RESUMEN
The Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome has been the most distinctive polymer protein complex. After recognizing the endogenous and exogenous danger signals, NLRP3 can cause inflammation by pyroptosis and secretion of mature, bioactive forms of IL-1ß and IL-18. The NLRP3 inflammasome is essential in the genesis and progression of infectious illnesses. Herein, we provide a comprehensive review of the NLRP3 inflammasome in infectious diseases, focusing on its two-sided effects. As an essential part of host defense with a protective impact, abnormal NLRP3 inflammasome activation, however, result in a systemic high inflammatory response, leading to subsequent damage. In addition, scientific evidence of small molecules, biologics, and phytochemicals acting on the NLRP3 inflammasome has been reviewed. We believe that the NLRP3 inflammasome helps us understand the pathological mechanism of different stages of infectious diseases and that inhibitors targeting the NLRP3 inflammasome will become a new and valuable research direction for the treatment of infectious diseases.
Asunto(s)
Enfermedades Transmisibles , Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Humanos , Inflamasomas/inmunología , Inflamasomas/metabolismo , Animales , Enfermedades Transmisibles/inmunología , Enfermedades Transmisibles/metabolismo , Inflamación/inmunología , Interleucina-1beta/metabolismo , Interleucina-1beta/inmunologíaRESUMEN
Pyroptosis, a lytic and pro-inflammatory cell death, is important in various pathophysiological processes. Host- and bacteria-derived extracellular vesicles (EVs), as natural nanocarriers messengers, are versatile mediators of intercellular communication between different types of cells. Recently, emerging research has suggested that EVs exhibit multifaceted roles in disease progression by manipulating pyroptosis. This review focuses on new findings concerning how EVs shape disease progression in infectious and non-infectious diseases by regulating pyroptosis. Understanding the characteristics and activity of EVs-mediated pyroptotic death may conducive to the discovery of novel mechanisms and more efficient therapeutic targets in infectious and non-infectious diseases.
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Vesículas Extracelulares , Piroptosis , Humanos , Vesículas Extracelulares/metabolismo , Animales , Enfermedades Transmisibles/metabolismo , Enfermedades Transmisibles/inmunologíaRESUMEN
Over the past decade, the development of three-dimensional (3D) models has increased exponentially, facilitating the unravelling of fundamental and essential cellular mechanisms by which cells communicate with each other, assemble into tissues and organs and respond to biochemical and biophysical stimuli under both physiological and pathological conditions. This section presents a concise overview of the most recent updates on the significant contribution of different types of 3D cell cultures including spheroids, organoids and organ-on-chip and bio-printed tissues in advancing our understanding of cellular and molecular mechanisms. The case studies presented include the 3D cultures of breast cancer (BC), endometriosis, the liver microenvironment and infections. In BC, the establishment of 3D culture models has permitted the visualization of the role of cancer-associated fibroblasts in the delivery of exosomes, as well as the significance of the physical properties of the extracellular matrix in promoting cell proliferation and invasion. This approach has also become a valuable tool in gaining insight into general and specific mechanisms of drug resistance. Given the considerable heterogeneity of endometriosis, 3D models offer a more accurate representation of the in vivo microenvironment, thereby facilitating the identification and translation of novel targeted therapeutic strategies. The advantages provided by 3D models of the hepatic environment, in conjunction with the high throughput characterizing various platforms, have enabled the elucidation of complex molecular mechanisms underlying various threatening hepatic diseases. A limited number of 3D models for gut and skin infections have been developed. However, a more profound comprehension of the spatial and temporal interactions between microbes, the host and their environment may facilitate the advancement of in vitro, ex vivo and in vivo disease models. Additionally, it may pave the way for the development of novel therapeutic approaches in diverse research fields. The interested reader will also find concluding remarks on the challenges and prospects of using 3D cell cultures for discovering cellular and molecular mechanisms in the research areas covered in this review.
