Biology subjects

Bator, C. M.

Publications and source records attributed to Bator, C. M..

3 recordsLinked to original sources

bioRxiv2020

Mechanisms of antibody binding revealed by asymmetric Fab-virus complexes

Overlap on the surface of parvovirus capsids between the antigenic epitope and the receptor binding site contributes to species jumping. Mab 14 strongly binds and neutralizes canine, but not feline parvovirus. The high resolution map of the canine parvovirus capsid complexed with Fab 14 was used to solve local structures of the Fab-bound and -unbound antigenic sites extracted from the same complex. The subsequent analysis includes a new method for using cryo EM to investigate complementarity of antibody binding.

microbiology↗

bioRxiv2020

High resolution cryo EM analysis of HPV16 identifies minor structural protein L2 and describes capsid flexibility

Human papillomavirus (HPV) is a significant health burden and leading cause of virus-induced cancers. HPV is epitheliotropic and its replication is tightly associated with terminal keratinocyte differentiation making production and purification of high titer virus preparations for research problematic, therefore alternative HPV production methods have been developed for virological and structural studies. In this study we use HPV16 quasivirus, composed of HPV16 L1/L2 capsid proteins with a packaged cottontail rabbit papillomavirus genome. We have achieved the first high resolution, 3.1[A], structure of HPV16 by using a local subvolume refinement approach. The high resolution enabled us to build L1 unambiguously and identify L2 protein strands. The L2 density is incorporated adjacent to conserved L1 residues on the interior of the capsid. Further interpretation with our own software for Icosahedral Subvolume Extraction and Correlated Classification (ISECC) revealed flexibility, on the whole-particle level through diameter analysis and local movement with inter-capsomer analysis. Inter-capsomer expansion or contraction, governed by the connecting arms, showed no bias in the magnitude or direction of capsomer movement. We propose that papillomavirus capsids are dynamic and capsomers move as rigid bodies connected by flexible linkers. The resulting virus structure will provide a framework for continuing biochemical, genetic and biophysical research for papillomaviruses. Furthermore, our approach has allowed insight into the resolution barrier that has previously been a limitation in papillomavirus structural studies.

microbiology↗

bioRxiv2020

Antibody Escape by Polyomavirus Capsid Mutation Facilitates Neurovirulence

JCPyV polyomavirus, a member of the human virome, causes Progressive Multifocal Leukoencephalopathy (PML), an oft-fatal demyelinating brain disease in individuals receiving immunomodulatory therapies. Mutations in the major viral capsid protein, VP1, are common in JCPyV from PML patients (JCPyV-PML) but whether they confer neurovirulence or escape from virus-neutralizing antibody (nAb) in vivo is unknown. A mouse polyomavirus (MuPyV) with a sequence-equivalent JCPyV-PML VP1 mutation replicated poorly in the kidney, a major reservoir for JCPyV persistence, but retained the CNS infectivity, cell tropism, and neuropathology of the parental virus. This mutation rendered MuPyV resistant to a monoclonal Ab (mAb), whose specificity overlapped the endogenous anti-VP1 response. Using cryo EM and a custom subvolume refinement approach, we resolved an MuPyV:Fab complex map to 3.1 [A] resolution. The structure revealed the mechanism of mAb evasion. Our findings demonstrate convergence between nAb evasion and CNS neurovirulence in vivo by a frequent JCPyV-PML VP1 mutation.

immunology↗