NKT Cells Research Articles

Identification of α-galactosylceramide as an endogenous mammalian antigen for iNKT cells.

Invariant natural killer T (iNKT) cells are unconventional T cells recognizing lipid antigens in a CD1d-restricted manner. Among these lipid antigens, α-galactosylceramide (α-GalCer), which was originally identified in marine sponges, is the most potent antigen. Although the presence of α-anomeric hexosylceramide and microbiota-derived branched α-GalCer is reported, antigenic α-GalCer has not been identified in mammals. Here, we developed a high-resolution separation and detection system, supercritical fluid chromatography tandem mass spectrometry (SFC/MS/MS), that can discriminate hexosylceramide diastereomers (α-GalCer, α-GlcCer, β-GalCer, or β-GlcCer). The B16 melanoma tumor cell line does not activate iNKT cells; however, ectopic expression of CD1d was sufficient to activate iNKT cells without adding antigens. B16 melanoma was unlikely to generate iNKT cell antigens; instead, antigen activity was detected in cell culture serum. Activity-based purification and SFC/MS/MS identified dihydrosphingosine-based saturated α-GalCer as an antigenic component in serum, bile, and lymphoid tissues. These results show the first evidence for the presence of potent antigenic α-GalCer in mammals.

A phase II study of agenT-797 (invariant natural killer T-cells), botensilimab (Fc-enhanced CTLA-4 inhibitor) and balstilimab (anti-PD-1) in patients with advanced, refractory gastroesophageal adenocarcinoma.

TPS515 Background: Esophagogastric (EG) cancer, the fifth most common cancer worldwide and second leading cause of cancer-related mortality, results in 1.3 million deaths annually. Despite recent advances in frontline management, nearly all patients with metastatic disease experience progression, highlighting the urgent need for novel therapies. Botensilimab (BOT), an Fc-enhanced, multifunctional anti-CTLA-4 antibody, has shown promise in combination with balstilimab (BAL, anti-PD-1) across multiple treatment-refractory cancers. Additionally, agenT-797, an allogeneic off-the-shelf invariant Natural Killer T (iNKT) cell therapy, enhances immune responses, including in settings refractory to immune checkpoint inhibitors (ICI), without requiring HLA matching or lymphodepletion. In a cohort of 82 previously treated patients, agenT-797 demonstrated a favorable safety profile with no severe Cytokine Release Syndrome, Graft-versus-Host Disease, or immune effector cell-associated neurotoxicity syndrome. Notably, in patients with relapsed/refractory gastric cancer, agenT-797 plus anti-PD-1 showed important clinical activity that warrants further exploration. Given their complementary mechanisms of action in modulating anti-tumor immunity, we aimed to evaluate the safety and efficacy of combining BOT, BAL, and agenT-797 with standard ramucirumab (anti-vascular endothelial growth factor receptor-2 antibody) and paclitaxel chemotherapy in patients with advanced EG cancer who have progressed on frontline therapy. Methods: This is an investigator-initiated, single-arm phase II trial in adult patients (≥18 years) with esophageal, gastric, or gastro-esophageal junction (GEJ) adenocarcinoma who have received one prior line of therapy, performed at Memorial Sloan Kettering Cancer Center. Eligible patients receive a single infusion of agenT-797 on cycle 1 day 1, BOT 75 mg on day 1 of cycles 1 through 3, BAL 240 mg on days 1 and 15, ramucirumab 8 mg/kg on days 1 and 15, and paclitaxel chemotherapy 80 mg/m 2 on days 1, 8, and 15 of a 28-day cycle. Treatment is continued until disease progression (defined by Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1), unacceptable toxicity, or withdrawal of consent. The primary endpoint is overall response rate. The secondary endpoints are safety and tolerability, disease control rate, duration of response, progression-free survival, and overall survival. The regimen will be considered worthy of further investigation if at least 15 out of 37 patients achieve an objective response. To date, 12 patients have been enrolled and started on treatment. This trial is registered with ClinicalTrials.gov, NCT06251793. Clinical trial information: NCT06251793 .