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Neoplasias de la Mama , Técnicas de Cultivo Tridimensional de Células , Endometriosis , Humanos , Endometriosis/patología , Endometriosis/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Femenino , Técnicas de Cultivo Tridimensional de Células/métodos , Enfermedades Transmisibles/metabolismo , Enfermedades Transmisibles/patología , Técnicas de Cultivo de Célula/métodos , Esferoides Celulares/patología , Esferoides Celulares/metabolismo , Hígado/patología , Hígado/metabolismo , Organoides/metabolismo , Organoides/patología , Hepatopatías/patología , Hepatopatías/metabolismo , AnimalesRESUMEN
Proper and functional immune response requires a complex interaction between innate and adaptive immune cells, which dendritic cells (DCs) are the primary actors in this coordination as professional antigen-presenting cells. DCs are armed with numerous pattern recognition receptors (PRRs) such as nucleotide-binding and oligomerization domain-like receptors (NLRs) like NLRP3, which influence the development of their activation state upon sensation of ligands. NLRP3 is a crucial component of the immune system for protection against tumors and infectious agents, because its activation leads to the assembly of inflammasomes that cause the formation of active caspase-1 and stimulate the maturation and release of proinflammatory cytokines. But, when NLRP3 becomes overactivated, it plays a pathogenic role in the progression of several autoimmune disorders. So, NLRP3 activation is strictly regulated by diverse signaling pathways that are mentioned in detail in this review. Furthermore, the role of NLRP3 in all of the diverse immune cells' subsets is briefly mentioned in this study because NLRP3 plays a pivotal role in modulating other immune cells which are accompanied by DCs' responses and subsequently influence differentiation of T cells to diverse T helper subsets and even impact on cytotoxic CD8+ T cells' responses. This review sheds light on the functional and therapeutic role of NLRP3 in DCs and its contribution to the occurrence and progression of autoimmune disorders, prevention of diverse tumors' development, and recognition and annihilation of various infectious agents. Furthermore, we highlight NLRP3 targeting potential for improving DC-based immunotherapeutic approaches, to be used for the benefit of patients suffering from these disorders.
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Enfermedades Autoinmunes , Autoinmunidad , Células Dendríticas , Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Neoplasias , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Humanos , Neoplasias/inmunología , Neoplasias/terapia , Inflamasomas/inmunología , Inflamasomas/metabolismo , Animales , Autoinmunidad/inmunología , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/terapia , Enfermedades Autoinmunes/metabolismo , Enfermedades Transmisibles/inmunología , Enfermedades Transmisibles/metabolismo , Enfermedades Transmisibles/terapiaRESUMEN
Infectious diseases are among the factors that account for a significant proportion of disease-related deaths worldwide. The primary treatment approach to combat microbial infections is the use of antibiotics. However, the widespread use of these drugs over the past two decades has led to the emergence of resistant microbial species, making the control of microbial infections a serious challenge. One of the most important solutions in the field of combating infectious diseases is the regulation of the host's defense system. Toll-like receptors (TLRs) play a crucial role in the first primary defense against pathogens by identifying harmful endogenous molecules released from dying cells and damaged tissues as well as invading microbial agents. Therefore, they play an important role in communicating and regulating innate and adaptive immunity. Of course, excessive activation of TLRs can lead to disruption of immune homeostasis and increase the risk of inflammatory reactions. Targeting TLR signaling pathways has emerged as a new therapeutic approach for infectious diseases based on host-directed therapy (HDT). In recent years, stem cell-derived exosomes have received significant attention as factors regulating the immune system. The regulation effects of exosomes on the immune system are based on the HDT strategy, which is due to their cargoes. In general, the mechanism of action of stem cell-derived exosomes in HDT is by regulating and modulating immunity, promoting tissue regeneration, and reducing host toxicity. One of their most important cargoes is microRNAs, which have been shown to play a significant role in regulating immunity through TLRs. This review investigates the therapeutic properties of stem cell-derived exosomes in combating infections through the interaction between exosomal microRNAs and Toll-like receptors.
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Exosomas , MicroARNs , Células Madre , Receptores Toll-Like , Exosomas/metabolismo , Receptores Toll-Like/metabolismo , Humanos , MicroARNs/metabolismo , MicroARNs/genética , Animales , Células Madre/metabolismo , Transducción de Señal , Inmunidad Innata , Enfermedades Transmisibles/inmunología , Enfermedades Transmisibles/metabolismo , Inmunidad AdaptativaRESUMEN
Multiple epidemiologic studies have revealed that gender is considered one of the important factors in the frequency and severity of certain infectious diseases, in which estrogens may play a vital role. There is growing evidence that estrogens as female sex hormone can modulate multiple biological functions outside of the reproductive system, such as in brain and cardiovascular system. However, it is largely unknown about the roles and mechanisms of estrogens/estrogen receptors in immune health and infection disease. Thence, by reading a lot of literature, we summarized the regulatory mechanisms of estrogens/estrogen receptors in immune cells and their roles in certain infectious diseases with gender differences. Therefore, estrogens may have therapeutic potentials to prevent and treat these infectious diseases, which needs further clinical investigation.
