RESUMO
Dengue disease caused by dengue virus (DENV) infection is the most common vector-borne viral disease worldwide. Currently, no treatment is available to fight dengue symptoms. We and others have demonstrated the antiviral and immunomodulatory properties of VitD3 as a possible therapy for DENV infection. MicroRNAs (miRNAs) are small non-coding RNAs responsible for the regulation of cell processes including antiviral defense. Previous transcriptomic analysis showed that VitD3 regulates the expression of genes involved in stress and immune response by inducing specific miRNAs. Here, we focus on the effects of VitD3 supplementation in the regulation of the expression of inflammatory-liked miR-182-5p, miR-130a-3p, miR125b-5p, miR146a-5p, and miR-155-5p during DENV-2 infection of monocyte-derived macrophages (MDMs). Further, we evaluated the effects of inhibition of these miRNAs in the innate immune response. Our results showed that supplementation with VitD3 differentially regulated the expression of these inflammatory miRNAs. We also observed that inhibition of miR-182-5p, miR-130a-3p, miR-125b-5p, and miR-155-5p, led to decreased production of TNF-α and TLR9 expression, while increased the expression of SOCS-1, IFN-ß, and OAS1, without affecting DENV replication. By contrast, over-expression of miR-182-5p, miR-130a-3p, miR-125b-5p, and miR-155-5p significantly decreased DENV-2 infection rates and also DENV-2 replication in MDMs. Our results suggest that VitD3 immunomodulatory effects involve regulation of inflammation-linked miRNAs expression, which might play a key role in the inflammatory response during DENV infection.
Assuntos
Dengue , Macrófagos , MicroRNAs , Vitamina D , Humanos , Dengue/imunologia , Vírus da Dengue , Regulação da Expressão Gênica , Macrófagos/imunologia , Macrófagos/virologia , MicroRNAs/genética , Replicação Viral , Vitamina D/farmacologiaRESUMO
Epidemics of dengue, an acute and potentially severe disease caused by mosquito-borne dengue virus (DENV), pose a major challenge to clinicians and health care services across the sub(tropics). Severe disease onset is associated with a dysregulated inflammatory response to the virus, and there are currently no drugs to alleviate disease symptoms. LL-37 is a potent antimicrobial peptide with a wide range of immunoregulatory properties. In this study, we assessed the effect of LL-37 on DENV-2-induced responses in human monocyte-derived macrophages (MDMs). We show that simultaneous exposure of exogenous LL-37 and DENV-2 resulted in reduced replication of the virus in MDMs, while the addition of LL-37 postexposure to DENV-2 did not. Interestingly, the latter condition reduced the production of IL-6 and increased the expression of genes involved in virus sensing and antiviral response. Finally, we demonstrate that low endogenous levels and limited production of LL-37 in MDMs in response to DENV-2 infection can be increased by differentiating MDMs in the presence of Vitamin D (VitD3). Taken together, this study demonstrates that in addition to its antimicrobial properties, LL-37 has immunomodulatory properties in the curse of DENV infection and its production can be increased by VitD3.
Assuntos
Vírus da Dengue , Dengue , Animais , Humanos , Imunidade Inata , Macrófagos , Replicação Viral , Vitamina D/metabolismo , Vitamina D/farmacologiaRESUMO
BACKGROUND: The pathogenesis associated with Dengue virus (DENV) infection is marked by the impairment of host immune response. Consequently, the modulation of immune response has emerged as an important therapeutic target for the control of DENV infection. Vitamin D has been shown to regulate the immune response in DENV infection, although the molecular mechanism remains poorly understood. Post-transcriptional regulation of mRNA by miRNAs offers an opportunity to gain insight into the immunomodulation mediated by vitamin D. OBJECTIVE: Previously, it has been observed that a high dose of vitamin D (4000 IU) decreased DENV-2 infection and inflammatory response in monocyte-derived macrophages (MDMs). Here, we examine whether high or low doses of vitamin D supplements exert differential effect on miRNA expression in DENV-infected macrophages. METHODS: We analyzed miRNA expression profiles in MDMs isolated from healthy individuals who were given either 1000 or 4000 IU/day of vitamin D for 10 days. MDMs before or after vitamin D supplementation were challenged with DENV-2, and miRNAs profiles were analyzed by qPCR arrays. RESULTS: DENV-2 infected MDMs supplemented with 4000 IU, showed up-regulation of miR-374a-5p, miR-363-3p, miR-101-3p, miR-9-5p, miR-34a-5p, miR-200a-3p, and the family of miRNAs miR-21-5p, and miR-590-p. The miRNA profile and predicted target mRNAs suggested regulatory pathways in MDMs obtained from healthy donors who received higher doses of vitamin D. These DENV-2 infected MDMs expressed a unique set of miRNAs that target immune and cellular stress response genes. CONCLUSION: The results suggest vitamin D dose-dependent differential expression of miRNAs target key signaling pathways of the pathogenesis of dengue disease.
