Monocyte subset redistribution from blood to kidneys in patients with Puumala virus caused hemorrhagic fever with renal syndrome

Innate immune cells like monocytes patrol the vasculature and mucosal surfaces, recognize pathogens, rapidly redistribute to affected tissues and cause inflammation by secretion of cytokines. We previously showed that monocytes are reduced in blood but accumulate in the airways of patients with Puumala virus (PUUV) caused hemorrhagic fever with renal syndrome (HFRS). However, the dynamics of monocyte infiltration to the kidneys during HFRS, and its impact on disease severity are currently unknown. Here, we examined longitudinal peripheral blood samples and renal biopsies from HFRS patients and performed in vitro experiments to investigate the fate of monocytes during HFRS. During the early stages of HFRS, circulating CD14-CD16+ nonclassical monocytes (NCMs) that patrol the vasculature were reduced in most patients. Instead, CD14+CD16- classical (CMs) and CD14+CD16+ intermediate monocytes (IMs) were increased in blood, in particular in HFRS patients with more severe disease. Blood monocytes from patients with acute HFRS expressed higher levels of HLA-DR, the endothelial adhesion marker CD62L and the chemokine receptors CCR7 and CCR2, as compared to convalescence, suggesting monocyte activation and migration to peripheral tissues during acute HFRS. Supporting this hypothesis, increased numbers of HLA-DR+, CD14+, CD16+ and CD68+ cells were observed in the renal tissues of acute HFRS patients compared to controls. In vitro, blood CD16+ monocytes upregulated CD62L after direct exposure to PUUV whereas CD16- monocytes upregulated CCR7 after contact with PUUV-infected endothelial cells, suggesting differential mechanisms of activation and response between monocyte subsets. Together, our findings suggest that NCMs are reduced in blood, potentially via CD62L-mediated attachment to endothelial cells and monocytes are recruited to the kidneys during HFRS. Monocyte mobilization, activation and functional impairment together may influence the severity of disease in acute PUUV-HFRS. Author summary Hantaviruses are re-emerging human pathogens that can cause severe disease, typically manifesting in the lungs or kidneys. The virus preferentially infects the endothelial cells without killing them. Therefore, the vascular leakage associated with hantavirus disease, and hemorrhagic fever with renal syndrome (HFRS) is believed to be a consequence of the dysregulated immune response to infection. In the present study, in a cohort of PUUV-infected patients with acute HFRS, we describe a striking depletion of nonclassical monocytes from circulation while classical and intermediate monocyte frequencies are increased. Importantly, we found increased numbers of cells expressing monocyte and macrophage markers in the kidneys of patients with HFRS. The monocytes remaining in circulation show signs of activation, migration to the periphery and impairment in their ability to respond to TLR stimulation. Interestingly, the magnitude of monocyte activation was associated with greater disease severity. In addition, we also noted that different monocyte subsets differ in how they recognize and respond to cell-free or cell-associated hantavirus exposure. Collectively, our study greatly adds to what is currently known about how monocytes behave during human hantavirus disease, and highlights the importance of studying functional differences across the major monocyte subsets at greater resolution.Peer reviewe

Clinical grade ACE2 as a universal agent to block SARS-CoV-2 variants

The recent emergence of multiple SARS-CoV-2 variants has caused considerable concern due to both reduced vaccine efficacy and escape from neutralizing antibody therapeutics. It is, therefore, paramount to develop therapeutic strategies that inhibit all known and future SARS-CoV-2 variants. Here, we report that all SARS-CoV-2 variants analyzed, including variants of concern (VOC) Alpha, Beta, Gamma, Delta, and Omicron, exhibit enhanced binding affinity to clinical grade and phase 2 tested recombinant human soluble ACE2 (APN01). Importantly, soluble ACE2 neutralized infection of VeroE6 cells and human lung epithelial cells by all current VOC strains with markedly enhanced potency when compared to reference SARS-CoV-2 isolates. Effective inhibition of infections with SARS-CoV-2 variants was validated and confirmed in two independent laboratories. These data show that SARS-CoV-2 variants that have emerged around the world, including current VOC and several variants of interest, can be inhibited by soluble ACE2, providing proof of principle of a pan-SARS-CoV-2 therapeutic

Taxonomy of the order Bunyavirales : second update 2018

In October 2018, the order Bunyavirales was amended by inclusion of the family Arenaviridae, abolishment of three families, creation of three new families, 19 new genera, and 14 new species, and renaming of three genera and 22 species. This article presents the updated taxonomy of the order Bunyavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).Non peer reviewe

Pathology of Puumala hantavirus infection in macaques

Peer reviewe

2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.

In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV

Andes Hantavirus-Infection of a 3D Human Lung Tissue Model Reveals a Late Peak in Progeny Virus Production Followed by Increased Levels of Proinflammatory Cytokines and VEGF-A

Andes virus (ANDV) causes hantavirus pulmonary syndrome (HPS), a severe acute disease with a 40% case fatality rate. Humans are infected via inhalation, and the lungs are severely affected during HPS, but little is known regarding the effects of ANDV-infection of the lung. Using a 3-dimensional air-exposed organotypic human lung tissue model, we analyzed progeny virus production and cytokine-responses after ANDV-infection. After a 7-10 day period of low progeny virus production, a sudden peak in progeny virus levels was observed during approximately one week. This peak in ANDV-production coincided in time with activation of innate immune responses, as shown by induction of type I and III interferons and ISG56. After the peak in ANDV production a low, but stable, level of ANDV progeny was observed until 39 days after infection. Compared to uninfected models, ANDV caused long-term elevated levels of eotaxin-1, IL-6, IL-8, IP-10, and VEGF-A that peaked 20-25 days after infection, i.e., after the observed peak in progeny virus production. Notably, eotaxin-1 was only detected in supernatants from infected models. In conclusion, these findings suggest that ANDV replication in lung tissue elicits a late proinflammatory immune response with possible long-term effects on the local lung cytokine milieu. The change from an innate to a proinflammatory response might be important for the transition from initial asymptomatic infection to severe clinical disease, HPS

