Lack of evidence on SARS-CoV-2 transmission dynamics has led to shifting isolation guidelines between airborne and droplet isolation precautions. During the initial isolation of 13 individuals confirmed positive with COVID-19 infection, air and surface samples were collected in eleven isolation rooms to examine viral shedding from isolated individuals. While all individuals were confirmed positive for SARS-CoV-2, symptoms and viral shedding to the environment varied considerably. Many commonly used items, toilet facilities, and air samples had evidence of viral contamination, indicating that SARS-CoV-2 is shed to the environment as expired particles, during toileting, and through contact with fomites. Disease spread through both direct (droplet and person-to-person) as well as indirect contact (contaminated objects and airborne transmission) are indicated, supporting the use of airborne isolation precautions. One Sentence Summary: SARS-CoV-2 is shed during respiration, toileting, and fomite contact, indicating that infection may occur in both direct and indirect contact.

Ebola virus (EBOV) is a filovirus that has become a global public health threat in recent years. EBOV is the causative agent of a severe, often fatal hemorrhagic fever. A productive viral infection relies on the successful recruitment of host factors for various stages of the viral life cycle. To date, several investigations have discovered specific host-pathogen interactions for various EBOV proteins. However, relatively little is known about the EBOV nucleoprotein (NP) with regard to host interactions. In the present study, we aimed to elucidate NP-host protein-protein interactions (PPIs). Affinity purification-mass spectrometry (AP-MS) was used to identify candidate NP cellular interactors. Candidate interactors RUVBL1 and RUVBL2, partner proteins belonging to the AAA+ (ATPases Associated with various cellular Activities) superfamily, were confirmed to interact with NP in co-immunoprecipitation (co-IP) and immunofluorescence (IF) experiments. Functional studies using a minigenome system revealed that the siRNA-mediated knockdown of RUVBL1 but not RUVBL2 moderately decreased EBOV minigenome activity. Super resolution structured illumination microscopy (SIM) was used to identify an association between NP and components of the R2TP complex, which includes RUVBL1, RUVBL2, RPAP3, and PIH1D1, suggesting a potential role for the R2TP complex in capsid formation. Moreover, the siRNA-mediated knockdown of RPAP3 and subsequent downregulation of PIH1D1 was shown to have no effect on minigenome activity, further suggesting a role in capsid formation. Overall, we identify RUVBL1 and RUVBL2 as novel interactors of EBOV NP and for the first time report EBOV NP recruitment of the R2TP complex, which may provide novel targets for broad-acting anti-EBOV therapeutics.

Nearly 4 billion people worldwide reside in dengue virus (DENV) endemic areas. Primary dengue infection generates both type-specific and cross-reactive immunity. While serotype-specific immunity provides long-term protection against homologous virus challenge, cross-reactive immunity is short-lived and, upon subsequent heterotypic exposure, can increase the risk of severe clinical outcomes. Therefore, it is critical to measure type-specific immunity. The current resource-intensive and technically demanding approach of removing antibodies using purified whole virions and subsequently assessing type-specific immunity through neutralization assays is practical only for small-scale studies. We developed a novel, straightforward method that uses transfected suspension cells stably expressing DENV non-structural protein 1 (NS1) de novo to selectively deplete targeted serotype-specific and cross-reactive NS1 antibodies from plasma and serum samples. The same cell lines are then used to establish an antibody profile of the depleted plasma to uncover type-specific serotype exposure history. This approach to antibody depletion offers several advantages over column- and bead-based depletion methods, such as (i) ease of antigenic substrate production; (ii) simplicity of the depletion procedure; and (iii) interpretability of the data. IMPORTANCE: Accurately determining dengue serotype exposure remains challenging because current serotyping methods are labor-intensive, costly, and often rely on engineered viral antigens or antibodies to capture native immune components. We developed a streamlined approach that removes NS1-specific antibodies from dengue convalescent plasma using transfected cells that express NS1 de novo . This procedure enables the characterization of the depleted sample for the antibodies left behind to understand the relative levels of different antibody specificities and uncover an individual’s dengue exposure history. The knowledge of viral antigen-antibody profiles refines the interpretation of downstream functional assays and establishes a practical framework for dissecting dengue immunity with greater precision.