RESUMEN
Inducible nucleosome remodeling at hundreds of latent enhancers and several promoters shapes the transcriptional response to Toll-like receptor 4 (TLR4) signaling in macrophages. We aimed to define the identities of the transcription factors that promote TLR-induced remodeling. An analysis strategy based on ATAC-seq and single-cell ATAC-seq that enriched for genomic regions most likely to undergo remodeling revealed that the transcription factor nuclear factor κB (NF-κB) bound to all high-confidence peaks marking remodeling during the primary response to the TLR4 ligand, lipid A. Deletion of NF-κB subunits RelA and c-Rel resulted in the loss of remodeling at high-confidence ATAC-seq peaks, and CRISPR-Cas9 mutagenesis of NF-κB-binding motifs impaired remodeling. Remodeling selectivity at defined regions was conferred by collaboration with other inducible factors, including IRF3- and MAP-kinase-induced factors. Thus, NF-κB is unique among TLR4-activated transcription factors in its broad contribution to inducible nucleosome remodeling, alongside its ability to activate poised enhancers and promoters assembled into open chromatin.
Asunto(s)
FN-kappa B , Receptor Toll-Like 4 , FN-kappa B/metabolismo , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo , Nucleosomas , Transducción de Señal , Regulación de la Expresión Génica , Factor de Transcripción ReIA/metabolismoRESUMEN
Plasma membranes of animal cells are enriched for cholesterol. Cholesterol-dependent cytolysins (CDCs) are pore-forming toxins secreted by bacteria that target membrane cholesterol for their effector function. Phagocytes are essential for clearance of CDC-producing bacteria; however, the mechanisms by which these cells evade the deleterious effects of CDCs are largely unknown. Here, we report that interferon (IFN) signals convey resistance to CDC-induced pores on macrophages and neutrophils. We traced IFN-mediated resistance to CDCs to the rapid modulation of a specific pool of cholesterol in the plasma membrane of macrophages without changes to total cholesterol levels. Resistance to CDC-induced pore formation requires the production of the oxysterol 25-hydroxycholesterol (25HC), inhibition of cholesterol synthesis and redistribution of cholesterol to an esterified cholesterol pool. Accordingly, blocking the ability of IFN to reprogram cholesterol metabolism abrogates cellular protection and renders mice more susceptible to CDC-induced tissue damage. These studies illuminate targeted regulation of membrane cholesterol content as a host defense strategy.
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Infecciones Bacterianas/inmunología , Toxinas Bacterianas/inmunología , Hidroxicolesteroles/metabolismo , Interferones/aislamiento & purificación , Fagocitos/inmunología , Estreptolisinas/inmunología , Animales , Bacterias/inmunología , Bacterias/metabolismo , Proteínas Bacterianas/administración & dosificación , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/metabolismo , Membrana Celular/metabolismo , Permeabilidad de la Membrana Celular/inmunología , Células Cultivadas , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades/inmunología , Femenino , Interacciones Microbiota-Huesped/inmunología , Humanos , Microscopía Intravital , Masculino , Ratones , Ratones Transgénicos , Fagocitos/citología , Fagocitos/metabolismo , Cultivo Primario de Células , Esteroide Hidroxilasas/genética , Esteroide Hidroxilasas/metabolismo , Estreptolisinas/administración & dosificación , Estreptolisinas/metabolismoRESUMEN
Mycobacterium leprae causes leprosy and is unique among mycobacterial diseases in producing peripheral neuropathy. This debilitating morbidity is attributed to axon demyelination resulting from direct interaction of the M. leprae-specific phenolic glycolipid 1 (PGL-1) with myelinating glia and their subsequent infection. Here, we use transparent zebrafish larvae to visualize the earliest events of M. leprae-induced nerve damage. We find that demyelination and axonal damage are not directly initiated by M. leprae but by infected macrophages that patrol axons; demyelination occurs in areas of intimate contact. PGL-1 confers this neurotoxic response on macrophages: macrophages infected with M. marinum-expressing PGL-1 also damage axons. PGL-1 induces nitric oxide synthase in infected macrophages, and the resultant increase in reactive nitrogen species damages axons by injuring their mitochondria and inducing demyelination. Our findings implicate the response of innate macrophages to M. leprae PGL-1 in initiating nerve damage in leprosy.