Andes Hantavirus-Infection of a 3D Human Lung Tissue Model Reveals a Late Peak in Progeny Virus Production Followed by Increased Levels of Proinflammatory Cytokines and VEGF-A

Andes virus (ANDV) causes hantavirus pulmonary syndrome (HPS), a severe acute disease with a 40% case fatality rate. Humans are infected via inhalation, and the lungs are severely affected during HPS, but little is known regarding the effects of ANDV-infection of the lung. Using a 3-dimensional air-exposed organotypic human lung tissue model, we analyzed progeny virus production and cytokine-responses after ANDV-infection. After a 7-10 day period of low progeny virus production, a sudden peak in progeny virus levels was observed during approximately one week. This peak in ANDV-production coincided in time with activation of innate immune responses, as shown by induction of type I and III interferons and ISG56. After the peak in ANDV production a low, but stable, level of ANDV progeny was observed until 39 days after infection. Compared to uninfected models, ANDV caused long-term elevated levels of eotaxin-1, IL-6, IL-8, IP-10, and VEGF-A that peaked 20-25 days after infection, i.e., after the observed peak in progeny virus production. Notably, eotaxin-1 was only detected in supernatants from infected models. In conclusion, these findings suggest that ANDV replication in lung tissue elicits a late proinflammatory immune response with possible long-term effects on the local lung cytokine milieu. The change from an innate to a proinflammatory response might be important for the transition from initial asymptomatic infection to severe clinical disease, HPS

Molecular Diagnosis of Hemorrhagic Fever with Renal Syndrome Caused by Puumala Virus

Rodent-borne hantaviruses cause two severe acute diseases: hemorrhagic fever with renal syndrome (HFRS) in Eurasia, and hantavirus pulmonary syndrome (HPS; also called hantavirus cardiopulmonary syndrome [HCPS]) in the Americas. Puumala virus (PUUV) is the most common causative agent of HFRS in Europe. Current routine diagnostic methods are based on serological analyses and can yield inconclusive results. Hantavirus-infected patients are viremic during the early phase of disease; therefore, detection of viral RNA genomes can be a valuable complement to existing serological methods. However, the high genomic sequence diversity of PUUV has hampered the development of molecular diagnostics, and currently no real-time reverse transcription- quantitative (RT)-PCR assay is available for routine diagnosis of HFRS. Here, we present a novel PUUV RT-PCR assay. The assay was validated for routine diagnosis of HFRS on samples collected in Sweden during the winter season from 2013 to 2014. The assay allowed detection of PUUV RNA in 98.7% of confirmed clinical HFRS samples collected within 8 days after symptomatic onset. In summary, this study shows that real-time RT-PCR can be a reliable alternative to serological tests during the early phase of HFRS

Serum Markers Associated with Severity and Outcome of Hantavirus Pulmonary Syndrome

BACKGROUND:Hantavirus pulmonary syndrome (HPS) is caused by Andes virus (ANDV) and related hantaviruses in the Americas. Despite a fatality rate of 40%, the pathogenesis of HPS is poorly understood and factors associated with severity, fatality and survival remain elusive.METHODS:Ninety-three ANDV-infected HPS patients, out of whom 34 had a fatal outcome, were retrospectively studied. Serum levels of cytokines and other inflammation-associated markers were analyzed using multiplex immunoassay and ELISA. Associations with disease severity, fatal outcome and survival were identified using logistic regression.RESULTS:HPS patients exhibited increased serum levels of markers associated with inflammation, intestinal damage and microbial translocation compared to controls. Patients with fatal outcome displayed higher levels of IL-6, IL-10, IFN-γ, sTRAIL, and intestinal fatty acid binding protein (I-FABP) than survivors. Levels of complement factor 5/5a were higher in survivors compared to fatal cases. IL-6 and I-FABP, the latter a marker for intestinal damage, were by multivariate analyses identified as independent markers associated with disease severity (odds ratio 2.25 95% CI 1.01-5.01) and fatal outcome (odds ratio 1.64 95% CI 1.01-2.64), respectively.CONCLUSIONS:HPS patients displayed a multifaceted, systemic inflammatory response, with IL-6 and I-FABP as independent markers of disease severity and fatality, respectively.Fil: Maleki, Kimia T. Center For Infectious Medicine, Department Of Medicine; SueciaFil: García, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Iglesias, Ayelén Aluminé. Direccion Nacional de Instituto de Investigacion. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Infecciosas. Departamento de Virologia; ArgentinaFil: Alonso, Daniel. Direccion Nacional de Instituto de Investigacion. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Infecciosas. Departamento de Virologia; ArgentinaFil: Ciancaglini, Matías. Direccion Nacional de Instituto de Investigacion. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Infecciosas. Departamento de Virologia; ArgentinaFil: Hammar, Ulf. Unit Of Biostatistics; SueciaFil: Ljunggren, Hans-Gustaf. Karolinska Huddinge Hospital; SueciaFil: Schierloh, Luis Pablo. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; ArgentinaFil: Martinez, Valeria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Klingstrom, Jonas. Direccion Nacional de Instituto de Investigacion. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Infecciosas. Departamento de Virologia; Argentin