RESUMO
Age is a risk factor for hematologic malignancies. Attributes of the aging hematopoietic system include increased myelopoiesis, impaired adaptive immunity, and a functional decline of the hematopoietic stem cells (HSCs) that maintain hematopoiesis. Changes in the composition of diverse HSC subsets have been suggested to be responsible for age-related alterations, however, the underlying regulatory mechanisms are incompletely understood in the context of HSC heterogeneity. In this study, we investigated how distinct HSC subsets, separated by CD49b, functionally and molecularly change their behavior with age. We demonstrate that the lineage differentiation of both lymphoid-biased and myeloid-biased HSC subsets progressively shifts to a higher myeloid cellular output during aging. In parallel, we show that HSCs selectively undergo age-dependent gene expression and gene regulatory changes in a progressive manner, which is initiated already in the juvenile stage. Overall, our studies suggest that aging intrinsically alters both cellular and molecular properties of HSCs.
Assuntos
Envelhecimento , Células-Tronco Hematopoéticas , Camundongos Endogâmicos C57BL , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/citologia , Animais , Envelhecimento/genética , Envelhecimento/fisiologia , Camundongos , Diferenciação Celular , Linhagem da Célula/genética , Hematopoese/genética , Células Mieloides/metabolismo , Células Mieloides/citologia , Masculino , Regulação da Expressão Gênica , FemininoRESUMO
BACKGROUND: Immunotherapy provided significant survival benefits for recurrent and metastatic patients with head and neck cancer. These improvements could not be reproduced in patients treated with curative-intent chemoradiotherapy (CRT) and the optimal radio-immunotherapy (RIT) concepts have yet to be designed. Exploration and analysis of the pre-therapeutic immune status of these patients and the changes occurring during the treatment course could be crucial in rationally designing future combined treatments. METHODS: Blood samples were collected from a cohort of 25 head and neck cancer patients treated with curative-intended (C)-RT prior to therapy, after the first week of treatment, and three months after treatment completion. Peripheral blood mononuclear cells (PBMCs) or all nucleated blood cells were isolated and analyzed via flow cytometry. RESULTS: At baseline, patients showed reduced monocyte and lymphocyte counts compared to healthy individuals. Although overall CD8+ T-cell frequencies were reduced, the proportion of memory subsets were increased in patients. Radiotherapy (RT) treatment led to a further increase in CD8+ effector memory T-cells. Among myeloid populations, tumor-promoting subsets became less abundant after RT, in favor of pro-inflammatory cells. CONCLUSION: The present study prospectively demonstrated a complex interplay and distinct longitudinal changes in the composition of lymphocytic and myeloid populations during curative (C)-RT of head and neck cancer. Further validation of this method in a larger cohort could allow for better treatment guidance and tailored incorporation of immunotherapies (IT) in the future.
Assuntos
Quimiorradioterapia , Neoplasias de Cabeça e Pescoço , Células Mieloides , Humanos , Neoplasias de Cabeça e Pescoço/terapia , Neoplasias de Cabeça e Pescoço/imunologia , Quimiorradioterapia/métodos , Masculino , Pessoa de Meia-Idade , Feminino , Idoso , Células Mieloides/imunologia , Estudos Longitudinais , Adulto , Estudos ProspectivosRESUMO
Histone H3-mutant gliomas are deadly brain tumors characterized by a dysregulated epigenome and stalled differentiation. In contrast to the extensive datasets available on tumor cells, limited information exists on their tumor microenvironment (TME), particularly the immune infiltrate. Here, we characterize the immune TME of H3.3K27M and G34R/V-mutant gliomas, and multiple H3.3K27M mouse models, using transcriptomic, proteomic and spatial single-cell approaches. Resolution of immune lineages indicates high infiltration of H3-mutant gliomas with diverse myeloid populations, high-level expression of immune checkpoint markers, and scarce lymphoid cells, findings uniformly reproduced in all H3.3K27M mouse models tested. We show these myeloid populations communicate with H3-mutant cells, mediating immunosuppression and sustaining tumor formation and maintenance. Dual inhibition of myeloid cells and immune checkpoint pathways show significant therapeutic benefits in pre-clinical syngeneic mouse models. Our findings provide a valuable characterization of the TME of oncohistone-mutant gliomas, and insight into the means for modulating the myeloid infiltrate for the benefit of patients.
