Diverse efficacy of vaccination therapy using the alpha-fetoprotein gene against mouse hepatocellular carcinoma

Area of Science:

• Immunology
• Oncology
• Gene Therapy

Background:

• Antitumor vaccination strategies utilizing plasmid DNA or viral vectors encoding tumor antigens are under investigation.
• Hepatocellular carcinoma (HCC) is a significant global health concern, necessitating novel therapeutic approaches.

Purpose of the Study:

• To evaluate the therapeutic efficacy of a vaccination strategy using the mouse alpha-fetoprotein (AFP) gene in a mouse model of HCC.
• To assess the impact of AFP expression levels and host immune response on vaccination outcomes.

Main Methods:

• Mice (C57L/J or C3H/HeN) received a prime vaccination with naked plasmid DNA expressing mouse AFP, followed by a booster with replication-defective adenovirus expressing mouse AFP.
• Mice were subsequently challenged with either high AFP-producing Hepa1-6 cells or low AFP-producing MH134 cells.
• Tumor growth rates and immune responses, specifically interferon-gamma production, were monitored.

Main Results:

• The plasmid-AFP prime/adenovirus-AFP booster vaccination induced protective immunity against Hepa1-6 cells in C57L/J mice, significantly increasing interferon-gamma-producing splenic cells.
• This vaccination protocol demonstrated efficacy in repressing the growth of pre-established Hepa1-6 tumors.
• However, the vaccination strategy did not confer protective immunity against MH134 cells in C3H/HeN mice, indicating a potential limitation based on AFP expression levels or host immunity.

Conclusions:

• Vaccination targeting the AFP gene represents a promising therapeutic strategy for HCC.
• The effectiveness of AFP-based vaccination may be influenced by the level of AFP expression in HCC cells and the host's immunological profile.