Assuntos
Vírus da Dengue , Dengue , MicroRNAs , Dengue/tratamento farmacológico , Dengue/genética , Vírus da Dengue/genética , Vírus da Dengue/metabolismo , Humanos , Macrófagos , MicroRNAs/genética , Replicação Viral , Vitamina D/metabolismo , Vitamina D/farmacologia , Vitamina D/uso terapêuticoRESUMO
A dysregulated or exacerbated inflammatory response is thought to be the key driver of the pathogenesis of severe disease caused by the mosquito-borne dengue virus (DENV). Compounds that restrict virus replication and modulate the inflammatory response could thus serve as promising therapeutics mitigating the disease pathogenesis. We and others have previously shown that macrophages, which are important cellular targets for DENV replication, differentiated in the presence of bioactive vitamin D (VitD3) are less permissive to viral replication, and produce lower levels of pro-inflammatory cytokines. Therefore, we here evaluated the extent and kinetics of innate immune responses of DENV-2 infected monocytes differentiated into macrophages in the presence (D3-MDMs) or absence of VitD3 (MDMs). We found that D3-MDMs expressed lower levels of RIG I, Toll-like receptor (TLR)3, and TLR7, as well as higher levels of SOCS-1 in response to DENV-2 infection. D3-MDMs produced lower levels of reactive oxygen species, related to a lower expression of TLR9. Moreover, although VitD3 treatment did not modulate either the expression of IFN-α or IFN-ß, higher expression of protein kinase R (PKR) and 2'-5'-oligoadenylate synthetase 1 (OAS1) mRNA were found in D3-MDMs. Importantly, the observed effects were independent of reduced infection, highlighting the intrinsic differences between D3-MDMs and MDMs. Taken together, our results suggest that differentiation of MDMs in the presence of VitD3 modulates innate immunity in responses to DENV-2 infection.
Assuntos
Diferenciação Celular , Vírus da Dengue/fisiologia , Dengue/imunologia , Macrófagos/citologia , Vitamina D/imunologia , 2',5'-Oligoadenilato Sintetase/genética , 2',5'-Oligoadenilato Sintetase/imunologia , Adulto , Animais , Dengue/genética , Dengue/fisiopatologia , Dengue/virologia , Vírus da Dengue/classificação , Vírus da Dengue/genética , Feminino , Humanos , Imunidade Inata , Interferon beta/genética , Interferon beta/imunologia , Macrófagos/imunologia , Masculino , Monócitos/citologia , Monócitos/imunologia , Replicação Viral , Adulto JovemRESUMO
Diseases caused by dengue virus (DENV) are a major public health problem worldwide, considered one of the infections with more prevalence in tropical and subtropical zones of the world. Despite the intense research in the pathogenesis of DENV, this feature is not well understood. One of the main target cells for DENV infection is monocytes; these phagocytes can play a dual role, since they are essential to control viremia, but they also participate in the induction of tissue damage during DENV infection. Monocytes produce different pro-inflammatory cytokines and chemokines in response to infection, and also mediate endothelial damage. In peripheral blood, monocytes can be divided into three different subpopulations, namely classical, intermediate and non-classical, which differ in frequency, cytokine production, among others. Studies in the last years suggest that non-classical monocytes have higher affinity for microvasculature endothelium compared to other type of monocytes, which implies that they could be more involved in the increase of endothelial permeability observed during DENV infection. This review provides a general view of the role of monocytes and their subpopulations in DENV pathogenesis and its effect in viral replication. Finally, the potential contribution of these phagocytes in the alterations of endothelial permeability is discussed.
