RESUMO
Human papillomavirus type 16 (HPV16) and other oncoviruses have been shown to block innate immune responses and to persist in the host. However, to avoid viral persistence, the immune response attempts to clear the infection. IL-1ß is a powerful cytokine produced when viral motifs are sensed by innate receptors that are members of the inflammasome family. Whether oncoviruses such as HPV16 can activate the inflammasome pathway remains unknown. Here, we show that infection of human keratinocytes with HPV16 induced the secretion of IL-1ß. Yet, upon expression of the viral early genes, IL-1ß transcription was blocked. We went on to show that expression of the viral oncoprotein E6 in human keratinocytes inhibited IRF6 transcription which we revealed regulated IL-1ß promoter activity. Preventing E6 expression using siRNA, or using E6 mutants that prevented degradation of p53, showed that p53 regulated IRF6 transcription. HPV16 abrogation of p53 binding to the IRF6 promoter was shown by ChIP in tissues from patients with cervical cancer. Thus E6 inhibition of IRF6 is an escape strategy used by HPV16 to block the production IL-1ß. Our findings reveal a struggle between oncoviral persistence and host immunity; which is centered on IL-1ß regulation.
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Regulação da Expressão Gênica/imunologia , Evasão da Resposta Imune/imunologia , Fatores Reguladores de Interferon/metabolismo , Interleucina-1beta/biossíntese , Infecções por Papillomavirus/imunologia , Papillomavirus Humano 16/imunologia , Humanos , Fatores Reguladores de Interferon/imunologia , Interleucina-1beta/imunologia , Queratinócitos/imunologia , Queratinócitos/metabolismo , Queratinócitos/virologia , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/metabolismo , Proteínas Repressoras/metabolismoRESUMO
Effective B cell responses such as cytokine secretion, proliferation, and Ab-specific responses are essential to clear hepatitis B virus (HBV) infection. However, HBV alters numerous immune pathways to persist in the host. B cell activity depends on activation of the innate sensor TLR9 by viral or bacterial DNA motifs. How HBV can deregulate B cell functions remains unknown. In this study, we show that HBV can enter and decrease TLR9 expression in human primary B cells. Using PBMCs from human blood donors, we show that TLR9 expression was reduced in all peripheral B cells subsets exposed to HBV. B cell function mediated by TLR9, but not TLR7, such as proliferation and proinflammatory cytokines secretion, were abrogated in the presence of HBV; however, global Ig secretion was not downregulated. Mechanistically, we show, using human myeloma B cell line RPMI 8226, that the surface Ag hepatitis B surface Ag was responsible for TLR9 dysfunction. hepatitis B surface Ag suppressed the phosphorylation and thus the activation of the transcription factor CREB, preventing TLR9 promoter activity. Finally, we corroborated our in vitro findings in a cohort of chronic HBV carriers and found that TLR9 expression and function were significantly suppressed. The effect of HBV on TLR9 activity in B cells gives insights into oncoviral immune escape strategies, providing knowledge to develop novel immunotherapeutic approaches in chronic HBV-carrier patients.
