Biology subjects

Arruda, E.

Publications and source records attributed to Arruda, E..

9 recordsLinked to original sources

bioRxiv2026

Long-term SARS-CoV-2 Persistence in Syrian Hamsters

SARS-CoV-2 persistence has been proposed as a potential contributor to the pathogenesis of long COVID, with reservoir tissues potentially serving as sites for viral persistence, intra-host evolution, and intermittent viral shedding. Here, we used experimentally infected Syrian hamsters to investigate long-term SARS-CoV-2 persistence across tissues, viral infectivity, and associated immunological and metabolic alterations. Syrian hamsters (Mesocricetus auratus) were intranasally infected with a SARS-CoV-2 parental strain or Gamma and Delta variants and monitored for up to one year, with samples collected at 3, 15, 30, 90, 150, and 365 days post-infection (dpi). During the acute phase, infected animals exhibited significant weight loss, viral shedding, and marked pulmonary inflammation, accompanied by increased expression of pro-inflammatory cytokines at 3 dpi. Infection was confirmed by seroconversion, with sustained IgG responses and low-titer neutralizing antibodies against Omicron. Viral nucleoprotein was detected in multiple tissues up to 365 dpi, while RT-qPCR identified persistent low-level viral RNA in the lungs, brain, spleen, and thymus throughout the observation period, without evidence of productive viral replication. Immune gene expression displayed organ-specific temporal patterns: acute pulmonary inflammation transitioned into broad late-stage suppression, except for sustained TGF-{beta} expression; the brain exhibited a late chemokine signature at 365 dpi; and the thymus showed a delayed immune activation peak at 150 dpi, particularly in Delta-infected animals. Metabolomic profiling revealed a shared acute-phase metabolic signature across variants that largely resolved by 365 dpi, whereas Delta-infected animals retained distinct residual metabolic alterations. Collectively, these findings establish a model of long-term SARS-CoV-2 tissue persistence characterized by organ-specific immune and metabolic signatures, providing a platform to investigate mechanisms underlying post-acute sequelae and evaluate potential therapeutic strategies.

microbiology↗

bioRxiv2024

Comprehensive Molecular Epidemiology of Influenza Viruses in Brazil: Insights from a Nationwide Analysis

Influenza A and B viruses pose significant global health threats, with substantial impacts on morbidity and mortality. Understanding their molecular epidemiology in Brazil, a key hub for the circulation and dissemination of these viruses in South America, remains limited. This study, part of the Center for Viral Surveillance and Serological Assessment (CeVIVAS) project, addresses this by analyzing data and samples from all Brazilian macroregions, along with publicly available sequences from 2021-2023. Phylogenetic analysis of the Hemagglutinin (HA) segment of Influenza A/H1N1pdm09, A/H3N2, and Influenza B/Victoria-lineage revealed the predominance of A/H3N2 2a.3 strain in 2021 and early 2022. This was succeeded by A/H3N2 2b until October 2022, after which A/H1N1pdm09 5a.2a and 5a.2a.1 lineages became prevalent, maintaining this status throughout 2023. B/Victoria circulated at low levels between December 2021 and September 2022, becoming co-prevalent with A/H1N1pdm09 5a.2a and 5a.2a.1 lineages. Comparing the vaccine strain A/Darwin/9/2021 with circulating A/H3N2 viruses from 2021-2023 revealed shared mutations to aspartic acid at residues 186 and 225, altering the RBD domains charge. For A/H1N1pdm09, the 2022 consensus of 5a.2a.1 and the vaccine strain A/Victoria/2570/2019 had 14 amino acid substitutions. Key residues such as H180, D187, K219, R223, E224, and T133 are involved in hydrogen interactions with sialic acids, while N130, K142, and D222 may influence distance interactions based on docking analyses. Distinct Influenza A lineage frequency patterns across Brazils macroregions underscore regional variations in virus circulation. This study characterizes the dynamics of Influenza A and B viruses in Brazil, offering valuable insights into their circulation patterns. These findings have significant public health implications, informing strategies to mitigate transmission risks, optimize vaccination efforts, and enhance outbreak control measures. Author summaryThis study investigates the molecular epidemiology of Influenza A and B viruses in Brazil from 2021 to 2023. Utilizing data from the Center for Viral Surveillance and Serological Assessment (CeVIVAS) and public databases, we performed a comprehensive phylogenetic analysis of the Hemagglutinin segments of Influenza A/H1N1pdm09, A/H3N2, and B/Victoria-lineage viruses across all Brazilian macroregions. Key findings reveal that the A/H3N2 2a.3 strain was predominant in 2021 and early 2022, followed by A/H3N2 2b, and later by A/H1N1pdm09 5a.2a and 5a.2a.1 lineages in late 2022 and throughout 2023. The B/Victoria strain circulated at low levels initially and later co-prevailed with A/H1N1pdm09 lineages. Comparing the vaccine strain A/Darwin/9/2021 with circulating A/H3N2 viruses from 2021-2023 and A/Victoria/2570/2019 with 5a.2a.1 of A/H1N1pdm09 circulating in 2022 revealed significant mutations which could affect the interaction of the viruses with sialic acids and potentially impact vaccine efficacy. Notably, we identified a substitution pattern among the predominant Influenza subtypes and observed distinct regional variations in Influenza A lineage frequencies across Brazil. These findings are critical for optimizing vaccination strategies and provide valuable data to inform public health policy and improve health outcomes.

