Characterization of large and small-plaque variants in the Zika virus clinical isolate ZIKV/Hu/S36/Chiba/2016

Abstract

An Asian/American lineage Zika virus (ZIKV) strain ZIKV/Hu/S36/Chiba/2016 formed 2 types in plaque size, large and small. Genomic analysis of the plaque-forming clones obtained from the isolate indicated that the clones forming small plaques commonly had an adenine nucleotide at position 796 (230Gln in the amino acid sequence), while clones forming large plaques had a guanine nucleotide (230Arg) at the same position, suggesting that this position was associated with the difference in plaque size. Growth kinetics of a large-plaque clone was faster than that of a small-plaque clone in Vero cells. Recombinant ZIKV G796A/rZIKV-MR766, which carries a missense G796A mutation, was produced using an infectious molecular clone of the ZIKV MR766 strain rZIKV-MR766/pMW119-CMVP. The plaque size of the G796A mutant was significantly smaller than that of the parental strain. The G796A mutation clearly reduced the growth rate of the parental virus in Vero cells. Furthermore, the G796A mutation also decreased the virulence of the MR766 strain in IFNAR1 knockout mice. These results indicate that the amino acid variation at position 230 in the viral polyprotein, which is located in the M protein sequence, is a molecular determinant for plaque morphology, growth property, and virulence in mice of ZIKV.

A systematic approach to the development of a safe live attenuated Zika vaccine

“…The importance of the flavivirus prM protein in affecting the host cell permissibility is only beginning to be explored with a recent demonstration of a S139N substitution in the prM protein as a likely contributor of increased microcephaly occurrences in the ZIKV outbreaks in French Polynesia and the Americas 60 . A more recent study also described a R15Q amino acid change in the M protein that decreased plaque sizes and slightly decreased virulence in IFNAR1-knockout C57BL/6 mice 61 . The M protein M66V single mutation we describe here is stable up to seven passages and also stabilized the viral genome considerably as compared to the multiple variations found in DN-1 upon serial passaging in Vero cells.…”

Establishment of Murine Infection Models with Biological Clones of Dengue Viruses Derived from a Single Clinical Viral Isolate

“…It is often observed that many viruses form heterogenous plaques of different sizes in vitro, indicating that viruses exist as quasispecies during transmission or passaging (Kato et al 2017;Moser et al 2018), but the virological differences among various phenotypic variants have not been carefully examined. Clinically, such viral diversity may assist arbovirus to survive under different selection pressure from two Fig.…”

Antigenicity, stability, and reproducibility of Zika reporter virus particles for long-term applications

“…For example, PRNT requires the use of live virus, which is fully infectious and therefore includes the risk of accidental exposure and infection. Certain viral strains may lead to false-negatives in the PRNT assay due to an inability of a strain to consistently form large enough plaques to be detected [18,59]. Moreover, PRNT is a labor-intensive, highly variable, and technically complex assay that is not readily adaptable to high-throughput analysis of large numbers of clinical samples.…”