Antiviral and Virucidal Activities of Uncaria tomentosa (Cat's Claw) against the Chikungunya Virus.

Uncaria tomentosa (UT) is a medicinal plant popularly known as cat's claw belonging to the Rubiaceae family that has been reported to display antiviral and anti-inflammatory activities. The chikungunya virus (CHIKV) outbreaks constitute a Brazilian public health concern. CHIKV infection develops an abrupt onset of fever, usually accompanied by a skin rash, besides incapacitating polyarthralgia. There is no vaccine available or treatment for CHIKV infection. The present study evaluates the hydroalcoholic extract of UT bark as a potential antiviral against CHIKV. The in vitro antiviral activity of the UT extract against the Brazilian CHIKV strain was assessed using quantitative reverse transcription polymerase chain reaction, flow cytometry, and plaque assay. Results obtained demonstrated that UT inhibits CHIKV infection in a dose-dependent manner. At the non-cytotoxic concentration of 100 µg/mL, UT exhibited antiviral activity above 90% as determined by plaque reduction assay, and it reduced the viral cytopathic effect. Similarly, a significant virucidal effect of 100 µg/mL UT was observed after 24 and 48 h post-infection. This is the first report on the antiviral activity of UT against CHIKV infection, and the data presented here suggests UT as a potential antiviral to treat CHIKV infection.

Retrospective molecular investigation of Mayaro and Oropouche viruses at the human-animal interface in West-central Brazil, 2016-2018.

Mayaro virus (MAYV, Togaviridae) and Oropouche orthobunyavirus (OROV, Peribunyaviridae) are emerging enzootic arboviruses in Latin America. Outbreaks of febrile illness associated with MAYV and OROV have been reported among humans mainly in the northern region of Brazil since the 1980s, and recent data suggest these viruses have circulated also in more populated areas of western Brazil. MAYV shares mosquito vectors with yellow fever virus and it has been historically detected during yellow fever epidemics. Aiming to investigate the transmission of OROV and MAYV at the human-animal interface during a yellow fever, chikungunya and Zika outbreaks in Brazil, we conducted a retrospective molecular investigation in 810 wild and domestic animals, 106 febrile patients, and 22.931 vectors collected from 2016 to 2018 in Cuiaba and Campo Grande metropolitan regions, western Brazil. All samples tested negative for OROV and MAYV RNA by RT-qPCR. Findings presented here suggest no active circulation of MAYV and OROV in the sampled hosts. Active surveillance and retrospective investigations are instrumental approaches for the detection of cryptic and subclinical activity of enzootic arboviruses and together serve as a warning system to implement appropriate actions to prevent outbreaks.

The Role of Growth Factors in the Pathogenesis of Dengue: A Scoping Review.

Growth factors (GFs) have a role in tissue repair and in the modulation of the expression of inflammatory cells in damage caused by pathogens. This study aims to systematize the evidence on the role of GFs in the pathogenesis of dengue. This scoping review considered all published peer-reviewed studies in the MEDLINE and Embase databases. Ultimately, 58 studies that analyzed GFs in dengue patients, published between 1998 and 2021, were included. DENV-2 infection and secondary infection were more frequent in the patients studied. ELISA and multiplex immunoassay (Luminex) were the most used measurement techniques. Increased levels of vascular endothelial growth factor, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, transforming growth factor beta, and hepatocyte growth factor as well as reduced levels of platelet-derived growth factor and epidermal growth factor were observed in severe dengue in most studies. Vascular endothelial growth factor and hepatocyte growth factor were identified as biomarkers of severity. In addition, there is evidence that the dengue virus can use the growth factor pathway to facilitate its entry into the cell and promote its viral replication. The use of tyrosine kinase inhibitors is an alternative treatment for dengue that is being studied.

Pro-Inflammatory Profile of Children Exposed to Maternal Chikungunya Virus Infection during the Intrauterine Period: A One-Year Follow-Up Study.

