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1.
Ann Hematol ; 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34651249

RESUMO

One of the physiologic mechanisms responsible to maintain asymmetric phospholipid distribution (in particular phosphatidylserine, PS) in human erythrocyte membranes is orchestrated by the balance between enzymes responsible for active transport of PS from the outer to the inner leaflet (ATP11C) and those whose counteracts these activities (PLSCR1). Using quantitative real-time polymerase chain reaction and standard flow cytometry procedures, we hypothesized that the aberrant expression of either or both ATP11C and PLSCR1 transcripts may disrupt the PS internalization/externalization process and become clinically relevant for patients with sickle cell anemia (SCA). Overall, neither ATP11C/PLSCR1 ratio or ATP11C and PLSCR1 (if analyzed separately) had impact on risk to present acute or chronic organ damage in 178 patients with SCA. By collecting a new set of samples from SCA patients during a vaso-occlusive crisis (VOC, crisis state, 13 patients) and comparing with new samples of patients in steady state (15 patients), we noticed that patients in steady state exhibited mean values of ATP11C/PLSCR1 ratio significantly higher (mean value: 18.2, range, 0.3-53) than those who were in crisis (mean value: 3.7, range, 0.5-9) (P = 0.013). Most importantly, there was a strong inverse correlation between PS exposure and ATP11C/PLSCR1 ratio in sickle erythrocytes (Pearson correlation coefficient, r: - 0.78). Based on these findings, it is conceivable that the ATP11C/PLSCR1 ratio may switch from high to low during a VOC, although the underlying reasons require further investigations.

2.
Viruses ; 13(5)2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33922819

RESUMO

The diagnostic of arbovirus-related obstetric complications in high-risk pregnancy and childbirth care is challenging, especially in endemic areas. We conducted a prospective study to track active or recent Zika (ZIKV), dengue (DENV), or chikungunya (CHIKV) virus infection among hospitalized pregnant women (PW) with obstetric complications in a hospital at the epicenter of Zika outbreak and ZIKV-related microcephaly in Brazil. Clinical data and blood samples were collected at enrollment and 10 days after the admission of study participants, between October 2018 and May 2019. Further clinical data were extracted from medical records. Samples were screened by molecular and serological tests. Out of 780 participants, 93.1% (95% CI: 91.1-94.7%) presented previous DENV exposure (IgG). ZIKV, CHIKV, and/or DENV laboratory markers of recent or active infection were detected in 130 PW, yielding a prevalence of 16.6% (95% CI: 14.2-19.5%); 9.4% (95% CI: 7.4-11.7%), 7.4% (95% CI: 5.7-9.7%), and 0.38% (95% CI: 0.1-1.2%) of CHIKV, ZIKV, and DENV infections, respectively. Most ZIKV infections were detected by molecular assays (89.6%), while CHIKV infections were detected by serology (95.9%). Our findings highlight the need for arbovirus infections screening in PW with obstetrical complications, potentially associated to these infections in endemic areas regardless of the signs or symptoms suggestive of arboviral disease.


Assuntos
Febre de Chikungunya/epidemiologia , Vírus Chikungunya , Infecção Hospitalar/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Infecção por Zika virus/epidemiologia , Zika virus , Adolescente , Adulto , Brasil/epidemiologia , Infecção Hospitalar/virologia , Suscetibilidade a Doenças , Feminino , Humanos , Incidência , Pessoa de Meia-Idade , Gravidez , Complicações Infecciosas na Gravidez/virologia , Estudos Prospectivos , Vigilância em Saúde Pública , Fatores de Risco , Adulto Jovem
3.
Cell Death Dis ; 12(4): 371, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33824267