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Antígenos Bacterianos/metabolismo , Modelos Animales de Enfermedad , Glucolípidos/metabolismo , Lepra/microbiología , Lepra/patología , Macrófagos/inmunología , Mycobacterium leprae/fisiología , Animales , Axones/metabolismo , Axones/patología , Enfermedades Desmielinizantes , Larva/crecimiento & desarrollo , Lepra/inmunología , Mycobacterium marinum/metabolismo , Vaina de Mielina/química , Vaina de Mielina/metabolismo , Vaina de Mielina/ultraestructura , Neuroglía/metabolismo , Neuroglía/patología , Óxido Nítrico/metabolismo , Pez CebraRESUMEN
Environmental insults are often detected by multiple sensors that activate diverse signaling pathways and transcriptional regulators, leading to a tailored transcriptional output. To understand how a tailored response is coordinated, we examined the inflammatory response elicited in mouse macrophages by ionizing radiation (IR). RNA-sequencing studies revealed that most radiation-induced genes were strongly dependent on only one of a small number of sensors and signaling pathways, notably the DNA damage-induced kinase ATM, which regulated many IR-response genes, including interferon response genes, via an atypical IRF1-dependent, STING-independent mechanism. Moreover, small, defined sets of genes activated by p53 and NRF2 accounted for the selective response to radiation in comparison to a microbial inducer of inflammation. Our findings reveal that genes comprising an environmental response are activated by defined sensing mechanisms with a high degree of selectivity, and they identify distinct components of the radiation response that might be susceptible to therapeutic perturbation.
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Regulación de la Expresión Génica/efectos de la radiación , Inflamación/genética , Inflamación/metabolismo , Radiación Ionizante , Transducción de Señal , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Animales , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Análisis por Conglomerados , Proteína Quinasa Activada por ADN/metabolismo , Relación Dosis-Respuesta en la Radiación , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas de Inactivación de Genes , Humanos , Interferones/metabolismo , Interferones/farmacología , Macrófagos/metabolismo , Macrófagos/efectos de la radiación , Proteínas de la Membrana/metabolismo , Ratones , Factor 88 de Diferenciación Mieloide/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptor de Interferón alfa y beta/genética , Receptor de Interferón alfa y beta/metabolismo , Transcripción Genética/efectos de la radiación , Activación Transcripcional , Regulador Transcripcional ERG/genética , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
BACKGROUND: Aberrant PI3K/AKT signaling in BRAF-mutant cancers contributes to resistance to BRAF inhibitors. The authors examined dual MAPK and PI3K pathway inhibition in patients who had BRAF-mutated solid tumors (ClinicalTrials.gov identifier NCT01902173). METHODS: Patients with BRAF V600E/V600K-mutant solid tumors received oral dabrafenib at 150 mg twice daily with dose escalation of oral uprosertib starting at 50 mg daily, or, in the triplet cohorts, with dose escalation of both oral trametinib starting at 1.5 mg daily and oral uprosertib starting at 25 mg daily. Dose-limiting toxicities (DLTs) were assessed within the first 56 days of treatment. Radiographic responses were assessed at 8-week intervals. RESULTS: Twenty-seven patients (22 evaluable) were enrolled in parallel doublet and triplet cohorts. No DLTs were observed in the doublet cohorts (N = 7). One patient had a DLT at the maximum administered dose of triplet therapy (dabrafenib 150 mg twice daily and trametinib 2 mg daily plus uprosertib 75 mg daily). Three patients in the doublet cohorts had partial responses (including one who had BRAF inhibitor-resistant melanoma). Two patients in the triplet cohorts had a partial response, and one patient had an unconfirmed partial response. Pharmacokinetic data suggested reduced dabrafenib and dabrafenib metabolite exposure in patients who were also exposed to both trametinib and uprosertib, but not in whose who were exposed to uprosertib without trametinib. CONCLUSIONS: Concomitant inhibition of both the MAPK and PI3K-AKT pathways for the treatment of BRAF-mutated cancers was well tolerated, leading to objective responses, but higher level drug-drug interactions affected exposure to dabrafenib and its metabolites.
