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Nature Communications Jun 2024Dexamethasone is the standard of care for critically ill patients with COVID-19, but the mechanisms by which it decreases mortality and its immunological effects in this...
Dexamethasone is the standard of care for critically ill patients with COVID-19, but the mechanisms by which it decreases mortality and its immunological effects in this setting are not understood. Here we perform bulk and single-cell RNA sequencing of samples from the lower respiratory tract and blood, and assess plasma cytokine profiling to study the effects of dexamethasone on both systemic and pulmonary immune cell compartments. In blood samples, dexamethasone is associated with decreased expression of genes associated with T cell activation, including TNFSFR4 and IL21R. We also identify decreased expression of several immune pathways, including major histocompatibility complex-II signaling, selectin P ligand signaling, and T cell recruitment by intercellular adhesion molecule and integrin activation, suggesting these are potential mechanisms of the therapeutic benefit of steroids in COVID-19. We identify additional compartment- and cell- specific differences in the effect of dexamethasone that are reproducible in publicly available datasets, including steroid-resistant interferon pathway expression in the respiratory tract, which may be additional therapeutic targets. In summary, we demonstrate compartment-specific effects of dexamethasone in critically ill COVID-19 patients, providing mechanistic insights with potential therapeutic relevance. Our results highlight the importance of studying compartmentalized inflammation in critically ill patients.
Topics: Dexamethasone; Humans; COVID-19 Drug Treatment; COVID-19; SARS-CoV-2; Lung; Cytokines; Critical Illness; Male; Single-Cell Analysis; Female; Middle Aged; T-Lymphocytes; Aged; Lymphocyte Activation
PubMed: 38942804
DOI: 10.1038/s41467-024-49756-2 -
Nature Communications Jun 2024Cancer treatment continues to shift from utilizing traditional therapies to targeted ones, such as protein kinase inhibitors and immunotherapy. Mobilizing dendritic...
Cancer treatment continues to shift from utilizing traditional therapies to targeted ones, such as protein kinase inhibitors and immunotherapy. Mobilizing dendritic cells (DC) and other myeloid cells with antigen presenting and cancer cell killing capacities is an attractive but not fully exploited approach. Here, we show that PIKFYVE is a shared gene target of clinically relevant protein kinase inhibitors and high expression of this gene in DCs is associated with poor patient response to immune checkpoint blockade (ICB) therapy. Genetic and pharmacological studies demonstrate that PIKfyve ablation enhances the function of CD11c cells (predominantly dendritic cells) via selectively altering the non-canonical NF-κB pathway. Both loss of Pikfyve in CD11c cells and treatment with apilimod, a potent and specific PIKfyve inhibitor, restrained tumor growth, enhanced DC-dependent T cell immunity, and potentiated ICB efficacy in tumor-bearing mouse models. Furthermore, the combination of a vaccine adjuvant and apilimod reduced tumor progression in vivo. Thus, PIKfyve negatively regulates the function of CD11c cells, and PIKfyve inhibition has promise for cancer immunotherapy and vaccine treatment strategies.
