Epstein–Barr Virus: Evaluation of gp350 and EBNA2 Gene Variability

Approximately 90% of the world’s population is infected with the Epstein–Barr virus (EBV). Damage to health and high economical costs require the development of vaccines against EBV. The variability of individual genes may affect the success of the vaccination campaign and will necessitate dynamic update of antigenic composition of vaccines. The aim of this study was to assess the variability of EBV gp350 and EBNA2 genes isolated from saliva of dental clinic personnel in Moscow oblast. Biosamples were obtained from 105 employees at four dental clinics. For EBV DNA-positive samples, the EBNA2 and gp350 genes were amplified using nested PCR. The nucleotide sequence of gp350 gene was determined during sequencing. A maximum likelihood phylogenetic tree was constructed from the N-terminal fragment of gp350 protein, using B95-8 strain as a reference genome. Phylogenetic analysis also included 222 EBV samples from the NCBI database. The EBNA2 genotype and the whole gp350 gene sequence were determined for 31 DNA samples. Based on the phylogenetic analysis of gp350 protein, the Russian virus population was uniformly distributed along the tree. Meanwhile, 30 samples fell into the Aa clade (A, genotype A for EBNA2 gene; a, similarity of the gp350 sequence with B95-8 [NC_007605.1]) and one sample belonged to the Bb clade (B, genotype B for EBNA2 ; b , similarity of gp350 with Jijoye [LN827800.1]). For 30 Russian samples of Aa genotype, 22 individual profiles and 16 unique mutations were found. Identical gp350 profiles were found amongst staff working in close professional contact. The identified features indicated the need for further phylogenetic studies of samples collected in Russia to develop and introduce vaccines and monitor their efficiency.