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Protocolos de Quimioterapia Combinada Antineoplásica , Imidazoles , Mutación , Neoplasias , Oximas , Inhibidores de Proteínas Quinasas , Proteínas Proto-Oncogénicas B-raf , Proteínas Proto-Oncogénicas c-akt , Piridonas , Pirimidinonas , Humanos , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Femenino , Masculino , Persona de Mediana Edad , Anciano , Adulto , Piridonas/administración & dosificación , Piridonas/efectos adversos , Pirimidinonas/administración & dosificación , Pirimidinonas/efectos adversos , Pirimidinonas/uso terapéutico , Imidazoles/administración & dosificación , Imidazoles/uso terapéutico , Imidazoles/efectos adversos , Imidazoles/farmacocinética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Oximas/administración & dosificación , Oximas/efectos adversos , Oximas/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/efectos adversos , Inhibidores de Proteínas Quinasas/uso terapéutico , Anciano de 80 o más Años , Terapia Molecular DirigidaRESUMEN
Microporous annealed particle (MAP) scaffolds are flowable, in situ crosslinked, microporous scaffolds composed of microgel building blocks and were previously shown to accelerate wound healing. To promote more extensive tissue ingrowth before scaffold degradation, we aimed to slow MAP degradation by switching the chirality of the crosslinking peptides from L- to D-amino acids. Unexpectedly, despite showing the predicted slower enzymatic degradation in vitro, D-peptide crosslinked MAP hydrogel (D-MAP) hastened material degradation in vivo and imparted significant tissue regeneration to healed cutaneous wounds, including increased tensile strength and hair neogenesis. MAP scaffolds recruit IL-33 type 2 myeloid cells, which is amplified in the presence of D-peptides. Remarkably, D-MAP elicited significant antigen-specific immunity against the D-chiral peptides, and an intact adaptive immune system was required for the hydrogel-induced skin regeneration. These findings demonstrate that the generation of an adaptive immune response from a biomaterial is sufficient to induce cutaneous regenerative healing despite faster scaffold degradation.
Asunto(s)
Hidrogeles/química , Hidrogeles/farmacología , Regeneración/efectos de los fármacos , Regeneración/inmunología , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/inmunología , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Femenino , Interleucina-33/metabolismo , Ratones , Porosidad , Piel/efectos de los fármacos , Piel/inmunología , Andamios del Tejido/químicaRESUMEN
BACKGROUND: Human papillomavirus (HPV) infection is known to promote the development of mucosal squamous cell carcinoma (mSCC), including pathologically high-grade lesions, but its role in cutaneous squamous cell carcinoma (cuSCC) remains unclear, particularly in lesions that are considered high risk. OBJECTIVE: We aimed to determine whether enhanced HPV transcriptional activity can be detected in high-risk cuSCC samples compared with low-grade SCC samples or normal skin. METHODS: We performed RNA sequencing of cuSCC across 23 risk-stratified skin lesions. A subset of samples was tested for the presence of HPV DNA. High-quality, non-human reads from each sample group were used for viral analysis using Microbiome Coverage Profiler. RESULTS: None of the samples analysed had detectable expression of HPV RNA, while 64% of samples tested positive for HPV DNA. All samples were found to have expression of human endogenous retrovirus, and multiple samples showed expression of other viruses. CONCLUSIONS: Viral and prophage gene expression can be monitored in cuSCC or normal skin biopsies, yet no sample in our study showed evidence of active HPV gene expression despite evidence of HPV genome presence. This suggests HPV transcription does not play a role in differentiating high-risk cuSCCs from low-risk cuSCCs or normal skin.
