Characterization of a new type HPV16 E7 variant isolated from cervical cancer highest incidence area in Hubei Province of China.
OBJECTIVE
To investigate the variation and biological properties of HPV16 E7 isolated from cervical cancer biopsy samples from highest incidence area in HuBei province of China.


METHODS
HVP16 E7 sequences isolated from the cervical cancer biopsies of 10 local patients were amplified, sequenced and compared with prototype E7 gene. Then the variant gene was cloned into different vectors to study the antigenicity, expression and immunogenicity of its protein by Western blot, immunofluorescence and genetic immunization in vitro or in vivo.


RESULTS
The results showed that 7 of 10 samples had the same mutations which led to a nonsense mutation at codon 43 of E7 sequence. The truncated E7 protein could be recognized by standard E7 monoclonal antibody in Western blot and expressed in NIH3T3 cells. In the blood sera of mice immunized intramuscularly by the plasmid DNA expressing the variant E7 gene specific E7 antibodies could be detected at week 2, 3, 5 and 6 after inoculation. However, no specific lymphoproliferation after E7 protein stimulation in vitro was detected by MTT colorimetric assay in comparison to the prototype E7 protein.


CONCLUSIONS
HPV16 E7 gene may show variation in China and the variant protein could be expressed and induce host humoral immune response, but could not elicit special cellular-immune response against it. These data might hold the key for future development of HPV16 vaccine in HuBei province of China.
Li
Hui
H
Department of Molecular Biology, Institute of Virology, Wuhan University Medical School, Wuhan 430071, P.R. China. huili0930@163.com
Zhao
Min
M
Qiu
Xiaoping
X
Ding
Xiaohua
X
Tan
Yun
Y
Wu
Xinxing
X
D000818:Animals; D001483:Base Sequence; D002681:China / Q000453:epidemiology; D018389:Codon, Nonsense; D005260:Female; D014644:Genetic Variation; D005822:Genetic Vectors; D006801:Humans; D015994:Incidence; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D009856:Oncogene Proteins, Viral / Q000235:genetics*; D027383:Papillomaviridae / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D050725:Papillomavirus E7 Proteins; D030361:Papillomavirus Infections / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control / Q000821:virology*; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control / Q000821:virology*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology
D018389:Codon, Nonsense; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D019444:Vaccines, DNA; C059731:oncogene protein E7, Human papillomavirus type 16