIV might look like "drug-free remission," where HIV reservoirs are kept under control by the immune system even if ART is stopped indefinitely. Current strategies for this potential eradication include using HIV latency-reversing agents (LRAs), ex vivo expansion of natural killer (NK) cells, and improving the ability to kill infected cells with broadly neutralizing antibodies against HIV. Here, we demonstrate that NK cells from PLWH can be expanded outside the body into "eNK" cells that specifically attack HIV-infected cells without harming uninfected ones, significantly reducing HIV reservoirs in vitro after LRA treatment.

Reprogramming of cellular metabolism is a hallmark of cancer, particularly ovarian cancer (OC), that contributes to rapid cancer growth and survival. However, studies using clinical specimens are limited. To identify metabolic alterations specific to OC, we performed metabolomic analysis of OC and benign ovarian tumors. The relationship between metabolomics and transcriptomics was investigated by transcriptome analysis. Fifty-one patients with OC and three with benign ovarian tumors, diagnosed between 2011 and 2014 using available frozen tissue and plasma specimens, were enrolled at the National Cancer Center Hospital. To identify metabolic alterations, plasma samples from 51 patients with OC and three with benign tumors, along with both cancerous and non-cancerous tissue samples from 44 of the 51 patients with OC, were analyzed using gas chromatography-mass spectrometry. In addition, we performed transcriptomic analysis of cancerous tissues obtained from 39 of the 44 patients with OC. It was not possible to classify patients based on plasma metabolite levels; therefore, the 44 patients with OC were classified into two groups based on metabolite levels: high and low, based on tissue analysis. The group with high metabolite levels had more advanced-stage tumors (P = 0.02). Transcriptome pathway analysis revealed suppression of pathways related to natural killer (NK) cells and immune responses in the group with high metabolite levels. NK cell percentages were lower in the group with high metabolite levels than in the group with low metabolite levels (P = 0.04). Thus, the group with high metabolite levels was associated with advanced stages and a reduced fraction of NK cells, suggesting that high metabolite levels may play a direct or indirect role in immune activity or in the malignant progression of OC.

Bile acids (BAs) have evolved from their classical role in lipid digestion to become central signaling molecules that integrate host metabolism, gut microbiota, and immune function. This review examines how diverse BAs regulate both innate and adaptive immunity through specific receptors—including farnesoid X receptor, Takeda G-protein-coupled receptor 5, vitamin D receptor, and retinoid orphan receptors—modulating the activity of macrophages, dendritic cells, T cells, natural killer cells, and natural killer T cells. Tissue−specific BA signaling influences immune homeostasis in the intestine, liver, central nervous system, and tumor microenvironment. Furthermore, we discuss the pathogenic role of dysregulated BA signaling in inflammatory, autoimmune, metabolic, and malignant diseases, and evaluate emerging therapeutic strategies that target BA pathways via synthetic ligands, engineered microbes, and dietary modulation. Leveraging BA-immune crosstalk to advance research on precision immunotherapy and microbiome-based interventions is a promising area of research.

Oxaliplatin resistance significantly impairs therapeutic outcomes in colorectal cancer. However, reliable diagnostic markers for early detection of resistance remain limited. This study aimed to identify novel diagnostic signatures through integrative bioinformatics and machine learning approaches. We performed comprehensive bioinformatics analyses combining transcriptomics data from multiple cohorts. The diagnostic signatures were identified and validated using machine learning algorithms. Weighted gene co-expression network analysis (WGCNA) was employed to explore resistance-associated gene modules. Multiple computational methods including functional enrichment, protein-protein interaction networks, and immune infiltration assessment were conducted to comprehensively characterize the molecular features of oxaliplatin resistance. Through integrative analysis and machine learning, we identified an 8-gene diagnostic signature (CHFR, TGFBRAP1, RPS4Y1, CYP26B1, NR4A2, FLJ20021, TNFSF9, CAV2) that demonstrated robust performance in distinguishing resistant cases (AUC = 0.868). Functional characterization revealed significant enrichment in metabolic reprogramming, DNA repair mechanisms, and immune modulation pathways. Systematic evaluation of tumor-immune interactions demonstrated distinct patterns of immune cell infiltration between resistant and sensitive groups, particularly in Natural killer cells and Activated CD8 T cells. Computational drug screening identified Glycidamide and orciprenaline as promising candidates, with favorable binding profiles against key resistance-associated targets. Our study establishes a novel multi-gene diagnostic signature for oxaliplatin resistance through integrative bioinformatics and machine learning approaches. The comprehensive molecular characterization and identification of potential therapeutic candidates provide new insights into resistance mechanisms and clinical management strategies for oxaliplatin-resistant colorectal cancer.

