Bing Mei

Genetic variation of E6 and E7 genes of human papillomavirus 52 from Central China

AbstractCervical cancer is the fourth most common malignant tumor in women worldwide and is closely related to human papillomavirus (HPV). Women have the highest susceptibility to HPV‐52 type in Jingzhou, China. In this study, E6‐E7 sequences of 183 HPV‐52 positive samples were amplified by a polymerase chain reaction and sequenced. HPV‐52 E6‐E7 gene variations were analyzed. The phylogenetic tree was constructed using the Kimura 2‐parameter method. The secondary structure of the protein was analyzed. The selective pressure to E6‐E7 genes was estimated using PAML. In addition, the B cell epitopes of the E6‐E7 sequences in HPV‐52 were predicted by the ABCpred server. In E6 sequences, 15 single nucleotide variants were observed, including 6 nonsynonymous variants and 9 synonymous variants. In E7 sequences, 19 single nucleotide variants occurred, including 10 nonsynonymous variants and 9 synonymous variants. Six amino acid variants, including 3 nonconservative substitutions, were found in sequences encoding the alpha helix. Eight amino acid variants, including three nonconservative substitutions, occurred in sequences encoding the strand. Through phylogenetic analysis, the E6‐E7 sequences were mainly distributed in B lineage. In HPV‐52 E6‐E7 sequences, no positively selected site was found. The nonconservative substitutions, such as K93R, K93E in E6, T37I, and D38N in E7, affected multiple hypothetical epitopes in the B cell. This study provides information for the investigation of HPV epidemic characters. The discovery of new variants of HPV‐52 may lay the basis for the development of the virus diagnosis, further study of cervical cancer, and vaccine design in Central China.

Genetic variability of E6 and E7 genes of human papillomavirus type 58 in Jingzhou, Hubei Province of central China

Abstract Background Cervical cancer is a common malignant tumor in women, with a high mortality rate, has great harm to women’s health. Long-term and persistent infection of high-risk human papillomavirus (HR-HPV) is the main reason of the occurrence and development of cervical cancer. Methods The infection rate of HPV-58 is higher in the Jingzhou area. In this study, 172 complete HPV-58 E6-E7 sequences were amplified by polymerase chain reaction (PCR), the amplified products were sequenced, and the gene variations of HPV-58 E6-E7 were analyzed. A Neighbor-Joining phylogenetic tree was constructed by MEGA 11. The secondary structure of E6 and E7 protein was investigated. PAML X was used to analyze the selective pressure. The B cell epitopes of E6 and E7 proteins in HPV-58 were predicted by ABCpred server. Results In E6 sequences, 10 single nucleotide variants were observed, including 7 synonymous and 3 non-synonymous variants. In E7 sequences, 12 single nucleotide variants were found, including 3 synonymous variants and 9 non-synonymous variants. There are 5 novel variants. The phylogenetic analysis showed that all the E6-E7 sequences were distributed in A lineage. No positively selected site was found in E6 sequence, but G63 in E7 sequences was identified as positively selected site. Some amino acid substitutions affected multiple B cell epitopes. Conclusion Various E6 and E7 mutational data may prove useful for development of better diagnostic and vaccines for the region of Jingzhou, Hubei province of central China.

Genetic variation of E6, E7, and L1 genes of human papillomavirus 51 from central China

AbstractThe incidence of cervical cancer is closely related to high‐risk human papillomavirus (HR‐HPV). Women in Jingzhou had relatively high susceptibility to HPV‐51, whose ratio was 9.61% (456/4743) among HR‐HPV‐positive samples and ranked fifth in all analyzed HR‐HPV types. In this study, variations and phylogenetic trees of HPV‐51 E6−E7 and L1 sequences were analyzed by MEGA‐X. The selective pressure was estimated using PAML. The B‐cell epitope of L1 amino acid sequences and T‐cell epitope of E6 and E7 amino acid sequences were further predicted by ABCpred server and IEDB website, respectively. In the E6−E7 sequences 14 single nucleotide variants occurred, among which 4 were nonsynonymous variants and 10 were synonymous variants. A total of 41 single nucleotide variants were identified in the L1 sequences, including 10 nonsynonymous variants and 31 synonymous variants. All the isolates of both E6−E7 and L1 were classified into the A variant lineage. In HPV‐51 E6−E7 and L1 sequences, no positively selected site was found. Two nonconservative substitutions, H119Y and N176S in L1, affected multiple hypothetical B‐cell epitopes. Three nonconservative substitutions, T86P, S100L in E6, and F29L in E7, affected multiple hypothetical T‐cell epitopes. Elucidation of the HR‐HPV prevalence characteristics and genetic variations of HPV‐51 in central China may contribute to future investigations of diagnostic probes, therapeutic or preventative vaccines with wider coverage.