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Estrógenos , Humanos , Estrógenos/metabolismo , Estrógenos/inmunología , Animales , Receptores de Estrógenos/metabolismo , Sistema Inmunológico/metabolismo , Sistema Inmunológico/inmunología , Enfermedades Transmisibles/inmunología , Enfermedades Transmisibles/metabolismo , Infecciones/inmunologíaRESUMEN
Post-infectious myalgic encephalomyelitis/chronic fatigue syndrome (PI-ME/CFS) is a disabling disorder, yet the clinical phenotype is poorly defined, the pathophysiology is unknown, and no disease-modifying treatments are available. We used rigorous criteria to recruit PI-ME/CFS participants with matched controls to conduct deep phenotyping. Among the many physical and cognitive complaints, one defining feature of PI-ME/CFS was an alteration of effort preference, rather than physical or central fatigue, due to dysfunction of integrative brain regions potentially associated with central catechol pathway dysregulation, with consequences on autonomic functioning and physical conditioning. Immune profiling suggested chronic antigenic stimulation with increase in naïve and decrease in switched memory B-cells. Alterations in gene expression profiles of peripheral blood mononuclear cells and metabolic pathways were consistent with cellular phenotypic studies and demonstrated differences according to sex. Together these clinical abnormalities and biomarker differences provide unique insight into the underlying pathophysiology of PI-ME/CFS, which may guide future intervention.
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Enfermedades Transmisibles , Síndrome de Fatiga Crónica , Humanos , Síndrome de Fatiga Crónica/metabolismo , Leucocitos Mononucleares/metabolismo , Enfermedades Transmisibles/metabolismo , Biomarcadores/metabolismo , FenotipoRESUMEN
Extracellular vesicles (EVs) show promising potential to be used as therapeutics, disease biomarkers, and drug delivery vehicles. We aimed to modify EVs with miR-155 to modulate macrophage immune response that can be potentially used against infectious diseases. Primarily, we characterized T cells (EL-4) EVs by several standardized techniques and confirmed that the EVs could be used for experimental approaches. The bioactivities of the isolated EVs were confirmed by the uptake assessment, and the results showed that target cells can successfully uptake EVs. To standardize the loading protocol by electroporation for effective biological functionality, we chose fluorescently labelled miR-155 mimics because of its important roles in the immune regulations to upload them into EVs. The loading procedure showed that the dosage of 1 µg of miRNA mimics can be efficiently loaded to the EVs at 100 V, further confirmed by flow cytometry. The functional assay by incubating these modified EVs (mEVs) with in vitro cultured cells led to an increased abundance of miR-155 and decreased the expressions of its target genes such as TSHZ3, Jarid2, ZFP652, and WWC1. Further evaluation indicated that these mEVs induced M1-type macrophage polarization with increased TNF-α, IL-6, IL-1ß, and iNOS expression. The bioavailability analysis revealed that mEVs could be detected in tissues of the livers. Overall, our study demonstrated that EVs can be engineered with miR-155 of interest to modulate the immune response that may have implications against infectious diseases.
