Biology subjects

Manuelyan, I.

Publications and source records attributed to Manuelyan, I..

4 recordsLinked to original sources

bioRxiv2026

Novel approaches to quantify defective interfering particle activity reveal a surrogate marker of interference in mammarenaviruses

Defective interfering particles (DIPs) profoundly influence viral replication and host responses yet it remains difficult to quantify their activity routinely in the laboratory. Here, using lymphocytic choriomeningitis virus (LCMV) as a model mammarenavirus, we establish complementary approaches for measuring interfering activity of DIPs across a range of experimental scales. First, we optimized plaque- and focus-based interference assays that directly quantify DIP-mediated suppression of standard infectious virus replication through a modified neutralization assay. Second, in cell monolayers saturated with both DIPs and infectious particles, we identified a complete loss of expression of the viral glycoprotein and matrix protein, which are each encoded in the positive-sense orientation of the mammarenavirus genome. Notably, this loss of protein expression mirrors the inhibition of plaque formation traditionally seen in this high DIP setting. The observed DIP-mediated loss of glycoprotein expression is a surrogate marker of interference and was used to develop an alternative assay of DIP activity. This glycoprotein expression assay recapitulated interference detected in traditional high-titer plaque assays (i.e. loss of plaques when all cells are saturated with DIPs and infectious particles) while substantially increasing scalability. These approaches enable sensitive and scalable quantification of DIP activity for LCMV as well as Junin virus and expand our experimental toolkit for studying arenavirus population dynamics, pathogenesis and immunity, and may help advance DIP-based antiviral strategies. This study also provides mechanistic details on how mammarenavirus DIPs interfere with infectious virus propagation.

microbiology↗

bioRxiv2026

Development and validation of two economical and flexible immunoassays for detecting antibodies against LCMV in mouse serum

Measurement of antibody responses to viral infection is essential for surveillance, diagnostics, epidemiological research, and natural history of infection studies. However, current methods to detect virus-specific antibodies are often resource-intensive and impractical for deployment in outbreak settings or in field-based studies. This manuscript presents two economical, high-throughput immunoassays--the cytoblot immunoassay (CBA) and strip immunoblot assay (SIA)--for detecting and quantifying anti-lymphocytic choriomeningitis mammarenavirus (LCMV) antibodies in mouse serum. To validate, we tested serum from acutely or persistently experimentally infected mice. Both assays detected LCMV-specific IgG and IgM antibodies with high sensitivity and specificity across multiple timepoints. By facilitating the study of immune responses in rodent reservoirs, these tools can enhance our understanding of zoonotic viral transmission, provide scalable platforms for outbreak preparedness, and serve as adaptable models for the development of rapid serological assays for other viral pathogens.

microbiology↗

bioRxiv2025

Specific and versatile monoclonal antibodies for hantavirus research

Rodent-borne hantaviruses pose a continual public health threat to humans through zoonotic transmission, with case fatality rates of up to 50% in some cases. Human infections can lead to hemorrhagic fever with renal syndrome (HFRS) or hantavirus cardio-pulmonary syndrome (HCPS), depending on the viral species. Despite the morbidity and mortality associated with this family of viruses, no anti-viral therapeutics or vaccines are available to treat and prevent hantavirus disease. The relative shortage of commercially available reagents to study hantavirus infections in vitro and in vivo likely contributes to the challenges in developing viral countermeasures. This report describes the generation of a panel of mouse monoclonal antibodies that collectively recognize the four viral proteins of Seoul virus (Orthohantavirus seoulense), an Old World hantavirus with worldwide distribution and the causative agent of HFRS. We have validated the specificity and versatility of these antibodies against a subset of Old World and New World hantaviruses in assays relying on antigen recognition in denatured or native conformations. We present several antibodies that specifically recognize the Seoul virus nucleoprotein and polymerase protein in Western blotting and immunostaining assays. We also identified three novel antibodies directed against the glycoprotein complex that are capable of binding to the N-terminal glycoprotein of all hantaviruses tested. These antibodies are freely available to all hantavirus researchers to add to the small, but growing, collection of reliable and available reagents to be used to study hantavirus biology, identify novel antiviral compounds, and measure viral prevalence in the laboratory and the field. ImportancePathogenic hantaviruses cause severe hemorrhagic disease and pose a significant public health threat world-wide. Insufficient research into the biology of these viruses has slowed the development of effective direct-acting antivirals and vaccines. Here, we describe the generation and validation of novel, specific monoclonal antibodies for the detection of Seoul virus proteins in vitro. These reagents can be used to fill in critical gaps in knowledge regarding hantavirus entry, protein expression, and particle generation.

microbiology↗

bioRxiv2021

A global map of the Zika virus phosphoproteome reveals host-driven regulation of viral budding

Flaviviruses are enveloped, positive-strand RNA viruses that cause millions of infections in the human population annually. Although Zika virus (ZIKV) had been detected in humans as early as the 1950s, its reemergence in South America in 2015 resulted in a global health crisis. While flaviviruses encode 10 proteins that can be post-translationally modified by host enzymes, little is known regarding post-translational modifications (PTMs) of the flavivirus proteome. We used mass spectrometry to comprehensively identify host-driven PTMs on the ZIKV proteome. This approach allowed us to identify 43 PTMs across 8 ZIKV proteins, including several that are highly conserved within the Flavivirus genus. Notably, we found two phosphosites on the ZIKV envelope protein that are functionally important for viral propagation. Both appear to regulate viral budding, while one also impacts ZIKV cytopathogenicity. Additionally, we discovered host kinases that interact with ZIKV proteins and determined that Bosutinib--an FDA-approved tyrosine kinase inhibitor that targets some of these host kinases--impairs ZIKV growth, in part by blocking phosphorylation of a tyrosine residue on the envelope protein. Thus, we have defined a high-resolution map of host-driven PTMs on ZIKV proteins as well as cellular interacting kinases, uncovered novel mechanisms of host driven-regulation of ZIKV budding and cytopathogenicity, and identified an FDA-approved inhibitor of ZIKV growth.

microbiology↗