Assuntos
Neoplasias Encefálicas , Glioma , Histonas , Mutação , Células Mieloides , Microambiente Tumoral , Animais , Glioma/genética , Glioma/imunologia , Glioma/patologia , Microambiente Tumoral/imunologia , Microambiente Tumoral/genética , Células Mieloides/metabolismo , Células Mieloides/imunologia , Histonas/metabolismo , Histonas/genética , Camundongos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Humanos , Linhagem Celular Tumoral , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Regulação Neoplásica da Expressão Gênica , Análise de Célula ÚnicaRESUMO
T cell immunoglobulin and mucin-containing molecule 3 (TIM-3) exhibits unique, cell type- and context-dependent characteristics and functions. Here, we report that TIM-3 on myeloid cells plays essential roles in modulating lung inflammation. We found that myeloid cell-specific TIM-3 knock-in (FSF-TIM3/LysM-Cre+) mice have lower body weight and shorter lifespan than WT mice. Intriguingly, the lungs of FSF-TIM3/LysM-Cre+ mice display excessive inflammation and features of disease-associated pathology. We further revealed that galectin-3 levels are notably elevated in TIM-3-overexpressing lung-derived myeloid cells. Furthermore, both TIM-3 blockade and GB1107, a galectin-3 inhibitor, ameliorated lung inflammation in FSF-TIM3/LysM-Cre+/- mice. Using an LPS-induced lung inflammation model with myeloid cell-specific TIM-3 knock-out mice, we demonstrated the association of TIM-3 with both lung inflammation and galectin-3. Collectively, our findings suggest that myeloid TIM-3 is an important regulator in the lungs and that modulation of TIM-3 and galectin-3 could offer therapeutic benefits for inflammation-associated lung diseases.
Assuntos
Galectina 3 , Receptor Celular 2 do Vírus da Hepatite A , Células Mieloides , Pneumonia , Animais , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Receptor Celular 2 do Vírus da Hepatite A/genética , Galectina 3/metabolismo , Galectina 3/genética , Células Mieloides/metabolismo , Camundongos , Pneumonia/metabolismo , Pneumonia/patologia , Pneumonia/genética , Camundongos Knockout , Camundongos Endogâmicos C57BL , Galectinas/metabolismo , Galectinas/genética , Pulmão/patologia , Pulmão/metabolismoRESUMO
Rationale: Dysregulated T-cell immune response-mediated inflammation plays critical roles in the pathology of diverse liver diseases, but the underlying mechanism of liver immune homeostasis control and the specific therapies for limiting T-cell overactivation remain unclear. Methods: The metabolic changes in concanavalin A (ConA) mice and autoimmune hepatitis (AIH) patients and their associations with liver injury were analyzed. The expression of purine catabolism nucleases (e.g., CD39 and CD73) on liver cells and immune cells was assessed. The effects of MCregs and their extracellular vesicles (EVs) on CD4+ T-cell overactivation and the underlying mechanism were also explored. Results: Our findings revealed significant alterations in purine metabolism in ConA mice and AIH patients, which correlated with liver injury severity and therapeutic response. CD39 and CD73 were markedly upregulated on CD11b+Gr-1+ MCs under liver injury conditions. The naturally expanded CD39+CD73+Gr-1highCD11b+ MCreg subset during early liver injury effectively suppressed CD4+ T-cell hyperactivation and liver injury both in vitro and in vivo. Mechanistically, MCregs released CD73high EVs, which converted extracellular AMP to immunosuppressive metabolites (e.g., adenosine and inosine), activating the cAMP pathway and inhibiting glycolysis and cytokine secretion in activated CD4+ T cells. Conclusions: This study provides insights into the mechanism controlling immune homeostasis during the early liver injury phase and highlights that MCreg or MCreg-EV therapy may be a specific strategy for preventing diverse liver diseases induced by T-cell overactivation.