Assuntos
Vírus da Dengue/patogenicidade , Dengue/virologia , Monócitos/virologia , Animais , Permeabilidade Capilar , Citocinas/imunologia , Citocinas/metabolismo , Dengue/imunologia , Dengue/metabolismo , Vírus da Dengue/crescimento & desenvolvimento , Vírus da Dengue/imunologia , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Células Endoteliais/virologia , Interações Hospedeiro-Patógeno , Humanos , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Microvasos/imunologia , Microvasos/metabolismo , Microvasos/virologia , Monócitos/imunologia , Monócitos/metabolismo , Fagocitose , Transdução de Sinais , Replicação ViralRESUMO
Although dengue can progress to severe stages, the exact causes of this phenomenon are unknown; however, the possibility of monocyte participation is acknowledged. It has been suggested that monocyte subsets (classical, intermediate and non-classical) play differential roles in dengue immunopathology. Therefore, we determined the count of monocyte subsets and obtained the clinical information of patients with dengue. We noted a significant decrease in the count of non-classical monocytes in patients compared with controls. With this finding, we focused on studying the phenotype of non-classical monocytes in the present study. An increase in activation and differentiation markers, such as CD64, CD86, the percentage of tumor necrosis factor-α+ cells and exposure of phosphatidylserine, were recorded in the non-classical monocytes of patients compared with controls. Moreover, a significant decrease in the expression of CX3CR1 with a corresponding increase in the expressions of CCR2, CCR5, CD11b and CD54 was detected in the non-classical monocytes of patients in comparison with that of the controls. Significant increases in the frequency of microparticles from endothelium and in the concentrations of interleukin-6 (IL-6), IL-8 and IL-10 were noted in the plasma of patients. These findings demonstrate that in patients with dengue, non-classical monocytes are activated, exhibiting a phenotype associated with more differentiation, produces tumor necrosis factor-α and has a profile of less endothelial surveillance closer to the cellular migration. These changes were associated with hepatic compromise, endothelial alteration and high concentration of circulating cytokines. Hence, alterations of non-classical monocytes seem to be associated with the immunopathology of dengue infection.
Assuntos
Dengue/imunologia , Endotélio Vascular/imunologia , Fígado/imunologia , Monócitos/imunologia , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Adolescente , Adulto , Idoso , Antígenos CD/imunologia , Citocinas/imunologia , Dengue/patologia , Endotélio Vascular/patologia , Feminino , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Monócitos/patologia , Receptores de Quimiocinas/imunologia , Síndrome de Resposta Inflamatória Sistêmica/patologiaRESUMO
Arthropod-borne viral diseases caused by dengue virus (DENV) are major re-emerging public health problem worldwide. In spite of intense research, DENV pathogenesis is not fully understood and remains enigmatic; however, current evidence suggests that dengue progression is associated with an inflammatory response, mainly in patients suffering from a second DENV infection. Monocytes are one of the main target cells of DENV infection and play an important role in pathogenesis since they are known to produce several inflammatory cytokines that can lead to endothelial dysfunction and therefore vascular leak. In addition, monocytes play an important role in antibody dependent enhancement, infection with consequences in viral load and immune response. Despite the physiological functions of monocytes in immune response, their life span in the bloodstream is very short, and activation of monocytes by DENV infection can trigger different types of cell death. For example, DENV can induce apoptosis in monocytes related with the production of Tumor necrosis factor alpha (TNF-α). Additionally, recent studies have shown that DENV-infected monocytes also exhibit a cell death process mediated by caspase-1 activation together with IL-1 production, referred to as pyroptosis. Taken together, the aforementioned studies strongly depict that multiple cell death pathways may be occurring in monocytes upon DENV-2 infection. This review provides insight into mechanisms of DENV-induced death of both monocytes and other cell types for a better understanding of this process. Further knowledge in cell death induced by DENV will help in the developing novel strategies to prevent disease progression.
Assuntos
Morte Celular , Vírus da Dengue/fisiologia , Dengue/patologia , Monócitos/patologia , Apoptose , Dengue/metabolismo , Dengue/virologia , Vírus da Dengue/patogenicidade , Humanos , Monócitos/metabolismo , Monócitos/virologia , Piroptose , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Replicação ViralRESUMO
BACKGROUND: Dengue virus (DENV) is the most common vector-borne viral infection worldwide with approximately 390 million cases and 25,000 reported deaths each year. MicroRNAs (miRNAs) are small non-coding RNA molecules responsible for the regulation of gene expression by repressing mRNA translation or inducing mRNA degradation. Although miRNAs possess antiviral activity against many mammalian-infecting viruses, their involvement in DENV replication is poorly understood. METHODS: Here, we explored the relationship between DENV and cellular microRNAs using bioinformatics tools. We overexpressed miRNA-133a in Vero cells to test its role in DENV replication and analyzed its expression using RT-qPCR. Furthermore, the expression of polypyrimidine tract binding protein (PTB), a protein involved in DENV replication, was analyzed by western blot. In addition, we profiled miRNA-133a expression in Vero cells challenged with DENV-2, using Taqman miRNA. RESULTS: Bioinformatic analysis revealed that the 3' untranslated region (3'UTR) of the DENV genome of all four DENV serotypes is targeted by several cellular miRNAs, including miRNA-133a. We found that overexpression of synthetic miRNA-133a suppressed DENV replication. Additionally, we observed that PTB transcription , a miRNA-133a target, is down-regulated during DENV infection. Based in our results we propose that 3'UTR of DENV down-regulates endogenous expression of miRNA-133a in Vero cells during the first hours of infection. CONCLUSIONS: miRNA-133a regulates DENV replication possibly through the modulation of a host factor such as PTB. Further investigations are needed to verify whether miRNA-133a has an anti-DENV effect in vivo.