Abstract
In the current study, a total of 74 single-infected HPV16 samples from females attending the gynecological outpatient clinic in four cities of Henan province were collected and applied to the L1, E6 and E7 sequencing. Variations of the HPV16 L1, E6 and E7 genes were characterized by comparison with reference sequence and the secondary structure analysis were conducted. Phylogenetic trees based on the L1 and E6-E7 sequences were constructed separately. B-cell epitopes of the HPV16 E6 and E7 proteins were predicted further. A total of thirty-seven novel variations, including twenty L1 genes and seventeen E6-E7 genes were identified. Compared with the reference sequence, twenty-eight variations (1.8%, 28/1596) were identified in L1 gene sequences and 10/28 (35.7%) were non-synonymous mutations. For E6-E7 sequences, twenty-five novel gene changes (including 16 mutations (3.4%, 16/477) in E6 gene, 9 mutations (3.0%, 9/297) in E7 gene) were found, 18/25 (72.0%) were non-synonymous and 10/28 (35.7%) were non-synonymous mutations. Phylogenetic analysis showed that 56.8% (42/74) of the samples were A1 sublineages, 37.8% (28/74) were A4, 4.1% (3/74) were A3 and 1.4% (1/74) was A2 sublineages. On the prediction of B-cell epitopes, seven potent epitopes for E6 and four for E7 were identified. Amino mutations, including L90V, R62K, R142Q and F76L in E6, S63F and N29S/H in E7 changed the score. HPV16 variants prevalent in the central China belong to European A1 sublineages. Sequences of HPV16 L1, E6 and E7 in this study may provide assistant for the improvement of HPV vaccines.