Chikungunya virus (CHIKV) vertical transmission occurs due to maternal viremia in the prepartum. Clinical presentation in neonates can be varied; however, the consequences of intrauterine exposure on the immune response are unclear. Thus, we aimed to analyze inflammatory alterations in children exposed to maternal CHIKV infection. This is a cross-sectional study that included children exposed to maternal CHIKV infection (confirmed by RT-qPCR and/or IgM). Circulant immune mediators were analyzed by a multiplex assay. RESULTS: We included 33 children, with a mean age of 3 ± 2.9 months-old, and 19 (57.6%) were male. Only one child presented neurological alterations. CHIKV-exposed infants showed elevated levels of MIP-1α, MIP-1ß, and CCL-2 (p < 0.05). Pro-inflammatory cytokines such as TNFα, IL-6, and IL-7 (p < 0.0001) were also increased. In addition, lower levels of PDGF-BB and GM-CSF were observed in the same group (p < 0.0001). Principal component (PC) analysis highlighted a distinction in the inflammatory profile between groups, where PC explained 56.6% of the alterations. Our findings suggest that maternal exposure to CHIKV can affect the circulating levels of pro-inflammatory cytokines during the infants' first year of life. The long-term clinical consequences of these findings should be investigated.

A Chikungunya Virus Multiepitope Recombinant Protein Expressed from the Binary System Insect Cell/Recombinant Baculovirus Is Useful for Laboratorial Diagnosis of Chikungunya.

Chikungunya virus (CHIKV) is an arbovirus currently distributed worldwide, causing a disease that shares clinical signs and symptoms with other illnesses, such as dengue and Zika and leading to a challenging clinical differential diagnosis. In Brazil, CHIKV emerged in 2014 with the simultaneous introduction of both Asian and East/Central/South African (ECSA) genotypes. Laboratorial diagnosis of CHIKV is mainly performed by molecular and serological assays, with the latter more widely used. Although many commercial kits are available, their costs are still high for many underdeveloped and developing countries where the virus circulates. Here we described the development and evaluation of a multi-epitope recombinant protein-based IgG-ELISA (MULTREC IgG-ELISA) test for the specific detection of anti-CHIKV antibodies in clinical samples, as an alternative approach for laboratorial diagnosis. The MULTREC IgG-ELISA showed 86.36% of sensitivity and 100% of specificity, and no cross-reactivity with other exanthematic diseases was observed. The recombinant protein was expressed from the binary system insect cell/baculovirus using the crystal-forming baculoviral protein polyhedrin as a carrier of the target recombinant protein to facilitate recovery. The crystals were at least 10 times smaller in size and had an amorphous shape when compared to the polyhedrin wild-type crystal. The assay uses a multi-epitope antigen, representing two replicates of 18 amino acid sequences from the E2 region and a sequence of 17 amino acids from the nsP3 region of CHIKV. The recombinant protein was highly expressed, easy to purify and has demonstrated its usefulness in confirming chikungunya exposure, indeed showing a good potential tool for epidemiological surveillance.

Subsets of Cytokines and Chemokines from DENV-4-Infected Patients Could Regulate the Endothelial Integrity of Cultured Microvascular Endothelial Cells.

Introduction: It is a consensus that inflammatory mediators produced by immune cells contribute to changes in endothelial permeability in dengue. We propose to relate inflammatory mediators seen in dengue patients with the in vitro alteration of endothelial cells (ECs) cultured with serum from these patients. Methods: Patients with mild (DF) to moderate and severe dengue (DFWS/Sev) were selected. ELISA quantified inflammatory mediators. Expression of adhesion molecules and CD147 were evaluated in the ECs cultured with the patient's serum by flow cytometry. We assessed endothelial permeability by measuring transendothelial electrical resistance in cocultures of ECs with patient serum. Results: Dengue infection led to an increase in inflammatory mediators-the IL-10 distinguished DF from DFWS/Sev. There were no changes in CD31, CD54, and CD106 but decreased CD147 expression in ECs. DFWS/Sev sera induced a greater difference in endothelial permeability than DF sera. Correlation statistical test indicated that low IL-10 and IFN-γ and high CCL5 maintain the integrity of ECs in DF patients. In contrast, increased TNF, IFN-γ, CXCL8, and CCL2 maintain EC integrity in DFWS/Sev patients. Conclusions: Our preliminary data suggest that a subset of inflammatory mediators may be related to the maintenance or loss of endothelial integrity, reflecting the clinical prognosis.

Innate Immune Response to Dengue Virus: Toll-like Receptors and Antiviral Response.