Topics: Animals; Humans; Dendritic Cells; Mice; Phosphatidylinositol 3-Kinases; CD11c Antigen; Morpholines; Cell Line, Tumor; Immunotherapy; Neoplasms; Mice, Inbred C57BL; Female; Immune Checkpoint Inhibitors; NF-kappa B; T-Lymphocytes; Protein Kinase Inhibitors; Hydrazones; Pyrimidines
PubMed: 38942798
DOI: 10.1038/s41467-024-48931-9 -
Scientific Reports Jun 2024Understanding the cellular and molecular mechanisms of inflammation requires robust animal models. Sheep are commonly used in immune-related studies, yet the validity of... (Comparative Study)
Comparative Study
Understanding the cellular and molecular mechanisms of inflammation requires robust animal models. Sheep are commonly used in immune-related studies, yet the validity of sheep as animal models for immune and inflammatory diseases remains to be established. This cross-species comparative study analyzed the in vitro inflammatory response of ovine (oPBMCs) and human PBMCs (hPBMCs) using mass spectrometry, profiling the proteome of the secretome and whole cell lysate. Of the entire cell lysate proteome (oPBMCs: 4217, hPBMCs: 4574 proteins) 47.8% and in the secretome proteome (oPBMCs: 1913, hPBMCs: 1375 proteins) 32.8% were orthologous between species, among them 32 orthologous CD antigens, indicating the presence of six immune cell subsets. Following inflammatory stimulation, 71 proteins in oPBMCs and 176 in hPBMCs showed differential abundance, with only 7 overlapping. Network and Gene Ontology analyses identified 16 shared inflammatory-related terms and 17 canonical pathways with similar activation/inhibition patterns in both species, demonstrating significant conservation in specific immune and inflammatory responses. However, ovine PMBCs also contained a unique WC1γδ T-cell subset, not detected in hPBMCs. Furthermore, differences in the activation/inhibition trends of seven canonical pathways and the sets of DAPs between sheep and humans, emphasize the need to consider interspecies differences in translational studies and inflammation research.
Topics: Humans; Animals; Sheep; Leukocytes, Mononuclear; Proteomics; Inflammation; Proteome
PubMed: 38942936
DOI: 10.1038/s41598-024-66059-0 -
Scientific Reports Jun 2024Helminth infections lead to an overdispersion of the parasites in humans as well as in animals. We asked whether early immune responses against migrating Ascaris larvae...
Helminth infections lead to an overdispersion of the parasites in humans as well as in animals. We asked whether early immune responses against migrating Ascaris larvae are responsible for the unequal distribution of worms in natural host populations and thus investigated a susceptible versus a resistant mouse strain. In mice, the roundworm larvae develop until the lung stage and thus early anti-Ascaris immune responses against the migrating larvae in the liver and lung can be deciphered. Our data show that susceptible C57BL/6 mice respond to Ascaris larval migration significantly stronger compared to resistant CBA mice and the anti-parasite reactivity is associated with pathology. Increased eosinophil recruitment was detected in the liver and lungs, but also in the spleen and peritoneal cavity of susceptible mice on day 8 post infection compared to resistant mice. In serum, eosinophil peroxidase levels were significantly higher only in the susceptible mice, indicating functional activity of the recruited eosinophils. This effect was associated with an increased IL-5/IL-13 production by innate lymphoid cells and CD4 T cells and a pronounced type 2 macrophage polarization in the lungs of susceptible mice. Furthermore, a comparison of wildtype BALB/c and eosinophil-deficient dblGATA-1 BALB/c mice showed that eosinophils were not essential for the early control of migrating Ascaris larvae. In conclusion, in primary infection, a strong local and systemic type 2 immune response during hepato-tracheal helminth larval migration is associated with pathology rather than protection.
Topics: Animals; Ascariasis; Larva; Mice; Th2 Cells; Mice, Inbred BALB C; Lung; Ascaris; Eosinophils; Mice, Inbred C57BL; Mice, Inbred CBA; Liver; Female
PubMed: 38942904
DOI: 10.1038/s41598-024-65281-0 -
Scientific Reports Jun 2024The tobacco alkaloid nicotine is known for its activation of neuronal nicotinic acetylcholine receptors. Nicotine is consumed in different ways such as through...
