ABSTRACT
Expression of HPV E5, E6 and E7 oncogenes are likely to overcome the regulation of cell proliferation and to escape immunological control, allowing uncontrolled growth and providing the potential for malignant transformation. Thus, their three oncogenic products may represent ideal target antigens for immunotherapeutic strategies. In previous attempts, we demonstrated that genetic vaccines against recombinant HPV16 E7 antigen were able to affect the tumor growth in a pre-clinical mouse model. To improve this anti-HPV strategy we developed a novel approach in which we explored the effects of E5-based genetic immunization. We designed novel HPV16 E5 genetic vaccines based on two different gene versions: whole E5 gene and E5Multi. The last one is a long multi epitope gene designed as a harmless E5 version. Both E5 genes were codon optimized for mammalian expression. In addition, we demonstrated that HPV 16 E5 oncogene is expressed in C3 mouse cell line making it an elective model for the study of E5 based vaccine. In this mouse model the immunological and biological activity of the E5 vaccines were assessed in parallel with the activity of anti-E7 and anti-E6 vaccines already reported to be effective in an immunotherapeutic setting. These E7 and E6 vaccines were made with mutated oncogenes, the E7GGG mutant that does not bind pRb and the E6F47R mutant that is less effective in inhibiting p53, respectively. Results confirmed the immunological activity of genetic formulations based on attenuated HPV16 oncogenes and showed that E5-based genetic immunization provided notable anti-tumor effects.
Subject(s)
Human papillomavirus 16/immunology , Oncogene Proteins, Viral/immunology , Papillomavirus Vaccines/immunology , Uterine Cervical Neoplasms/prevention & control , Vaccines, DNA/immunology , Animals , Cell Line, Tumor , Female , Human papillomavirus 16/genetics , Mice, Inbred C57BL , Oncogene Proteins, Viral/genetics , Papillomavirus Vaccines/administration & dosage , Papillomavirus Vaccines/genetics , Vaccines, DNA/administration & dosage , Vaccines, DNA/geneticsABSTRACT
Objective To find out a proper way to detect green fluorescent protein (GFP). Methods Kidneys, livers and femurs from GFP transgenic mice and C57BL/6J wild type mice were employed for in vivo study.The samples were dehydrated with alcohol and acetone individually before embedding, then frozen, paraffin and resin sections were made for the detection of GFP. C3 P12 cells which derived from calvaria bone cells of GFP transgenic mouse were used for the detection of GFP in vitro. Cells were exposed to alcohol, acetone and PBS after paraformaldehyde fixation. Laser scanning microscopy was employed for GFP detection. Results In frozen sections, both kidney and liver samples which exposed to 4% buffered paraformaldehyde fixation had strong GFP signals, while GFP signal disappeared completely in fresh frozen sections without fixation. Much stronger GFP intensity was found in acetone treated samples than in alcohol treated paraffin sections, but without apparent difference in GFP intensity in acetone and alcohol treated resin samples. Acetone and alcohol made no difference in fixed C3 cells in different time courses. Conclusion Acetone treated paraffin sections are preferable for GFP detection.
