Biology subjects

McVoy, M. A.

Publications and source records attributed to McVoy, M. A..

3 recordsLinked to original sources

bioRxiv2025

Replication-Deficient Whole-Virus Vaccines Against Cytomegalovirus Induce Protective Immunity in a Guinea Pig Congenital Infection Model

Vaccines are needed to prevent congenital cytomegalovirus (CMV) infections. This study used the guinea pig cytomegalovirus (GPCMV) model to examine replication-deficient whole-virus vaccines against maternal viremia and congenital infection. Two recombinant GPCMVs, GP51-DD and GP52-DD, were engineered with destabilization domains fused to essential viral late proteins GP51 and GP52. These viruses, predicted to replicate in the presence of the synthetic ligand Shield-1 but not in its absence, were evaluated for Shield-1-dependence in vitro and for safety, immunogenicity, and efficacy in a pregnancy/challenge model. GP52-DD was profoundly Shield-1-dependent, producing no detectable infectious progeny in its absence. In contrast, the replication of GP51-DD was delayed in the absence of Shield-1, but the virus reached similar peak titers with or without the compound. GPCMV-seronegative guinea pigs received two subcutaneous injections of placebo (sham-immunized), GP51-DD, GP52-DD, or wild-type GPCMV (WT-GPCMV). DNAemia post-vaccination was detected in only one of 14 dams in each of the GP51-DD- and GP52-DD-immunized groups compared to 10/10 control animals immunized with WT-GPCMV, confirming the recombinant viruses were attenuated. GPCMV-specific antibody responses were similar in all three vaccinated groups. When immunized dams were bred and challenged with virulent GPCMV, DNAemia was detected in all sham-immunized controls and in 44% of GP52-DD-immunized dams (at significantly reduced levels) but was absent in dams immunized with GP51-DD or WT-GPCMV. Notably, immunization with GP52-DD, GP51-DD, or WT-GPCMV significantly reduced congenital GPCMV transmission (protective efficacies of 89%, 94%, and 100%, respectively). Thus, the replication-deficient GP52-DD vaccine was attenuated and protected against intrauterine GPCMV transmission. ImportanceCongenital cytomegalovirus (CMV) infections could be prevented by a vaccine, but most of the vaccine designs that have advanced to clinical trials have been subunit vaccines. These viral envelope glycoprotein-targeting designs have not yielded an effective vaccine that provides durable immunity. A vaccine that confers immune responses to a broader repertoire of viral immunogens, such as vaccines based on the whole virus, could enhance protection. However, there are concerns about the safety of live attenuated CMV vaccines. Using the guinea pig/guinea pig cytomegalovirus model of congenital infection, this study demonstrates that two replication-deficient whole virus vaccines are attenuated in animals while also being highly immunogenic, providing protective immunity against maternal viremia and fetal infection at levels similar to that conferred by a wild-type virus.

immunology↗

bioRxiv2020

Human Cytomegalovirus Drives WDR5 to the Virion Assembly Compartment to Facilitate Virion Assembly

We previously reported that human cytomegalovirus (HCMV) utilizes the cellular protein WDR5 to facilitate capsid nuclear egress. Here, we further show that HCMV infection drives WDR5 to the perinuclear region by a mechanism that requires viral replication and intact microtubules. WDR5 accumulated in the virion assembly compartment (vAC) and co-localized with vAC markers of gamma-tubulin ({gamma}-tubulin), early endosomes, and viral vAC marker proteins pp65, pp28, and glycoprotein B (gB). WDR5 interacted with multiple virion proteins, including MCP, pp150, pp65, pIRS1, and pTRS1, which may explain the increasing WDR5 accumulation in the vAC during infection. WDR5 was then incorporated into HCMV virions and localized to the tegument layer, as demonstrated by fractionation and immune-gold electron microscopy. Thus, WDR5 is driven to the vAC and incorporated into virions, suggesting that WDR5 facilitates HCMV replication at later stage of virion assembly besides the capsid nuclear egress stage. These data highlight that WDR5 is a potential target for antiviral therapy. ImportanceHuman cytomegalovirus (HCMV) has a large (~235-kb) genome that contains over 170 ORFs and exploits numerous cellular factors to facilitate its replication. In the late phase of HCMV infection cytoplasmic membranes are profoundly reconfigured to establish the virion assembly compartment (vAC), which is important for efficient assembly of progeny virions. We previously reported that WDR5 promotes HCMV nuclear egress. Here, we show that WDR5 is further driven to the vAC and incorporated into virions, perhaps to facilitate efficient virion maturation. This work identified potential roles for WDR5 in HCMV replication in the cytoplasmic stages of virion assembly. Taken together, WDR5 plays a critical role in HCMV capsid nuclear egress and is important for virion assembly, and thus is a potential target for antiviral treatment of HCMV-associated diseases.

pathology↗

bioRxiv2018

Single-cell transcriptome analysis of CD34+ stem cell-derived myeloid cells identifies a CFU-GEMM-like population permissive to human cytomegalovirus infection.

Myeloid cells are important sites of lytic and latent infection by human cytomegalovirus (CMV). We previously showed that only a small subset of myeloid cells differentiated from CD34+ hematopoietic stem cells is permissive to CMV replication, underscoring the heterogeneous nature of these populations. The exact identity of susceptible and resistant cell types, and the cellular features characterizing permissive cells, however, could not be dissected using averaging transcriptional analysis tools such as microarrays and, hence, remained enigmatic. Here, we profile the transcriptomes of [~] 7000 individual cells at day one post-infection using the 10X genomics platform. We show that viral transcripts are detectable in the majority of the cells, suggesting that virion entry is unlikely to be the main target of cellular restriction mechanisms. We further show that viral replication occurs in a small but specific sub-group of cells transcriptionally related to, and likely derived from, a cluster of cells expressing markers of Colony Forming Unit - Granulocyte, Erythrocyte, Monocyte, Megakaryocyte (CFU-GEMM) oligopotent progenitors. Compared to the remainder of the population, CFU-GEMM cells are enriched in transcripts with functions in mitochondrial energy production, cell proliferation, RNA processing and protein synthesis, and express similar or higher levels of interferon-related genes. While expression levels of the former are maintained in infected cells, the latter are strongly down-regulated. We thus propose that the preferential infection of CFU-GEMM cells may be due to the presence of a pre-established pro-viral environment, requiring minimal optimization efforts from viral effectors, rather than to the absence of specific restriction factors. Together, these findings identify a potentially new population of myeloid cells susceptible to CMV replication, and provide a possible rationale for their preferential infection.\n\nAUTHOR SUMMARYMyeloid cells such as monocytes and dendritic cells are critical targets of CMV infection. To identify the cellular factors that confer susceptibility or resistance to infection, we profiled the transcriptomes of [~] 7,000 single cells from a population of semi-permissive myeloid cells infected with CMV. We found that viral RNAs are detectable in the majority of the cells, but that marked expression of CMV lytic genes occurs in only a small subset of cells transcriptionally related to a cluster of CFU-GEMM progenitors that express similar amounts of transcripts encoding interferon-related anti-viral factors as the rest of the population but higher levels of transcripts encoding proteins required for energy, RNA, and protein production. We thus conclude that the preferential infection of CFU-GEMM cells might be due to the pre-existing presence of an intracellular environment conducive to infection onset, rather than to the absence of anti-viral factors restricting viral entry or initial gene expression. Together, these findings uncover a new type of myeloid cells potentially permissive to CMV infection, expand our understanding of the cellular requirements for successful initiation of CMV infection, and provide new pro- and anti-viral gene candidates for future analyses and therapeutic interventions.

microbiology↗