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1.
Proc Natl Acad Sci U S A ; 120(23): e2220005120, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37252973

RESUMO

Dengue virus (DENV) is the most important human virus transmitted by mosquitos. Dengue pathogenesis is characterized by a large induction of proinflammatory cytokines. This cytokine induction varies among the four DENV serotypes (DENV1 to 4) and poses a challenge for live DENV vaccine design. Here, we identify a viral mechanism to limit NF-κB activation and cytokine secretion by the DENV protein NS5. Using proteomics, we found that NS5 binds and degrades the host protein ERC1 to antagonize NF-κB activation, limit proinflammatory cytokine secretion, and reduce cell migration. We found that ERC1 degradation involves unique properties of the methyltransferase domain of NS5 that are not conserved among the four DENV serotypes. By obtaining chimeric DENV2 and DENV4 viruses, we map the residues in NS5 for ERC1 degradation, and generate recombinant DENVs exchanging serotype properties by single amino acid substitutions. This work uncovers a function of the viral protein NS5 to limit cytokine production, critical to dengue pathogenesis. Importantly, the information provided about the serotype-specific mechanism for counteracting the antiviral response can be applied to improve live attenuated vaccines.


Assuntos
Vírus da Dengue , Dengue , Proteínas não Estruturais Virais , Humanos , Citocinas , NF-kappa B/metabolismo , Sorogrupo , Proteínas não Estruturais Virais/metabolismo
2.
Front Immunol ; 13: 992370, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36225925

RESUMO

The COVID-19 pandemic has particularly affected older adults residing in nursing homes, resulting in high rates of hospitalisation and death. Here, we evaluated the longitudinal humoral response and neutralising capacity in plasma samples of volunteers vaccinated with different platforms (Sputnik V, BBIBP-CorV, and AZD1222). A cohort of 851 participants, mean age 83 (60-103 years), from the province of Buenos Aires, Argentina were included. Sequential plasma samples were taken at different time points after vaccination. After completing the vaccination schedule, infection-naïve volunteers who received either Sputnik V or AZD1222 exhibited significantly higher specific anti-Spike IgG titers than those who received BBIBP-CorV. Strong correlation between anti-Spike IgG titers and neutralising activity levels was evidenced at all times studied (rho=0.7 a 0.9). Previous exposure to SARS-CoV-2 and age <80 years were both associated with higher specific antibody levels. No differences in neutralising capacity were observed for the infection-naïve participants in either gender or age group. Similar to anti-Spike IgG titers, neutralising capacity decreased 3 to 9-fold at 6 months after initial vaccination for all platforms. Neutralising capacity against Omicron was between 10-58 fold lower compared to ancestral B.1 for all vaccine platforms at 21 days post dose 2 and 180 days post dose 1. This work provides evidence about the humoral response and neutralising capacity elicited by vaccination of a vulnerable elderly population. This data could be useful for pandemic management in defining public health policies, highlighting the need to apply reinforcements after a complete vaccination schedule.


Assuntos
COVID-19 , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais , Argentina/epidemiologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , ChAdOx1 nCoV-19 , Humanos , Imunoglobulina G , Pandemias , SARS-CoV-2 , Vacinação
3.
Front Immunol ; 13: 909995, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36263055

RESUMO

Background: Recent studies have shown the presence of SARS-CoV-2-specific antibodies in the milk of breastfeeding mothers vaccinated with mRNA and convalescent. However, limited information is available in lactating women receiving other vaccine platforms used in developing countries, such as the inactivated SARS-CoV-2 vaccine BBIBP-CorV (Sinopharm) and the non-replicating adenovirus vaccines Sputnik V (Gamaleya Institute) and ChAdOx1-S (Oxford AstraZeneca). Methods: Here, we evaluated anti-SARS-CoV-2 IgG and IgA levels in both serum and milk samples using a longitudinal and a cross-sectional cohort of 208 breastfeeding vaccinated women from Argentina with or without previous SARS-CoV-2 infection. Results: The analysis showed that IgA levels remain constant in serum and milk of breastfeeding mothers between the first and second doses of vector-based vaccines (Sputnik V and ChAdOx1-S). After the second dose, anti-spike IgA was found positive in 100% of the serum samples and in 66% of breastmilk samples. In addition, no significant differences in milk IgA levels were observed in participants receiving BBIBP-CorV, Sputnik V or ChAdOx1-S. IgG levels in milk increased after the second dose of vector-based vaccines. Paired longitudinal samples taken at 45 and 120 days after the second dose showed a decrease in milk IgG levels over time. Study of IgA levels in serum and milk of vaccinated naïve of infection and vaccinated-convalescent breastfeeding participants showed significantly higher levels in vaccinated-convalescent than in participants without previous infection. Conclusion: This study is relevant to understand the protection against SARS-CoV-2 by passive immunity in newborns and children who are not yet eligible to receive vaccination.