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Enfermedades Transmisibles , Vesículas Extracelulares , MicroARNs , Humanos , Linfocitos T/metabolismo , Macrófagos , MicroARNs/genética , Vesículas Extracelulares/metabolismo , Enfermedades Transmisibles/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/farmacología , Proteínas de Homeodominio/metabolismo , Proteínas de Homeodominio/farmacologíaRESUMEN
BACKGROUND: During infectious diseases, proinflammatory cytokines transiently destabilize interactions between adjacent vascular endothelial cells (ECs) to facilitate the passage of immune molecules and cells into tissues. However, in the lung, the resulting vascular hyperpermeability can lead to organ dysfunction. Previous work identified the transcription factor ERG (erythroblast transformation-specific-related gene) as a master regulator of endothelial homeostasis. Here we investigate whether the sensitivity of pulmonary blood vessels to cytokine-induced destabilization is due to organotypic mechanisms affecting the ability of endothelial ERG to protect lung ECs from inflammatory injury. METHODS: Cytokine-dependent ubiquitination and proteasomal degradation of ERG were analyzed in cultured HUVECs (human umbilical vein ECs). Systemic administration of TNFα (tumor necrosis factor alpha) or the bacterial cell wall component lipopolysaccharide was used to cause a widespread inflammatory challenge in mice; ERG protein levels were assessed by immunoprecipitation, immunoblot, and immunofluorescence. Murine Erg deletion was genetically induced in ECs (Ergfl/fl;Cdh5[PAC]-CreERT2), and multiple organs were analyzed by histology, immunostaining, and electron microscopy. RESULTS: In vitro, TNFα promoted the ubiquitination and degradation of ERG in HUVECs, which was blocked by the proteasomal inhibitor MG132. In vivo, systemic administration of TNFα or lipopolysaccharide resulted in a rapid and substantial degradation of ERG within lung ECs but not ECs of the retina, heart, liver, or kidney. Pulmonary ERG was also downregulated in a murine model of influenza infection. Ergfl/fl;Cdh5(PAC)-CreERT2 mice spontaneously recapitulated aspects of inflammatory challenges, including lung-predominant vascular hyperpermeability, immune cell recruitment, and fibrosis. These phenotypes were associated with a lung-specific decrease in the expression of Tek-a gene target of ERG previously implicated in maintaining pulmonary vascular stability during inflammation. CONCLUSIONS: Collectively, our data highlight a unique role for ERG in pulmonary vascular function. We propose that cytokine-induced ERG degradation and subsequent transcriptional changes in lung ECs play critical roles in the destabilization of pulmonary blood vessels during infectious diseases.
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Enfermedades Transmisibles , Factores de Transcripción , Humanos , Ratones , Animales , Factores de Transcripción/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Lipopolisacáridos/farmacología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Citocinas/metabolismo , Enfermedades Transmisibles/metabolismo , Células Cultivadas , Regulador Transcripcional ERG/genética , Regulador Transcripcional ERG/metabolismoRESUMEN
Immunosenescence refers to the development of weakened and/or dysfunctional immune responses associated with aging. Several commensal bacteria can be pathogenic in immunosuppressed individuals. Although Klebsiella pneumoniae is a commensal bacterium that colonizes human mucosal surfaces, the gastrointestinal tract, and the oropharynx, it can cause serious infectious diseases, such as pneumonia, urinary tract infections, and liver abscesses, primarily in elderly patients. However, the reason why K. pneumoniae is a more prevalent cause of infection in the elderly population remains unclear. This study aimed to determine how the host's intestinal immune response to K. pneumoniae varies with age. To this end, the study analyzed an in vivo K. pneumoniae infection model using aged mice, as well as an in vitro K. pneumoniae infection model using a Transwell insert co-culture system comprising epithelial cells and macrophages. In this study, we demonstrate that growth arrest-specific 6 (Gas6), released by intestinal macrophages that recognize K. pneumoniae, inhibits bacterial translocation from the gastrointestinal tract by enhancing tight-junction barriers in the intestinal epithelium. However, in aging mice, Gas6 was hardly secreted under K. pneumoniae infection due to decreasing intestinal mucosal macrophages; therefore, K. pneumoniae can easily invade the intestinal epithelium and subsequently translocate to the liver. Moreover, the administration of Gas6 recombinant protein to elderly mice prevented the translocation of K. pneumoniae from the gastrointestinal tract and significantly prolonged their survival. From these findings, we conclude that the age-related decrease in Gas6 secretion in the intestinal mucosa is the reason why K. pneumoniae can be pathogenic in the elderly, thereby indicating that Gas6 could be effective in protecting the elderly against infectious diseases caused by gut pathogens.