Asunto(s)
Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/virología , Expresión Génica , Papillomaviridae/genética , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/patología , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/virología , Anciano , Biopsia , Sondas de ADN de HPV , Femenino , Humanos , Masculino , Medición de RiesgoRESUMEN
Upon recognition of a microbial pathogen, the innate and adaptive immune systems are linked to generate a cell-mediated immune response against the foreign invader. The culture filtrate of Mycobacterium tuberculosis contains ligands, such as M. tuberculosis tRNA, that activate the innate immune response and secreted Ags recognized by T cells to drive adaptive immune responses. In this study, bioinformatics analysis of gene-expression profiles derived from human PBMCs treated with distinct microbial ligands identified a mycobacterial tRNA-induced innate immune network resulting in the robust production of IL-12p70, a cytokine required to instruct an adaptive Th1 response for host defense against intracellular bacteria. As validated by functional studies, this pathway contained a feed-forward loop, whereby the early production of IL-18, type I IFNs, and IL-12p70 primed NK cells to respond to IL-18 and produce IFN-γ, enhancing further production of IL-12p70. Mechanistically, tRNA activates TLR3 and TLR8, and this synergistic induction of IL-12p70 was recapitulated by the addition of a specific TLR8 agonist with a TLR3 ligand to PBMCs. These data indicate that M. tuberculosis tRNA activates a gene network involving the integration of multiple innate signals, including types I and II IFNs, as well as distinct cell types to induce IL-12p70.
Asunto(s)
Interleucina-12/inmunología , Mycobacterium tuberculosis/inmunología , ARN Bacteriano/inmunología , ARN de Transferencia/inmunología , Tuberculosis/inmunología , Diferenciación Celular/inmunología , Redes Reguladoras de Genes/inmunología , Humanos , Inmunidad Celular/inmunología , Inmunidad Innata/inmunología , Interleucina-12/biosíntesis , Activación de Linfocitos/inmunología , Receptores de Reconocimiento de Patrones/inmunología , Células TH1/inmunologíaRESUMEN
Delivery to the proper tissue compartment is a major obstacle hampering the potential of cellular therapeutics for medical conditions. Delivery of cells within biomaterials may improve localization, but traditional and newer void-forming hydrogels must be made in advance with cells being added into the scaffold during the manufacturing process. Injectable, in situ cross-linking microporous scaffolds are recently developed that demonstrate a remarkable ability to provide a matrix for cellular proliferation and growth in vitro in three dimensions. The ability of these scaffolds to deliver cells in vivo is currently unknown. Herein, it is shown that mesenchymal stem cells (MSCs) can be co-injected locally with microparticle scaffolds assembled in situ immediately following injection. MSC delivery within a microporous scaffold enhances MSC retention subcutaneously when compared to cell delivery alone or delivery within traditional in situ cross-linked nanoporous hydrogels. After two weeks, endothelial cells forming blood vessels are recruited to the scaffold and cells retaining the MSC marker CD29 remain viable within the scaffold. These findings highlight the utility of this approach in achieving localized delivery of stem cells through an injectable porous matrix while limiting obstacles of introducing cells within the scaffold manufacturing process.
Asunto(s)
Células Madre/citología , Andamios del Tejido/química , Animales , Células Cultivadas , Técnica del Anticuerpo Fluorescente , Células Madre Mesenquimatosas/citología , Ratones , Ratones Endogámicos C57BL , Microfluídica/métodos , Ingeniería de Tejidos/métodosRESUMEN
Successful host defense against pathogens requires innate immune recognition of the correct pathogen associated molecular patterns (PAMPs) by pathogen recognition receptors (PRRs) to trigger the appropriate gene program tailored to the pathogen. While many PRR pathways contribute to the innate immune response to specific pathogens, the relative importance of each pathway for the complete transcriptional program elicited has not been examined in detail. Herein, we used RNA-sequencing with wildtype and mutant macrophages to delineate the innate immune pathways contributing to the early transcriptional response to Staphylococcus aureus, a ubiquitous microorganism that can activate a wide variety of PRRs. Unexpectedly, two PRR pathways-the Toll-like receptor (TLR) and Stimulator of Interferon Gene (STING) pathways-were identified as dominant regulators of approximately 95% of the genes that were potently induced within the first four hours of macrophage infection with live S. aureus. TLR signaling predominantly activated a pro-inflammatory program while STING signaling activated an antiviral/type I interferon response with live but not killed S. aureus. This STING response was largely dependent on the cytosolic DNA sensor cyclic guanosine-adenosine synthase (cGAS). Using a cutaneous infection model, we found that the TLR and STING pathways played opposite roles in host defense to S. aureus. TLR signaling was required for host defense, with its absence reducing interleukin (IL)-1ß production and neutrophil recruitment, resulting in increased bacterial growth. In contrast, absence of STING signaling had the opposite effect, enhancing the ability to restrict the infection. These results provide novel insights into the complex interplay of innate immune signaling pathways triggered by S. aureus and uncover opposing roles of TLR and STING in cutaneous host defense to S. aureus.