The tobacco alkaloid nicotine is known for its activation of neuronal nicotinic acetylcholine receptors. Nicotine is consumed in different ways such as through conventional smoking, e-cigarettes, snuff or nicotine pouches. The use of snuff has been associated with several adverse health effects, such as inflammatory reactions of the oral mucosa and oral cavity cancer. We performed a metabolomic analysis of nicotine-exposed THP-1 human monocytes. Cells were exposed to 5 mM of the alkaloid for up to 4 h, and cell extracts and medium subjected to untargeted liquid chromatography high-resolution mass spectrometry. Raw data processing revealed 17 nicotine biotransformation products. Among these, cotinine and nornicotine were identified as the two major cellular biotransformation products. The application of multi- and univariate statistical analyses resulted in the annotation, up to a certain level of identification, of 12 compounds in the cell extracts and 13 compounds in the medium that were altered by nicotine exposure. Of these, four were verified as methylthioadenosine, cytosine, uric acid, and L-glutamate. Methylthioadenosine levels were affected in both cells and the medium, while cytosine, uric acid, and L-glutamate levels were affected in the medium only. The effects of smoking on the pathways involving these metabolites have been previously demonstrated in humans. Most of the other discriminating compounds, which were merely tentatively or not fully identified, were amino acids or amino acid derivatives. In conclusion, our preliminary data suggest that some of the potentially adverse effects related to smoking may also be expected when nicotine is consumed via snuff or nicotine pouches.
Topics: Humans; Nicotine; Metabolomics; Monocytes; Mass Spectrometry; THP-1 Cells; Cotinine; Chromatography, Liquid; Metabolome; Glutamic Acid
PubMed: 38942832
DOI: 10.1038/s41598-024-65733-7 -
Annual Review of Immunology Jun 2024Regionalized immune surveillance relies on the concerted efforts of diverse memory T cell populations. Of these, tissue-resident memory T (T) cells are strategically... (Review)
Review
Regionalized immune surveillance relies on the concerted efforts of diverse memory T cell populations. Of these, tissue-resident memory T (T) cells are strategically positioned in barrier tissues, where they enable efficient frontline defense against infections and cancer. However, the long-term persistence of these cells has been implicated in a variety of immune-mediated pathologies. Consequently, modulating T cell populations represents an attractive strategy for novel vaccination and therapeutic interventions against tissue-based diseases. Here, we provide an updated overview of T cell heterogeneity and function across tissues and disease states. We discuss mechanisms of T cell-mediated immune protection and their potential contributions to autoimmune disorders. Finally, we examine how T cell responses might be durably boosted or dampened for therapeutic gain.
Topics: Humans; Animals; Immunologic Memory; Memory T Cells; Autoimmune Diseases; Organ Specificity; T-Lymphocyte Subsets; Immunologic Surveillance
PubMed: 38941605
DOI: 10.1146/annurev-immunol-101320-020220 -
Annual Review of Immunology Jun 2024The intestine is the largest peripheral lymphoid organ in animals, including humans, and interacts with a vast array of microorganisms called the gut microbiota.... (Review)
Review
The intestine is the largest peripheral lymphoid organ in animals, including humans, and interacts with a vast array of microorganisms called the gut microbiota. Comprehending the symbiotic relationship between the gut microbiota and our immune system is essential not only for the field of immunology but also for understanding the pathogenesis of various systemic diseases, including cancer, cardiometabolic disorders, and extraintestinal autoimmune conditions. Whereas microbe-derived antigens are crucial for activating the intestinal immune system, particularly T and B cells, as environmental cues, microbes and their metabolites play a critical role in directing the differentiation of these immune cells. Microbial metabolites are regarded as messengers from the gut microbiota, since bacteria have the ability to produce unique molecules that humans cannot, and many immune cells in the intestine express receptors for these molecules. This review highlights the distinct relationships between microbial metabolites and the differentiation and function of the immune system.
Topics: Humans; Animals; Gastrointestinal Microbiome; Cell Differentiation; B-Lymphocytes; T-Lymphocytes; Bacteria
PubMed: 38941602
DOI: 10.1146/annurev-immunol-090222-102035 -
Science Immunology Jun 2024Activation of natural killer (NK) cells with the cytokines interleukin-12 (IL-12), IL-15, and IL-18 induces their differentiation into memory-like (ML) NK cells;...