Dengue is a mosquito-borne viral disease caused by the dengue virus (DENV1-4). The clinical manifestations range from asymptomatic to life-threatening dengue hemorrhagic fever (DHF) and/or Dengue Shock Syndrome (DSS). Viral and host factors are related to the clinical outcome of dengue, although the disease pathogenesis remains uncertain. The innate antiviral response to DENV is implemented by a variety of immune cells and inflammatory mediators. Blood monocytes, dendritic cells (DCs) and tissue macrophages are the main target cells of DENV infection. These cells recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs). Pathogen recognition is a critical step in eliciting the innate immune response. Toll-like receptors (TLRs) are responsible for the innate recognition of pathogens and represent an essential component of the innate and adaptive immune response. Ten different TLRs are described in humans, which are expressed in many different immune cells. The engagement of TLRs with viral PAMPs triggers downstream signaling pathways leading to the production of inflammatory cytokines, interferons (IFNs) and other molecules essential for the prevention of viral replication. Here, we summarize the crucial TLRs' roles in the antiviral innate immune response to DENV and their association with viral pathogenesis.

Comparative Analysis of Circulating Levels of SARS-CoV-2 Antibodies and Inflammatory Mediators in Healthcare Workers and COVID-19 Patients.

Advances in knowledge of the pathophysiology of COVID-19 have been acquired; however, the host factors that could explain the mild and severe forms of the disease are not fully understood. Thus, we proposed to evaluate anti-SARS-CoV-2 antibodies and the inflammatory response of different groups of individuals, including healthcare workers (HCW), sick and dead COVID-19 patients and also recovered patients to contribute to this knowledge gap. Our objective is to relate the clinical evolution of these individuals with the level of detection and functionality of specific antibodies and with the production of inflammatory mediators. As main findings, IgA and IgG anti-SARS-CoV-2 were detected in asymptomatic HCW. IFN-γ and TNF-α levels were higher in symptomatic HCWs than patients with COVID-19 and those who died. Patients who died had higher levels of IL-6, IL-10, and CCL2/MCP-1. We found an imbalance between antiviral and pro-inflammatory mediators in the groups, in which IFN-γ and TNF-α seem to be more associated with protection and IL-6 and CCL2/MCP-1 with pathology. Our work is pioneering the Brazilian population and corroborates data from people from other countries.

Was It Chikungunya? Laboratorial and Clinical Investigations of Cases Occurred during a Triple Arboviruses' Outbreak in Rio de Janeiro, Brazil.

The co-circulation of chikungunya virus (CHIKV), dengue virus (DENV) and Zika virus (ZIKV) in Rio de Janeiro (RJ), Brazil, caused a challenging triple epidemic, as they share similar clinical signs and symptoms and geographical distribution. Here, we aimed to investigate the clinical and laboratorial aspects of chikungunya suspected cases assisted in RJ during the 2018 outbreak, focusing on the differential diagnosis with dengue and zika. All suspected cases were submitted to molecular and/or serological differential diagnostic approaches to arboviruses. A total of 242 cases suspected of arbovirus infection were investigated and 73.6% (178/242) were molecular and/or serologically confirmed as chikungunya. In RT-qPCR confirmed cases, cycle threshold (Ct) values ranged from 15.46 to 35.13, with acute cases presenting lower values. Chikungunya cases were mainly in females (64%) and the most frequently affected age group was adults between 46 to 59 years old (27%). Polyarthralgia affected 89% of patients, especially in hands and feet. No dengue virus (DENV) and Zika virus (ZIKV) infections were confirmed by molecular diagnosis, but 9.5% (23/242) had serological evidence of DENV exposure by the detection of specific anti-DENV IgM or NS1, and 42.7% (76/178) of chikungunya positive cases also presented recent DENV exposure reflected by a positive anti-DENV IgM or NS1 result. A significantly higher frequency of arthritis (p = 0.023) and limb edema (p < 0.001) was found on patients with CHIKV monoinfection compared to dengue patients and patients exposed to both viruses. Lastly, phylogenetic analysis showed that the chikungunya cases were caused by the ECSA genotype. Despite the triple arboviruses' epidemic in the state of RJ, most patients with fever and arthralgia investigated here were diagnosed as chikungunya cases, and the incidence of CHIKV/DENV co-detection was higher than that reported in other studies.