Colorectal cancer (CRC) remains a significant global health concern and is among the leading causes of cancer-related mortality. The disease often progresses to more advanced and treatment-resistant stages. By 2040, the incidence of CRC is projected to increase substantially worldwide, particularly in low- and middle-income countries. Despite the availability of various treatment modalities, CRC incidence remains elevated. Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, represent a novel approach for CRC therapy and diagnosis. EVs possess distinct biological characteristics and exhibit both immunosuppressive and immunostimulatory properties within the tumour microenvironment. Tumour-derived EVs facilitate CRC progression and metastasis by transferring oncogenic proteins and microRNAs that promote epithelial-mesenchymal transition and alter recipient cell behaviour. Conversely, immune-derived EVs produced by dendritic cells, natural killer cells, T lymphocytes, B lymphocytes, and macrophages enhance anti-tumour immune responses and contribute to the elimination of cancer cells. Due to their stable encapsulation of nucleic acids, proteins, and lipids, EVs serve as highly sensitive and specific biomarkers for CRC diagnosis, prognosis, and therapeutic monitoring. Additionally, EVs have demonstrated both abscopal and bystander effects, highlighting their capacity to induce systemic antitumor responses. Recent advances in EV engineering, together with emerging technologies such as artificial intelligence, CRISPR/Cas9 genome editing, and chimeric antigen receptor (CAR)-T cell therapy, present new opportunities to optimise EV-based interventions and broaden their translational applications. Nevertheless, substantial challenges persist, including EV heterogeneity, technical barriers in isolation and characterisation, and limited understanding of their functional diversity. Addressing these limitations, particularly in the development of EV-based vaccines, enhancement of immunostimulatory properties, and further integration of artificial intelligence, will be essential for realising the full clinical potential of EVs in colorectal cancer management.

Chimeric antigen receptor natural killer (CAR-NK) cells represent a promising "off-the-shelf" alternative to CAR-T cells, offering a superior safety profile and inherent multi-antigen targeting capabilities. However, their clinical potential is constrained by the "CRISPR ceiling", a set of practical limitations of DSB-based CRISPR-Cas9 such as DNA double-strand break (DSB)-associated chromosomal rearrangements and p53-mediated fitness loss, low efficiency for safe, large, multicistronic knock-ins, and rigid promoter-driven transgene expression that can cause tonic signaling. Importantly, next-generation, DSB-free base and prime editors reduce or eliminate the DSB-associated genotoxic stress observed with nuclease cutting, CRISPR-associated transposases now enable programmable, targeted insertion strategies that can accommodate larger cassettes, and synthetic/epigenetic circuits provide dynamic, context-dependent transgene control that avoids constitutive promoter-driven tonic signaling. This review explores technological approaches beyond conventional CRISPR, highlighting next-generation precision engineering tools that may enable improved CAR-NK therapies and represent potential advances in safety and efficacy. We detail how base editing, epigenetic reprogramming, targeted transposon systems, and synthetic biology circuits can be synergistically integrated to overcome critical clinical challenges. These advanced technologies enable the precise enhancement of three fundamental pillars of efficacy: Persistence through endogenous cytokine armoring and metabolic engineering; Trafficking via chemokine receptor matching and stromal barrier degradation; and Tumor Eradication using logic-gated targeting, immunomodulatory payloads, and bispecific engagers. By synthesizing these cutting-edge advances, we provide a roadmap for developing next-generation CAR-NK cells capable of durable, potent, and safe antitumor responses against both hematological and solid malignancies, ultimately forging a new frontier in accessible cellular immunotherapy.

Adoptive natural killer (NK) cell therapy for solid tumors faces critical challenges, including tumor antigen heterogeneity, impaired tumor infiltration, and suboptimal activation imposed by the immunosuppressive microenvironment. Here we developed an engineered nanoplatform featuring transmembrane DNA nanochannel-engineered artificial receptors (NCAR) to direct NK cells against solid tumors through two synergistic mechanisms: 1) Tumor Microenvironment (TME) Reprogramming: leveraging cholesterol-mediated insertion, NCAR incorporates into tumor membranes to disrupt phospholipid bilayers, inducing immunogenic cell death with the release of damage-associated molecular patterns (DAMPs; e.g., HMGB1, CRT), which remodels immunosuppression TME and recruits/activates NK cells. 2) Precision Targeting: NCAR forms programmable synthetic immune synapses with DNA nanoartificial ligands (NAL) engineered on NK cells via base-pairing. This antigen-independent assembly network establishes a universal membrane interface, enabling sustained tumor-targeted NK cell activation. The dual-component system enables sustained intratumoral accumulation of NK cells (>96 h), with a 15.1-fold increase in activated NKP46+GZB+ NK cells compared to controls. By bridging DNA nanotechnology with cell immunotherapy, our nanoplatform provides a universal strategy for navigating tumor-immune interactions, addressing key limitations of adoptive NK cell immunotherapy in solid tumors.