Assuntos
Vacinas contra Adenovirus , COVID-19 , Vacinas Virais , Recém-Nascido , Criança , Humanos , Feminino , Vacinas contra COVID-19 , SARS-CoV-2 , Leite Humano , Estudos Transversais , Lactação , COVID-19/prevenção & controle , Anticorpos Antivirais , Imunoglobulina G , Imunoglobulina A , RNA Mensageiro
4.
J Neurochem ; 163(4): 338-356, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36205031

RESUMO

Human immunodeficiency virus (HIV) neuroinvasion occurs early after infection through the trafficking of virus-infected immune cells into the central nervous system (CNS) and viral dissemination into the brain. There, it can infect resident brain cells including astrocytes, the most abundant cell type that is crucial to brain homeostasis. In this report, we examined the HIV-related mechanism able to induce bystander cell death in astrocytes mediated by cell-to-cell contact with productively infected (PI) ones. We first demonstrate that HIV-induced bystander cell death involves mitochondrial dysfunction that promotes exacerbated reactive oxygen species production. Such a phenomenon is a contagious cell death that requires contact with HIV-PI astrocytes that trigger caspase-dependent (apoptosis and pyroptosis) and caspase-independent cell death pathways. The HIV accessory proteins Nef, Vpu, and Vpr counteract astrocyte death among PI cells but, in contrast, participate to promote contagious bystander cell death by inducing mitochondrial reactive oxygen species production. Our findings indicate that astrocytes PI by HIV became capable to counteract infection-derived death signals, surviving, and spreading the bystander cell death into neighboring uninfected cells by a cell-to-cell contact-dependent mechanism. Considering that astrocytes have been proposed as a long-term HIV reservoir in the CNS, ascertaining the mechanism of survival and contagious bystander death will afford clear targets in the current goal to achieve a functional cure.


Assuntos
Infecções por HIV , HIV-1 , Humanos , Astrócitos/metabolismo , HIV-1/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Morte Celular , Caspases/metabolismo
5.
Cell Rep Med ; 3(8): 100706, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35926505

RESUMO

Heterologous vaccination against coronavirus disease 2019 (COVID-19) provides a rational strategy to rapidly increase vaccination coverage in many regions of the world. Although data regarding messenger RNA (mRNA) and ChAdOx1 vaccine combinations are available, there is limited information about the combination of these platforms with other vaccines widely used in developing countries, such as BBIBP-CorV and Sputnik V. Here, we assess the immunogenicity and reactogenicity of 15 vaccine combinations in 1,314 participants. We evaluate immunoglobulin G (IgG) anti-spike response and virus neutralizing titers and observe that a number of heterologous vaccine combinations are equivalent or superior to homologous schemes. For all cohorts in this study, the highest antibody response is induced by mRNA-1273 as the second dose. No serious adverse events are detected in any of the schedules analyzed. Our observations provide rational support for the use of different vaccine combinations to achieve wide vaccine coverage in the shortest possible time.


Assuntos
COVID-19 , Vacinas Virais , Vacina de mRNA-1273 contra 2019-nCoV , Anticorpos Antivirais , COVID-19/prevenção & controle , Humanos , Imunização , RNA Mensageiro/genética , SARS-CoV-2 , Vacinação
8.
mBio ; 13(1): e0344221, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35073758