Assuntos
Vesículas Extracelulares , Hepatite Autoimune , Camundongos Endogâmicos C57BL , Purinas , Animais , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/imunologia , Camundongos , Purinas/metabolismo , Hepatite Autoimune/imunologia , Hepatite Autoimune/metabolismo , Hepatite Autoimune/patologia , Humanos , Apirase/metabolismo , Fígado/metabolismo , Fígado/imunologia , Fígado/patologia , Células Mieloides/metabolismo , Células Mieloides/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Masculino , 5'-Nucleotidase/metabolismo , Ativação Linfocitária/imunologia , Concanavalina A , Feminino , Modelos Animais de Doenças , Inflamação/metabolismo , Inflamação/imunologia , Antígenos CDRESUMO
Myeloid cells are the first line of defence against pathogens. Mitochondrial apoptosis signalling is a crucial regulator of myeloid cell lifespan and modulates the function of myeloid cells. The anti-apoptotic protein BCL-2-family protein BCL2A1/A1/BFL-1 is strongly upregulated in inflammation in macrophages. We analysed the contribution of A1 to apoptosis regulation in a conditional system of in vitro differentiation of murine macrophages from immortalised progenitors. We disabled the expression of A1 by targeting all murine A1 isoforms in the genome. Specific inhibitors were used to inactivate other anti-apoptotic proteins. Macrophage progenitor survival mainly depended on the anti-apoptotic proteins MCL-1, BCL-XL and A1 but not BCL-2. Deletion of A1 on its own had little effect on progenitor cell survival but was sensitised to cell death induction when BCL-XL or MCL-1 was neutralised. In progenitors, A1 was required for survival in the presence of the inflammatory stimulus LPS. Differentiated macrophages were resistant to inhibition of single anti-apoptotic proteins, but A1 was required to protect macrophages against inhibition of either BCL-XL or MCL-1; BCL-2 only had a minor role in these cells. Cell death by neutralisation of anti-apoptotic proteins completely depended on BAX with a small contribution of BAK only in progenitors in the presence of LPS. A1 and NOXA appeared to stabilise each other at the posttranscriptional level suggesting direct binding. Co-immunoprecipitation experiments showed the binding of A1 to NOXA and BIM. Interaction between A1 and Noxa may indirectly prevent neutralisation and destabilization of MCL-1. Our findings suggest a unique role for A1 as a modulator of survival in the macrophage lineage in concert with MCL-1 and BCL-XL, especially in a pro-inflammatory environment.
Assuntos
Apoptose , Diferenciação Celular , Sobrevivência Celular , Macrófagos , Proteína de Sequência 1 de Leucemia de Células Mieloides , Proteínas Proto-Oncogênicas c-bcl-2 , Proteína bcl-X , Animais , Proteína bcl-X/metabolismo , Macrófagos/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Antígenos de Histocompatibilidade Menor/genética , Lipopolissacarídeos/farmacologia , Células Mieloides/metabolismoRESUMO
In allergen-specific immunotherapy, adjuvants are explored for modulating allergen-specific Th2 immune responses to re-establish clinical tolerance. One promising class of adjuvants are ß-glucans, which are naturally derived sugar structures and components of dietary fibers that activate C-type lectin (CLR)-, "Toll"-like receptors (TLRs), and complement receptors (CRs). We characterized the immune-modulating properties of six commercially available ß-glucans, using immunological (receptor activation, cytokine secretion, and T cell modulating potential) as well as metabolic parameters (metabolic state) in mouse bone marrow-derived myeloid dendritic cells (mDCs). All tested ß-glucans activated the CLR Dectin-1a, whereas TLR2 was predominantly activated by Zymosan. Further, the tested ß-glucans differentially induced mDC-derived cytokine secretion and activation of mDC metabolism. Subsequent analyses focusing on Zymosan, Zymosan depleted, ß-1,3 glucan, and ß-1,3 1,6 glucan revealed robust mDC activation with the upregulation of the cluster of differentiation 40 (CD40), CD80, CD86, and MHCII to different extents. ß-glucan-induced cytokine secretion was shown to be, in part, dependent on the activation of the intracellular Dectin-1 adapter molecule Syk. In co-cultures of mDCs with Th2-biased CD4+ T cells isolated from birch allergen Bet v 1 plus aluminum hydroxide (Alum)-sensitized mice, these four ß-glucans suppressed allergen-induced IL-5 secretion, while only Zymosan and ß-1,3 glucan significantly suppressed allergen-induced interferon gamma (IFNγ) secretion, suggesting the tested ß-glucans to have distinct effects on mDC T cell priming capacity. Our experiments indicate that ß-glucans have distinct immune-modulating properties, making them interesting adjuvants for future allergy treatment.