Involvement of Th1Th17 Cell Subpopulations in the Immune Responses of Mothers Who Gave Birth to Children with Congenital Zika Syndrome (CZS).

High levels of T helper 17 cell (Th17)-related cytokines have been shown in acute Zika virus (ZIKV) infection. We hypothesized that the high levels of Th17-related cytokines, associated with a regulatory environment during pregnancy, create a favorable milieu for the differentiation of CD4+Th17 cells. We present data from a cross-sectional study on mothers who confirmed ZIKV infection by qRT-PCR and their children. We also recruited non-pregnant women infected with ZIKV in the same period. ZIKV infection occurred between 2015 and 2017. We collected samples for this study between 2018 and 2019, years after the initial infection. We highlight that, after in vitro stimulation with ZIKV CD4 megapool (ZIKV MP), we found a lower frequency of IL-17-producing CD4+ T cells (Th17), especially in the mothers, confirmed by the decrease in IL-17 production in the supernatant. However, a higher frequency of CD4+ IL-17+ IFN-γ+ T cells (Th1Th17) responding to the ZIKV MP was observed in the cells of the mothers and children but not in those of the non-pregnant women. Our data indicate that the priming of CD4 T cells of the Th1Th17 phenotype occurred preferentially in the mothers who gave birth to children with CZS and in the children.

Increased circulating levels of High Mobility Group Box 1 (HMGB1) in acute-phase Chikungunya virus infection: Potential disease biomarker.

BACKGROUND: Chikungunya virus (CHIKV) causes a febrile syndrome with intense and debilitating arthralgia that can persist for several months or years after complete virus clearance. As there is no specific antiviral treatment or vaccine against CHIKV, identification of serological markers that help clinical management of CHIKV patients is urgent. The High Mobility Group Box 1 (HMGB1) protein is secreted to extracellular milieu and triggers an intense inflammatory process by inducing the overexpression of pro-inflammatory cytokines. HMGB1 plays an important role in several virus diseases as well as in rheumatoid arthritis. OBJECTIVES: This study focus on the investigation of HMGB1 serum levels in a sera panel from CHIKV-infected patients in an attempt to assess its potential as a biomarker for chikungunya clinical management. STUDY DESIGN: Eighty CHIKV-positive samples and 32 samples from healthy donors were subjected to a quantitative HMGB1 ELISA assay to assess the HMGB1 circulating levels. RESULTS: HMGB1 levels were significantly higher in CHIKV-positive samples (516.12 ng/mL, SEM ± 48.83 ng/mL) compared to negative control (31.20 ng/mL, SEM ± 3.24 ng/mL, p < 0.0001). Circulating levels of HMGB1 persisted elevated during the whole acute-phase of disease and correlated with virus titer (p < 0.05). CONCLUSIONS: The present study is the first to describe increased serum levels of HMGB1 in CHIKV infection and its positive correlation with virus titer, suggesting its potential use as a biomarker for diagnosis and treatment of chikungunya fever.

Different Profiles of Cytokines, Chemokines and Coagulation Mediators Associated with Severity in Brazilian Patients Infected with Dengue Virus.

The incidence of dengue in Latin America has increased dramatically during the last decade. Understanding the pathogenic mechanisms in dengue is crucial for the identification of biomarkers for the triage of patients. We aimed to characterize the profile of cytokines (IFN-γ, TNF-α, IL-1ß, IL-6, IL-18 and IL-10), chemokines (CXCL8/IL-8, CCL2/MCP-1 and CXCL10/IP-10) and coagulation mediators (Fibrinogen, D-dimer, Tissue factor-TF, Tissue factor pathway inhibitor-TFPI and Thrombomodulin) during the dengue-4 epidemic in Brazil. Laboratory-confirmed dengue cases had higher levels of TNF-α (p < 0.001), IL-6 (p = 0.005), IL-10 (p < 0.001), IL-18 (p = 0.001), CXCL8/IL-8 (p < 0.001), CCL2/MCP-1 (p < 0.001), CXCL10/IP-10 (p = 0.001), fibrinogen (p = 0.037), D-dimer (p = 0.01) and TFPI (p = 0.042) and lower levels of TF (p = 0.042) compared to healthy controls. A principal component analysis (PCA) distinguished between two profiles of mediators of inflammation and coagulation: protective (TNF-α, IL-1ß and CXCL8/IL-8) and pathological (IL-6, TF and TFPI). Lastly, multivariate logistic regression analysis identified high aspartate aminotransferase-to-platelet ratio index (APRI) as independent risk factors associated with severity (adjusted OR: 1.33; 95% CI 1.03-1.71; p = 0.027), the area under the receiver operating characteristics curve (AUC) was 0.775 (95% CI 0.681-0.869) and an optimal cutoff value was 1.4 (sensitivity: 76%; specificity: 79%), so it could be a useful marker for the triage of patients attending primary care centers.