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Linfócitos B/imunologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Antígenos de Superfície da Hepatite B/metabolismo , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/imunologia , Receptor Toll-Like 9/metabolismo , Adulto , Idoso , Linfócitos B/virologia , Linhagem Celular Tumoral , Proliferação de Células , Estudos de Coortes , Citocinas/metabolismo , Regulação para Baixo , Feminino , Antígenos de Superfície da Hepatite B/imunologia , Humanos , Evasão da Resposta Imune , Tolerância Imunológica , Integrases/genética , Integrases/metabolismo , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Fosforilação , Regiões Promotoras Genéticas/genética , Adulto JovemRESUMO
Several lines of evidence indicate that cutaneous human papillomavirus (HPV) types belonging to the beta genus of the HPV phylogenetic tree synergize with UV radiation in the development of skin cancer. Accordingly, the E6 and E7 oncoproteins from some beta HPV types are able to deregulate pathways related to immune response and cellular transformation. Toll-like receptor 9 (TLR9), in addition to playing a role in innate immunity, has been shown to be involved in the cellular stress response. Using primary human keratinocytes as experimental models, we have shown that UV irradiation (and other cellular stresses) activates TLR9 expression. This event is closely linked to p53 activation. Silencing the expression of p53 or deleting its encoding gene affected the activation of TLR9 expression after UV irradiation. Using various strategies, we have also shown that the transcription factors p53 and c-Jun are recruited onto a specific region of the TLR9 promoter after UV irradiation. Importantly, the E6 and E7 oncoproteins from beta HPV38, by inducing the accumulation of the p53 antagonist ΔNp73α, prevent the UV-mediated recruitment of these transcription factors onto the TLR9 promoter, with subsequent impairment of TLR9 gene expression. This study provides new insight into the mechanism that mediates TLR9 upregulation in response to cellular stresses. In addition, we show that HPV38 E6 and E7 are able to interfere with this mechanism, providing another explanation for the possible cooperation of beta HPV types with UV radiation in skin carcinogenesis.IMPORTANCE Beta HPV types have been suggested to act as cofactors in UV-induced skin carcinogenesis by altering several cellular mechanisms activated by UV radiation. We show that the expression of TLR9, a sensor of damage-associated molecular patterns produced during cellular stress, is activated by UV radiation in primary human keratinocytes (PHKs). Two transcription factors known to be activated by UV radiation, p53 and c-Jun, play key roles in UV-activated TLR9 expression. The E6 and E7 oncoproteins from beta HPV38 strongly inhibit UV-activated TLR9 expression by preventing the recruitment of p53 and c-Jun to the TLR9 promoter. Our findings provide additional support for the role that beta HPV types play in skin carcinogenesis by preventing activation of specific pathways upon exposure of PHKs to UV radiation.
Assuntos
Transformação Celular Neoplásica/patologia , Ativação Enzimática/efeitos da radiação , Queratinócitos/metabolismo , Papillomaviridae/crescimento & desenvolvimento , Proteínas E7 de Papillomavirus/metabolismo , Receptor Toll-Like 9/metabolismo , Receptor Toll-Like 9/efeitos da radiação , Proteínas Virais/metabolismo , Proliferação de Células/genética , Células Cultivadas , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Regiões Promotoras Genéticas/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Pele/parasitologia , Pele/virologia , Neoplasias Cutâneas/virologia , Receptor Toll-Like 9/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Raios UltravioletaRESUMO
The liver is the largest gland in the human body and functions as an innate immune organ. Liver macrophages called Kupffer cells (KC) constitute the largest group of macrophages in the human body. Innate immune responses involving KC represent the first line of defense against pathogens in the liver. Human monocyte-derived macrophages have been used to characterize inflammasome responses that lead to the release of the proinflammatory cytokines IL-1ß and IL-18, but it has not yet been determined whether human KC contain functional inflammasomes. We show, to our knowledge for the first time, that KC express genes and proteins that make up several different inflammasome complexes. Moreover, activation of KC in response to the absent in melanoma 2 (AIM2) inflammasome led to the production of IL-1ß and IL-18, which activated IL-8 transcription and hepatic NK cell activity, respectively. Other inflammasome responses were also activated in response to selected bacteria and viruses. However, hepatitis B virus inhibited the AIM2 inflammasome by reducing the mRNA stability of IFN regulatory factor 7, which regulated AIM2 transcription. These data demonstrate the production of IL-1ß and IL-18 in KC, suggesting that KC contain functional inflammasomes that could be important players in the innate immune response following certain infections of the liver. We think our findings could potentially aid therapeutic approaches against chronic liver diseases that activate the inflammasome.