Asunto(s)
Citosol/inmunología , Proteínas de la Membrana/inmunología , Infecciones Estafilocócicas/inmunología , Staphylococcus aureus/fisiología , Receptores Toll-Like/inmunología , Animales , Citosol/microbiología , ADN , ADN Bacteriano/genética , ADN Bacteriano/inmunología , Femenino , Humanos , Inmunidad Innata , Interferón Tipo I/genética , Interferón Tipo I/inmunología , Masculino , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/inmunología , Transducción de Señal , Infecciones Estafilocócicas/genética , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/genética , Staphylococcus aureus/inmunología , Receptores Toll-Like/genéticaRESUMEN
Interleukin (IL)-18 is an important effector of innate and adaptive immunity, but its expression must also be tightly regulated because it can potentiate lethal systemic inflammation and death. Healthy and septic human neonates demonstrate elevated serum concentrations of IL-18 compared with adults. Thus, we determined the contribution of IL-18 to lethality and its mechanism in a murine model of neonatal sepsis. We find that IL-18-null neonatal mice are highly protected from polymicrobial sepsis, whereas replenishing IL-18 increased lethality to sepsis or endotoxemia. Increased lethality depended on IL-1 receptor 1 (IL-1R1) signaling but not adaptive immunity. In genome-wide analyses of blood mRNA from septic human neonates, expression of the IL-17 receptor emerged as a critical regulatory node. Indeed, IL-18 administration in sepsis increased IL-17A production by murine intestinal γδT cells as well as Ly6G(+) myeloid cells, and blocking IL-17A reduced IL-18-potentiated mortality to both neonatal sepsis and endotoxemia. We conclude that IL-17A is a previously unrecognized effector of IL-18-mediated injury in neonatal sepsis and that disruption of the deleterious and tissue-destructive IL-18/IL-1/IL-17A axis represents a novel therapeutic approach to improve outcomes for human neonates with sepsis.
Asunto(s)
Interleucina-17/antagonistas & inhibidores , Interleucina-17/inmunología , Interleucina-18/inmunología , Sepsis Neonatal/inmunología , Sepsis Neonatal/terapia , Tasa de Supervivencia , Animales , Animales Recién Nacidos , Anticuerpos Monoclonales/uso terapéutico , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Terapia Molecular Dirigida/métodos , Sepsis Neonatal/patología , Resultado del TratamientoRESUMEN
Sepsis is a major cause of neonatal mortality and morbidity worldwide. A recent report suggested that murine neonatal host defense against infection could be compromised by immunosuppressive CD71(+) erythroid splenocytes. We examined the impact of CD71(+) erythroid splenocytes on murine neonatal mortality to endotoxin challenge or polymicrobial sepsis and characterized circulating CD71(+) erythroid (CD235a(+)) cells in human neonates. Adoptive transfer or an Ab-mediated reduction in neonatal CD71(+) erythroid splenocytes did not alter murine neonatal survival to endotoxin challenge or polymicrobial sepsis challenge. Ex vivo immunosuppression of stimulated adult CD11b(+) cells was not limited to neonatal splenocytes; it also occurred with adult and neonatal bone marrow. Animals treated with anti-CD71 Ab showed reduced splenic bacterial load following bacterial challenge compared with isotype-treated mice. However, adoptive transfer of enriched CD71(+) erythroid splenocytes to CD71(+)-reduced animals did not reduce bacterial clearance. Human CD71(+)CD235a(+) cells were common among cord blood mononuclear cells and were shown to be reticulocytes. In summary, a lack of effect on murine survival to polymicrobial sepsis following adoptive transfer or diminution of CD71(+) erythroid splenocytes under these experimental conditions suggests that the impact of these cells on neonatal infection risk and progression may be limited. An unanticipated immune priming effect of anti-CD71 Ab treatment, rather than a reduction in immunosuppressive CD71(+) erythroid splenocytes, was likely responsible for the reported enhanced bacterial clearance. In humans, the well-described rapid decrease in circulating reticulocytes after birth suggests that they may have a limited role in reducing inflammation secondary to microbial colonization.