RESUMO

Although the mixed lineage leukemia 5 (MLL5) gene has prognostic implications in acute promyelocyte leukemia (APL), the underlying mechanism remains to be elucidated. Here, we demonstrate the critical role exerted by MLL5 in APL regarding cell proliferation and resistance to drug-induced apoptosis, through mtROS regulation. Additionally, MLL5 overexpression increased the responsiveness of APL leukemic cells to all-trans retinoic acid (ATRA)-induced differentiation, via regulation of the epigenetic modifiers SETD7 and LSD1. In silico analysis indicated that APL blasts with MLL5high transcript levels were associated with retinoic acid binding and downstream signaling, while MLL5low blasts displayed decreased expression of epigenetic modifiers (such as KMT2C, PHF8 and ARID4A). Finally, APL xenograft transplants demonstrated improved engraftment of MLL5-expressing cells and increased myeloid differentiation over time. Concordantly, evaluation of engrafted blasts revealed increased responsiveness of MLL5-expressing cells to ATRA-induced granulocytic differentiation. Together, we describe the epigenetic changes triggered by the interaction of MLL5 and ATRA resulting in enhanced granulocytic differentiation.


Assuntos
Antineoplásicos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Xenoenxertos/imunologia , Leucemia Promielocítica Aguda/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Xenoenxertos/metabolismo , Histona Desmetilases/efeitos dos fármacos , Histona Desmetilases/metabolismo , Humanos , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/metabolismo
4.
Curr Pharm Biotechnol ; 22(4): 514-522, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32484769

RESUMO

BACKGROUND: Zika virus is an emerging arbovirus of global importance. ZIKV infection is associated with a range of neurological complications such as the Congenital Zika Syndrome and Guillain Barré Syndrome. Despite the magnitude of recent outbreaks, there is no specific therapy to prevent or to alleviate disease pathology. OBJECTIVE: To investigate the role of P-MAPA immunomodulator in Zika-infected THP-1 cells. METHODS: THP-1 cells were subjected to Zika virus infection (Multiplicity of Infection = 0.5) followed by treatment with P-MAPA for until 96 hours post-infection. After that, the cell death was analyzed by annexin+/ PI+ and caspase 3/ 7+ staining by flow cytometry. In addition, virus replication and cell proliferation were accessed by RT-qPCR and Ki67 staining, respectively. RESULTS: We demonstrate that P-MAPA in vitro treatment significantly reduces Zika virus-induced cell death and caspase-3/7 activation on THP-1 infected cells, albeit it has no role in virus replication and cell proliferation. CONCLUSION: Our study reveals that P-MAPA seems to be a satisfactory alternative to inhibit the effects of Zika virus infection in mammalian cells.


Assuntos
Apoptose/efeitos dos fármacos , Fatores Imunológicos/farmacologia , Ácidos Linoleicos/farmacologia , Ácidos Oleicos/farmacologia , Infecção por Zika virus/patologia , Antivirais/farmacologia , Caspase 3/metabolismo , Caspase 7/metabolismo , Proliferação de Células , Ativação Enzimática/efeitos dos fármacos , Citometria de Fluxo , Humanos , Antígeno Ki-67 , Reação em Cadeia da Polimerase em Tempo Real , Células THP-1 , Replicação Viral/efeitos dos fármacos , Zika virus
5.
Science ; 371(6526): 288-292, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33293339

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly in Manaus, the capital of Amazonas state in northern Brazil. The attack rate there is an estimate of the final size of the largely unmitigated epidemic that occurred in Manaus. We use a convenience sample of blood donors to show that by June 2020, 1 month after the epidemic peak in Manaus, 44% of the population had detectable immunoglobulin G (IgG) antibodies. Correcting for cases without a detectable antibody response and for antibody waning, we estimate a 66% attack rate in June, rising to 76% in October. This is higher than in São Paulo, in southeastern Brazil, where the estimated attack rate in October was 29%. These results confirm that when poorly controlled, COVID-19 can infect a large proportion of the population, causing high mortality.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/epidemiologia , Epidemias , Imunoglobulina G/sangue , SARS-CoV-2/isolamento & purificação , Adolescente , Adulto , Idoso , Doadores de Sangue , Brasil/epidemiologia , COVID-19/sangue , COVID-19/mortalidade , Monitoramento Epidemiológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , Estudos Soroepidemiológicos , Adulto Jovem
6.
J Trop Med ; 2020: 2071325, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32695184