Assuntos
Vírus da Hepatite B/imunologia , Hepatite B Crônica/imunologia , Inflamassomos/metabolismo , Células Matadoras Naturais/imunologia , Células de Kupffer/fisiologia , Fígado/imunologia , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Humanos , Imunidade Inata , Fator Regulador 7 de Interferon/metabolismo , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Ativação LinfocitáriaRESUMO
Recent studies of immune populations in nonlymphoid organs have highlighted the great diversity of the innate lymphoid system. It has also become apparent that mouse and human innate lymphoid cells (ILCs) have distinct phenotypes and properties. In this issue of the European Journal of Immunology, Harmon et al. [Eur. J. Immunol. 2016. 46: 2111-2120] characterized human hepatic NK-cell subsets. The authors report that hepatic CD56(bright) NK cells resemble mouse liver ILC1s in that they express CXCR6 and have an immature phenotype. However, unlike mouse ILC1s, they express high levels of Eomes and low levels of T-bet, and upon stimulation with tumor cells, secrete low amounts of cytokines. These unexpected findings further support the differences between human and mouse immune populations and prompt the study of the role of hepatic ILC subsets in immune responses.
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Imunidade Inata/imunologia , Células Matadoras Naturais/imunologia , Animais , Citocinas , Hepatócitos , Humanos , Fígado/imunologia , CamundongosRESUMO
UNLABELLED: Innate immunity is the first line of host defense against infections. Many oncogenic viruses can deregulate several immune-related pathways to guarantee the persistence of the infection. Here, we show that the cutaneous human papillomavirus 38 (HPV38) E6 and E7 oncoproteins suppress the expression of the double-stranded DNA sensor Toll-like receptor 9 (TLR9) in human foreskin keratinocytes (HFK), a key mediator of the antiviral innate immune host response. In particular, HPV38 E7 induces TLR9 mRNA downregulation by promoting accumulation of ΔNp73α, an antagonist of p53 and p73. Inhibition of ΔNp73α expression by antisense oligonucleotide in HPV38 E6/E7 HFK strongly rescues mRNA levels of TLR9, highlighting a key role of ΔNp73α in this event. Chromatin immunoprecipitation experiments showed that ΔNp73α is part of a negative transcriptional regulatory complex with IκB kinase beta (IKKß) that binds to a NF-κB responsive element within the TLR9 promoter. In addition, the Polycomb protein enhancer of zeste homolog 2 (EZH2), responsible for gene expression silencing, is also recruited into the complex, leading to histone 3 trimethylation at lysine 27 (H3K27me3) in the same region of the TLR9 promoter. Ectopic expression of TLR9 in HPV38 E6/E7 cells resulted in an accumulation of the cell cycle inhibitors p21(WAF1) and p27(Kip1), decreased CDK2-associated kinase activity, and inhibition of cellular proliferation. In summary, our data show that HPV38, similarly to other viruses with well-known oncogenic activity, can downregulate TLR9 expression. In addition, they highlight a new role for TLR9 in cell cycle regulation. IMPORTANCE: The mucosal high-risk HPV types have been clearly associated with human carcinogenesis. Emerging lines of evidence suggest the involvement of certain cutaneous HPV types in development of skin squamous cell carcinoma, although this association is still under debate. Oncogenic viruses have evolved different strategies to hijack the host immune system in order to guarantee the persistence of the infection. Their capability to evade the immune system is as important as their ability to promote cellular transformation. Therefore, understanding the viral mechanisms involved in viral persistence is a valid tool to evaluate their potential role in human carcinogenesis. Here, we show that E6 and E7 oncoproteins from the cutaneous HPV38 downregulate the expression of the double-stranded DNA sensor TLR9 of innate immunity. We also present evidence that the HPV38-mediated downregulation of TLR9 expression, in addition to its potential impact on the innate immune response, is linked to cell cycle deregulation.