Assuntos
Citocinas , Células Dendríticas , Lectinas Tipo C , beta-Glucanas , Animais , Células Dendríticas/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , beta-Glucanas/farmacologia , beta-Glucanas/química , Camundongos , Lectinas Tipo C/metabolismo , Citocinas/metabolismo , Adjuvantes Imunológicos/farmacologia , Zimosan/farmacologia , Células Mieloides/efeitos dos fármacos , Células Mieloides/imunologia , Células Mieloides/metabolismo , Receptor 2 Toll-Like/metabolismo , Camundongos Endogâmicos C57BL , Quinase Syk/metabolismoRESUMO
Bruton tyrosine kinase (BTK) is a kinase expressed by various immune cells and is often activated under proinflammatory states. Although the majority of BTK-related research has historically focused on B cells, understanding the role of BTK in non-B cell populations is critical given myeloid cells also express BTK at comparable levels. In this study, we investigated and compared how BTK inhibition in human and murine myeloid cells alters cell phenotype and function. All experiments were performed using two BTK inhibitors (evobrutinib and tolebrutinib) that are currently in late-stage clinical trials for the treatment of multiple sclerosis. Assays were performed to assess the impact of BTK inhibition on cytokine and microRNA expression, phagocytic capacity, and cellular metabolism. In all cells, both evobrutinib and tolebrutinib significantly decreased phosphorylated BTK and LPS-induced cytokine release. BTK inhibition also significantly decreased the oxygen consumption rate and extracellular acidification rate in myeloid cells, and significantly decreased phagocytosis in murine-derived cells, but not human macrophages. To further elucidate the mechanism, we also investigated the expression of microRNAs known to impact the function of myeloid cells. BTK inhibition resulted in an altered microRNA expression profile (i.e., decreased miR-155-5p and increased miR-223-3p), which is consistent with a decreased proinflammatory myeloid cell phenotype. In summary, these results provide further insights into the mechanism of action of BTK inhibitors in the context of immune-related diseases, while also highlighting important species-specific and cell-specific differences that should be considered when interpreting and comparing results between preclinical and human studies.
Assuntos
Tirosina Quinase da Agamaglobulinemia , Inflamação , MicroRNAs , Células Mieloides , Fagocitose , Tirosina Quinase da Agamaglobulinemia/metabolismo , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Animais , Humanos , Camundongos , Fagocitose/efeitos dos fármacos , Células Mieloides/metabolismo , Células Mieloides/efeitos dos fármacos , Inflamação/metabolismo , Inflamação/tratamento farmacológico , MicroRNAs/metabolismo , MicroRNAs/genética , Inibidores de Proteínas Quinases/farmacologia , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Citocinas/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Objective: To evaluate the causal relationship between lipids and ulcerative colitis (UC) through Mendelian Randomization (MR), and to further investigate the involvement of immune cells in mediating this process. Methods: Utilizing summary statistics from genome-wide association studies (GWAS) of individuals with European ancestry, we analyzed the causal link between 179 lipid types and UC (2,569 UC cases and 453,779 controls) through Two-sample Mendelian randomization (2SMR) and Bayesian-weighted MR (BWMR). Based on this, a mediation screening of 731 immune cell phenotypes was conducted to identify exposure and mediator factors. Lastly, the role and proportion of immune cells in mediating the causal effects of lipids on UC were assessed via reverse MR (RMR) and two-step MR. Results: The results of MR showed that there was a causal relationship between the six genetically predicted lipid types and UC (P <0.05), and the four immune cell phenotypes were identified as mediators of the association between lipids and UC. Notably, Phosphatidylcholine (PC) (16:0_0:0) served as the exposure factor, and myeloid cells CD11b on CD33+ HLA DR+ CD14dim acted as the mediator. Mediation analysis showed that CD11b on CD33+ HLA DR+ CD14dim had a mediation effect of -0.0205 between PC (16:0_0:0) and UC, with the mediation effect ratio at 15.38%. Conclusion: Our findings elucidate the causal effect of lipids on UC and identify the significant mediating role of myeloid cells CD11b on CD33+ HLA DR+ CD14dim in regulating UC through PC (16:0_0:0), offering new pathways and strategies for UC clinical treatment.
Assuntos
Colite Ulcerativa , Estudo de Associação Genômica Ampla , Lipídeos , Análise da Randomização Mendeliana , Células Mieloides , Humanos , Colite Ulcerativa/imunologia , Colite Ulcerativa/genética , Células Mieloides/imunologia , Células Mieloides/metabolismo , Teorema de Bayes , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Tunneling nanotubes (TNTs) are cellular connections, which represent a novel route for cell-to-cell communication. Strong evidence points to a role for TNTs in the intercellular transfer of signals, molecules, organelles, and pathogens, involving them in many cellular functions. In myeloid cells (e.g., monocytes/macrophages, dendritic cells, and osteoclasts), intercellular communication via TNT contributes to their differentiation and immune functions, by favoring material and pathogen transfer, as well as cell fusion. This chapter addresses the complexity of the definition and characterization of TNTs in myeloid cells, the different processes involved in their formation, their existence in vivo, and finally their function(s) in health and infectious diseases, with the example of HIV-1 infection.