RESUMO

Chikungunya fever (CHIK) has caused important epidemic outbreaks in the Americas, with musculoskeletal involvement being the main manifestation, causing chronic symptoms in half of the affected patients. This study was performed to evaluate the clinical course of the infection in 168 patients with autoimmune inflammatory disease using biological disease-modifying antirheumatic drugs (bDMARDs), comparing this group with 56 household controls. Anti-CHIKV IgG serology was positive in 42 (25%) of the patients in the bDMARD group and in 15 (27%) of the controls (p=0.79). Of those with positive serology, 32 (76%) and 14 (93%) were symptomatic among subjects in the bDMARD and control groups, respectively (p=0.87). Persistence of musculoskeletal symptoms for more than three months occurred in 64% of the patients in the control group and only in 28% in the bDMARD group (p=0.021), maintaining a statistically significant difference only for users of anti-TNF. This study found that patients affected by chikungunya fever using bDMARDs did not present severe forms or complications in the acute phase of the disease, and patients using anti-TNF biologicals had a lower frequency of chronic joint symptoms than the household controls. This favorable outcome may be related to the cytokine blockade, with a reduction in the inflammatory response and joint damage.

8.
PLoS Negl Trop Dis ; 13(10): e0007763, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31589611

RESUMO

Defining cases of Zika virus (ZIKV) infection is a critical challenge for epidemiological research. Due to ZIKV's overlapping clinical features and potential immunologic cross-reactivity with other flaviviruses and the current lack of an optimal ZIKV-specific diagnostic assay, varying approaches for identifying ZIKV infections have been employed to date. This paper presents the laboratory results and diagnostic criteria developed by the Microcephaly Epidemic Research Group for defining cases of maternal ZIKV infection in a cohort of pregnant women with rash (N = 694) recruited during the declining 2015-2017 epidemic in northeast Brazil. For this investigation, we tested maternal sera for ZIKV by quantitative reverse transcription polymerase chain reaction (qRT-PCR), Immunoglobulin (Ig) M and IgG3 enzyme-linked immunosorbent assays (ELISAs), and Plaque Reduction Neutralization Test (PRNT50). Overall, 23.8% of participants tested positive by qRT-PCR during pregnancy (range of detection: 0-72 days after rash onset). However, the inter-assay concordance was lower than expected. Among women with qRT-PCR-confirmed ZIKV and further testing, only 10.1% had positive IgM tests within 90 days of rash, and only 48.5% had ZIKV-specific PRNT50 titers ≥20 within 1 year of rash. Given the complexity of these data, we convened a panel of experts to propose an algorithm for identifying ZIKV infections in pregnancy based on all available lines of evidence. When the diagnostic algorithm was applied to the cohort, 26.9% of participants were classified as having robust evidence of a ZIKV infection during pregnancy, 4.0% as having moderate evidence, 13.3% as having limited evidence of a ZIKV infection but with uncertain timing, and 19.5% as having evidence of an unspecified flavivirus infection before or during pregnancy. Our findings suggest that integrating longitudinal data from nucleic acid and serologic testing may enhance diagnostic sensitivity and underscore the need for an on-going dialogue regarding the optimization of strategies for defining cases of ZIKV in research.


Assuntos
Exantema/epidemiologia , Exantema/imunologia , Complicações na Gravidez/imunologia , Infecção por Zika virus/complicações , Infecção por Zika virus/imunologia , Algoritmos , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Brasil/epidemiologia , Estudos de Coortes , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Exantema/diagnóstico , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Testes de Neutralização , Gravidez , Zika virus/imunologia , Infecção por Zika virus/epidemiologia
9.
Front Immunol ; 10: 1928, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474994

