Administration of DNA vaccine containing E6 gene of HPV16 in order to evaluate cellular immunity

Abstract number: 1733_582

Soleimanjahi H., Hassan Z., Poorpak Z., Meshkat Z., Mirshahabi H., Meshkat M.

Objective: Cervical cancer is the second most common cause of cancer deaths in women worldwide. Human papillomaviruses (HPVs) are thought to be the primary causative agent in >90% of cervical cancers, with HPV 16 being the type most frequently found in these tumours. HPVs are thought to induce cervical carcinoma most likely through the expression of E6 and E7 genes presumably by inactivating the tumour suppressor protein, p53 and p Rb, respectively. E6 is a multifunctional protein that affects cell growth and proliferation. The E6-mediated activities include cell immortalisation, transformation, tumour formation, and apoptosis. E6 and E7 oncoproteins are the most logical target molecules for therapeutic vaccines. In the present study E6 was chosen as target gene in order to evaluate CMI responses.

Methods: The HPV16 E6 ORF was obtained by PCR amplification using designed specific primers and cloned into pcDNA3 expression vector. The constructed was used for immunisation of mice after confirmation. Animal receiving to injection of target expression vector (pcDNA3-HPV16 E6) and pcDNA3 vector as a negative control were evaluated for specific T helper immune responses.

Results: Mice receiving pcDNA3-HPV16 E6 demonstrated high level production of IFN-g versus negative control group where as IL4 production was not statistically significant.

Conclusion: Based on the results, the injection of pcDNA3-HPV16 E6 examination plasmid could efficiently induce IFN-g, an indicator of Th1 responses, with has an important role in cancer therapy. The ability of the vaccine to elicit specific T cell responses and modulate a relevant cytokine secretion pattern is the key to DNA vaccine efficacy.