RESUMO

Recent studies have shown a temporal increase in the neutralizing antibody potency and breadth to SARS-CoV-2 variants in coronavirus disease 2019 (COVID-19) convalescent individuals. Here, we examined longitudinal antibody responses and viral neutralizing capacity to the B.1 lineage virus (Wuhan related), to variants of concern (VOC; Alpha, Beta, Gamma, and Delta), and to a local variant of interest (VOI; Lambda) in volunteers receiving the Sputnik V vaccine in Argentina. Longitudinal serum samples (N = 536) collected from 118 volunteers obtained between January and October 2021 were used. The analysis indicates that while anti-spike IgG levels significantly wane over time, the neutralizing capacity for the Wuhan-related lineages of SARS-CoV-2 and VOC is maintained within 6 months of vaccination. In addition, an improved antibody cross-neutralizing ability for circulating variants of concern (Beta and Gamma) was observed over time postvaccination. The viral variants that displayed higher escape to neutralizing antibodies with respect to the original virus (Beta and Gamma variants) were the ones showing the largest increase in susceptibility to neutralization over time after vaccination. Our observations indicate that serum neutralizing antibodies are maintained for at least 6 months and show a reduction of VOC escape to neutralizing antibodies over time after vaccination. IMPORTANCE Vaccines have been produced in record time for SARS-CoV-2, offering the possibility of halting the global pandemic. However, inequalities in vaccine accessibility in different regions of the world create a need to increase international cooperation. Sputnik V is a recombinant adenovirus-based vaccine that has been widely used in Argentina and other developing countries, but limited information is available about its elicited immune responses. Here, we examined longitudinal antibody levels and viral neutralizing capacity elicited by Sputnik V vaccination. Using a cohort of 118 volunteers, we found that while anti-spike antibodies wane over time, the neutralizing capacity to viral variants of concern and local variants of interest is maintained within 4 months of vaccination. In addition, we observed an increased cross-neutralization activity over time for the Beta and Gamma variants. This study provides valuable information about the immune response generated by a vaccine platform used in many parts of the world.


Assuntos
Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Estudos Longitudinais , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinação , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/uso terapêutico
9.
Cell Rep Med ; 2(8): 100359, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34308389

RESUMO

Massive vaccination offers great promise for halting the global COVID-19 pandemic. However, the limited supply and uneven vaccine distribution create an urgent need to optimize vaccination strategies. We evaluate SARS-CoV-2-specific antibody responses after Sputnik V vaccination of healthcare workers in Argentina, measuring IgG anti-spike titers and neutralizing capacity after one and two doses in a cohort of naive or previously infected volunteers. By 21 days after receiving the first dose of the vaccine, 94% of naive participants develop spike-specific IgG antibodies. A single Sputnik V dose elicits higher antibody levels and virus-neutralizing capacity in previously infected individuals than in naive ones receiving the full two-dose schedule. The high seroconversion rate after a single dose in naive participants suggests a benefit of delaying administration of the second dose to increase the number of people vaccinated. The data presented provide information for guiding public health decisions in light of the current global health emergency.


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Vacinas Sintéticas/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Argentina/epidemiologia , COVID-19/imunologia , Chlorocebus aethiops , Células HEK293 , Pessoal de Saúde , Humanos , Pandemias , SARS-CoV-2/patogenicidade , Soroconversão , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinação , Vacinas , Células Vero
10.
Front Cell Dev Biol ; 9: 640094, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33816487

RESUMO

Mitophagy and zymophagy are selective autophagy pathways early induced in acute pancreatitis that may explain the mild, auto limited, and more frequent clinical presentation of this disease. Adequate mitochondrial bioenergetics is necessary for cellular restoration mechanisms that are triggered during the mild disease. However, mitochondria and zymogen contents are direct targets of damage in acute pancreatitis. Cellular survival depends on the recovering possibility of mitochondrial function and efficient clearance of damaged mitochondria. This work aimed to analyze mitochondrial dynamics and function during selective autophagy in pancreatic acinar cells during mild experimental pancreatitis in rats. Also, using a cell model under the hyperstimulation of the G-coupled receptor for CCK (CCK-R), we aimed to investigate the mechanisms involved in these processes in the context of zymophagy. We found that during acute pancreatitis, mitochondrial O2 consumption and ATP production significantly decreased early after induction of acute pancreatitis, with a consequent decrease in the ATP/O ratio. Mitochondrial dysfunction was accompanied by changes in mitochondrial dynamics evidenced by optic atrophy 1 (OPA-1) and dynamin-related protein 1 (DRP-1) differential expression and ultrastructural features of mitochondrial fission, mitochondrial elongation, and mitophagy during the acute phase of experimental mild pancreatitis in rats. Mitophagy was also evaluated by confocal assay after transfection with the pMITO-RFP-GFP plasmid that specifically labels autophagic degradation of mitochondria and the expression and redistribution of the ubiquitin ligase Parkin1. Moreover, we report for the first time that vacuole membrane protein-1 (VMP1) is involved and required in the mitophagy process during acute pancreatitis, observable not only by repositioning around specific mitochondrial populations, but also by detection of mitochondria in autophagosomes specifically isolated with anti-VMP1 antibodies as well. Also, VMP1 downregulation avoided mitochondrial degradation confirming that VMP1 expression is required for mitophagy during acute pancreatitis. In conclusion, we identified a novel DRP1-Parkin1-VMP1 selective autophagy pathway, which mediates the selective degradation of damaged mitochondria by mitophagy in acute pancreatitis. The understanding of the molecular mechanisms involved to restore mitochondrial function, such as mitochondrial dynamics and mitophagy, could be relevant in the development of novel therapeutic strategies in acute pancreatitis.