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Enfermedades Transmisibles , Inmunosenescencia , Infecciones por Klebsiella , Anciano , Animales , Humanos , Ratones , Enfermedades Transmisibles/metabolismo , Mucosa Intestinal/microbiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae , Hígado/patologíaRESUMEN
Influenza A virus can induce nasal inflammation by stimulating the death of nasal mucosa epithelium, however, the mechanism is not clear. In this study, to study the causes and mechanisms of nasal mucosa epithelial cell death caused by Influenza A virus H1N1, we isolated and cultured human nasal epithelial progenitor cells (hNEPCs) and exposed them to H1N1 virus after leading differentiation. Then we performed high-resolution untargeted metabolomics and RNAseq analysis of human nasal epithelial cells (hNECs) infected with H1N1 virus. Surprisingly, H1N1 virus infection caused the differential expression of a large number of ferroptosis related genes and metabolites in hNECs. Furthermore, we have observed a significant reduction in Nrf2/KEAP1 expression, GCLC expression, and abnormal glutaminolysis. By constructing overexpression vector of GCLC and the shRNAs of GCLC and Keap1, we determined the role of NRF2-KEAP1-GCLC signaling pathway in H1N1 virus-induced ferroptosis. In addition, A glutaminase antagonist, JHU-083, also demonstrated that glutaminolysis can regulate the NRF2-KEAP1-GCLC signal pathway and ferroptosis. According to this study, H1N1 virus can induce the ferroptosis of hNECs via the NRF2-KEAP1-GCLC signal pathway and glutaminolysis, leading to nasal mucosal epithelial inflammation. This discovery is expected to provide an attractive therapeutic target for viral-induced nasal inflammation.
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Enfermedades Transmisibles , Ferroptosis , Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Humana , Humanos , Enfermedades Transmisibles/metabolismo , Células Epiteliales/metabolismo , Glutamato-Cisteína Ligasa/genética , Inflamación/metabolismo , Virus de la Influenza A/metabolismo , Subtipo H1N1 del Virus de la Influenza A/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Mucosa Nasal/metabolismo , Factor 2 Relacionado con NF-E2/metabolismoRESUMEN
Mastitis is a common and widespread infectious disease in dairy farms around the world, resulting in reduced milk production and quality. Staphylococcus aureus is one of the main pathogenic bacteria causing subclinical mastitis in dairy cows. S. aureus can activate inflammatory signaling pathways in bovine mammary epithelial cells. Exosomes produced by cells can directly transfer pathogen-related molecules from cell to cell, thus affecting the process of infection. Protein is the material basis of the immune defense function in the body; therefore, a comprehensive comparison of proteins in exosomes derived from S. aureus-infected (SA group) and normal (control group [C group]) bovine mammary epithelial MAC-T cells was performed using shotgun proteomics by a DIA approach. A total of 7,070 proteins were identified and quantified. Compared with the C group, there were 802 differentially expressed proteins (DEPs) identified in the SA group (absolute log2 fold change [|log2FC|] of ≥0.58; false discovery rate [FDR] of <0.05), among which 325 proteins were upregulated and 477 were downregulated. The upregulated proteins, including complement 3 (C3), integrin alpha-6 (ITGA6), apolipoprotein A1 (APOA1), annexin A2 (ANXA2), tripeptidyl peptidase II (TPP2), keratin 8 (KRT8), and recombinant desmoyokin (AHNAK), are involved mostly in host defense against pathogens, inflammation, and cell structure maintenance. KEGG enrichment analysis indicated that DEPs in S. aureus infection were involved in the complement and coagulation cascade, phagosome, extracellular matrix (ECM)-receptor interaction, and focal adhesion pathways. The results of this study provide novel information about proteins in the exosomes of MAC-T cells infected with S. aureus and could contribute to an understanding of the infectious mechanism of bovine mastitis. IMPORTANCE Mastitis is a widespread infectious disease in dairy farms, resulting in reduced milk production and quality. Staphylococcus aureus is one of the main pathogenic bacteria causing subclinical mastitis. Exosomes contain proteins, lipids, and nucleic acids, which are involved in many physiological and pathological functions. The expression of proteins in exosomes derived from bovine mammary epithelial cells infected by S. aureus is still barely understood. These results provide novel information about MAC-T-derived exosomal proteins, reveal insights into their functions, and lay a foundation for further studying the biological function of exosomes during the inflammatory response.