Deer antler velvet (Cervus elaphus L.) is a traditional material in oriental medicine, extensively utilized for its anti-aging, antioxidant, and immune-boosting properties. Our prior research revealed that enzyme-derived deer antler velvet extract (YC-1101) stimulated the immune system by activating macrophages and augmenting splenocyte proliferation. In this study, we investigated the effect of YC-1101 on the proliferation, activation, and cytotoxicity of natural killer (NK) cells, emphasizing activation-receptor upregulation, cytokine secretion, and antitumor efficacy. Our findings demonstrated that YC-1101 treatment markedly enhanced NK cell proliferation in a dose-dependent and time-dependent manner by preserving mitochondrial function. NK cells expanded through YC-1101 treatment exhibited a significant increase in surface expression of activating NK receptors, NKG2D, and NKp44. Additionally, levels of immune-related cytokines like tumor necrosis factor-alpha, interferon-gamma, and granulocyte-macrophage colony-stimulating factor were substantially elevated in the YC-1101-treated group compared with control. Notably, NK cell activation induced by YC-1101 intensified cytotoxicity against various cancer cell lines, and combining YC-1101 with immune checkpoint inhibition synergistically enhanced antitumor activity. Collectively, our results indicate that integration of YC-1101 with expanded NK cells could be a promising approach to augment cancer treatment efficacy.

Natural killer (NK) cell antibody-dependent cellular cytotoxicity (ADCC) contributes to effective antiviral immunity, yet the relative contribution of NK cell-intrinsic factors and antibodies in mediating these responses remain poorly understood. Here, we combined functional ADCC assays with single-cell transcriptomics of peripheral NK cells from COVID-19 participants. Our analysis revealed distinct transcriptional programs between participants with different ADCC response levels: NK cells from participants with lower ADCC responses upregulated proliferation pathways, while those with high ADCC responses showed enhanced expression of interferon-stimulated genes and NKG2D. Blocking NKG2D significantly reduced NK cell ADCC degranulation and cytokine responses. Paradoxically, greater interferon-mediated NK cell activation was associated with reduced proficiency of participants' antibodies to mediate ADCC, suggesting a regulatory checkpoint mechanism. These findings enhance our understanding of the molecular determinants of ADCC responses and provide novel insights into leveraging these responses for more effective vaccination and therapeutic strategies.

This parallel randomised controlled trial examined the effect of a 4-week, high dose (Lf-High, 600mg/d) or low dose (Lf-Low, 200mg/d) oral lactoferrin (Lf) intervention versus placebo, on immune cell responses to respiratory virus, circulating immune cell subsets, and systemic inflammation. In healthy older adults (n=103, ≥50 years old), ex vivo cytokine release of interferon (IFN)-α2, IFN-γ, interleukin (IL)-6, and tumour necrosis factor (TNF)-α from isolated peripheral blood mononuclear cells (PBMCs) stimulated with rhinovirus A-16 (RV-16) or influenza A virus (H1N1), circulating immune cell subsets, and plasma IL-6, C-reactive protein (CRP) and TNF-α were assessed at baseline and 4 weeks. Ninety-seven participants completed the intervention (Lf-High n=32, Lf-Low n=31, placebo n=34, withdrawals n=6). There was no difference in RV-16 or H1N1-induced IFN-γ release between groups. At 4-weeks, RV-16-induced IL-6 was lower in Lf-High compared to placebo (P=0.001), and RV-16-induced IFN-α2 was higher in Lf-High compared to Lf-Low (P=0.04). Lf-High increased total T cells (P=0.03) and CD4+ T cells (P=0.03) compared to placebo. Lf-Low reduced neutrophil (P=0.04), natural killer cell (P=0.045), activated CD8+ T cell (P=0.03), and γδ T cell (P=0.03) frequency compared to placebo. Plasma IL-6 (P=0.004) and CRP (P=0.03) were lower following Lf-High compared to Lf-Low, but not placebo. Both high and low dose lactoferrin altered ex vivo immune cell responses after 4 weeks. High dose lactoferrin increased T-cell subsets, promoting adaptive immunity, and reduced systemic inflammation, while low dose lactoferrin reduced proinflammatory and cytotoxic immune cells. High and low dose lactoferrin supplements may have immunoceutical benefits in older adults.

