Last data update: Sep 16, 2024. (Total: 47680 publications since 2009)
Records 1-5 (of 5 Records) |
Query Trace: Realegeno S [original query] |
---|
Identification of Human Monkeypox Virus Genome Deletions That Impact Diagnostic Assays.
Garrigues JM , Hemarajata P , Lucero B , Alarcón J , Ransohoff H , Marutani AN , Kim M , Marlowe EM , Realegeno SE , Kagan RM , Montero CI , Chen NFG , Grubaugh ND , Vogels CBF , Green NM . J Clin Microbiol 2022 60 (12) e0165522 In August 2022, the Los Angeles County Department of Public Health initiated an investigation into human monkeypox virus (MPXV) cases with unusual results from a multiplex laboratory-developed test used by Quest Diagnostics, which is based on the CDC nonvariola Orthopoxvirus (NVO) (1) and MPXV clade II (MPXV-WA) (2) real-time PCR assays. These specimens returned NVO–positive and either MPXV-WA–negative or positive results with high Ct values, which differ from the strong dual-positive results typically associated with the current outbreak. Since these patients met the case definition for probable human MPXV infection, (3) these discordant results were presumed to be due to a mutation affecting the performance of the MPXV-WA assay. |
Conserved Oligomeric Golgi (COG) Complex Proteins Facilitate Orthopoxvirus Entry, Fusion and Spread.
Realegeno S , Priyamvada L , Kumar A , Blackburn JB , Hartloge C , Puschnik AS , Sambhara S , Olson VA , Carette JE , Lupashin V , Satheshkumar PS . Viruses 2020 12 (7) Although orthopoxviruses (OPXV) are known to encode a majority of the genes required for replication in host cells, genome-wide genetic screens have revealed that several host pathways are indispensable for OPXV infection. Through a haploid genetic screen, we previously identified several host genes required for monkeypox virus (MPXV) infection, including the individual genes that form the conserved oligomeric Golgi (COG) complex. The COG complex is an eight-protein (COG1-COG8) vesicle tethering complex important for regulating membrane trafficking, glycosylation enzymes, and maintaining Golgi structure. In this study, we investigated the role of the COG complex in OPXV infection using cell lines with individual COG gene knockout (KO) mutations. COG KO cells infected with MPXV and vaccinia virus (VACV) produced small plaques and a lower virus yield compared to wild type (WT) cells. In cells where the KO phenotype was reversed using a rescue plasmid, the size of virus plaques increased demonstrating a direct link between the decrease in viral spread and the KO of COG genes. KO cells infected with VACV displayed lower levels of viral fusion and entry compared to WT suggesting that the COG complex is important for early events in OPXV infection. Additionally, fewer actin tails were observed in VACV-infected KO cells compared to WT. Since COG complex proteins are required for cellular trafficking of glycosylated membrane proteins, the disruption of this process due to lack of individual COG complex proteins may potentially impair the virus-cell interactions required for viral entry and egress. These data validate that the COG complex previously identified in our genetic screens plays a role in OPXV infection. |
An ELISA-based method for detection of rabies virus nucleoprotein-specific antibodies in human antemortem samples
Realegeno S , Niezgoda M , Yager PA , Kumar A , Hoque L , Orciari L , Sambhara S , Olson VA , Satheshkumar PS . PLoS One 2018 13 (11) e0207009 Rabies is a fatal encephalitic disease in humans and animals caused by lyssaviruses, most commonly rabies virus (RABV). Human antemortem diagnosis of rabies is a complex process involving multiple sample types and tests for the detection of antibodies, antigen (protein), and nucleic acids (genomic RNA). Serological diagnosis of human rabies includes the detection of either neutralizing or binding antibodies in the cerebrospinal fluid (CSF) or serum samples from unimmunized individuals without prior rabies vaccination or passive immunization with purified immunoglobulins. While neutralizing antibodies are targeted against the surface-expressed glycoprotein (G protein), binding antibodies to viral antigens are predominantly against the nucleoprotein (N protein), although there can be antibodies against all RABV-expressed proteins. To determine N protein-specific antibody responses in the CSF and serum during RABV infection, we developed an enzyme-linked immunosorbent assay (ELISA) with purified recombinant N protein expressed in E. coli. N protein-specific immunoglobulin (Ig) subtypes IgG and IgM were detected in the CSF or serum of previously diagnosed human rabies cases. In addition, anti-N protein seroconversion was demonstrated over the course of illness in individual rabies cases. We compared the N protein ELISA results to those of an indirect fluorescent antibody (IFA) test, the current binding antibody assay used in diagnosis, and show that our ELISA is consistent with the IFA test. Sensitivity and specificity of the N protein ELISA ranged from 78.38-100% and 75.76-96.77% with respect to the IFA results. Our data provide evidence for the use of an N protein ELISA as an additional option for the detection of RABV-specific IgG or IgM antibodies in human CSF or serum specimens. |
