Biology subjects

Moscona, A.

Publications and source records attributed to Moscona, A..

3 recordsLinked to original sources

bioRxiv2021

Measles fusion complexes from central nervous system clinical isolates: decreased interaction between hemagglutinin and fusion proteins

Measles virus (MeV) viral entry is mediated by a fusion complex comprised of a receptor binding protein (hemagglutinin, H) and a fusion protein (F). The wild type H/F complex requires interaction with specific proteinaceous receptors (CD150/SLAM and nectin-4) in order to be activated. In contrast the H/F complexes isolated from viruses infecting the central nervous system (CNS) do not require a specific receptor. A single amino acid change in the F protein (L454W) was previously identified in two patients with lethal sequelae of MeV CNS infection, and the F bearing this mutation mediates fusion even without the H protein. We show here that viruses bearing the L454W fusion complex are less efficient than wt virus at targeting receptor expressing cells and that this defect is associated with a decreased interaction between the H and the F proteins. ImportanceMeasles (Mev) infection can cause serious complications including measles inclusion body encephalitis (MIBE) and subacute sclerosing panencephalitis (SSPE). MIBE and SSPE are relatively rare but lethal. We have shown that the fusion complex of CNS adapted clinical samples can spread in the absence of known receptor. We now provide evidence that HRC mutations leading to CNS adaptation come at a cost to the efficiency of viral entry. One Sentence SummaryMeasles CNS adapted fusion complexes have altered H/F interaction.

microbiology↗

bioRxiv2021

Engineering protease-resistant peptides to inhibit human parainfluenza viral respiratory infection

The lower respiratory tract infections affecting children worldwide are in large part caused by the parainfluenza viruses (HPIVs), particularly HPIV3, along with human metapneumovirus and respiratory syncytial virus, enveloped negative-strand RNA viruses. There are no vaccines for these important human pathogens, and existing treatments have limited or no efficacy. Infection by HPIV is initiated by viral glycoprotein-mediated fusion between viral and host cell membranes. A viral fusion protein (F), once activated in proximity to a target cell, undergoes a series of conformational changes that first extend the trimer subunits to allow insertion of the hydrophobic domains into the target cell membrane, and then refold the trimer into a stable postfusion state, driving the merger of the viral and host cell membranes. Lipopeptides derived from the C-terminal heptad repeat (HRC) domain of HPIV3 F inhibit infection by interfering with the structural transitions of the trimeric F assembly. Clinical application of this strategy, however, requires improving the in vivo stability of antiviral peptides. We show that the HRC peptide backbone can be modified via partial replacement of -amino acid residues with {beta}-amino acid residues to generate /{beta}-peptides that retain antiviral activity but are poor protease substrates. Relative to a conventional -lipopeptide, our best /{beta}-lipopeptide exhibits improved persistence in vivo and improved anti-HPIV3 antiviral activity in animals.

microbiology↗

bioRxiv2020

In vivo antiviral host response to SARS-CoV-2 by viral load, sex, and age

Despite limited genomic diversity, SARS-CoV-2 has shown a wide range of clinical manifestations in different patient populations. The mechanisms behind these host differences are still unclear. Here, we examined host response gene expression across infection status, viral load, age, and sex among shotgun RNA-sequencing profiles of nasopharyngeal swabs from 430 individuals with PCR-confirmed SARS-CoV-2 and 54 negative controls. SARS-CoV-2 induced a strong antiviral response with upregulation of antiviral factors such as OAS1-3 and IFIT1-3, and Th1 chemokines CXCL9/10/11, as well as a reduction in transcription of ribosomal proteins. SARS-CoV-2 culture in human airway epithelial cultures replicated the in vivo antiviral host response. Patient-matched longitudinal specimens (mean elapsed time = 6.3 days) demonstrated reduction in interferon-induced transcription, recovery of transcription of ribosomal proteins, and initiation of wound healing and humoral immune responses. Expression of interferon-responsive genes, including ACE2, increased as a function of viral load, while transcripts for B cell-specific proteins and neutrophil chemokines were elevated in patients with lower viral load. Older individuals had reduced expression of Th1 chemokines CXCL9/10/11 and their cognate receptor, CXCR3, as well as CD8A and granzyme B, suggesting deficiencies in trafficking and/or function of cytotoxic T cells and natural killer (NK) cells. Relative to females, males had reduced B and NK cell-specific transcripts and an increase in inhibitors of NF-{kappa}B signaling, possibly inappropriately throttling antiviral responses. Collectively, our data demonstrate that host responses to SARS-CoV-2 are dependent on viral load and infection time course, with observed differences due to age and sex that may contribute to disease severity.

microbiology↗