Analysis of a Routinely Used Commercial Anti-Chikungunya IgM ELISA Reveals Cross-Reactivities with Dengue in Brazil: A New Challenge for Differential Diagnosis?

In Brazil, chikungunya emerged in 2014, and by 2016, co-circulated with other arbovirosis, such as dengue and zika. ELISAs (Enzyme-Linked Immunosorbent Assays) are the most widely used approach for arboviruses diagnosis. However, some limitations include antibody cross reactivities when viruses belong to the same genus, and sensitivity variations in distinct epidemiological scenarios. As chikungunya virus (CHIKV) is an alphavirus, no serological cross reactivity with dengue virus (DENV) should be observed. Here, we evaluated a routinely used chikungunya commercial IgM (Immunoglobulin M) ELISA test (Anti-Chikungunya IgM ELISA, Euroimmun) to assess its performance in confirming chikungunya in a dengue endemic area. Samples (n = 340) representative of all four DENV serotypes, healthy individuals and controls were tested. The Anti-CHIKV IgM ELISA test had a sensitivity of 100% and a specificity of 25.3% due to the cross reactivities observed with dengue. In dengue acute cases, the chikungunya test showed an overall cross-reactivity of 31.6%, with a higher cross-reactivity with DENV-4. In dengue IgM positive cases, the assay showed a cross-reactivity of 46.7%. Serological diagnosis may be challenging and, despite the results observed here, more evaluations shall be performed. Because distinct arboviruses co-circulate in Brazil, reliable diagnostic tools are essential for disease surveillance and patient management.

Differential Longevity of Memory CD4 and CD8 T Cells in a Cohort of the Mothers With a History of ZIKV Infection and Their Children.

Background: Zika virus (ZIKV) infection causes for mild and self-limiting disease in healthy adults. In newborns, it can occasionally lead to a spectrum of malformations, the congenital Zika syndrome (CZS). Thus, little is known if mothers and babies with a history of ZIKV infection were able to develop long-lasting T-cell immunity. To these issues, we measure the prevalence of ZIKV T-cell immunity in a cohort of mothers infected to the ZIKV during pregnancy in the 2016-2017 Zika outbreak, who gave birth to infants affected by neurological complications or asymptomatic ones. Results: Twenty-one mothers and 18 children were tested for IFN-γ ELISpot and T-cell responses for flow cytometry assays in response to CD4 ZIKV and CD8 ZIKV megapools (CD4 ZIKV MP and CD8 ZIKV MP). IFN-γ ELISpot responses to ZIKV MPs showed an increased CD4 and CD8 T-cell responses in mothers compared to children. The degranulation activity and IFN-γ-producing CD4 T cells were detected in most mothers, and children, while in CD8 T-cells, low responses were detected in these study groups. The total Temra T cell subset is enriched for IFN-γ+ CD4 T cells after stimulation of CD4 ZIKV MP. Conclusion: Donors with a history of ZIKV infection demonstrated long-term CD4 T cell immunity to ZIKV CD4 MP. However, the same was not observed in CD8 T cells with the ZIKV CD8 MP. One possibility is that the cytotoxic and pro-inflammatory activities of CD8 T cells are markedly demonstrated in the early stages of infection, but less detected in the disease resolution phase, when the virus has already been eliminated. The responses of mothers' T cells to ZIKV MPs do not appear to be related to their children's clinical outcome. There was also no marked difference in the T cell responses to ZIKV MP between children affected or not with CZS. These data still need to be investigated, including the evaluation of the response of CD8 T cells to other ZIKV peptides.

Risk factors associated with mortality in patients hospitalized for coronavirus disease 2019 in Rio de Janeiro, Brazil.