Asunto(s)
Antígenos CD/inmunología , Células de la Médula Ósea/inmunología , Células Eritroides/inmunología , Receptores de Transferrina/inmunología , Sepsis/inmunología , Traslado Adoptivo , Animales , Anticuerpos/inmunología , Antígeno CD11b/metabolismo , Endotoxinas/farmacología , Femenino , Sangre Fetal/citología , Sangre Fetal/inmunología , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Reticulocitos/inmunología , Bazo/citología , Bazo/inmunologíaRESUMEN
Current evidence suggests that neonatal immunity is functionally distinct from adults. Although TLR signaling through the adaptor protein, MyD88, has been shown to be critical for survival to sepsis in adults, little is known about the role of MyD88 or TRIF in neonatal sepsis. We demonstrate that TRIF(-/-) but not MyD88(-/-) neonates are highly susceptible to Escherichia coli peritonitis and bacteremia. This was associated with decreased innate immune recruitment and function. Importantly, we found that the reverse was true in adults that MyD88(-/-) but not TRIF(-/-) or wild-type adults are susceptible to E. coli peritonitis and bacteremia. In addition, we demonstrate that TRIF but not MyD88 signaling is critical for the TLR4 protective adjuvant effect we have previously demonstrated. These data suggest a differential requirement for the survival of neonates versus adults to Gram-negative infection, and that modulation of TRIF in neonates can be used to augment survival to neonatal sepsis.
Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular/genética , Infecciones por Bacterias Gramnegativas/genética , Infecciones por Bacterias Gramnegativas/inmunología , Inmunidad Innata , Sepsis/genética , Sepsis/inmunología , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Animales , Animales Recién Nacidos , Quimiocina CXCL10/metabolismo , Quimiocinas/biosíntesis , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades/inmunología , Escherichia coli/inmunología , Femenino , Predisposición Genética a la Enfermedad , Infecciones por Bacterias Gramnegativas/metabolismo , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Gramnegativas/mortalidad , Granulocitos/inmunología , Granulocitos/metabolismo , Interferón Tipo I/metabolismo , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Masculino , Ratones , Ratones Noqueados , Neutrófilos/inmunología , Neutrófilos/metabolismo , Fagocitosis/genética , Fagocitosis/inmunología , Especies Reactivas de Oxígeno/metabolismo , Sepsis/metabolismo , Sepsis/microbiología , Sepsis/mortalidad , Receptores Toll-Like/metabolismoRESUMEN
Injectable hydrogels can provide a scaffold for in situ tissue regrowth and regeneration, yet gel degradation before tissue reformation limits the gels' ability to provide physical support. Here, we show that this shortcoming can be circumvented through an injectable, interconnected microporous gel scaffold assembled from annealed microgel building blocks whose chemical and physical properties can be tailored by microfluidic fabrication. In vitro, cells incorporated during scaffold formation proliferated and formed extensive three-dimensional networks within 48 h. In vivo, the scaffolds facilitated cell migration that resulted in rapid cutaneous-tissue regeneration and tissue-structure formation within five days. The combination of microporosity and injectability of these annealed gel scaffolds should enable novel routes to tissue regeneration and formation in vivo.