Assuntos
Comunicação Celular , Células Mieloides , Humanos , Comunicação Celular/fisiologia , Animais , Infecções por HIV/imunologia , HIV-1/fisiologia , Estruturas da Membrana Celular , NanotubosRESUMO
The impact of dietary nutrients on tumor immunity remains an area of ongoing investigation, particularly regarding the specific role of vitamins and their mechanism. Here, we demonstrate that vitamin B3 (VB3) induces antitumor immunity against liver cancer through biased GPR109A axis in myeloid cell. Nutritional epidemiology studies suggest that higher VB3 intake reduces liver cancer risk. VB3 supplementation demonstrates antitumor efficacy in multiple mouse models through alleviating the immunosuppressive tumor microenvironment (TME) mediated by tumor-infiltrating myeloid cell, thereby augmenting effectiveness of immunotherapy or targeted therapy in a CD8+ T cell-dependent manner. Mechanically, the TME induces aberrant GPR109A/nuclear factor κB (NF-κB) activation in myeloid cell to shape the immunosuppressive TME. In contrast, VB3 activates ß-Arrestin-mediated GPR109A degradation and NF-κB inhibition to suppress the immunosuppressive polarization of myeloid cell, thereby activating the cytotoxic function of CD8+ T cell. Overall, these results expand the understanding of how vitamins regulate the TME, suggesting that dietary VB3 supplementation is an adjunctive treatment for liver cancer.
Assuntos
Linfócitos T CD8-Positivos , Suplementos Nutricionais , Neoplasias Hepáticas , Células Mieloides , NF-kappa B , Receptores Acoplados a Proteínas G , Receptores Nicotínicos , Transdução de Sinais , Microambiente Tumoral , Animais , Receptores Acoplados a Proteínas G/metabolismo , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Camundongos , Transdução de Sinais/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Células Mieloides/metabolismo , Células Mieloides/efeitos dos fármacos , Células Mieloides/imunologia , NF-kappa B/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Humanos , Receptores Nicotínicos/metabolismo , Camundongos Endogâmicos C57BL , Linhagem Celular Tumoral , MasculinoRESUMO
Ischemic retinopathies including diabetic retinopathy are major causes of vision loss. Inner blood-retinal barrier (BRB) breakdown with retinal vascular hyperpermeability results in macular edema. Although dysfunction of the neurovascular unit including neurons, glia, and vascular cells is now understood to underlie this process, there is a need for fuller elucidation of the underlying events in BRB dysfunction in ischemic disease, including a systematic analysis of myeloid cells and exploration of cellular cross-talk. We used an approach for microglia depletion with the CSF-1R inhibitor PLX5622 (PLX) in the retinal ischemia-reperfusion (IR) model. Under non-IR conditions, PLX treatment successfully depleted microglia in the retina. PLX suppressed the microglial activation response following IR as well as infiltration of monocyte-derived macrophages. This occurred in association with reduction of retinal expression of chemokines including CCL2 and the inflammatory adhesion molecule ICAM-1. In addition, there was a marked suppression of retinal neuroinflammation with reduction in expression of IL-1b, IL-6, Ptgs2, TNF-a, and Angpt2, a protein that regulates BRB permeability. PLX treatment significantly suppressed inner BRB breakdown following IR, without an appreciable effect on neuronal dysfunction. A translatomic analysis of Müller glial-specific gene expression in vivo using the Ribotag approach demonstrated a strong suppression of Müller cell expression of multiple pro-inflammatory genes following PLX treatment. Co-culture studies of Müller cells and microglia demonstrated that activated microglia directly upregulates Müller cell-expression of these inflammatory genes, indicating Müller cells as a downstream effector of myeloid cells in retinal IR. Co-culture studies of these two cell types with endothelial cells demonstrated the ability of both activated microglia and Müller cells to compromise EC barrier function. Interestingly, quiescent Müller cells enhanced EC barrier function in this co-culture system. Together this demonstrates a pivotal role for myeloid cells in inner BRB breakdown in the setting of ischemia-associated disease and indicates that myeloid cells play a major role in iBRB dysregulation, through direct and indirect effects, while Müller glia participate in amplifying the neuroinflammatory effect of myeloid cells.