Abstract TP346: Investigating Transcriptomic Profiles of Peripheral Blood Mononuclear Cells in Moyamoya Disease Using Single-Cell RNAseq

Objectives: Moyamoya Disease (MMD) is a complex cerebrovascular disease marked by progressive narrowing in the cerebral arteries. Previous studies have suggested that dysregulated genes in the peripheral blood of MMD patients are involved in extracellular matrix organization and immune responses. However, the mechanism by which the immune response contributes to MMD progression is unclear. In this study we investigated the immune landscape in the peripheral blood mononuclear cells (PBMCs) of MMD patients using single-cell RNA sequencing (scRNA-seq). Methods: Blood samples were collected from 3 bilateral MMD patients and 2 healthy controls. PBMCs were isolated and processed for 10x single-cell RNA sequencing. Immune cell heterogeneity and differentially expressed genes (DEGs) in each cell type were identified. Top biological pathways were determined using Ingenuity Pathway Analysis (IPA). Flow cytometry with an 11-fluorochrome panel was use to validate key immune populations and fluorescence-activated cell sorting (FACS) was used to isolate specific immune populations for transcriptome analysis. Results: Preliminary analysis revealed notable increase of cell percentages in certain cell types in MMD, such as CD8+T (9.21% vs 7.11%), B cells (6.94% vs 3.45%) and CD4+NKT (5.78% vs 3.22%), and decrease in CD8+NKT (9.59% vs 15.74%), compared to controls. Higher transcriptome dynamics were observed in certain cell type in MMD, with 2402 DEGs in classical monocytes, 1379 DEGs in CD4+T, 1312 DEGs in CD8+NKT and 997 DEGs in B cells. Interestingly, many cell types, except for classical and non-classical monocytes, displayed a higher number of downregulated DEGs in MMD, particularly in T cells, B cells, and NKT cells. Pathway analysis indicated that CD4+T, CD8+NKT, and B cells show predicted inhibition in several pathways, including T cell receptor and mTOR signaling, interleukins and CXCR4 signaling, as well as cell surface interactions at the vascular wall. Conclusion: These preliminary findings point to a distinct immunological profile in MMD, suggesting significant alterations in both immune cell activity and interaction within the vascular environment. Ongoing studies utilize FACS to validate specific immune populations and their transcriptomes in a larger cohort. These findings reveal unique transcriptomic signatures of peripheral blood immune cells in MMD and highlight key immune cell types that may contribute to its pathogenesis.

Patient-Derived Organoid Models for NKT Cell-Based Cancer Immunotherapy

Invariant Natural Killer T (iNKT) cells are a unique subset of T cells that bridge innate and adaptive immunity, displaying potent anti-tumor properties through cytokine secretion, direct cytotoxicity, and recruitment of immune effector cells such as CD8+ T cells and NK cells. Despite their therapeutic potential, the immunosuppressive tumor microenvironment (TME), characterized by regulatory T cells, myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs), limits iNKT cell efficacy. Patient-derived organoid (PDO) platforms provide an innovative model for dissecting these complex interactions and evaluating strategies to reinvigorate iNKT cell functionality within the TME. PDOs closely mimic the genetic, phenotypic, and structural characteristics of primary tumors, enabling the study of tumor–immune dynamics. Integrating iNKT cells into PDOs offers a robust platform for investigating CD1d-mediated interactions, Th1-biased immune responses driven by glycolipid analogs like α-GalCer, and combination therapies such as immune checkpoint inhibitors. Additionally, PDO systems can assess the effects of metabolic modulation, including reducing lactic acid accumulation or targeting glutamine pathways, on enhancing iNKT cell activity. Emerging innovations, such as organoid-on-a-chip systems, CRISPR-Cas9 gene editing, and multi-omics approaches, further expand the potential of PDO–iNKT platforms for personalized immunotherapy research. Although the application of iNKT cells in PDOs is still undeveloped, these systems hold immense promise for bridging preclinical studies and clinical translation. By addressing the challenges of the TME and optimizing therapeutic strategies, PDO–iNKT platforms offer a transformative avenue for advancing cancer immunotherapy and personalized medicine.

Current Landscape of Adoptive Cell Therapy and Challenge to Develop "Off-The-Shelf" Therapy for Hepatocellular Carcinoma.

