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Ganaie, S.

Publications and source records attributed to Ganaie, S..

4 recordsLinked to original sources

Lrp1 facilitates infection of neurons by Jamestown Canyon virus

Jamestown Canyon virus (JCV) is a bunyavirus and arbovirus responsible for neuroinvasive disease in the United States. Little is known about JCV pathogenesis, and no host factors required for cellular infection have been identified. Recently, we identified low-density lipoprotein receptor related protein 1 (Lrp1) as a host entry factor for two other bunyaviruses Rift Valley fever virus (RVFV) and Oropouche virus (OROV). Here, we assessed the role of Lrp1 in mediating JCV cellular infection of neurons. Both neuronal and non-neuronal immortalized cell lines deficient for Lrp1 displayed reduction in infection with JCV, and early stages of infection such as binding and internalization were impacted by lack of Lrp1. In primary rat neurons, Lrp1 was highly expressed, and the neurons were highly permissive for JCV infection. Treatment of primary neurons with recombinant receptor-associated protein (RAP), a high affinity ligand for Lrp1, resulted in reduced infectivity with JCV. In addition, pretreatment of cells with RVFV Gn inhibited JCV infection, suggesting that the two viruses may share overlapping binding sites. These results provide compelling evidence that Lrp1 is an important cellular factor for efficient infection by JCV, and thus multiple bunyaviruses with varying clinical manifestations and tissue tropism are facilitated by the host cell Lrp1. Reliance of multiple bunyaviruses on Lrp1 makes it a promising target for pan-bunyaviral antivirals and therapeutics.

microbiology↗

Oropouche orthobunyavirus infection is mediated by the cellular host factor Lrp1

Oropouche orthobunyavirus (OROV; Peribunyaviridae) is a mosquito-transmitted virus that causes widespread cases of human febrile illness in South America, with occasional progression to neurologic effects. Host entry factors mediating cellular entry of OROV are undefined. Here, we show that OROV requires the host protein low density lipoprotein-related protein 1 (Lrp1) for cellular infection. Cells from evolutionarily distinct species lacking Lrp1 were less permissive to OROV infection than cells with Lrp1. Treatment of cells with either the high-affinity Lrp1 ligand receptor-associated protein (RAP) or recombinant ectodomain truncations of Lrp1 significantly reduced OROV infection. Thus, Lrp1 is an important host factor required for infection of cells by OROV. Taken together with our results showing that Lrp1 is a newly identified receptor for Rift Valley fever virus (RVFV), Lrp1 may play a broader role in cellular infection by bunyaviruses than previously appreciated.

microbiology↗

Tetravalent SARS-CoV-2 Neutralizing Antibodies Show Enhanced Potency and Resistance to Escape Mutations

Neutralizing antibodies (nAbs) hold promise as effective therapeutics against COVID-19. Here, we describe protein engineering and modular design principles that have led to the development of synthetic bivalent and tetravalent nAbs against SARS-CoV-2. The best nAb targets the host receptor binding site of the viral S-protein and its tetravalent versions can block entry with a potency that exceeds the bivalent nAbs by an order of magnitude. Structural studies show that both the bivalent and tetravalent nAbs can make multivalent interactions with a single S-protein trimer, observations consistent with the avidity and potency of these molecules. Significantly, we show that the tetravalent nAbs show much increased tolerance to potential virus escape mutants. Bivalent and tetravalent nAbs can be produced at large-scale and are as stable and specific as approved antibody drugs. Our results provide a general framework for developing potent antiviral therapies against COVID-19 and related viral threats, and our strategy can be readily applied to any antibody drug currently in development.

synthetic biology↗

Synthetic Antibodies neutralize SARS-CoV-2 infection of mammalian cells

Coronaviruses (CoV) are a large family of enveloped, RNA viruses that circulate in mammals and birds. Three highly pathogenic strains have caused zoonotic infections in humans that result in severe respiratory syndromes including the Middle East Respiratory Syndrome CoV (MERS), Severe Acute Respiratory Syndrome CoV (SARS), and the ongoing Coronavirus Disease 2019 (COVID-19) pandemic. Here, we describe a panel of synthetic monoclonal antibodies, built on a human IgG framework, that bind to the spike protein of SARS-CoV-2 (the causative agent of COVID-19), compete for ACE2 binding, and potently inhibit SARS-CoV-2. All antibodies that exhibited neutralization potencies at sub-nanomolar concentrations against SARS-CoV-2/USA/WA1 in Vero E6 cells, also bound to the receptor binding domain (RBD), suggesting competition for the host receptor ACE2. These antibodies represent strong immunotherapeutic candidates for treatment of COVID-19.

biochemistry↗