Assuntos
Barreira Hematorretiniana , Células Ependimogliais , Células Mieloides , Barreira Hematorretiniana/efeitos dos fármacos , Barreira Hematorretiniana/metabolismo , Barreira Hematorretiniana/patologia , Animais , Camundongos , Células Ependimogliais/metabolismo , Células Ependimogliais/efeitos dos fármacos , Células Ependimogliais/patologia , Células Mieloides/metabolismo , Células Mieloides/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Doenças Retinianas/patologia , Doenças Retinianas/metabolismo , Isquemia/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Masculino , Microglia/metabolismo , Microglia/efeitos dos fármacos , Compostos OrgânicosRESUMO
Demyelination and axonal injury in chronic-progressive Multiple Sclerosis (MS) are presumed to be driven by a neurotoxic bystander effect of meningeal-based myeloid infiltrates. There is an unmet clinical need to attenuate disease progression in such forms of CNS-compartmentalized MS. The failure of systemic immune suppressive treatments has highlighted the need for neuroprotective and repair-inducing strategies. Here, we examined whether direct targeting of CNS myeloid cells and modulating their toxicity may prevent irreversible tissue injury in chronic immune-mediated demyelinating disease. To that end, we utilized the experimental autoimmune encephalomyelitis (EAE) model in Biozzi mice, a clinically relevant MS model. We continuously delivered intracerebroventricularly (ICV) a retinoic acid receptor alpha agonist (RARα), as a potent regulator of myeloid cells, in the chronic phase of EAE. We assessed disease severity and performed pathological evaluations, functional analyses of immune cells, and single-cell RNA sequencing on isolated spinal CD11b+ cells. Although initiating treatment in the chronic phase of the disease, the RARα agonist successfully improved clinical outcomes and prevented axonal loss. ICV RARα agonist treatment inhibited pro-inflammatory pathways and shifted CNS myeloid cells toward neuroprotective phenotypes without affecting peripheral infiltrating myeloid cell phenotypes, or peripheral immunity. The treatment regulated cell-death pathways across multiple myeloid cell populations and suppressed apoptosis, resulting in paradoxically marked increased neuroinflammatory infiltrates, consisting mainly of microglia and CNS / border-associated macrophages. This work establishes the notion of bystander neurotoxicity by CNS immune infiltrates in chronic demyelinating disease. Furthermore, it shows that targeting compartmentalized neuroinflammation by selective regulation of CNS myeloid cell toxicity and survival reduces irreversible tissue injury, and may serve as a novel disease-modifying approach.
Assuntos
Modelos Animais de Doenças , Encefalomielite Autoimune Experimental , Células Mieloides , Neuroproteção , Animais , Camundongos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Células Mieloides/metabolismo , Células Mieloides/efeitos dos fármacos , Neuroproteção/efeitos dos fármacos , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/metabolismo , Camundongos Endogâmicos C57BL , Feminino , Receptor alfa de Ácido Retinoico/metabolismo , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/patologia , Esclerose Múltipla Crônica Progressiva/tratamento farmacológico , Esclerose Múltipla Crônica Progressiva/patologia , Fármacos Neuroprotetores/farmacologiaRESUMO
Folate uptake is largely mediated by folate receptor (FR)ß, encoded by FOLR2 gene, in myeloid immune cells such as granulocytes, monocytes, and especially in macrophages that constitute the reticuloendothelial system (RES) and infiltrate the tumor microenvironment. Since the myeloid immune compartment dynamically changes during tumorigenesis, it is critical to assess the infiltration status of the tumors by FRß-expressing myeloid cells to better define the targeting efficacy of folate-functionalized drug delivery systems. On the other hand, clearance by RES is a major limitation for the targeting efficacy of nanoparticles decorated with folate. Therefore, the aims of this study are (i) to determine the amount and subtypes of FRß+ myeloid cells infiltrating the tumors at different stages, (ii) to compare the amount and subtype of FRß+ myeloid cells in distinct organs of tumor-bearing and healthy animals, (iii) to test if the cancer-targeting efficacy and biodistribution of a prototypic folate-functionalized nanoparticle associates with the density of FRß+ myeloid cells. Here, we report that myeloid cell infiltration was enhanced and FRß was upregulated at distinct stages of tumorigenesis in a mouse breast cancer model. The CD206+ subset of macrophages highly expressed FRß, prominently both in tumor-bearing and healthy mice. In tumor-bearing mice, the amount of all myeloid cells, but particularly granulocytes, was remarkably increased in the tumor, liver, lungs, spleen, kidneys, lymph nodes, peritoneal cavity, bone marrow, heart, and brain. Compared with macrophages, the level of FRß was moderate in granulocytes and monocytes. The density of FRß+ immune cells in the tumor microenvironment was not directly associated with the tumor-targeting efficacy of the folate-functionalized cyclodextrin nanoparticles. The lung was determined as a preferential site of accumulation for folate-functionalized nanoparticles, wherein FRß+CD206+ macrophages significantly engulfed cyclodextrin nanoparticles. In conclusion, our results demonstrate that the tumor formation augments the FR levels and alters the infiltration and distribution of myeloid immune cells in all organs which should be considered as a major factor influencing the targeting efficacy of nanoparticles for drug delivery.