Adoptive cell therapy (ACT) is a type of immunotherapy in which autologous or allogeneic immune cells, such as tumor-infiltrating lymphocytes or engineered lymphocytes, are infused into patients with cancer to eliminate malignant cells. Recently, autologous T cells modified to express a chimeric antigen receptor (CAR) targeting CD19 showed a positive response in clinical studies for hematologic malignancies and have begun to be used in clinical practice. This article discusses the current status and promise of ACT research in hepatocellular carcinoma (HCC), focusing on challenges in off-the-shelf ACT using primary cells or induced pluripotent stem cells (iPSCs) with or without genetic engineering. Early clinical trials of autologous GPC-3-, MUC1-, or CEA-targeted CAR-T cell therapies are underway for HCC. There is a growing demand for the development of off-the-shelf therapies due to the high cost and manufacturing issues associated with autologous CAR-T. The development of ACT from various cell sources, such as NK cells, NKT cells, macrophages, and γδ T cells without MHC restriction other than T cells has been proposed. Advances in genome editing, including HLA gene knockout to avoid GvHD, and strategies to enhance efficacy in overcoming the suppressive tumor microenvironment, are used to create universal 'off-the-shelf' CAR-T cells which can be used immediately as therapeutic products from healthy donors or iPSC-derived immune cells. Despite several limitations, cell-based immunotherapy is expected to become a key cancer treatment modality for both hematologic malignancies and solid tumors including HCC, thanks to technological advancements overcoming these challenges.

Promising Cellular Immunotherapy for Colorectal Cancer Using Classical Dendritic Cells and Natural Killer T Cells

Colorectal cancer (CRC) remains one of the leading causes of cancer-related morbidity and mortality around the world. Despite advances in surgery, chemotherapy, and targeted therapies, the prognosis for patients with metastatic or advanced CRC remains poor. Immunotherapies comprising immune checkpoint inhibitors showed disappointing responses in metastatic CRC (mCRC). However, cellular immunotherapy, specifically using classical dendritic cells (cDCs), may hold unique promise in immune recognition for CRC antigens. cDCs are substantial players in immune recognition and are instrumental in orchestrating innate and adaptive immune responses by processing and presenting tumor antigens to effector cells. Natural killer T (NKT) cells are insufficiently studied but unique effector cells because of their ability to bridge innate and adaptive immune reactions and the crosstalk with dendritic cells in cancer. This review explores the therapeutic potential of using both cDCs and NKT cells as a synergistic therapy in CRC, focusing on their biological roles, strategies for harnessing their capabilities, clinical applications, and the challenges within the tumor microenvironment. Both cDCs and NKT cells can be used as a new effective approach for cell-based therapies in cancers to provide a new hope for CRC patients that are challenging to treat.

DOP095 IL-23-activated cells as response biomarkers for risankizumab in Crohn’s disease patients