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Pontos de Checagem do Ciclo Celular/genética , Papillomaviridae/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Receptor Toll-Like 9/biossíntese , Linhagem Celular , Proliferação de Células/genética , Quinase 2 Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Regulação para Baixo , Proteína Potenciadora do Homólogo 2 de Zeste , Histonas/metabolismo , Humanos , Quinase I-kappa B/metabolismo , Queratinócitos/metabolismo , Queratinócitos/virologia , Metilação , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Complexo Repressor Polycomb 2/metabolismo , Regiões Promotoras Genéticas/genética , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno , RNA Viral/genética , Receptor Toll-Like 9/antagonistas & inibidores , Receptor Toll-Like 9/genética , Quinases Ativadas por p21/metabolismoRESUMO
Toll-like and interleukin-1 (IL-1) family receptors recognize microbial or endogenous ligands and inflammatory mediators, respectively, and with the exception of Toll-like receptor 3 (TLR3), signal via the adaptor molecule myeloid differentiation factor 88 (MyD88). MyD88 is involved in oncogene-induced cell intrinsic inflammation and in cancer-associated extrinsic inflammation, and as such MyD88 contributes to skin, liver, pancreatic, and colon carcinogenesis, as well as sarcomagenesis. MyD88 is also protective, for example in oncogenic virus carcinogenesis or, acting downstream of IL-18R to strengthen mucosal repair, in azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colon carcinogenesis. Here, we discuss the mechanisms of the divergent effects of MyD88 and the balance of its protumor role in cancer-enhancing inflammation and immunity and its antitumor role in tissue homeostasis, repair, and immunity against the tumor or oncogenic pathogens.
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Transformação Celular Neoplásica/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Animais , HumanosRESUMO
The stimulation of TLRs by pathogen-derived molecules leads to the production of proinflammatory cytokines. Because uncontrolled inflammation can be life threatening, TLR regulation is important; however, few studies have identified the signaling pathways that contribute to the modulation of TLR expression. In this study, we examined the relationship between activation and the transcriptional regulation of TLR9. We demonstrate that infection of primary human epithelial cells, B cells, and plasmacytoid dendritic cells with dsDNA viruses induces a regulatory temporary negative-feedback loop that blocks TLR9 transcription and function. TLR9 transcriptional downregulation was dependent on TLR9 signaling and was not induced by TLR5 or other NF-κB activators, such as TNF-α. Engagement of the TLR9 receptor induced the recruitment of a suppressive complex, consisting of NF-κBp65 and HDAC3, to an NF-κB cis element on the TLR9 promoter. Knockdown of HDAC3 blocked the transient suppression in which TLR9 function was restored. These results provide a framework for understanding the complex pathways involved in transcriptional regulation of TLR9, immune induction, and inflammation against viruses.
Assuntos
Infecções por Vírus de DNA/imunologia , Vírus de DNA/imunologia , Regiões Promotoras Genéticas/imunologia , Receptor Toll-Like 9/imunologia , Transcrição Gênica/imunologia , Animais , Infecções por Vírus de DNA/genética , Infecções por Vírus de DNA/patologia , Células Dendríticas/imunologia , Células Dendríticas/patologia , Células Epiteliais/imunologia , Células Epiteliais/patologia , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Histona Desacetilases/genética , Histona Desacetilases/imunologia , Humanos , Masculino , Camundongos , Células NIH 3T3 , Plasmócitos/imunologia , Plasmócitos/patologia , Receptor Toll-Like 9/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologia , Transcrição Gênica/genéticaRESUMO
Establishment of a chronic infection is a key event in virus-mediated carcinogenesis. Several cancer-associated, double-stranded DNA (dsDNA) viruses act via their oncoproteins to downregulate Toll-like receptor 9 (TLR9), a key receptor in the host innate immune response that senses viral or bacterial dsDNA. A novel oncogenic virus, Merkel cell polyomavirus (MCPyV), has been recently identified that causes up to 80% of Merkel cell carcinomas (MCCs). However, it is not yet known whether this oncogenic virus also disrupts immune-related pathways. We find that MCPyV large T antigen (LT) expression downregulates TLR9 expression in epithelial and MCC-derived cells. Accordingly, silencing of LT expression results in upregulation of mRNA TLR9 levels. In addition, small T antigen (sT) also appears to inhibit TLR9 expression, since inhibition of its expression also resulted in an increase of TLR9 mRNA levels. LT inhibits TLR9 expression by decreasing the mRNA levels of the C/EBPß transactivator, a positive regulator of the TLR9 promoter. Chromatin immunoprecipitation reveals that C/EBPß binding at a C/EBPß response element (RE) in the TLR9 promoter is strongly inhibited by expression of MCPyV early genes and that mutation of the C/EBP RE prevents MCPyV downregulation of TLR9. A survey of BK polyomavirus (BKPyV), JC polyomavirus (JCPyV), KI polyomavirus (KIPyV), MCPyV, simian virus 40 (SV40), and WU polyomavirus (WUPyV) early genes revealed that only BKPyV and MCPyV are potent inhibitors of TLR9 gene expression. MCPyV LT targeting of C/EBP transactivators is likely to play an important role in viral persistence and potentially inhibit host cell immune responses during MCPyV tumorigenesis.