Asunto(s)
Ingeniería de Tejidos/instrumentación , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Cicatrización de Heridas , Materiales Biocompatibles , Línea Celular , Movimiento Celular , Proliferación Celular , Fibroblastos/metabolismo , Humanos , Hidrogeles/química , Ensayo de Materiales , Microfluídica , Porosidad , Regeneración , Piel/metabolismoRESUMEN
Cancer progression is associated with inflammation, increased metabolic demand, infection, cachexia, and eventually death. Myeloid-derived suppressor cells (MDSCs) commonly expand during cancer and are associated with adaptive immune suppression and inflammatory metabolite production. We propose that cancer-induced cachexia is driven at least in part by the expansion of MDSCs. MDSC expansion in 4T1 mammary carcinoma-bearing hosts is associated with induction of a hepatic acute-phase protein response and altered host energy and fat metabolism, and eventually reduced survival to polymicrobial sepsis and endotoxemia. Similar results are also seen in mice bearing a Lewis lung carcinoma and a C26 colon adenocarcinoma. However, a similar cachexia response is not seen with equivalent growth of the 66C4 subclone of 4T1, in which MDSC expansion does not occur. Importantly, reducing MDSC numbers in 4T1-bearing animals can ameliorate some of these late responses and reduce susceptibility to inflammation-induced organ injury and death. In addition, administering MDSCs from both tumor- and nontumor-bearing mice can produce an acute-phase response. Thus, we propose a previously undescribed mechanism for the development of cancer cachexia, whereby progressive MDSC expansion contributes to changes in host protein and energy metabolism and reduced resistance to infection.
Asunto(s)
Caquexia/inmunología , Tolerancia Inmunológica , Células Mieloides/inmunología , Neoplasias Experimentales/inmunología , Animales , Caquexia/etiología , Línea Celular Tumoral , Femenino , Ratones , Ratones Endogámicos BALB C , Células Mieloides/patología , Neoplasias Experimentales/patologíaRESUMEN
Although ectopic lymphoid tissue formation is associated with many autoimmune diseases, it is unclear whether it serves a functional role in autoimmune responses. 2,6,10,14-Tetramethylpentadecane causes chronic peritoneal inflammation and lupus-like disease with autoantibody production and ectopic lymphoid tissue (lipogranuloma) formation. A novel transplantation model was used to show that transplanted lipogranulomas retain their lymphoid structure over a prolonged period in the absence of chronic peritoneal inflammation. Recipients of transplanted lipogranulomas produced anti-U1A autoantibodies derived exclusively from the donor, despite nearly complete repopulation of the transplanted lipogranulomas by host lymphocytes. The presence of ectopic lymphoid tissue alone was insufficient, as an anti-U1A response was not generated by the host in the absence of ongoing peritoneal inflammation. Donor-derived anti-U1A autoantibodies were produced for up to 2 mo by plasma cells/plasmablasts recruited to the ectopic lymphoid tissue by CXCR4. Although CD4(+) T cells were not required for autoantibody production from the transplanted lipogranulomas, de novo generation of anti-U1A plasma cells/plasmablasts was reduced following T cell depletion. Significantly, a population of memory B cells was identified in the bone marrow and spleen that did not produce anti-U1A autoantibodies unless stimulated by LPS to undergo terminal differentiation. We conclude that 2,6,10,14-tetramethylpentadecane promotes the T cell-dependent development of class-switched, autoreactive memory B cells and plasma cells/plasmablasts. The latter home to ectopic lymphoid tissue and continue to produce autoantibodies after transplantation and in the absence of peritoneal inflammation. However, peritoneal inflammation appears necessary to generate autoreactive B cells de novo.