Abstract Background The interleukin (IL)-23 signaling is a vital pathway in Crohn’s disease (CD). IL-23 activates T-helper (Th) 17 cells, IL-17-secreting CD8 T (Tc)17 cells, γδ T cells, natural killer (NK) T cells, and group 3 innate lymphoid cells (ILC3) to secrete inflammatory cytokines including IL-17, IFN-γ, and TNF-α. Risankizumab is the first selective IL-23 antagonist approved for moderate-to-severe CD; however, no biomarker currently exists to predict response to this medication. Here, we characterized the phenotypes of IL-23-activated cells that predict response to risankizumab in CD patients. Methods Adult patients with active ileal/colonic CD were included (n = 28). Blood samples were collected before and after initiation of risankizumab. Peripheral blood mononuclear cells (PBMC) were isolated and cryopreserved for batch analysis. After stimulation with IL-23, PBMCs were stained using a pre-optimized and validated antibody panel for 37 lineage markers and cytokines for CyTOF. Cell clusters were resolved using UMAP (Figure 1), opt-SNE and FlowJo. Patients’ responses were evaluated 12-40 weeks after initiation of risankizumab based on clinical symptoms (e.g., CDAI) and endoscopic/radiographic assessment. Results Among the IL-23-activated cells, increased frequency of NKT cells was identified in the peripheral blood of non-responders before initiation of risankizumab (not shown). In pre-risankizumab PBMCs, we identified significantly elevated TNF-α in Th17 cells, Tc17 cells, NKT cells, and MAIT cells in non-responders vs. responders (Figure 2A). Similarly, in PBMCs 4 weeks after 1st risankizumab infusion, Tc17 cells, γδ T cells, NKT cells, and MAIT cells in non-responders produced significantly more TNF-α compared to those cells from responders. In addition, we observed increased IL-17A in multiple IL-23-activated cells in non-responders 4 weeks after starting risankizumab (Figure 2B). Peripheral and mucosal IL-23-activated cells from later non-responders before and 4 weeks after treatment spontaneously secreted TNF-α and IL-17A without stimulation. A similar correlation between therapeutic response and expression of TNF-α or IL-17A was not observed in ustekinumab, an anti-IL-12/IL-23 antibody (not shown). Conclusion CyTOF of patients’ PBMCs before and after starting risankizumab revealed previously unknown molecular signatures, especially augmented TNF-a production in multiple IL-23-activated cells, which predict non-response to risankizumab in CD patients. Those findings identified a novel mechanism of anti-IL-23 resistance, may help identify response biomarkers for IL-23 antagonists and provide a rationale for anti-IL-23/anti-TNF combination therapy in a subset of patients with refractory CD.

Comprehensive single-cell atlas of colorectal neuroendocrine tumors with liver metastases: unraveling tumor microenvironment heterogeneity between primary lesions and metastases

BackgroundColorectal neuroendocrine tumors with liver metastases (CRNELM) are associated with a poorer prognosis compared to their nonmetastatic counterparts. A comprehensive understanding of the tumor microenvironment (TME) heterogeneity between primary lesions (PL) and liver metastases (LM) could provide crucial insights for enhancing clinical management strategies for these patients.MethodsWe utilized single-cell RNA sequencing to analyze fresh tissue samples from CRNELM patients, aiming to elucidate the variations in TME between PL and LM. Complementary multidimensional validation was achieved through spatial transcriptomics, bulk RNA sequencing, and multiplex immunohistochemistry/immunofluorescence.ResultsOur single-cell RNA sequencing analysis revealed that LM harboured a higher proportion of CD8 + T cells, CD4 + T cells, NK cells, NKT cells, and B cells exhibiting a stress-like phenotype compared to PL. RGS5 + pericytes may play a role in the stress-like phenotype observed in immune cells within LM. MCs in PL (PL_MCs) and LM (LM_MCs) exhibit distinct activation of tumor-associated signaling pathways. Notably, COLEC11 + matrix cancer-associated fibroblasts (COLEC11_mCAFs) were found to be significantly associated with LM_MCs. Cell communication analysis unveiled potential targetable receptor-ligand interactions between COLEC11_mCAFs and LM_MCs. Multidimensional validation confirmed the prominence of the characteristic stress-like phenotypes, including HSPA6_CD8_Tstr, HSPA6_NK, and COLEC11_mCAFs in LM. Moreover, a higher abundance of COLEC11_mCAFs correlated with poorer survival rates in the neuroendocrine tumor patient cohort.ConclusionOverall, our study provides the first single-cell analysis of the cellular and molecular differences between PL and LM in CRNELM patients. We identified distinct cell subsets and receptor-ligand interactions that may drive TME discrepancies and support metastatic tumor growth. These insights highlight potential therapeutic targets and inform strategies for better managing CRNELM patients.

Hyaluronan-coated gold nanoshells for enhanced synergistic effect and immunogenic cell response of chemo-photothermal therapy on lung cancer.