INTRODUCTION: Understanding the mortality-associated risk factors of coronavirus disease 2019 will impact clinical decisions. METHODS: This retrospective longitudinal study included patients hospitalized for coronavirus disease in Rio de Janeiro, Brazil. The Kaplan-Meier method and multivariate Cox regression analysis were used. RESULTS: Sequential Organ Failure Assessment score of ≥2 (hazard ratio 4.614; 95% confidence interval =2.210-9.634; p<0.001) and neutrophil/lymphocyte ratio of >5 (hazard ratio=2.616; 95% confidence interval=1.303-5.252; p=0.007) were independently associated with mortality. CONCLUSIONS: Sequential Organ Failure Assessment score and neutrophil/lymphocyte ratio on admission can identify coronavirus disease patients at increased risk of death and guide subsequent clinical decisions.

Risk factors associated with mortality in patients hospitalized for coronavirus disease 2019 in Rio de Janeiro, Brazil

Abstract INTRODUCTION: Understanding the mortality-associated risk factors of coronavirus disease 2019 will impact clinical decisions. METHODS: This retrospective longitudinal study included patients hospitalized for coronavirus disease in Rio de Janeiro, Brazil. The Kaplan-Meier method and multivariate Cox regression analysis were used. RESULTS: Sequential Organ Failure Assessment score of ≥2 (hazard ratio 4.614; 95% confidence interval =2.210-9.634; p<0.001) and neutrophil/lymphocyte ratio of >5 (hazard ratio=2.616; 95% confidence interval=1.303-5.252; p=0.007) were independently associated with mortality. CONCLUSIONS: Sequential Organ Failure Assessment score and neutrophil/lymphocyte ratio on admission can identify coronavirus disease patients at increased risk of death and guide subsequent clinical decisions.

Clinical, Virological, and Immunological Profiles of DENV, ZIKV, and/or CHIKV-Infected Brazilian Patients.

BACKGROUND: Arboviruses co-circulating within a population that are transmitted by the same vector have the potential to cause coinfections. Coinfections with dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV) have been occurring in Brazil, but it is not well-understood how human responses vary during mono- or coinfections and whether they play different roles in pathogenesis. METHODS: We investigated the clinical, virological, and immunological status during patients' acute infections, focusing on the CCL/CXC chemokines, proinflammatory, as well as anti-inflammatory cytokines levels quantified by ELISAs. Viral load was determined by qRT-PCR in serum samples from 116 acute DENV, ZIKV, CHIKV, DENV/ZIKV, and CHIKV/ZIKV-infected adult patients from Brazil. RESULTS: Most of the acute patients displayed fever, headache, prostration, and myalgia, regardless of the type of arbovirus infection. Zika viral load was higher in CHIKV/ZIKV coinfected patients compared with ZIKV or DENV/ZIKV infections. All infected individuals presented increased concentrations of C-X-C motif chemokine ligand 10/interferon protein-10 (CXCL10/IP-10), C-C motif chemokine ligand 2/monocyte chemoattractant protein-1 (CCL2/MCP-1), and tumor necrosis factor alpha (TNF-α) compared to healthy donors. Interestingly, the ZIKV group separated from CHIKV/ZIKV due to higher levels of interleukin-10 (IL-10) and lower levels of TNF-α. While DENV/ZIKV differentiated from CHIKV due to their higher levels of CCL2/MCP-1, in CHIKV- and CHIKV/ZIKV-infected patients, levels of CXC10/IP-10, CCL2/MCP-1, and migration inhibitory factor (MIF) were associated with CHIKV viral load. By contrast, in DENV/ZIKV- and CHIKV/ZIKV-infected patients, levels of CXCL10/IP-10, CCL2/MCP-1, and TNF-α showed a significant inverse correlation with ZIKV viral load. CONCLUSIONS: From all the circulating mediators measured, we detected differences of IL-10, TNF-α, and CCL2/MCP-1 between arbovirus groups. We hypothesize that CXC10/IP-10, CCL2/MCP-1, and MIF in the CHIKV-infected group could regulate the CHIKV viral load, while CXC10/IP-10, CCL2/MCP-1, and TNF-α in DENV/ZIKV, and CHIKV/ZIKV groups, could regulate ZIKV viral load.

Successful DAA therapy for chronic hepatitis C reduces HLA-DR on monocytes and circulating immune mediators: A long-term follow-up study.