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Enfermedades Transmisibles , Exosomas , Mastitis Bovina , Infecciones Estafilocócicas , Bovinos , Animales , Femenino , Humanos , Staphylococcus aureus/fisiología , Exosomas/metabolismo , Mastitis Bovina/microbiología , Infecciones Estafilocócicas/veterinaria , Infecciones Estafilocócicas/microbiología , Células Epiteliales/fisiología , Enfermedades Transmisibles/metabolismo , Enfermedades Transmisibles/veterinaria , Glándulas Mamarias Animales/microbiologíaRESUMEN
The phenomenon of 'T cell exhaustion', a state of T cell dysfunction observed during chronic infections and cancers, has been a major obstacle in mounting appropriate immune responses against infectious agents or tumor antigens. The exhausted T cells are characterized by poor effector functions mainly due to the overexpression of inhibitory receptors such as programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and mucin-domain containing 3 (TIM3), lymphocyte activation gene 3 (LAG3), and T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT), commonly referred to as immune checkpoint (ICP) molecules. ICP blockade, especially of PD-1 that can potentially reverse T cell exhaustion and thereby re-stimulate the impaired immune system, is widely used in clinics as a promising therapeutic strategy for various cancers and is more recently being investigated in infectious diseases as well. In fact, cancer patients represent a population of immunocompromised individuals who are more susceptible to infections and associated complications, and thus the need for protective vaccinations against these diseases is of prime importance in this category. When it comes to vaccinating anti-PD-1-treated cancer patients against infectious diseases including COVID-19 and influenza, a special focus should be brought on the revived immune cells, which could be dynamically affected by the antigenic stimulation. However, since cancer patients are not generally included in clinical trials for designing vaccines against infectious diseases, the possible interaction between vaccine immune responses and ICP therapy is largely unexplored. Mechanistically, the reversal of T cell exhaustion by ICP in an otherwise immunocompromised population could be beneficial for the vaccine's efficacy, helping the immune system to mount a robust immune response. Nevertheless, patients with cancer undergoing anti-PD-1 blockade are known to experience immune-related adverse effects (irAEs). The risk of increasing the irAEs due to the overstimulation of the immune system during vaccination is a major concern. Therefore, while routine vaccination is indispensable for the protection of cancer patients, the impact of PD-1 blockade on vaccine responses against infectious agents requires careful consideration to avoid undesirable adverse effects that could impair the efficacy of anti-cancer treatment.
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COVID-19 , Enfermedades Transmisibles , Neoplasias , Humanos , COVID-19/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Enfermedades Transmisibles/metabolismo , Linfocitos T , Vacunación , InmunoterapiaRESUMEN
Neuroinfections of the central nervous system (CNS) can be triggered by various pathogens. Viruses are the most widespread and have the potential to induce long-term neurologic symptoms with potentially lethal outcomes. In addition to directly affecting their host cells and inducing immediate changes in a plethora of cellular processes, viral infections of the CNS also trigger an intense immune response. Regulation of the innate immune response in the CNS depends not only on microglia, which are fundamental immune cells of the CNS, but also on astrocytes. These cells align blood vessels and ventricle cavities, and consequently, they are one of the first cell types to become infected after the virus breaches the CNS. Moreover, astrocytes are increasingly recognized as a potential viral reservoir in the CNS; therefore, the immune response initiated by the presence of intracellular virus particles may have a profound effect on cellular and tissue physiology and morphology. These changes should be addressed in terms of persisting infections because they may contribute to recurring neurologic sequelae. To date, infections of astrocytes with different viruses originating from genetically distinct families, including Flaviviridae, Coronaviridae, Retroviridae, Togaviridae, Paramyxoviridae, Picomaviridae, Rhabdoviridae, and Herpesviridae, have been confirmed. Astrocytes express a plethora of receptors that detect viral particles and trigger signaling cascades, leading to an innate immune response. In this review, we summarize the current knowledge on virus receptors that initiate the release of inflammatory cytokines from astrocytes and depict the involvement of astrocytes in immune functions of the CNS.
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Enfermedades Transmisibles , Enfermedades del Sistema Nervioso , Virus , Humanos , Astrocitos/metabolismo , Sistema Nervioso Central , Citocinas/metabolismo , Microglía , Enfermedades Transmisibles/metabolismo , Inmunidad Innata , Enfermedades del Sistema Nervioso/metabolismoRESUMEN
The intracellular viral, bacterial, or parasitic pathogens evade the host immune challenges to propagate and cause fatal diseases. The microbes overpower host immunity at various levels including during entry into host cells, phagosome formation, phagosome maturation, phagosome-lysosome fusion forming phagolysosomes, acidification of phagolysosomes, and at times after escape into the cytosol. Phagolysosome is the final organelle in the phagocyte with sophisticated mechanisms to degrade the pathogens. The immune evasion strategies by the pathogens include the arrest of host cell apoptosis, decrease in reactive oxygen species, the elevation of Th2 anti-inflammatory response, avoidance of autophagy and antigen cross-presentation pathways, and escape from phagolysosomal killing. Since the phagolysosome organelle in relation to infection/cure is seldom discussed in the literature, we summarize here the common host as well as pathogen targets manipulated or utilized by the pathogens established in phagosomes and phagolysosomes, to hijack the host immune system for their benefit. These common molecules or pathways can be broad-spectrum therapeutic targets for drug development for intervention against infectious diseases caused by different intracellular pathogens.