11.
PLoS Pathog ; 17(1): e1009161, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33444413

RESUMO

We report the emergency development and application of a robust serologic test to evaluate acute and convalescent antibody responses to SARS-CoV-2 in Argentina. The assays, COVIDAR IgG and IgM, which were produced and provided for free to health authorities, private and public health institutions and nursing homes, use a combination of a trimer stabilized spike protein and the receptor binding domain (RBD) in a single enzyme-linked immunosorbent assay (ELISA) plate. Over half million tests have already been distributed to detect and quantify antibodies for multiple purposes, including assessment of immune responses in hospitalized patients and large seroprevalence studies in neighborhoods, slums and health care workers, which resulted in a powerful tool for asymptomatic detection and policy making in the country. Analysis of antibody levels and longitudinal studies of symptomatic and asymptomatic SARS-CoV-2 infections in over one thousand patient samples provided insightful information about IgM and IgG seroconversion time and kinetics, and IgM waning profiles. At least 35% of patients showed seroconversion within 7 days, and 95% within 45 days of symptoms onset, with simultaneous or close sequential IgM and IgG detection. Longitudinal studies of asymptomatic cases showed a wide range of antibody responses with median levels below those observed in symptomatic patients. Regarding convalescent plasma applications, a protocol was standardized for the assessment of end point IgG antibody titers with COVIDAR with more than 500 plasma donors. The protocol showed a positive correlation with neutralizing antibody titers, and was used for clinical trials and therapies across the country. Using this protocol, about 80% of convalescent donor plasmas were potentially suitable for therapies. Here, we demonstrate the importance of providing a robust and specific serologic assay for generating new information about antibody kinetics in infected individuals and mitigation policies to cope with pandemic needs.


Assuntos
COVID-19/virologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Formação de Anticorpos , Argentina/epidemiologia , COVID-19/epidemiologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2/isolamento & purificação , Estudos Soroepidemiológicos
12.
N Engl J Med ; 384(7): 619-629, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33232588

RESUMO

BACKGROUND: Convalescent plasma is frequently administered to patients with Covid-19 and has been reported, largely on the basis of observational data, to improve clinical outcomes. Minimal data are available from adequately powered randomized, controlled trials. METHODS: We randomly assigned hospitalized adult patients with severe Covid-19 pneumonia in a 2:1 ratio to receive convalescent plasma or placebo. The primary outcome was the patient's clinical status 30 days after the intervention, as measured on a six-point ordinal scale ranging from total recovery to death. RESULTS: A total of 228 patients were assigned to receive convalescent plasma and 105 to receive placebo. The median time from the onset of symptoms to enrollment in the trial was 8 days (interquartile range, 5 to 10), and hypoxemia was the most frequent severity criterion for enrollment. The infused convalescent plasma had a median titer of 1:3200 of total SARS-CoV-2 antibodies (interquartile range, 1:800 to 1:3200). No patients were lost to follow-up. At day 30 day, no significant difference was noted between the convalescent plasma group and the placebo group in the distribution of clinical outcomes according to the ordinal scale (odds ratio, 0.83; 95% confidence interval [CI], 0.52 to 1.35; P = 0.46). Overall mortality was 10.96% in the convalescent plasma group and 11.43% in the placebo group, for a risk difference of -0.46 percentage points (95% CI, -7.8 to 6.8). Total SARS-CoV-2 antibody titers tended to be higher in the convalescent plasma group at day 2 after the intervention. Adverse events and serious adverse events were similar in the two groups. CONCLUSIONS: No significant differences were observed in clinical status or overall mortality between patients treated with convalescent plasma and those who received placebo. (PlasmAr ClinicalTrials.gov number, NCT04383535.).