Activation of natural killer (NK) cells with the cytokines interleukin-12 (IL-12), IL-15, and IL-18 induces their differentiation into memory-like (ML) NK cells; however, the underlying epigenetic and transcriptional mechanisms are unclear. By combining ATAC-seq, CITE-seq, and functional analyses, we discovered that IL-12/15/18 activation results in two main human NK fates: reprogramming into enriched memory-like (eML) NK cells or priming into effector conventional NK (effcNK) cells. eML NK cells had distinct transcriptional and epigenetic profiles and enhanced function, whereas effcNK cells resembled cytokine-primed cNK cells. Two transcriptionally discrete subsets of eML NK cells were also identified, eML-1 and eML-2, primarily arising from CD56 or CD56 mature NK cell subsets, respectively. Furthermore, these eML subsets were evident weeks after transfer of IL-12/15/18-activated NK cells into patients with cancer. Our findings demonstrate that NK cell activation with IL-12/15/18 results in previously unappreciated diverse cellular fates and identifies new strategies to enhance NK therapies.
Topics: Humans; Killer Cells, Natural; Epigenesis, Genetic; Immunologic Memory; Cytokines; Gene Expression Regulation; Cell Differentiation; Interleukin-15
PubMed: 38941480
DOI: 10.1126/sciimmunol.adk4893 -
Science Immunology Jun 2024KLRG1 CD8 T cells persist for months after clearance of acute infections and maintain high levels of effector molecules, contributing protective immunity against...
KLRG1 CD8 T cells persist for months after clearance of acute infections and maintain high levels of effector molecules, contributing protective immunity against systemic pathogens. Upon secondary infection, these long-lived effector cells (LLECs) are incapable of forming other circulating KLRG1 memory subsets such as central and effector memory T cells. Thus, KLRG1 memory T cells are frequently referred to as a terminally differentiated population that is relatively short lived. Here, we show that after viral infection of mice, effector cells derived from LLECs rapidly enter nonlymphoid tissues and reduce pathogen burden but are largely dependent on receiving antigen cues from vascular endothelial cells. Single-cell RNA sequencing reveals that secondary memory cells in nonlymphoid tissues arising from either KLRG1 or KLRG1 memory precursors develop a similar resident memory transcriptional signature. Thus, although LLECs cannot differentiate into other circulating memory populations, they still retain the flexibility to enter tissues and establish residency.
Topics: Animals; Receptors, Immunologic; Mice; Lectins, C-Type; Mice, Inbred C57BL; Memory T Cells; Immunologic Memory; CD8-Positive T-Lymphocytes; Female; Mice, Knockout
PubMed: 38941479
DOI: 10.1126/sciimmunol.adj8356 -
Science Immunology Jun 2024Immune cells have intensely physical lifestyles characterized by structural plasticity and force exertion. To investigate whether specific immune functions require...
Immune cells have intensely physical lifestyles characterized by structural plasticity and force exertion. To investigate whether specific immune functions require stereotyped mechanical outputs, we used super-resolution traction force microscopy to compare the immune synapses formed by cytotoxic T cells with contacts formed by other T cell subsets and by macrophages. T cell synapses were globally compressive, which was fundamentally different from the pulling and pinching associated with macrophage phagocytosis. Spectral decomposition of force exertion patterns from each cell type linked cytotoxicity to compressive strength, local protrusiveness, and the induction of complex, asymmetric topography. These features were validated as cytotoxic drivers by genetic disruption of cytoskeletal regulators, live imaging of synaptic secretion, and in silico analysis of interfacial distortion. Synapse architecture and force exertion were sensitive to target stiffness and size, suggesting that the mechanical potentiation of killing is biophysically adaptive. We conclude that cellular cytotoxicity and, by implication, other effector responses are supported by specialized patterns of efferent force.
Topics: Animals; Immunological Synapses; Single-Cell Analysis; Mice; T-Lymphocytes, Cytotoxic; Biomechanical Phenomena; Cytotoxicity, Immunologic; Macrophages; Mice, Inbred C57BL
PubMed: 38941478
DOI: 10.1126/sciimmunol.adj2898