Lung cancer (LC) is the predominant cause of cancer-related fatalities globally, with the highest death rates in both genders, primarily attributed to smoking. The non-kinase transmembrane cell surface glycoprotein, CD44, enhances LC cell migration and invasion, leading to drug resistance and an unfavorable prognosis. This research formulated a cisplatin-loaded gold nanoshell (HCP@GNS) integrated with hyaluronan (HCP@GNS@HA) to enhance targeting capability and realize a synergistic effect of chemo-photothermal therapy (chemo-PTT) against LC. The coating of hyaluronic acid (HA) facilitated the uptake of HCP@GNS@HA into CD44-rich cancer cells, maintaining the superior photothermal conversion capacity of HCP@GNS nanoparticles for hyperthermia and photothermal eradication of tumor tissues under near-infrared exposure. As a nanocarrier, HCP@GNS@HA exhibited high biocompatibility and hemocompatibility, showing stronger cytotoxicity than either the free drug or photothermal therapy alone when combined with NIR irradiation, especially at high cis-diamminedichloroplatinum (II) (CDDP) concentrations. The chemo-PTT mediated by HCP@GNS@HA effectively curtailed tumor growth without adverse effects, significantly mobilizing B cells, DC cells, macrophages, natural killer (NK) cells, and NKT cells in the distal tumor against tumor growth. In conclusion, the developed hyaluronic acid (HA)-coated gold nanoshells could potentially serve as a promising candidate for nanomedicine, tackling both primary and distal LC growth.

Generating allogeneic CAR-NKT cells for off-the-shelf cancer immunotherapy with genetically engineered HSP cells and feeder-free differentiation culture.

The clinical potential of current chimeric antigen receptor-engineered T (CAR-T) cell therapy is hampered by its autologous nature that poses considerable challenges in manufacturing, costs and patient selection. This spurs demand for off-the-shelf therapies. Here we introduce an ex vivo feeder-free culture method to differentiate gene-engineered hematopoietic stem and progenitor (HSP) cells into allogeneic invariant natural killer T (AlloNKT) cells and their CAR-armed derivatives (AlloCAR-NKT cells). We include detailed information on lentivirus generation and titration, as well as the five stages of ex vivo culture required to generate AlloCAR-NKT cells, including HSP cell engineering, HSP cell expansion, NKT cell differentiation, NKT cell deep differentiation and NKT cell expansion. In addition, we describe procedures for evaluating the pharmacology, antitumor efficacy and mechanism of action of AlloCAR-NKT cells. It takes ~2 weeks to generate and titrate lentiviruses and ~6 weeks to generate mature AlloCAR-NKT cells. Competence with human stem cell and T cell culture, gene engineering and flow cytometry is required for optimal results.

The Role of Sulfatides in Liver Health and Disease.

Sulfatides or 3-O-sulfogalactosylceramide are negatively charged sulfated glycosphingolipids abundant in the brain and kidneys and play crucial roles in nerve impulse conduction and urinary pH regulation. Sulfatides are present in the liver, specifically in the biliary tract. Sulfatides are self-lipid antigens presented by cholangiocytes to activate cluster of differentiation 1d (CD1d)-restricted type II natural killer T (NKT) cells. These cells are involved in alcohol-related liver disease (ArLD) and ischemic liver injury and exert anti-inflammatory effects by regulating the activity of pro-inflammatory type I NKT cells. Loss of sulfatides has been implicated in the chronic inflammatory disorder of the liver known as primary sclerosing cholangitis (PSC); bile ducts deficient in sulfatides increase their permeability, resulting in the spread of bile into the liver parenchyma. Previous studies have shown elevated levels of sulfatides in hepatocellular carcinoma (HCC), where sulfatides could act as adhesive molecules that contribute to cancer metastasis. We have recently demonstrated how loss of function of GAL3ST1, a limiting enzyme involved in sulfatide synthesis, reduces tumorigenic capacity in cholangiocarcinoma (CCA) cells. The biological function of sulfatides in the liver is still unclear; however, this review aims to summarize the existing findings on the topic.

PRDM1 is a key regulator of the natural killer T-cell central memory program and effector function.