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Enfermedades Transmisibles , Evasión Inmune , Humanos , Macrófagos/metabolismo , Macrófagos/microbiología , Fagosomas/metabolismo , Fagosomas/microbiología , Autofagia , Enfermedades Transmisibles/metabolismoRESUMEN
BACKGROUND: Infection is a major cause of death in children, and it is particularly important to identify biological indicators of early infection. Previous studies showed that the neutrophil CD64 (nCD64) index may be a useful biomarker for infection. The purpose of this study was to investigate use of the nCD64 index to identify infection in children from a pediatric ICU (PICU) in China. METHODS: This prospective observational study enrolled 201 children who were admitted to our PICU and were divided into an infection group and a non-infection group. In each patient, C-reactive protein (CRP), nCD64 index, procalcitonin (PCT), and white blood cell count were measured during the first 24 h after admission. Receiver operating characteristic (ROC) analyses were used to determine the sensitivity, specificity, and diagnostic value of the nCD64 index for infection. RESULTS: Among all 201 children, the infection group had greater levels of CRP, nCD64 index, and PCT (all p < 0.05). ROC analysis indicated the nCD64 index had a sensitivity of 68.8%, specificity of 90.7%, accuracy of 80.5%, and an optimal cut-off value of 0.14, which had better diagnostic value than CRP or PCT. For children with postoperative fever, the nCD64 index also distinguished systemic inflammatory response syndrome (SIRS) from infection with accuracy of 79%. CONCLUSIONS: The nCD64 index is a useful biomarker for the diagnosis of early infection in children admitted to the PICU.
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Enfermedades Transmisibles , Sepsis , Niño , Humanos , Estudios Prospectivos , Receptores de IgG/metabolismo , Neutrófilos/metabolismo , Proteína C-Reactiva/análisis , Curva ROC , Biomarcadores , Síndrome de Respuesta Inflamatoria Sistémica , Unidades de Cuidado Intensivo Pediátrico , Polipéptido alfa Relacionado con Calcitonina , Enfermedades Transmisibles/metabolismo , Sepsis/diagnósticoRESUMEN
Research of the last decade has remarkably increased our understanding of innate lymphoid cells (ILCs). ILCs, in analogy to T helper (Th) cells and their cytokine and transcription factor profile, are categorized into three distinct populations: ILC1s express the transcription factor T-bet and secrete IFNγ, ILC2s depend on the expression of GATA-3 and release IL-5 and IL-13, and ILC3s express RORγt and secrete IL-17 and IL-22. Noteworthy, ILCs maintain a level of plasticity, depending on exposed cytokines and environmental stimuli. Furthermore, ILCs are tissue resident cells primarily localized at common entry points for pathogens such as the gut-associated lymphoid tissue (GALT). They have the unique capacity to initiate rapid responses against pathogens, provoked by changes of the cytokine profile of the respective tissue. Moreover, they regulate tissue inflammation and homeostasis. In case of intracellular pathogens entering the mucosal tissue, ILC1s respond by secreting cytokines (e.g., IFNγ) to limit the pathogen spread. Upon infection with helminths, intestinal epithelial cells produce alarmins (e.g., IL-25) and activate ILC2s to secrete IL-13, which induces differentiation of intestinal stem cells into tuft and goblet cells, important for parasite expulsion. Additionally, during bacterial infection ILC3-derived IL-22 is required for bacterial clearance by regulating antimicrobial gene expression in epithelial cells. Thus, ILCs can limit infectious diseases via secretion of inflammatory mediators and interaction with other cell types. In this review, we will address the role of ILCs during enteric infectious diseases.