Assuntos
Anticorpos Neutralizantes/sangue , COVID-19/terapia , Imunoglobulina G/sangue , Pneumonia Viral/terapia , SARS-CoV-2/imunologia , Idoso , Idoso de 80 Anos ou mais , Transfusão de Componentes Sanguíneos , COVID-19/complicações , COVID-19/mortalidade , Progressão da Doença , Método Duplo-Cego , Feminino , Hospitalização , Humanos , Imunização Passiva , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/etiologia , Pneumonia Viral/mortalidade , Índice de Gravidade de Doença , Soroterapia para COVID-19
13.
J Virol ; 94(18)2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32581095

RESUMO

Zika virus (ZIKV) is an emerging flavivirus, mainly transmitted by mosquitoes, which represents a global health threat. A common feature of flavivirus-infected cells is the accumulation of viral noncoding subgenomic RNAs by partial degradation of the viral genome, known as sfRNAs, involved in immune evasion and pathogenesis. Although great effort is being made to understand the mechanism by which these sfRNAs function during infection, the picture of how they work is still incomplete. In this study, we developed new genetic tools to dissect the functions of ZIKV RNA structures for viral replication and sfRNA production in mosquito and human hosts. ZIKV infections mostly accumulate two kinds of sfRNAs, sfRNA1 and sfRNA2, by stalling genome degradation upstream of duplicated stem loops (SLI and SLII) of the viral 3' untranslated region (UTR). Although the two SLs share conserved sequences and structures, different functions have been found for ZIKV replication in human and mosquito cells. While both SLs are enhancers for viral infection in human cells, they play opposite roles in the mosquito host. The dissection of determinants for sfRNA formation indicated a strong cooperativity between SLI and SLII, supporting a high-order organization of this region of the 3' UTR. Using recombinant ZIKV with different SLI and SLII arrangements, which produce different types of sfRNAs or lack the ability to generate these molecules, revealed that at least one sfRNA was necessary for efficient infection and transmission in Aedes aegypti mosquitoes. Importantly, we demonstrate an absolute requirement of sfRNAs for ZIKV propagation in human cells. In this regard, viruses lacking sfRNAs, constructed by deletion of the region containing SLI and SLII, were able to infect human cells but the infection was rapidly cleared by antiviral responses. Our findings are unique for ZIKV, since in previous studies, other flaviviruses with deletions of analogous regions of the genome, including dengue and West Nile viruses, accumulated distinct species of sfRNAs and were infectious in human cells. We conclude that flaviviruses share common strategies for sfRNA generation, but they have evolved mechanisms to produce different kinds of these RNAs to accomplish virus-specific functions.IMPORTANCE Flaviviruses are important emerging and reemerging human pathogens. Understanding the molecular mechanisms for viral replication and evasion of host antiviral responses is relevant to development of control strategies. Flavivirus infections produce viral noncoding RNAs, known as sfRNAs, involved in viral replication and pathogenesis. In this study, we dissected molecular determinants for Zika virus sfRNA generation in the two natural hosts, human cells and mosquitoes. We found that two RNA structures of the viral 3' UTR operate in a cooperative manner to produce two species of sfRNAs and that the deletion of these elements has a profoundly different impact on viral replication in the two hosts. Generation of at least one sfRNA was necessary for efficient Zika virus infection of Aedes aegypti mosquitoes. Moreover, recombinant viruses with different 3' UTR arrangements revealed an essential role of sfRNAs for productive infection in human cells. In summary, we define molecular requirements for Zika virus sfRNA accumulation and provide new ideas of how flavivirus RNA structures have evolved to succeed in different hosts.