Natural killer T cells (NKTs) are a promising platform for cancer immunotherapy, but few genes involved in regulation of NKT therapeutic activity have been identified. To find regulators of NKT functional fitness, we developed a CRISPR/Cas9-based mutagenesis screen that employs a guide RNA (gRNA) library targeting 1,118 immune-related genes. Unmodified NKTs and NKTs expressing a GD2-specific chimeric antigen receptor (GD2.CAR) were transduced with the gRNA library and exposed to CD1d+ leukemia or CD1d-GD2+ neuroblastoma cells, respectively, over six challenge cycles in vitro. Quantification of gRNA abundance revealed enrichment of PRDM1-specific gRNAs in both NKTs and GD2.CAR NKTs, a result that was validated through targeted PRDM1 knockout. Transcriptional, phenotypic, and functional analyses demonstrated that CAR NKTs with PRDM1 knockout underwent central memory-like differentiation and resisted exhaustion. However, these cells downregulated the cytotoxic mediator granzyme B and showed reduced in vitro cytotoxicity and only moderate in vivo antitumor activity in a xenogeneic neuroblastoma model. In contrast, shRNA-mediated PRDM1 knockdown preserved effector function while promoting central memory differentiation, resulting in GD2.CAR NKTs with potent in vivo antitumor activity. Thus, we have identified PRDM1 as a regulator of NKT memory differentiation and effector function that can be exploited to improve the efficacy of NKT-based cancer immunotherapies.

GIMAP1 interacts with TMX1 to improve lung adenocarcinoma prognosis by influencing tumor immune microenvironment.

Recent studies have indicated that the GIMAP family is downregulated in lung cancer and correlates with poor prognosis, although the underlying mechanisms remain unclear. This study aimed to elucidate the mechanism behind GIMAP1 downregulation in lung cancer. Bioinformatics tools were employed to assess the correlation between the GIMAP family and various cancers. Specifically, GIMAP1 was selected for further investigation, and its role in lung adenocarcinoma was confirmed through RNA sequencing analysis, Gene Set Enrichment Analysis (GSEA) of differentially expressed genes, correlation analysis with immune cell infiltration, and assay of the GIMAP1-TMX1 interaction. Based on bioinformatics analysis and real-world cohort studies, it was found that GIMAP1 was underexpressed in lung cancer tissues but exhibited elevated expression following immunotherapy. Overexpression of GIMAP1 was shown to influence several immune signaling pathways. In patients with high GIMAP1 expression, there was a significant increase in the infiltration of CD8+ T cells, activated memory CD4+ T cells, monocytes, and M1 macrophages; conversely, infiltration by M0 macrophages, resting dendritic cells (DCs), and plasma cells was significantly reduced. In vitro experiments showed that high levels of GIMAP1 increased the percentage of Treg, NK, and NKT cells. Additionally, GIMAP1 directly interacted with TMX1 and modulated the expression of downstream immune-related genes including CMTM5, IL17F, TRAV34, and XCR1. Therefore, GIMAP1 may serve as a promising therapeutic target in lung cancer, influencing both disease initiation and progression.

Lipid Antigens: Revealing the Hidden Players in Adaptive Immune Responses.

Traditionally, research on the adaptive immune system has focused on protein antigens, but emerging evidence has underscored the essential role of lipid antigens in immune modulation. Lipid antigens are presented by CD1 molecules and activate invariant natural killer T (iNKT) cells and group 1 CD1-restricted T cells, whereby they impact immune responses to pathogens and tumors. Recent advances in mass spectrometry, imaging techniques, and lipidomics have revolutionized the identification and characterization of lipid antigens and enhanced our understanding of their structural diversity and functional significance. These advancements have paved the way for lipid-based vaccines and immunotherapies through the application of nanoparticles and synthetic lipid antigens designed to boost immune responses against cancers and infectious diseases. Lipid trafficking, CD1 molecule interactions, and the immune system's response to lipid antigens are yet to be completely understood, particularly in the context of autoimmunity and microbial infections. In the years to come, continued research efforts are needed to uncover its underlying biological mechanisms and to exploit the full potential of therapies directed against lipid antigens.

Macrophages and Pulmonary Fibrosis.

Most chronic respiratory diseases often lead to the clinical manifestation of pulmonary fibrosis. Inflammation and immune disorders are widely recognized as primary contributors to the onset of pulmonary fibrosis. Given that macrophages are predominantly responsible for inflammation and immune disorders, in this review, we first focused on the role of different subpopulations of macrophages in the lung and discussed the crosstalk between macrophages and other immune cells, such as neutrophils, regulatory T cells, NKT cells, and B lymphocytes during pulmonary fibrogenesis. Subsequently, we analyzed the interaction between macrophages and fibroblasts as a possible new research direction. Finally, we proposed that exosomes, which function as a means of communication between macrophages and target cells to maintain cellular homeostasis, are a strategy for targeting lung drugs in the future. By comprehending the mechanisms underlying the interplay between macrophages and other lung cells, we aim to enhance our understanding of pulmonary fibrosis, leading to improved diagnostics, preventative measures, and the potential development of macrophage-based therapeutics.