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Enfermedades Gastrointestinales , Inmunidad Innata , Linfocitos , Humanos , Enfermedades Transmisibles/inmunología , Enfermedades Transmisibles/metabolismo , Citocinas/metabolismo , Inmunidad Innata/fisiología , Interleucina-13/metabolismo , Linfocitos/metabolismo , Enfermedades Gastrointestinales/inmunología , Enfermedades Gastrointestinales/microbiologíaRESUMEN
While pluripotent stem cell-derived kidney organoids are now being used to model renal disease, the proximal nephron remains immature with limited evidence for key functional solute channels. This may reflect early mispatterning of the nephrogenic mesenchyme and/or insufficient maturation. Here we show that enhanced specification to metanephric nephron progenitors results in elongated and radially aligned proximalised nephrons with distinct S1 - S3 proximal tubule cell types. Such PT-enhanced organoids possess improved albumin and organic cation uptake, appropriate KIM-1 upregulation in response to cisplatin, and improved expression of SARS-CoV-2 entry factors resulting in increased viral replication. The striking proximo-distal orientation of nephrons resulted from localized WNT antagonism originating from the organoid stromal core. PT-enhanced organoids represent an improved model to study inherited and acquired proximal tubular disease as well as drug and viral responses.
Asunto(s)
COVID-19 , Enfermedades Transmisibles , Albúminas/metabolismo , Diferenciación Celular/fisiología , Cisplatino/metabolismo , Cisplatino/farmacología , Enfermedades Transmisibles/metabolismo , Humanos , Riñón , Nefronas/metabolismo , Organoides/metabolismo , SARS-CoV-2RESUMEN
Background: Clara cell 16 kDa protein (CC16) is a secretory protein primarily expressed in epithelial cells in the lungs. Previous studies show that CC16 exerts anti-inflammatory and immune-modulatory properties in both acute and chronic pulmonary diseases. However, despite the evidence of CC16's high biomarker potential, evaluation of its role in infectious diseases is yet very limited. Methods: Serum CC16 concentrations were measured by ELISA and assessed in two different types of severe infections. Using a case-control study design, patients treated for either severe SARS-CoV-2 or severe non-pulmonary sepsis infection were compared to age- and sex-matched healthy human subjects. Results: Serum CC16 was significantly increased in both types of infection (SARS-CoV-2: 96.22 ± 129.01 ng/ml vs. healthy controls: 14.05 ± 7.48 ng/ml, p = 0.022; sepsis: 35.37 ± 28.10 ng/ml vs. healthy controls: 15.25 ± 7.51 ng/ml, p = 0.032) but there were no distinct differences between infections with and without pulmonary focus (p = 0.089). Furthermore, CC16 serum levels were positively correlated to disease duration and inversely to the platelet count in severe SARS-CoV-2 infection. Conclusions: Increased CC16 serum levels in both SARS-CoV-2 and sepsis reinforce the high potential as a biomarker for epithelial cell damage and bronchoalveolar-blood barrier leakage in pulmonary as well as non-pulmonary infectious diseases.
Asunto(s)
COVID-19 , Enfermedades Transmisibles , Sepsis , Humanos , Biomarcadores , Proteínas Sanguíneas/metabolismo , Estudios de Casos y Controles , Enfermedades Transmisibles/metabolismo , Células Epiteliales/metabolismo , Informe de Investigación , SARS-CoV-2 , Sepsis/metabolismo , Uteroglobina/metabolismoRESUMEN
Cells communication in response to extracellular or biophysical stimulus relies on elaborated systems of signal transduction. In the course of most signal pathway, the cascades involve signal protein complexes, which are often assembled by adaptor proteins. Tumor necrosis factor receptor type 1-associated death domain protein (TRADD) is an adaptor molecule involved in various signal pathways and mediating multiple biological activities, including cell survival, cell proliferation, cell differentiation, apoptosis, necroptosis and inflammation. TRADD contains an N terminal tumor necrosis factor receptor-associated factor 2 (TRAF2) binding domain and a C terminal death domain (DD) for interacting with multiple DD-containing proteins. Following activation of specific receptors, such as tumor necrosis factor receptor 1 (TNFR1), death receptor 3 (DR3), tumor necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAILR1, DR4), TRAILR1 (DR5), DR6 and p75 neurotrophin receptor (p75NTR)ï¼TRADD can bind to the receptors, serving as a platform for the recruitment of the downstream molecules for signal propagating and thus mediating various physiological and pathological processes. In this review, we provide a brief overview of the current knowledge on TRADD and discuss the roles of TRADD in infectious and inflammatory diseases, cardiovascular diseases, central nervous system diseases, cancer, endometriosis, hepatocyte proliferation, preterm birth and perinatal development.