Assuntos
Genoma Viral , RNA Viral/genética , Infecção por Zika virus/virologia , Zika virus/genética , Regiões 3' não Traduzidas , Aedes , Animais , Pareamento de Bases , Sequência de Bases , Linhagem Celular , Chlorocebus aethiops , Feminino , Especificidade de Hospedeiro , Humanos , Conformação de Ácido Nucleico , Filogenia , Estabilidade de RNA , RNA Viral/química , RNA Viral/metabolismo , Células Vero , Replicação Viral , Zika virus/classificação , Zika virus/metabolismo
14.
J Int AIDS Soc ; 22(9): e25375, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31536177

RESUMO

INTRODUCTION: HIV worsens HCV-related liver disease by accelerating fibrosis progression; however, progression rates are extremely variable among HIV/HCV-coinfected individuals. NK cells are associated with modulation of liver fibrosis and are profoundly altered during HCV and HIV infections. CD4+ T-cells modulate NK cell function, and are also affected by HIV infection. Here, we aim to characterize the association of hepatic fibrosis with both the phenotype and function of peripheral NK cells and their regulation by CD4+ T-cells, in HIV/HCV-coinfected individuals. METHODS: Thirty-four HIV/HCV-coinfected individuals with minimal (n = 16) and advanced (n = 18) fibrosis (METAVIR F0/F1 and F4 scores respectively) and 20 healthy volunteers were enrolled. PBMC were obtained from peripheral blood samples and NK and CD4+ T-cells were isolated and analysed. NK cell phenotype (CD25, CD69, Nkp46, NKG2D, PD-1), degranulation (CD107a) and IFN-γ and TNF-α production, as well as CD4+ T-cell activation (CD69, CD25 and CD38) were measured by flow cytometry. CD4+ T-cell conditioned medium (CM) derived from F0/F1 or F4 individuals was assessed for IL-2 levels by ELISA. Modulation of NK cell functionality by these CMs was also analysed. RESULTS: When comparing to NK cells from individuals with minimal fibrosis, degranulation and cytokine secretion by NK cells from subjects with F4 scores was significantly impaired, while PD-1 expression was augmented. On the one hand, neither the expression of activation markers nor IL-2 secretion was distinctly induced in CD4+ T-cells from subjects with F0/F1 or F4 METAVIR scores. Finally, NK cell degranulation and cytokine secretion were not differentially modulated by CD4+ T-cell CM, whether CD4+ T-cells derived from subjects with minimal or advanced fibrosis. CONCLUSIONS: Low levels of NK and CD4+ T-cells in HIV/HCV-coinfected individuals with advanced liver fibrosis have been previously described. Here, we show that advanced liver fibrosis in coinfected individuals is associated to a defective function of NK cells and an increased expression of the exhaustion/senescence marker PD-1. This NK signature could not be attributed to changes in the ability of CD4+ T-cells to modulate NK cell function.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Coinfecção/imunologia , Infecções por HIV/imunologia , Hepatite C/imunologia , Células Matadoras Naturais/imunologia , Cirrose Hepática/imunologia , Adulto , Idoso , Coinfecção/complicações , Coinfecção/virologia , Feminino , Infecções por HIV/complicações , Infecções por HIV/virologia , HIV-1/fisiologia , Hepacivirus/fisiologia , Hepatite C/complicações , Hepatite C/virologia , Humanos , Leucócitos Mononucleares/imunologia , Cirrose Hepática/complicações , Cirrose Hepática/virologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Adulto Jovem
15.
Biochim Biophys Acta Mol Basis Dis ; 1865(10): 2657-2670, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31299217

RESUMO

Staphylococcus aureus is the most prominent cause of skin and soft tissue infections (SSTI) worldwide. Mortality associated with invasive SSTI is a major threat to public health considering the incidence of antibiotic resistant isolates in particular methicillin resistant S. aureus both in the hospital (HA-MRSA) and in the community (CA-MRSA). To overcome the increasing difficulties in the clinical management of SSTI due to MRSA, new prophylactic and therapeutic approaches are urgently needed and a preventive vaccine would be welcome. The rational design of an anti-S. aureus vaccine requires a deep knowledge of the role that the different bacterial virulence factors play according to the type of infection. In the present study, using a set of isogenic deficient mutants and their complemented strains we determined that the staphylococcal surface proteins SpA and Sbi play an important role in the induction of inflammatory cytokines and chemokines in the skin during SSTI. SpA and Sbi initiate signaling cascades that lead to the early recruitment of neutrophils, modulate their lifespan in the skin milieu and contribute to proper abscess formation and bacterial eradication. Moreover, the expression of SpA and Sbi appear critical for skin repair and wound healing. Thus, these results indicate that SpA and Sbi can promote immune responses in the skin that are beneficial for the host and therefore, should not be neutralized with vaccine formulations designed to prevent SSTI.