Assuntos
Receptor 2 de Folato , Ácido Fólico , Sistema Fagocitário Mononuclear , Células Mieloides , Nanopartículas , Microambiente Tumoral , Animais , Ácido Fólico/química , Ácido Fólico/farmacocinética , Receptor 2 de Folato/metabolismo , Camundongos , Nanopartículas/química , Células Mieloides/metabolismo , Células Mieloides/efeitos dos fármacos , Distribuição Tecidual , Feminino , Sistema Fagocitário Mononuclear/metabolismo , Humanos , Microambiente Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Camundongos Endogâmicos BALB CRESUMO
Pancreatic ductal adenocarcinoma (PDAC) is highly lethal and resistant to immunotherapy. Although immune recognition can be enhanced with immunomodulatory agents including checkpoint inhibitors and vaccines, few patients experience clinical efficacy because the tumor immune microenvironment (TiME) is dominated by immunosuppressive myeloid cells that impose T cell inhibition. Inhibition of phosphodiesterase-5 (PDE5) was reported to downregulate metabolic regulators arginase and inducible NOS in immunosuppressive myeloid cells and enhance immunity against immune-sensitive tumors, including head and neck cancers. We show for the first time to our knowledge that combining a PDE5 inhibitor, tadalafil, with a mesothelin-specific vaccine, anti-programmed cell death protein 1, and anti-cytotoxic T lymphocyte-associated protein 4 yields antitumor efficacy even against immune-resistant PDAC. To determine immunologic advantages conferred by tadalafil, we profiled the TiME using mass cytometry and single-cell RNA-sequencing analysis with Domino to infer intercellular signaling. Our analyses demonstrated that tadalafil reprograms myeloid cells to be less immunosuppressive. Moreover, tadalafil synergized with the vaccine, enhancing T cell activation including mesothelin-specific T cells. Tadalafil treatment was also associated with myeloid/T cell signaling axes important for antitumor responses (e.g., Cxcr3, Il12). Our study shows that PDE5 inhibition combined with vaccine-based immunotherapy promotes pro-inflammatory states of myeloid cells, activation of T cells, and enhanced myeloid/T cell crosstalk to yield antitumor efficacy against immune-resistant PDAC.
Assuntos
Vacinas Anticâncer , Carcinoma Ductal Pancreático , Imunoterapia , Células Mieloides , Neoplasias Pancreáticas , Inibidores da Fosfodiesterase 5 , Tadalafila , Microambiente Tumoral , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/terapia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Células Mieloides/imunologia , Células Mieloides/efeitos dos fármacos , Tadalafila/farmacologia , Tadalafila/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Vacinas Anticâncer/farmacologia , Humanos , Camundongos , Imunoterapia/métodos , Animais , Inibidores da Fosfodiesterase 5/farmacologia , Inibidores da Fosfodiesterase 5/uso terapêutico , Microambiente Tumoral/imunologia , Microambiente Tumoral/efeitos dos fármacos , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/tratamento farmacológico , Linhagem Celular Tumoral , MesotelinaRESUMO
Lectin-glycan interactions play a crucial role in the immune system. An important class of lectins in the innate immune system is myeloid C-type lectin receptors (CLRs). Myeloid CLRs act as pattern recognition receptors and are predominantly expressed by myeloid cells, such as macrophages, dendritic cells, and neutrophils. In innate immunity, CLRs contribute to self/non-self discrimination. While the recognition of pathogen-associated molecular patterns (PAMPs) by CLRs may contribute to a protective immune response, CLR engagement can also be exploited by pathogens for immune evasion. Since various CLRs act as endocytic receptors and trigger distinct signaling pathways in myeloid cells, CLR targeting has proven useful for drug/antigen delivery into antigen-presenting cells and the modulation of immune responses. This review covers recent discoveries of pathogen/CLR interactions and novel approaches for CLR targeting within the period of the past two years.