Assuntos
Antígenos Virais de Tumores/metabolismo , Carcinoma de Célula de Merkel/genética , Regulação para Baixo , Poliomavírus das Células de Merkel/metabolismo , Infecções por Polyomavirus/genética , Receptor Toll-Like 9/genética , Antígenos Virais de Tumores/genética , Carcinoma de Célula de Merkel/metabolismo , Carcinoma de Célula de Merkel/virologia , Interações Hospedeiro-Patógeno , Humanos , Células de Merkel/metabolismo , Células de Merkel/virologia , Poliomavírus das Células de Merkel/genética , Infecções por Polyomavirus/metabolismo , Infecções por Polyomavirus/virologia , Regiões Promotoras Genéticas , Receptor Toll-Like 9/metabolismo , Infecções Tumorais por Vírus/genética , Infecções Tumorais por Vírus/metabolismo , Infecções Tumorais por Vírus/virologiaRESUMO
Glioblastoma multiforme (GBM) is regarded as a highly aggressive brain cancer with a poor prognosis. There is an increase in the expression of P-glycoprotein (P-gp), responsible for multidrug resistance (MDR), making it a potential target for improving drug responses. Additionally, glioblastoma stem cells (GSCs) increase resistance to chemo- and radiotherapy and play a major role in cancer relapse. In this study, we targeted P-gp using a small molecule inhibitor, reversan (RV), to inhibit MDR that prolonged the retention of drugs in the cytosolic milieu. To eliminate GBM and GSCs, we have used two well-established anti-cancer drugs, regorafenib (RF) and curcumin (CMN). To improve the pharmacokinetics and decrease systemic delivery of drugs, we developed nanostructure hybrid lipid capsules (nHLCs), where hydrophobic drugs can be loaded in the core, and their physicochemical properties were determined by dynamic light scattering (DLS) and cryo-scanning electron microscopy (SEM). Inhibition of MDR by RV has also shown enhanced retention of nHLC in GBM cells. Co-delivery of drug-loaded nHLCs, pre-treated with RV, exhibited superior cytotoxicity in both GBM and GSCs than their individual doses and effectively reduced the size and stemness of tumor spheres and accelerated the rate of apoptosis, suggesting a promising treatment for glioblastoma.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Células-Tronco Neoplásicas , Resistência a Múltiplos Medicamentos , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Lipídeos , Linhagem Celular TumoralRESUMO
Acute and chronic wounds are vulnerable to infection and delayed healing and require critical care and advanced wound protection. To overcome the challenges, dual therapy of antibacterial and growth factors will be a novel wound care strategy. The present study explores airbrushed core-shell nanofiber for dual delivery of epidermal growth factor (EGF) and amoxicillin (AMOX) in a sustained manner. A blend of polycaprolactone (PCL)-polyethylene oxide (PEO) was used to prepare the shell compartment for amoxicillin loading and poly-DL-lactide (PDLLA) core for EGF loading by using a customized airbrush setup. Characterization result shows a uniform distribution of nanofibers ranging between 200 and 500 nm in diameter. Amoxicillin loading in the shell compartment offers an initial burst release followed by a sustained release for up to 14 days. Whereas EGF in the core part shows a continuous sustained release throughout the release study.In-vitrostudy indicates the biocompatibility of EGF-AMOX loaded core-shell nanofibers with human dermal fibroblast cell (HDF) cells and a higher cellular proliferation compared to control samples. Gene expression data show an increase in fold change of collagen I and tropoelastin expression, indicating the regenerative properties of EGF-AMOX encapsulated nanofiber. The combination of bioactive core (EGF) and antibiotic shell (amoxicillin) in an airbrushed nanofibrous scaffold is a novel approach, which is the first time explored to deliver sustainable therapy to treat skin wounds. Our results demonstrate that PCL-PEO-Amoxicillin/PDLLA-EGF-loaded core-shell nanofibers are promising dual therapy scaffolds to deliver effective skin wound care, with the possibility of direct deposition on the wound.