Assuntos
Abscesso/imunologia , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Pele/imunologia , Infecções dos Tecidos Moles/metabolismo , Infecções Estafilocócicas/metabolismo , Staphylococcus aureus/metabolismo , Cicatrização/fisiologia , Abscesso/metabolismo , Abscesso/microbiologia , Animais , Quimiocinas/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Queratinócitos , Staphylococcus aureus Resistente à Meticilina/metabolismo , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Pele/microbiologia , Pele/patologia , Infecções dos Tecidos Moles/imunologia , Infecções dos Tecidos Moles/microbiologia , Infecções dos Tecidos Moles/patologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/patogenicidade
17.
Front Immunol ; 9: 2633, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30515154

RESUMO

Despite more than 30 years of extensive research efforts, a complete understanding of the neurological consequences of HIV central nervous system (CNS) infection remains elusive. HIV is not only able to establish a viral reservoir in the CNS but also to initiate manifestation of neurodegenerative diseases. These neurological disorders may arise because of virus-induced activation of the inflammasome in CNS cells, including astrocytes. Nevertheless, in some productive viral infection scenarios, selective autophagy may reduce inflammation through mitochondrial degradation ("mitophagy") to counteract inflammasome activation. In this study, using cultured human astrocytes, we demonstrate that-depending on the HIV infection outcome-cells may resist death, or succumb by inflammasome activation when viral infection is productive or abortive, respectively. Cells productively infected with HIV were able to attenuate both mitochondrial ROS production and mitochondrial membrane potential dissipation, thus exhibiting cell death resistance. Interestingly, mitochondrial injury was counteracted by increasing the autophagic flux and by activating mitophagy. Conversely, astrocytes exposed to HIV in an abortive scenario showed prominent mitochondrial damage, inflammasome activation, and cell death. This bystander effect occurred after cell-to-cell contact with HIV-productively infected astrocytes. In summary, we demonstrate a tight functional crosstalk between viral infection mode, inflammasome activation, autophagy pathways and cell fate in the context of HIV infection. Moreover, mitophagy is crucial for cell death resistance in HIV-productively infected astrocytes, but its impairment may favor inflammasome-mediated cell death in abortively infected cells.


Assuntos
Astrócitos/imunologia , Efeito Espectador/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Inflamassomos/imunologia , Mitofagia/imunologia , Astrócitos/patologia , Morte Celular/imunologia , Infecções por HIV/patologia , Humanos
18.
Artigo em Inglês | MEDLINE | ID: mdl-28824880

RESUMO

The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease. In immunosuppressed individuals, as it occurs in the coinfection with human immunodeficiency virus (HIV), the central nervous system may be affected. In this regard, reactivation of Chagas disease is severe and often lethal, and it accounts for meningoencephalitis. Astrocytes play a crucial role in the environment maintenance of healthy neurons; however, they can host HIV and T. cruzi. In this report, human astrocytes were infected in vitro with both genetically modified-pathogens to express alternative fluorophore. As evidenced by fluorescence microscopy and flow cytometry, HIV and T. cruzi coexist in the same astrocyte, likely favoring reciprocal interactions. In this context, lower rates of cell death were observed in both T. cruzi monoinfected-astrocytes and HIV-T. cruzi coinfection in comparison with those infected only with HIV. The level of HIV replication is significantly diminished under T. cruzi coinfection, but without affecting the infectivity of the HIV progeny. This interference with viral replication appears to be related to the T. cruzi multiplication rate or its increased intracellular presence but does not require their intracellular cohabitation or infected cell-to-cell contact. Among several Th1/Th2/Th17 profile-related cytokines, only IL-6 was overexpressed in HIV-T. cruzi coinfection exhibiting its cytoprotective role. This study demonstrates that T. cruzi and HIV are able to coinfect astrocytes thus altering viral replication and apoptosis.


Assuntos
Apoptose , Astrócitos/imunologia , Doença de Chagas/complicações , Coinfecção , Infecções por HIV/complicações , Replicação Viral/fisiologia , Apoptose/efeitos dos fármacos , Astrócitos/parasitologia , Astrócitos/virologia , Morte Celular , Linhagem Celular , Doença de Chagas/imunologia , Doença de Chagas/virologia , Citocinas/metabolismo , HIV/fisiologia , Infecções por HIV/imunologia , Herpesvirus Humano 2/fisiologia , Humanos , Interleucina-6 , Nitroimidazóis/farmacologia , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia , Trypanosoma cruzi/genética , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/fisiologia
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