evolutionary biology↗

bioRxiv2024

Differential action modes of Neutrophil Extracellular Trap-targeted drugs define T cell responses in SARS-CoV-2 infection.

Neutrophil extracellular traps (NETs) play a dual role in SARS-CoV-2 infection, aiding early immune defense but also contributing to lung damage. While NET targeting may improve clinical outcomes in SARS-CoV-2 infection, its impact on adaptive immunity, crucial for fighting the virus, remains unclear. Our study demonstrates that both recombinant human DNase (rhDNase), degrading NET structure, and GSK484, inhibiting NET formation, reduce lung NET concentration and improve clinical outcomes in infected mice, yet they differ in their influence on T cell responses. We show that rhDNase does not impact T cell responses, whereas GSK484 diminishes virus-specific T cell responses. In vitro, GSK484 decreases dendritic cell antigen presentation by impairing antigen uptake and reduces IL-2 signaling by affecting its production by T cells. In a model of lung inflammation, GSK484 diminishes antigen-specific T cell activation and proliferation, while rhDNase shows a potential to boost T cell responses via the presence of NET fragments that reduce T cell activation threshold. Our findings suggest that NET targeting with rhDNase or GSK484 holds therapeutic potential for treating SARS-CoV-2 infection, while their distinct modes of action shape T cell responses during the infection.

immunology↗

bioRxiv2022

In Vitro Inhibition of SARS-CoV-2 Infection by Bromhexine hydrochloride

The world is enduring the SARS CoV-2 pandemic, and although extensive research has been conducted on the issue, only a few antivirals have been approved to treat patients with COVID-19. Bromhexine hydrochloride was previously identified as a potent inhibitor of TMPRSS2, an essential protease for ACE-2 virus receptor interactions. In the present study, we investigated whether bromhexine treatment could reduce SARS CoV-2 replication in vitro. To evaluate bromhexines effectiveness against SARS COV-2 infection, viral load was measured using Caco-2 cell lines expressing TMPRSS2. Our molecular docking results indicate that bromhexine displays an affinity with the active site of TMPRSS2. The drug significantly inhibited SARS CoV-2, both parental and P1 variant strains, infection in the Caco-2 cell line, reducing about 40% of SARS-CoV-2 entrance and about 90% of viral progeny in the supernatant 48h post-infection. Furthermore, bromhexine did not exhibit any direct virucidal activity on SARS CoV-2. In conclusion, bromhexine hydrochloride efficiently disrupts SARS CoV-2 infection in vitro and has the potential to become an effective antiviral agent in COVID-19 treatment.

pharmacology and toxicology↗

bioRxiv2022

Ultrasound treatment inhibits SARS-CoV-2 in vitro infectivity

The global spreading of SARS-CoV-2 and the emergence of new variants underscore the ongoing need to develop new vaccines and antiviral drugs. While electromagnetic and acoustic waves have well-known virucidal properties, their application in therapeutic settings has been limited due to harming effects in biological matter. Here, we investigates the potential of ultrasound to interfere with SARS-CoV-2. Specifically, we study the effects of acoustic waves in the 1-20 MHz frequency range to determine their impact on the viral envelope of SARS-CoV-2. Our in vitro experiments demonstrate ultrasound exhibits a virucidal effect on SARS-CoV-2 without production of heat or cavitation. This study offers a promising physics-based approach to combat SARS-CoV-2 and potentially other spherical viruses, broadening the scope of antiviral treatments.

biophysics↗

bioRxiv2022

Targeting C5aR1 signaling reduced neutrophil extracellular traps and ameliorates COVID-19 pathology

Patients with severe COVID-19 develop acute respiratory distress syndrome (ARDS) that may progress to cytokine storm syndrome, organ dysfunction, and death. Considering that complement component 5a (C5a), through its cellular receptor C5aR1, has potent proinflammatory actions, and plays immunopathological roles in inflammatory diseases, we investigated whether C5a/C5aR1 pathway could be involved in COVID-19 pathophysiology. C5a/C5aR1 signaling increased locally in the lung, especially in neutrophils of critically ill COVID-19 patients compared to patients with influenza infection, as well as in the lung tissue of K18-hACE2 Tg mice (Tg mice) infected with SARS-CoV-2. Genetic and pharmacological inhibition of C5aR1 signaling ameliorated lung immunopathology in Tg-infected mice. Mechanistically, we found that C5aR1 signaling drives neutrophil extracellular trap (NET)s-dependent immunopathology. These data confirm the immunopathological role of C5a/C5aR1 signaling in COVID-19 and indicate that antagonist of C5aR1 could be useful for COVID-19 treatment.