Assuntos
Fator de Crescimento Epidérmico , Nanofibras , Humanos , Preparações de Ação Retardada , Cicatrização , Poliésteres , Antibacterianos/farmacologia , AmoxicilinaRESUMO
Breast cancer is a significant global issue, ranking as the second most common cancer among women worldwide and a leading cause of cancer-related deaths. Although the exact causes of this increase remain unclear, factors such as genetics, epigenetics, obesity, sedentary lifestyle, tobacco use, and vitamin D deficiency have been implicated. The Toll-like receptor 9 (TLR9) is recognized for its role in inflammation and innate immunity; however, its specific involvement in breast cancer pathogenesis requires further investigation. This study aims to systematically review the existing literature on TLR9 expression in normal and cancerous breast tissue, providing current knowledge and identifying gaps. Relevant articles in English were from PubMed, Scopus, and Google Scholar, with the inclusion criteria focusing on studies evaluating TLR9 mRNA and protein expression. The review found that TLR9 mRNA and protein exhibit variable expressions in both normal and cancerous breast tissue, highlighting the need for further research to clarify TLR9's role in breast cancer.
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The need for reliable biomarkers to predict clinical benefit from anti-PD1 treatment in metastatic melanoma (MM) patients remains unmet. Several parameters have been considered in the tumor environment or the blood, but none has yet achieved sufficient accuracy for routine clinical practice. Whole blood samples from MM patients receiving second-line anti-PD1 treatment (NCT02626065), collected longitudinally, were analyzed by flow cytometry to assess the immune cell subsets absolute numbers, the expression of immune checkpoints or ligands on T cells and the functionality of innate immune cells and T cells. Clinical response was assessed according to Progression-Free Survival (PFS) status at one-year following initiation of anti-PD1 (responders: PFS > 1 year; non-responders: PFS ≤ 1 year). At baseline, several phenotypic and functional alterations in blood immune cells were observed in MM patients compared to healthy donors, but only the proportion of polyfunctional memory CD4+ T cells was associated with response to anti-PD1. Under treatment, a decreased frequency of HVEM on CD4+ and CD8+ T cells after 3 months of treatment identified responding patients, whereas its receptor BTLA was not modulated. Both reduced proportion of CD69-expressing CD4+ and CD8+ T cells and increased number of polyfunctional blood memory T cells after 3 months of treatment were associated with response to anti-PD1. Of upmost importance, the combination of changes of all these markers accurately discriminated between responding and non-responding patients. These results suggest that drugs targeting HVEM/BTLA pathway may be of interest to improve anti-PD1 efficacy.