Association of Healthy Eating Index-2015 Total and Component Scores with Measures of Inflammation and Immune Activation in Healthy Adults.

The Healthy Eating Index (HEI)-2015 measures diet quality and is associated with a lower risk of death from chronic disease. Dietary components may affect health via multiple mechanisms, including decreasing inflammation and affecting immune activation. We hypothesized that the overall HEI-2015 score, or individual component scores, would be associated with altered inflammation and immune activation in healthy adults. The association of HEI-2015 scores with 88 inflammation and immune activation markers was examined in 346 adults without diagnosed disease using general linear models to adjust for covariates, including visceral fat mass index (VFMI). The overall HEI-2015 score was inversely associated with plasma C-reactive protein (CRP) and leukocyte concentrations, which are markers of inflammation, but these associations lost statistical significance with adjustment for VFMI. However, even with VFMI adjustment, the total vegetable score was inversely associated with total lymphocyte concentration (β = -0.157 ± 0.052, P = 0.019) and with monocyte and neutrophil activation (e.g., classic monocyte CD11b β = -0.153 ± 0.055, P = 0.030; neutrophil CD11b β = -0.122 ± 0.051, P = 0.049). The refined grain score was inversely associated with percent NK-T cells (β =-0.171 ± 0.058, P = 0.037), IL-10 production by T cells (β = -0.204 ± 0.057, P = 0.0039), and positively associated with plasma soluble CD14 (β = 0.220 ± 0.059, P = 0.0041). The total dairy score was positively associated with production of multiple cytokines by lipopolysaccharide-stimulated peripheral blood mononuclear cells [e.g., interleukin (IL)-1β β = 0.182 ± 0.054, P = 0.0066]. Adjustment for VFMI decreased the association of HEI-2015 with inflammation, consistent with the known role of adiposity in mediating effects of poor diet on inflammation. This study also identified component scores associated with various aspects of immune activation that bear further study to clarify possible health benefits. This trial was registered at clinicaltrials.gov as NCT02367287.

The transcriptional profile of iron deficiency in patients with heart failure: Heme-sparing and reduced immune processes.

Iron deficiency (ID) is highly prevalent in patients with heart failure (HF) and associated with morbidity and poor prognosis, but pathophysiological mechanisms are unknown. We aimed to identify novel biological pathways affected by ID. We studied 881 patients with HF from the BIOSTAT-CHF cohort. ID was defined as a transferrin saturation <20%. Transcriptome profiling was performed in whole blood. Identified targets were validated in a human in vitro stem cell-derived cardiomyocyte ID model utilizing deferoxamine as iron chelator. ID was identified in 554 (62.9%) patients, and 89 differentially expressed genes between ID and non-ID were identified, of which 60 were up- and 29 were downregulated. Upregulated genes were overrepresented in pathways of erythrocyte development and homeostasis. Heme biosynthetic processes were confirmed as relatively upregulated in ID, while iron-sulfur cluster assembly was downregulated. Downregulated processes further included natural killer cell and lymphocyte mediated immunity. In agreement with patient data, cardiomyocyte iron depletion significantly induced the expression of two genes (SIAH2 and CLIC4), which could be normalized upon iron supplementation. Both SIAH2 and CLIC4 are associated with increased mortality in patients with HF (hazard ratio 2.40, 95% confidence interval 1.86-3.11, p < 0.001 hazard ratio 1.78, 95% confidence interval 1.53-2.07, p < 0.001, respectively). Iron deficiency is associated with the preservation of heme-related processes at the cost of iron-sulfur clusters. Immune processes are downregulated, uncovering another high energy demand system affected. SIAH2 and CLIC4 might be modifiable factors in the relation between ID and impaired prognosis.