RESUMO

Zika virus (ZIKV) infection during pregnancy is associated with microcephaly, a congenital malformation resulting from neuroinflammation and direct effects of virus replication on the developing central nervous system (CNS). However, the exact changes in the affected CNS remain unknown. Here, we show by transcriptome analysis (at 48 h post-infection) and multiplex immune profiling that human induced-neuroprogenitor stem cells (hiNPCs) respond to ZIKV infection with a strong induction of type-I interferons (IFNs) and several type-I IFNs stimulated genes (ISGs), notably cytokines and the pro-apoptotic chemokines CXCL9 and CXCL10. By comparing the inflammatory profile induced by a ZIKV Brazilian strain with an ancestral strain isolated from Cambodia in 2010, we observed that the response magnitude differs among them. Compared to ZIKV/Cambodia, the experimental infection of hiNPCs with ZIKV/Brazil resulted in a diminished induction of ISGs and lower induction of several cytokines (IFN-α, IL-1α/ß, IL-6, IL-8, and IL-15), consequently favoring virus replication. From ZIKV-confirmed infant microcephaly cases, we detected a similar profile characterized by the presence of IFN-α, CXCL10, and CXCL9 in cerebrospinal fluid (CSF) samples collected after birth, evidencing a sustained CNS inflammation. Altogether, our data suggest that the CNS may be directly affected due to an unbalanced and chronic local inflammatory response, elicited by ZIKV infection, which contributes to damage to the fetal brain.


Assuntos
Sistema Nervoso Central/imunologia , Células-Tronco Pluripotentes Induzidas/citologia , Microcefalia/imunologia , Células-Tronco Neurais/citologia , Zika virus/imunologia , Brasil , Camboja , Células Cultivadas , Sistema Nervoso Central/patologia , Sistema Nervoso Central/virologia , Quimiocina CXCL10/líquido cefalorraquidiano , Quimiocina CXCL10/imunologia , Quimiocina CXCL9/líquido cefalorraquidiano , Quimiocina CXCL9/imunologia , Citocinas/análise , Feminino , Perfilação da Expressão Gênica , Humanos , Lactente , Inflamação/imunologia , Inflamação/patologia , Interferon-alfa/líquido cefalorraquidiano , Interferon-alfa/imunologia , Interferon beta/imunologia , Masculino , Microcefalia/patologia , Gravidez , Complicações Infecciosas na Gravidez/virologia , Replicação Viral/imunologia , Infecção por Zika virus/imunologia
10.
Front Immunol ; 10: 3108, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32082301

RESUMO

The Chikungunya virus (CHIKV) is a re-emerging arbovirus, in which its infection causes a febrile illness also commonly associated with severe joint pain and myalgia. Although the immune response to CHIKV has been studied, a better understanding of the virus-host interaction mechanisms may lead to more effective therapeutic interventions. In this context, neutrophil extracellular traps (NETs) have been described as a key mediator involved in the control of many pathogens, including several bacteria and viruses, but no reports of this important protective mechanism were documented during CHIKV infection. Here we demonstrate that the experimental infection of mouse-isolated neutrophils with CHIKV resulted in NETosis (NETs release) through a mechanism dependent on TLR7 activation and reactive oxygen species generation. In vitro, mouse-isolated neutrophils stimulated with phorbol 12-myristate 13-acetate release NETs that once incubated with CHIKV, resulting in further virus capture and neutralization. In vivo, NETs inhibition by the treatment of the mice with DNase resulted in the enhanced susceptibility of IFNAR-/- mice to CHIKV experimental acute infection. Lastly, by accessing the levels of MPO-DNA complex on the acutely CHIKV-infected patients, we found a correlation between the levels of NETs and the viral load in the blood, suggesting that NETs are also released in natural human infection cases. Altogether our findings characterize NETosis as a contributing natural process to control CHIKV acute infection, presenting an antiviral effect that helps to control systemic virus levels.


Assuntos
Febre de Chikungunya/imunologia , Febre de Chikungunya/virologia , Vírus Chikungunya/imunologia , Armadilhas Extracelulares/imunologia , Interações Hospedeiro-Patógeno/imunologia , Neutrófilos/imunologia , Animais , Biomarcadores , Linhagem Celular , Febre de Chikungunya/genética , Modelos Animais de Doenças , Suscetibilidade a Doenças , Armadilhas Extracelulares/genética , Interações Hospedeiro-Patógeno/genética , Imunidade Inata , Glicoproteínas de Membrana , Camundongos , Camundongos Knockout , Testes de Neutralização , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptor 7 Toll-Like , Carga Viral , Replicação Viral , Zika virus/imunologia
11.
BMC Infect Dis ; 18(1): 388, 2018 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-30097025