Assuntos
Melanoma , Receptor de Morte Celular Programada 1 , Receptores Imunológicos , Membro 14 de Receptores do Fator de Necrose Tumoral , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Melanoma/tratamento farmacológico , Melanoma/imunologia , Melanoma/patologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Receptores Imunológicos/metabolismo , Membro 14 de Receptores do Fator de Necrose Tumoral/metabolismo , Resultado do TratamentoRESUMO
HIV-1, hepatitis B virus, hepatitis C virus, and human papillomavirus type 16 cause persistent infections that frequently precede cancer development. Virions of these viruses are weak inducers of interferon-α and impair Toll-like receptor (TLR)9 function. Loss of TLR9 responsiveness also occurs in tumors without viral etiology such as breast, ovary, and head and neck carcinomas. Recent reports have suggested that viruses and components of the tumor microenviroment interact with regulatory receptors on plasmacytoid dendritic cells (pDCs) to impair TLR7 and TLR9 signaling, and to downregulate TLR9 gene expression. The limited responsiveness of pDCs might contribute to reduced innate immune responses during chronic viral infections and oncogenesis, and represent a target for new therapeutic approaches based on TLR agonists.
Assuntos
Hepatite Crônica/complicações , Neoplasias/imunologia , Neoplasias/virologia , Transdução de Sinais , Receptor 7 Toll-Like/imunologia , Receptor Toll-Like 9/imunologia , Animais , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/etiologia , Receptor 7 Toll-Like/agonistas , Receptor 7 Toll-Like/metabolismo , Receptor Toll-Like 9/agonistas , Receptor Toll-Like 9/metabolismoRESUMO
The glioblastoma stem cell (GSC) population in glioblastoma multiforme (GBM) poses major complication in clinical oncology owing to increased resistance to chemotherapeutic drugs, thereby limiting treatment in patients with recurring glioblastoma. To completely eradicate glioblastoma, a single therapy module is not enough; therefore, there is a need to develop a multimodal approach to eliminate bulk tumors along with the CSC population. With an aim to target transporters associated with multidrug resistance (MDR), such as P-glycoprotein (P-gp), a small-molecule inhibitor, reversan (RV) was used along with multifunctional magnetic nanoparticles (MNPs) for hyperthermia (HT) therapy and targeted drug delivery. Higher efflux of free doxorubicin (Dox) from the cells was stabilized by encapsulation in PPS-MnFe nanoparticles, whose physicochemical properties were determined by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Treatment with RV also enhanced the cellular uptake of PPS-MnFe-Dox, whereas RV and magnetic hyperthermia (MHT) together showed prolonged retention of fluorescence dye, Rhodamine123 (R123), in glioblastoma cells compared with individual treatment. Overall, in this work, we demonstrated the synergistic action of RV and HT to combat MDR in GBM and GSCs, and chemo-hyperthermia therapy enhanced the cytotoxic effect of the chemotherapeutic drug Dox (with lower effective concentration) and induced a higher degree of apoptosis compared to single-drug dosage.
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Glioblastoma , Hipertermia Induzida , Humanos , Glioblastoma/tratamento farmacológico , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Resistência a Múltiplos Medicamentos , Células-TroncoRESUMO
There is increasing evidence that viral infections are the source/origin of various types of encephalitis, encephalomyelitis, and other neurological and cognitive disorders. While the involvement of certain viruses, such as the Nipah virus and measles virus, is known, the mechanisms of neural invasion and the factors that trigger intense immune reactions are not fully understood. Based on recent publications, this review discusses the role of the immune response, interactions between viruses and glial cells, and cytokine mediators in the development of inflammatory diseases in the central nervous system. It also highlights the significant gaps in knowledge regarding these mechanisms.