immunology↗

bioRxiv2022

Targeting Neutrophils Extracellular Traps (NETs) reduces multiple organ injury in a COVID-19 mouse model

COVID-19 is characterized by severe acute lung injury, which is associated with neutrophils infiltration and release of neutrophil extracellular traps (NETs). COVID-19 treatment options are scarce. Previous work has shown an increase in NETs release in the lung and plasma of COVID-19 patients suggesting that drugs that prevent NETs formation or release could be potential therapeutic approaches for COVID-19 treatment. Here, we report the efficacy of NET-degrading DNase I treatment in a murine model of COVID-19. DNase I decreased detectable levels of NETs, improved clinical disease, and reduced lung, heart, and kidney injuries in SARS-CoV-2-infected K18-hACE2 mice. Furthermore, our findings indicate a potential deleterious role for NETs lung tissue in vivo and lung epithelial (A549) cells in vitro, which might explain part of the pathophysiology of severe COVID-19. This deleterious effect was diminished by the treatment with DNase I. Together, our results support the role of NETs in COVID-19 immunopathology and highlight NETs disruption pharmacological approaches as a potential strategy to ameliorate COVID-19 clinical outcomes.

pharmacology and toxicology↗

bioRxiv2020

The replication of the human respiratory syncytial virus in a T cell line has multiple ineffective steps

Human respiratory syncytial virus is the most frequent cause of severe respiratory disease in children. The main targets of HRSV infection are epithelial cells of the respiratory tract and the great majority of the studies regarding HRSV infection are done in respiratory cells. Recently, the interest on respiratory virus infection of lymphoid cells has been growing, but details of the interaction of HRSV with lymphoid cells remain unknown. Therefore, this study was done to assess the relationship of HRSV with A3.01 cells, a CD4+ T cell line. We found by flow cytometry and fluorescent focus assay that A3.01 cells are susceptible but virtually not permissive to HRSV infection. De-quenching experiments revealed that the fusion process of HRSV in A3.01 cells is reduced in comparison to HEp-2 cells, an epithelial cell lineage. Quantification of viral RNA by qPCR determined that the replication of HRSV in A3.01 cells was modest. Western blot and quantitative flow cytometry analyses demonstrated that the production of HRSV proteins in A3.01 was significantly lower than in HEp-2 cells. Additionally, we found by fluorescence in situ hybridization that the inclusion body-associated granules (IBAGs) are almost absent in HRSV inclusion bodies in A3.01 cells. We also assessed the intracellular trafficking of HRSV proteins and found that HRSV proteins co-localized partially with the secretory pathway in A3.01 cells, but these HRSV proteins and viral filaments are present only scarcely at the plasma membrane. HRSV infection of A3.01 CD4+ T cells is virtually unproductive as compared to HEp-2 cells, with virion production hampered by low fusion, hypofunctional inclusion bodies, altered trafficking of viral proteins to the plasma membrane.

microbiology↗

bioRxiv2020

Infection of human lymphomononuclear cells by SARS-CoV-2

Although SARS-CoV-2 severe infection is associated with a hyperinflammatory state, lymphopenia is an immunological hallmark, and correlates with poor prognosis in COVID-19. However, it remains unknown if circulating human lymphocytes and monocytes are susceptible to SARS-CoV-2 infection. In this study, SARS-CoV-2 infection of human peripheral blood mononuclear cells (PBMCs) was investigated both in vitro and in vivo. We found that in vitro infection of whole PBMCs from healthy donors was productive of virus progeny. Results revealed that monocytes, as well as B and T lymphocytes, are susceptible to SARS-CoV-2 active infection and viral replication was indicated by detection of double-stranded RNA. Moreover, flow cytometry and immunofluorescence analysis revealed that SARS-CoV-2 was frequently detected in monocytes and B lymphocytes from COVID-19 patients, and less frequently in CD4+T lymphocytes. The rates of SARS-CoV-2-infected monocytes in PBMCs from COVID-19 patients increased over time from symptom onset. Additionally, SARS-CoV-2-positive monocytes and B and CD4+T lymphocytes were detected by immunohistochemistry in post mortem lung tissue. SARS-CoV-2 infection of blood circulating leukocytes in COVID-19 patients may have important implications for disease pathogenesis, immune dysfunction, and virus spread within the host.

microbiology↗