RESUMO

BACKGROUND: Zika virus (ZIKV) is a recently emerged arbovirus, which infection during pregnancy is associated with a series of congenital malformations, collectively denominated Congenital Zika Syndrome (CZS). Following infection, ZIKV RNA has a median duration period of 10 days in plasma and up to 6 months in semen in immunocompetent adult individuals. Moreover, ZIKV is able to replicate and persist in fetal brains and placentas, consequently, infection is associated with pregnancy loss, albeit the pathogenic mechanisms are still unknown. CASE PRESENTATION: Here we report a CZS case of an infant born during the ZIKV outbreak in northeast Brazil, the child presented recurrent episodes of seizures with prolonged presence of ZIKV RNA on the central nervous system (CNS) and blood. ZIKV RNA was identified and partially sequenced from a sample of cerebrospinal fluid (CSF) obtained from the infant with 6 months of life, and later from another sample after the infant completed 17 months of life. Commonly congenital infections were discarded based on STORCH (syphilis, toxoplasmosis, rubella, cytomegalovirus and herpes simplex virus) negative laboratory results. Presence of specific ZIKV antibodies on both mother and children confirmed the association of severe microcephaly and ZIKV infection, diagnosed after birth. CONCLUSIONS: Altogether, our data raise the possibility that CZS cases may result in prolonged viral presence, these findings could be useful for therapy and diagnostic recommendations.


Assuntos
Microcefalia/virologia , Infecção por Zika virus/congênito , Infecção por Zika virus/complicações , Adulto , Brasil , Epilepsia/etiologia , Epilepsia/patologia , Epilepsia/virologia , Feminino , Humanos , Lactente , Recém-Nascido , Microcefalia/patologia , Gravidez , Complicações Infecciosas na Gravidez/virologia , RNA Viral/isolamento & purificação , Índice de Gravidade de Doença , Zika virus/genética , Zika virus/isolamento & purificação , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/patologia
13.
Emerg Microbes Infect ; 6(8): e69, 2017 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-28790458

RESUMO

Zika virus (ZIKV) is a flavivirus that has recently been associated with an increased incidence of neonatal microcephaly and other neurological disorders. The virus is primarily transmitted by mosquito bite, although other routes of infection have been implicated in some cases. The Aedes aegypti mosquito is considered to be the main vector to humans worldwide; however, there is evidence that other mosquito species, including Culex quinquefasciatus, transmit the virus. To test the potential of Cx. quinquefasciatus to transmit ZIKV, we experimentally compared the vector competence of laboratory-reared Ae. aegypti and Cx. quinquefasciatus. Interestingly, we were able to detect the presence of ZIKV in the midgut, salivary glands and saliva of artificially fed Cx. quinquefasciatus. In addition, we collected ZIKV-infected Cx. quinquefasciatus from urban areas with high microcephaly incidence in Recife, Brazil. Corroborating our experimental data from artificially fed mosquitoes, ZIKV was isolated from field-caught Cx. quinquefasciatus, and its genome was partially sequenced. Collectively, these findings indicate that there may be a wider range of ZIKV vectors than anticipated.


Assuntos
Culex/virologia , Mosquitos Vetores/virologia , Replicação Viral , Zika virus/fisiologia , Aedes/virologia , Animais , Brasil/epidemiologia , Genoma Viral , Humanos , Microcefalia/epidemiologia , Mosquitos Vetores/fisiologia , Saliva/virologia , Glândulas Salivares/virologia , Análise de Sequência de DNA , Zika virus/genética , Zika virus/isolamento & purificação , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia
15.
J Infect Dis ; 215(5): 781-785, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28039355

RESUMO

Anti-Flavivirus antibodies are highly cross-reactive and may facilitate Zika virus (ZIKV) infection through the antibody-dependent enhancement (ADE) mechanism. We demonstrate that dengue-specific antibodies enhance the infection of a primary Brazilian ZIKV isolate in a FcγRII-expressing K562 cell line. In addition, we demonstrate that serum samples from dengue-immune pregnant women enhanced ZIKV infection. These findings highlight the need for epidemiological studies and animal models to further confirm the role of ADE in the development of congenital and neurological complications associated with ZIKV infections.