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Immunotherapy involves the therapeutic alteration of the patient's immune system to identify, target, and eliminate cancer cells. Dendritic cells, macrophages, myeloid-derived suppressor cells, and regulatory T cells make up the tumor microenvironment. In cancer, these immune components (in association with some non-immune cell populations like cancer-associated fibroblasts) are directly altered at a cellular level. By dominating immune cells with molecular cross-talk, cancer cells can proliferate unchecked. Current clinical immunotherapy strategies are limited to conventional adoptive cell therapy or immune checkpoint blockade. Targeting and modulating key immune components presents an effective opportunity. Immunostimulatory drugs are a research hotspot, but their poor pharmacokinetics, low tumor accumulation, and non-specific systemic toxicity limit their use. This review describes the cutting-edge research undertaken in the field of nanotechnology and material science to develop biomaterials-based platforms as effective immunotherapeutics. Various biomaterial types (polymer-based, lipid-based, carbon-based, cell-derived, etc.) and functionalization methodologies for modulating tumor-associated immune/non-immune cells are explored. Additionally, emphasis has been laid on discussing how these platforms can be used against cancer stem cells, a fundamental contributor to chemoresistance, tumor relapse/metastasis, and failure of immunotherapy. Overall, this comprehensive review strives to provide up-to-date information to an audience working at the juncture of biomaterials and cancer immunotherapy. STATEMENT OF SIGNIFICANCE: Cancer immunotherapy possesses incredible potential and has successfully transitioned into a clinically lucrative alternative to conventional anti-cancer therapies. With new immunotherapeutics getting rapid clinical approval, fundamental problems associated with the dynamic nature of the immune system (like limited clinical response rates and autoimmunity-related adverse effects) have remained unanswered. In this context, treatment approaches that focus on modulating the compromised immune components within the tumor microenvironment have garnered significant attention amongst the scientific community. This review aims to provide a critical discussion on how various biomaterials (polymer-based, lipid-based, carbon-based, cell-derived, etc.) can be employed along with immunostimulatory agents to design innovative platforms for selective immunotherapy directed against cancer and cancer stem cells.
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Materiais Biocompatíveis , Neoplasias , Humanos , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/uso terapêutico , Neoplasias/patologia , Imunoterapia/métodos , Células-Tronco Neoplásicas/patologia , Lipídeos , Microambiente TumoralRESUMO
Recent advances in causal inference techniques, more specifically, in the theory of structural causal models, provide the framework for identifying causal effects from observational data in cases where the causal graph is identifiable, i.e., the data generation mechanism can be recovered from the joint distribution. However, no such studies have been performed to demonstrate this concept with a clinical example. We present a complete framework to estimate the causal effects from observational data by augmenting expert knowledge in the model development phase and with a practical clinical application. Our clinical application entails a timely and essential research question, the effect of oxygen therapy intervention in the intensive care unit (ICU). The result of this project is helpful in a variety of disease conditions, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) patients in the ICU. We used data from the MIMIC-III database, a widely used health care database in the machine learning community with 58,976 admissions from an ICU in Boston, MA, to estimate the oxygen therapy effect on morality. We also identified the model's covariate-specific effect on oxygen therapy for more personalized intervention.
Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Unidades de Terapia Intensiva , Oxigênio , Bases de Dados FactuaisRESUMO
Endometrial cancer (EC) is the seventh most common tumor in women, and prognosis of recurrent and metastatic disease is poor. Cervical cancer (CC) represents the fifth most common gynecological cancer. While ECs are more common in developed countries, the incidence of CC has decreased due to the recent implementation of large screening and vaccination programs. Until very recently, patients with advanced or unresectable EC or CC had very limited treatment options and were receiving in first line setting platinum/taxane-based chemotherapy (CT). Significant progress in the treatment of gynecological cancers has occurred in the last few years, with the use of innovative targeted therapies and immunotherapy. However, targeting the immune system in patients with gynecological tumors remains challenging and is not always successful. In ovarian cancer, several immunotherapy treatment regimens have been investigated (as monotherapy and combination therapy in first and subsequent lines of treatment) and showed poor responses. Therefore, we specifically focused our review on EC and CC for their specific immune-related features and therapeutic results demonstrated with immunotherapy. We report recent and current immunotherapy-based clinical trials and provide a review of emerging data that are likely to impact immunotherapy development based on increased biomarkers' identification to monitor response and overcome resistance.