INTRODUCTION: After DAA treatment for chronic hepatitis C infection, peripheral monocyte subsets from patients who achieved sustained virological response (SVR) reduced compared to healthy control. Improvement in inflammatory parameters and liver stiffness has been observed. However, little is known about the long-term impact of DAA treatment on peripheral monocyte subsets and immune mediators levels. OBJECTIVES: We aimed to examine peripheral monocyte subsets and immune mediators levels in Brazilian chronic HCV patients after long-term successful IFN-free SOF-based treatment. MATERIAL AND METHODS: We analyzed CD14++CD16-, CD14++CD16+ and CD14+CD16++ monocytes and 27 immune mediators by flow cytometry and analysis of multiple secreted proteins assay, respectively, in monoinfected chronic HCV patients receiving IFN-free sofosbuvir-based regimens followed before treatment, at SVR and one year after the end of treatment (1y). RESULTS: Twenty-one biomarkers decreased significantly at 1y and 55-80 % of patients this reduction at 1y. Experimented patients presented a greater modulation of immune mediators at 1y. HLA-DR expression significantly decreased on CD14++CD16- and CD14++CD16+ monocytes at 1y when compared to SVR. CONCLUSIONS: Successful DAA therapy did not modify monocyte subsets frequency but reduced monocyte activation at 1y and sustained the downregulation and restoration of circulating immune mediators, indicating that long-term reversal of inflammation status could occur after HCV eradication.

Apoptosis characterization in mononuclear blood leukocytes of HIV patients during dengue acute disease.

Dengue virus (DENV) co-circulation in Brazil represents a challenge for treatment and vaccine development. Despite public health impact, the occurrence of coinfections with other viruses is a common event. Increased T cell activation and altered inflammatory response are found during DENV coinfection with Human Immunodeficiency Virus (HIV) impacting HIV-pathogenesis. Even with Antiretroviral therapy (ART), HIV- treated patients had chronic immune activation and lymphocyte apoptosis. However, apoptotic mechanisms have not been investigated during coinfection with DENV. Our attention was attracted to apoptotic cell markers expressions in PBMCs from DENV and DENV/HIV coinfected patients. We found CD4/CD8 ratio inversion in most coinfected patients. CD4 T and CD8 T-cell subsets from DENV and DENV/HIV groups expressed low levels of anti-apoptotic protein Bcl-2. Furthermore, CD8 CD95 double positive cells frequency expressing low levels of Bcl-2 were significantly higher in these patients. Additionally, the density of Bcl-2 on classical monocytes (CD14++CD16-) was significantly lower during DENV infection. Upregulation of pro-apoptotic proteins and anti-apoptotic proteins were found in DENV and DENV/HIV, while catalase, an antioxidant protein, was upregulated mainly in DENV/HIV coinfection. These findings provide evidence of apoptosis triggering during DENV/HIV coinfection, which may contribute to knowledge of immunological response during DENV acute infection in HIV-patients treated with ART.

Renal Injury in DENV-4 Fatal Cases: Viremia, Immune Response and Cytokine Profile.

Dengue virus (DENV) infections may result in asymptomatic cases or evolve into a severe disease, which involves multiple organ failure. Renal involvement in dengue can be potentially related to an increased mortality. Aiming to better understand the role of DENV in renal injury observed in human fatal cases, post-mortem investigations were performed in four DENV-4 renal autopsies during dengue epidemics in Brazil. Tissues were submitted to histopathology, immunohistochemistry, viral quantification, and characterization of cytokines and inflammatory mediators. Probably due the high viral load, several lesions were observed in the renal tissue, such as diffuse mononuclear infiltration around the glomerulus in the cortical region and in the medullary vessels, hyalinosis arteriolar, lymphocytic infiltrate, increased capsular fibrosis, proximal convoluted tubule (PCT) damage, edema, PCT debris formation, and thickening of the basal vessel membrane. These changes were associated with DENV-4 infection, as confirmed by the presence of DENV-specific NS3 protein, indicative of viral replication. The exacerbated presence of mononuclear cells at several renal tissue sites culminated in the secretion of proinflammatory cytokines and chemokines. Moreover, it can be suggested that the renal tissue injury observed here may have been due to the combination of both high viral load and exacerbated host immune response.