Assuntos
Anticorpos Antivirais/sangue , Anticorpos Facilitadores , Vírus da Dengue , Infecção por Zika virus/imunologia , Zika virus/patogenicidade , Anticorpos Antivirais/imunologia , Antivirais/farmacologia , Brasil , Reações Cruzadas , Feminino , Humanos , Células K562 , Gravidez , Receptores de IgG/imunologia , Infecção por Zika virus/sangue
16.
Nat Immunol ; 18(3): 344-353, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28114290

RESUMO

Although master transcription factors (TFs) are key to the development of specific T cell subsets, whether additional transcriptional regulators are induced by the same stimuli that dominantly repress the development of other, non-specific T cell lineages has not been fully elucidated. Through the use of regulatory T cells (Treg cells) induced by transforming growth factor-ß (TGF-ß), we identified the TF musculin (MSC) as being critical for the development of induced Treg cells (iTreg cells) by repression of the T helper type 2 (TH2) transcriptional program. Loss of MSC reduced expression of the Treg cell master TF Foxp3 and induced TH2 differentiation even under iTreg-cell-differentiation conditions. MSC interrupted binding of the TF GATA-3 to the locus encoding TH2-cell-related cytokines and diminished intrachromosomal interactions within that locus. MSC-deficient (Msc-/-) iTreg cells were unable to suppress TH2 responses, and Msc-/- mice spontaneously developed gut and lung inflammation with age. MSC therefore enforced Foxp3 expression and promoted the unidirectional induction of iTreg cells by repressing the TH2 developmental program.


Assuntos
Diferenciação Celular , Inflamação , Mucosa Intestinal/imunologia , Pneumonia/imunologia , Linfócitos T Reguladores/fisiologia , Células Th2/fisiologia , Fatores de Transcrição/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Células Cultivadas , Fatores de Transcrição Forkhead/metabolismo , Fator de Transcrição GATA3/metabolismo , Regulação da Expressão Gênica , Inflamação/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fatores de Transcrição/genética , Transcrição Genética , Fator de Crescimento Transformador beta/metabolismo
17.
ACS Omega ; 2(7): 3913-3920, 2017 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-30023708

RESUMO

B-cell epitope sequences from Zika virus (ZIKV) NS1 protein have been identified using epitope prediction tools. Mapping these sequences onto the NS1 surface reveals two major conformational epitopes and a single linear one. Despite an overall average sequence identity of ca. 55% between the NS1 from ZIKV and the four dengue virus (DENV) serotypes, epitope sequences were found to be highly conserved. Nevertheless, nonconserved epitope-flanking residues are responsible for a dramatically divergent electrostatic surface potential on the epitope regions of ZIKV and DENV2 serotypes. These findings suggest that strategies for differential diagnostics on the basis of short linear NS1 sequences are likely to fail due to immunological cross-reactions. Overall, results provide the molecular basis of differential discrimination between Zika and DENVs by NS1 monoclonal antibodies.

18.
Oncotarget ; 8(5): 8475-8483, 2017 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-28035072

RESUMO

Here, we evaluated whether the overexpression of transcriptionally inactive ΔNp73 cooperates with PML/RARA fusion protein in the induction of an APL-leukemic phenotype, as well as its role in vitro in proliferation, myeloid differentiation, and drug-induced apoptosis. Using lentiviral gene transfer, we showed in vitro that ΔNp73 overexpression resulted in increased proliferation in murine bone marrow (BM) cells from hCG-PML/RARA transgenic mice and their wild-type (WT) counterpart, with no accumulation of cells at G2/M or S phases; instead, ΔNp73-expressing cells had a lower rate of induced apoptosis. Next, we evaluated the effect of ΔNp73 on stem-cell self-renewal and myeloid differentiation. Primary BM cells lentivirally infected with human ΔNp73 were not immortalized in culture and did not present significant changes in the percentage of CD11b. Finally, we assessed the impact of ΔNp73 on leukemogenesis or its possible cooperation with PML/RARA fusion protein in the induction of an APL-leukemic phenotype. After 120 days of follow-up, all transplanted mice were clinically healthy and, no evidence of leukemia/myelodysplasia was apparent. Taken together, our data suggest that ΔNp73 had no leukemic transformation capacity by itself and apparently did not cooperate with the PML/RARA fusion protein to induce a leukemic phenotype in a murine BM transplantation model. In addition, the forced expression of ΔNp73 in murine BM progenitors did not alter the ATRA-induced differentiation rate in vitro or induce aberrant cell proliferation, but exerted an important role in cell survival, providing resistance to drug-induced apoptosis.