We present the single-cell transcriptomic analysis of peripheral blood mononuclear cells (PBMC) from individuals during acute HIV-1 infection caused by viral strains circulating in Russia and the Former Soviet Union (FSU) countries. Using 10x Genomics single-cell RNA sequencing (scRNA-seq) on the Illumina NextSeq 550 platform, we have analyzed scRNA-seq data from three treatment-naive patients (viral load > 1 × 106 copies/mL, estimated infection duration ≤ 4 weeks) and three healthy donors. Data integration (Seurat, Harmony), automated cell-type annotation (CellTypist), and GeneOntology (GO) enrichment analysis for highly expressed and low-expressed genes revealed a profound reorganization of transcriptional programs across key immune populations, including memory CD4+ and CD8+ T cells, non-classical monocytes and natural killer cells (NK-cells). We observed signatures of hyperactivation of pro-inflammatory pathways (NF-kB, TNF, and type I/II interferon signaling), upregulation of genes associated with cellular migration (CXCR4, CCR7) and metabolic adaptation (oxidative phosphorylation components), alongside a mixed pro- and anti-apoptotic expression profile. Notably, our data pointed to a pronounced dysregulation of the TGF-β and mTOR signaling cascades, disrupted intercellular communication networks—particularly between cytotoxic cells and their regulators—altered expression of genes implicated in disease progression (OLR1, SERPINB2, COPS9) and viral persistence control (NEAT1, NAF1). This work provides an initial single-cell transcriptional atlas characterizing early immune responses to HIV-1 sub-subtypes A6 and CRF63_02A6, the predominant drivers of the HIV epidemic across the FSU region.

The incorporation of organoids with immune cells in co-culture systems signifies a groundbreaking advancement in the fields of cancer research and immunology. These three-dimensional models, derived from primary tumor specimens or stem cells, provide a more accurate representation of the tumor microenvironment (TME) than conventional two-dimensional cultures or animal models. This enhanced model allows for a thorough examination of the intricate interactions between cancer cells and the immune system. Although the success rates for organoid initiation can vary, averaging 36.8% across 13 different tumor types, successful organoid establishment enables the co-culture with a variety of immune cells, such as T cells, tumor-infiltrating lymphocytes (TILs), peripheral blood mononuclear cells (PBMCs), macrophages, dendritic cells, and natural killer (NK) cells. This platform enables the study of immune responses to cancer, mechanisms of immune evasion, and the influence of the TME on immune activation and suppression. The review emphasizes research involving intestinal, pancreatic, brain, liver, and cervical organoids, highlighting their role in elucidating disease mechanisms, assessing the effectiveness of immunotherapies (including checkpoint inhibitors and therapeutic vaccines), and conducting preclinical drug evaluations. Notable examples include modeling graft-versus-host disease with intestinal organoids, investigating the influence of DCLK1 on immunosuppression in pancreatic cancer, evaluating the effectiveness of engineered T cells against neuroblastoma using brain organoids, and analyzing the effects of cancer-associated fibroblasts on drug responses in colon cancer. Additionally, the potential of organoids in vaccine development and testing, particularly for influenza and other viral infections, is examined, demonstrating their utility in assessing immune responses and vaccine effectiveness. Despite existing challenges, such as the relatively low efficiency of organoid generation and the complexities involved in fully mimicking the TME, ongoing technological innovations, including tumor-on-chip systems and enhanced matrix materials, are expected to improve the functionality and clinical applicability of these advanced in vitro models.

Natural killer (NK) and innate lymphoid cells (ILCs) regulate tissue homeostasis and immune responses, by acting as early sensors of cellular stress and tissue dysfunction. Their functions are tightly controlled by regulatory circuits, often referred to as checkpoints, and are profoundly shaped by local environments. In cancer, tissue perturbations cause immune cell recruitment, spatial re-distribution, and accordant functional adaptations. Here, we discuss how tissue-specific cues regulate NK/ILC functions in cancer, and how local regulatory circuits shape their cellular states and effector programs. We address how targeting innate checkpoints could aid existing, and inform novel strategies for treating solid malignancies.