Assuntos
Interações Hospedeiro-Patógeno , Lectinas Tipo C , Polissacarídeos , Lectinas Tipo C/metabolismo , Humanos , Polissacarídeos/metabolismo , Animais , Imunidade Inata , Células Mieloides/metabolismoRESUMO
Psoriasis is a chronic inflammatory skin disease occurring worldwide. Initially viewed as a keratinocyte disorder, psoriasis is now recognized to involve a complex interplay between genetic predisposition, environmental triggers, and a dysregulated immune system, with a significant role of CD4+ T cells producing IL-17. Recent genetic studies have identified susceptibility loci that underscore the importance of innate immune responses, particularly the roles of myeloid cells, such as dendritic cells, macrophages, and neutrophils. These cells initiate and sustain inflammation through cytokine production triggered by external stimuli. They influence keratinocyte behavior and interact with adaptive immune cells. Recent techniques have further revealed the heterogeneity of myeloid cells in psoriatic lesions, highlighting the contributions of less-studied subsets, such as eosinophils and mast cells. This review examines the multifaceted roles of myeloid innate immune cells in psoriasis, emphasizing their functional diversity in promoting psoriatic inflammation. It also describes current treatment targeting myeloid innate immune cells and explores potential new therapeutic strategies based on the functional characteristics of these subsets. Future research should focus on the detailed characterization of myeloid subsets and their interactions to develop targeted treatments that address the complex immune landscape of psoriasis.
Assuntos
Imunidade Inata , Células Mieloides , Psoríase , Humanos , Psoríase/imunologia , Psoríase/etiologia , Psoríase/genética , Psoríase/patologia , Células Mieloides/imunologia , Células Mieloides/metabolismo , Animais , Células Dendríticas/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismoRESUMO
Apoptosis, inflammation, and wound healing are critical pathophysiological events associated with various liver diseases. Currently, there is a lack of in vivo approaches to study hepatocyte apoptosis-induced liver injury and repair. To address this critical knowledge gap, we developed a unique genetically modified mouse model, namely, 3-Transgene (Tg) with inducible Hepatocyte-Specific Apoptosis Phenotype (3xTg-iHAP) in this study. The 3xTg-iHAP mice possess three transgenes including Alb-Cre, Rosa26-rtTA, and tetO-Fasl on a B6 background. These mice are phenotypically normal, viable, and fertile. After subcutaneous administration of a single dose of doxycycline (5 mg/kg, Dox) to 3xTg-iHAP mice, we observed a complete histological spectrum of sterile liver wound-healing responses: asymptomatic hepatocyte apoptosis at 8 h, necrotic liver injury and sterile inflammation at 48 h, followed by hepatocyte mitosis and regeneration within 7 days. During the injury phase, the mice exhibited an increase in the biomarkers of alanine aminotransferase (ALT), chemokine (C-X-C motif) ligand 1 (CXCL1), and IL-6 in peripheral blood, as well as α-smooth muscle actin (α-SMA) protein in liver tissues. Conversely, the mice displayed a decrease in these markers in the recovery phase. Remarkably, this model shows that the sterile liver injury following elevated hepatocyte apoptosis is associated with an increase in myeloid cells in the liver. Within 7 days post-Dox administration, the liver of Dox-treated 3xTg-iHAP mice displays a normal histological structure, indicating the completion of wound healing. Together, we established a novel mouse model of injury and regeneration induced by hepatocyte apoptosis. This tool provides a robust in vivo platform for studying the pathophysiology of sterile liver inflammation, regeneration, and new therapeutic interventions for liver diseases.NEW & NOTEWORTHY Bu et al. present a triple-transgenic mouse model, namely, 3xTg-iHAP mice that are engineered to explore hepatocyte apoptosis-triggered sterile liver injury and regeneration. This model demonstrates a full spectrum of liver wound-healing responses from asymptomatic apoptosis to injury, myeloid cell-dominant sterile inflammation, and repair after induction of hepatocyte-specific apoptosis. The robust nature of this model makes it an invaluable in vivo tool for studying sterile liver inflammation, regeneration, and new therapeutic strategies.
Assuntos
Apoptose , Modelos Animais de Doenças , Hepatócitos , Regeneração Hepática , Camundongos Transgênicos , Células Mieloides , Animais , Hepatócitos/metabolismo , Hepatócitos/patologia , Camundongos , Células Mieloides/metabolismo , Fígado/metabolismo , Fígado/patologia , Cicatrização , Camundongos Endogâmicos C57BL , Quimiocina CXCL1/metabolismo , Quimiocina CXCL1/genéticaRESUMO
Cytomegaloviruses (CMVs) transmit via chronic shedding from the salivary glands. How this relates to the broad cell tropism they exhibit in vitro is unclear. Human CMV (HCMV) infection presents only after salivary gland infection is established. Murine CMV (MCMV) is therefore useful to analyse early infection events. It reaches the salivary glands via infected myeloid cells. Three adjacent spliced genes designated as m131/129 (MCK-2), sgg1 and sgg1.1, positional homologues of the HCMV UL128/130/131 tropism determinants, are implicated. We show that a sgg1 null mutant is defective in infected myeloid cell entry into the salivary glands, a phenotype distinct from MCMV lacking MCK-2. These data point to a complex, multi-step process of salivary gland colonization.