Assuntos
Apoptose , Leucemia/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteína da Leucemia Promielocítica/metabolismo , Receptor alfa de Ácido Retinoico/metabolismo , Proteína Tumoral p73/metabolismo , Animais , Antimetabólitos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Transplante de Medula Óssea , Catepsina G/genética , Catepsina G/metabolismo , Diferenciação Celular , Proliferação de Células , Autorrenovação Celular , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Células Cultivadas , Citarabina/farmacologia , Regulação Leucêmica da Expressão Gênica , Predisposição Genética para Doença , Leucemia/tratamento farmacológico , Leucemia/genética , Leucemia/patologia , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Fenótipo , Proteína da Leucemia Promielocítica/genética , Receptor alfa de Ácido Retinoico/genética , Transdução de Sinais , Fatores de Tempo , Transfecção , Proteína Tumoral p73/genética , Regulação para Cima
19.
J Neuroinflammation ; 13(1): 159, 2016 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-27334012

RESUMO

BACKGROUND: Viral encephalitis is a common cause of lethal infections in humans, and several different viruses are documented to be responsible. Rocio virus is a flavivirus that causes a severe lethal encephalitis syndrome in humans and also mice, providing an interesting model to study the CNS compartmentalized immune response. Interleukin 33 (IL-33), a member of the IL-1 family, is an immunomodulatory cytokine that is highly expressed in the CNS. However, the role of IL-33 on viral encephalitis remains unclear. Therefore, we aimed to explore how the IL-33/ST2 axis regulates the local immune response during Rocio virus infection. METHODS: Wild-type (WT), ST2 (ST2(-/-)), and nitric oxide synthase-deficient mice (iNOS(-/-)) and Stat6 (Stat6(-/-))-deficient mice were infected with different concentrations of the Rocio virus by intraperitoneal route, the cytokine mRNA level in CNS was analyzed by qPCR, and cellular immunophenotyping was performed on infected mice by the flow cytometry of isolated CNS mononuclear cells. RESULTS: We have shown that the mRNA expression of IL-33 and ST2 receptors is increased in the CNS of Rocio virus-infected WT mice and that ST2(-/-) mice showed increased susceptibility to infection. ST2 deficiency was correlated with increased tissue pathology, cellular infiltration, and tumor necrosis factor alpha (TNF-α) and interferon-gamma (IFN-γ) mRNA levels and higher viral load in the CNS, compared with wild-type mice. The increased Th1 cytokine levels released in the CNS acted on infiltrating macrophages, as evidenced by flow cytometry characterization of cellular infiltrates, inducing the expression of iNOS, contributing to brain injury. Moreover, iNOS(-/-) mice were more resistant to Rocio virus encephalitis, presenting a lower clinical score and reduced mortality rate, despite the increased tissue pathology. CONCLUSIONS: We provide evidences of a specific role for IL-33 receptor signaling in nitric oxide induction through local IFN-γ modulation, suggesting that nitric oxide overproduction might have an important role in the progression of experimental viral encephalitis.


Assuntos
Sistema Nervoso Central , Encefalite Viral/patologia , Interleucina-33/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Animais , Antígenos de Diferenciação/metabolismo , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/patologia , Sistema Nervoso Central/virologia , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Regulação para Baixo/genética , Feminino , Infecções por Flaviviridae/patologia , Citometria de Fluxo , Proteína 1 Semelhante a Receptor de Interleucina-1/deficiência , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Interleucina-33/genética , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Óxido Nítrico Sintase Tipo II/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT6/deficiência , Fator de Transcrição STAT6/genética , Transdução de Sinais/fisiologia
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