Asunto(s)
Autoanticuerpos/biosíntesis , Subgrupos de Linfocitos B/inmunología , Células de la Médula Ósea/inmunología , Memoria Inmunológica , Tejido Linfoide/inmunología , Células Plasmáticas/inmunología , Ribonucleoproteínas Nucleares Pequeñas/inmunología , Animales , Autoanticuerpos/metabolismo , Subgrupos de Linfocitos B/citología , Células de la Médula Ósea/citología , Células de la Médula Ósea/metabolismo , Coristoma/inmunología , Femenino , Granuloma/sangre , Granuloma/inmunología , Granuloma/patología , Tejido Linfoide/citología , Tejido Linfoide/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Células Plasmáticas/metabolismoRESUMEN
Current antigen delivery platforms, such as alum and nanoparticles, are not readily tunable, thus may not generate optimal adaptive immune responses. We created an antigen delivery platform by loading lyophilized Microporous Annealed Particle (MAP) with aqueous solution containing target antigens. Upon administration of antigen loaded MAP (VaxMAP), the biomaterial reconstitution forms an instant antigen-loaded porous scaffold area with a sustained release profile to maximize humoral immunity. VaxMAP induced CD4+ T follicular helper (Tfh) cells and germinal center (GC) B cell responses in the lymph nodes similar to Alum. VaxMAP loaded with SARS-CoV-2 spike protein improved the magnitude and duration of anti-receptor binding domain antibodies compared to Alum and mRNA-vaccinated mice. A single injection of Influenza specific HA1-loaded-VaxMAP enhanced neutralizing antibodies and elicited greater protection against influenza virus challenge than HA1-loaded-Alum. Thus, VaxMAP is a platform that can be used to promote adaptive immune cell responses to generate more robust neutralizing antibodies, and better protection upon pathogen challenge.
RESUMEN
Case Presentation: A 30-year-old male with a past medical history of hypertension and renal failure on peritoneal dialysis presented to the emergency department with a chief complaint of a rash on his anterior trunk for the prior three weeks. Dermatological examination revealed multiple, discrete folliculocentric, erythematous, and hyperpigmented papules, with scattered adjacent angulated erosions. Discussion: Perforating folliculitis is a rare and often difficult to diagnose skin condition classically seen in patients with chronic renal disease or underlying immunodeficiency.
RESUMEN
Current antigen delivery platforms, such as alum and nanoparticles, are not readily tunable, thus may not generate optimal adaptive immune responses. We created an antigen delivery platform by loading lyophilized Microporous Annealed Particle (MAP) with aqueous solution containing target antigens. Upon administration of antigen loaded MAP (VaxMAP), the biomaterial reconstitution forms an instant antigen-loaded porous scaffold area with a sustained release profile to maximize humoral immunity. VaxMAP induced CD4+ T follicular helper (Tfh) cells and germinal center (GC) B cell responses in the lymph nodes similar to Alum. VaxMAP loaded with SARS-CoV-2 spike protein improved the magnitude, neutralization, and duration of anti-receptor binding domain antibodies compared to Alum vaccinated mice. A single injection of Influenza specific HA1-loaded-VaxMAP enhanced neutralizing antibodies and elicited greater protection against influenza virus challenge than HA1-loaded-Alum. Thus, VaxMAP is a platform that can be used to promote adaptive immune cell responses to generate more robust neutralizing antibodies, and better protection upon pathogen challenge.
Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Inmunidad Humoral , Glicoproteína de la Espiga del Coronavirus , Animales , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/administración & dosificación , Ratones , COVID-19/prevención & control , COVID-19/inmunología , Porosidad , Femenino , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Materiales Biocompatibles/química , Ratones Endogámicos BALB C , Linfocitos B/inmunología , SARS-CoV-2/inmunología , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/administración & dosificación , Ratones Endogámicos C57BL , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/prevención & controlRESUMEN
Biomaterial wound dressings, such as hydrogels, interact with host cells to regulate tissue repair. This study investigates how crosslinking of gelatin-based hydrogels influences immune and stromal cell behavior and wound healing in female mice. We observe that softer, lightly crosslinked hydrogels promote greater cellular infiltration and result in smaller scars compared to stiffer, heavily crosslinked hydrogels. Using single-cell RNA sequencing, we further show that heavily crosslinked hydrogels increase inflammation and lead to the formation of a distinct macrophage subpopulation exhibiting signs of oxidative activity and cell fusion. Conversely, lightly crosslinked hydrogels are more readily taken up by macrophages and integrated within the tissue. The physical properties differentially affect macrophage and fibroblast interactions, with heavily crosslinked hydrogels promoting pro-fibrotic fibroblast activity that drives macrophage fusion through RANKL signaling. These findings suggest that tuning the physical properties of hydrogels can guide cellular responses and improve healing, offering insights for designing better biomaterials for wound treatment.