COVID-19 Serostatus Does Not Affect the Intrauterine Transfer of Micronutrients and Fatty Acids or Maternal–fetal Lymphocyte Cell Composition: An Observational Study

Objective Studies on the effects of coronavirus disease 2019 (COVID-19) on pregnant mothers and their newborns, specifically in relation to their micronutrient status, fatty acids (FAs), and inflammatory status are sparse. We hypothesized that COVID-19 infection would adversely affect the transfer of nutrients, and FAs from mothers to their fetuses via the umbilical cord and maternal–fetal distribution of inflammatory cells. This study aimed to determine the effect of COVID-19 on micronutrients, inflammatory markers, and FAs profiles in pregnant mothers and their newborns' cord blood. Study Design This was a cross-sectional study of 212 pregnant mothers in the third trimester and their newborns, recruited after testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serostatus. Peripheral blood of mothers and cord blood were collected at birth and analyzed for vitamin B12 (Vit B12), folic acid, 25(OH)D3, FAs, and peripheral blood mononuclear cells. Student's t-test or analysis of variance (ANOVA) was used to express statistical significance. Non-normal data were tested using the Mann–Whitney U test and Kruskal–Wallis test, with proportions compared with the chi-square test. Results Vit B12 levels were significantly low and adrenic acid levels significantly high in COVID-19 seropositive mothers while 25(OH)D3 was significantly low in seropositive cord blood. Irrespective of COVID-19 serostatus, folate, vit B12, saturated FA levels were significantly high in cord blood indicating their increased transfer from mothers to the fetus. However, monounsaturated (MUFA) and polyunsaturated fatty acid (PUFA) levels were significantly lower in cord blood. Irrespective of COVID-19 serostatus, CD4+ T helper cells (percentage of lymphocytes) were significantly higher in cord blood, while NK cells, NK-T cells, and CD8+ T-cytotoxic cells—percentage of lymphocytes—were significantly lower in cord blood when compared with corresponding mother's blood. Conclusion The results indicate that while COVID-19 did not impede the transfer of essential nutrients such as MUFA and PUFA from mother to fetus, or affect maternal–fetal immune cell responses, it did appear to affect the levels of vit B12, vitamin D, and adrenic acid. Key Points

The α glycolipid rules the NKT cell TCR.

In this issue of JEM, Hosono et al. (https://doi.org/10.1084/jem.20240728) characterize a putative self- glycolipid that engages the iNKT cell TCR when bound to CD1d. The expression and distribution of this compound helps to explain some of the unusual properties of invariant NKT cells.

Can there be calm during a cytokine storm? Immune checkpoint pathways affecting the severity of COVID-19 disease

IntroductionThe COVID-19 pandemic has become a global health crisis, eliciting varying severity in infected individuals. This study aimed to explore the immune profiles between moderate and severe COVID-19 patients experiencing a cytokine storm and their association with mortality. This study highlights the role of PD-1/PD-L1 and the TIGIT/CD226/CD155/CD112 pathways in COVID-19 patients.MethodsWe performed a study using flow cytometry to compare the phenotypic and functional characteristics of peripheral blood mononuclear cells in patients with moderate or severe disease and healthy individuals. Soluble immune checkpoint molecule and ligand levels were measured by Luminex.ResultsSevere patients show reduced CD8+ T cell frequency, hyperactivation of CD8+ T, NK and NKT cells with concurrent upregulation of immune checkpoint ligands in monocytes. TIGIT expression by CD8+ T and NK cells and PD-1 by NKT cells suggest a spectrum of immune dysfunction, encompassing both hyperactivation and features of exhaustion. This dual phenomenon likely contributes to the impaired viral clearance and the exacerbation of inflammation characteristic of severe disease. Additionally, the study suggests that increased activation and cytotoxicity of NK cells may be associated with fatal outcomes in severe COVID-19 infection.ConclusionThese findings shed light on the intricate immune response regulation in COVID-19, emphasizing the importance of immune checkpoint pathways and activation signatures in disease severity. A novel aspect of this study is that it includes only COVID-19 patients experiencing cytokine storms, allowing for a focused analysis of immune dysregulation during this critical phase of the disease.