Suppression of poxvirus replication by resveratrol
Cao S , Realegeno S , Pant A , Satheshkumar PS , Yang Z . Front Microbiol 2017 8 2196 Poxviruses continue to cause serious diseases even after eradication of the historically deadly infectious human disease, smallpox. Poxviruses are currently being developed as vaccine vectors and cancer therapeutic agents. Resveratrol is a natural polyphenol stilbenoid found in plants that has been shown to inhibit or enhance replication of a number of viruses, but the effect of resveratrol on poxvirus replication is unknown. In the present study, we found that resveratrol dramatically suppressed the replication of vaccinia virus (VACV), the prototypic member of poxviruses, in various cell types. Resveratrol also significantly reduced the replication of monkeypox virus, a zoonotic virus that is endemic in Western and Central Africa and causes human mortality. The inhibitory effect of resveratrol on poxviruses is independent of VACV N1 protein, a potential resveratrol binding target. Further experiments demonstrated that resveratrol had little effect on VACV early gene expression, while it suppressed VACV DNA synthesis, and subsequently post-replicative gene expression. |
Monkeypox virus host factor screen in haploid cells identifies essential role of GARP complex in extracellular virus formation.
Realegeno S , Puschnik AS , Kumar A , Goldsmith C , Burgado J , Sambhara S , Olson VA , Carroll D , Damon I , Hirata T , Kinoshita T , Carette JE , Satheshkumar PS . J Virol 2017 91 (11) Monkeypox virus (MPXV) is a human pathogen that is a member of the Orthopoxvirus genus, which includes Vaccinia virus and Variola virus (the causative agent of smallpox). Human monkeypox is considered an emerging zoonotic infectious disease. To identify host factors required for MPXV infection, we performed a genome-wide insertional mutagenesis screen in human haploid cells. The screen revealed several candidate genes, including those involved in Golgi trafficking, glycosaminoglycan biosynthesis and glycosylphosphatidylinositol (GPI) - anchor biosynthesis. We validated the role of a set of vacuolar protein sorting (VPS) genes during infection, VPS51-54, which comprise the Golgi-associated retrograde protein (GARP) complex. The GARP complex is a tethering complex involved in retrograde transport of endosomes to the trans-Golgi apparatus. Our data demonstrate that VPS52 and VPS54 were dispensable for mature virus (MV) production but were required for extracellular virus (EV) formation. For comparison, a known antiviral compound, ST-246, was used in our experiments demonstrating that EV titers in VPS52 and VPS54 knockout (KO) cells were comparable to levels exhibited by ST-246 treated wildtype cells. Confocal microscopy was used to examine actin tail formation, one of the viral egress mechanisms for cell-to-cell dissemination, and revealed an absence of actin tails in VPS52KO or VPS54KO infected cells. Further evaluation of these cells by electron microscopy demonstrated a decrease in wrapped viruses (WV) compared to wild type control. Collectively, our data demonstrate the role of GARP complex genes in double-membrane wrapping of MV necessary for EV formation, implicating the host endosomal trafficking pathway in orthopoxvirus infection.IMPORTANCE Human monkeypox is an emerging zoonotic infectious disease caused by Monkeypox virus (MPXV). Of the two MPXV clades, the Congo Basin strain is associated with severe disease, higher mortality, and increased human-to-human transmission relative to the West African strain. Monkeypox is endemic to regions of western and central Africa but was introduced into the United States in 2003 from the importation of infected animals. The threat of MPXV and other orthopoxviruses is increasing due to the absence of routine smallpox vaccination leading to a higher proportion of naive populations. In this study, we have identified and validated candidate genes that are required for MPXV infection, specifically the Golgi-associated retrograde protein (GARP) complex. Identifying host targets required for infection that prevents extracellular virus formation such as the GARP complex or the retrograde pathway can provide a potential target for anti-viral therapy. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Sep 16, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure