Cancer immunotherapy using the Fusion gene of Sendai virus

Area of Science:

• Immunology
• Virology
• Oncology

Background:

• Inactivated Sendai virus particle (HVJ-E) exhibits anti-tumor properties by activating anti-tumor immunity.
• The HVJ-E envelope contains fusion (F) and hemagglutinin-neuraminidase (HN) glycoproteins; F protein alone demonstrated anti-tumor activity in previous studies.
• Previous research suggested F protein elicits anti-tumor activity by inducing IL-6 secretion in dendritic cells (DCs).

Purpose of the Study:

• To investigate the anti-tumor efficacy of F gene therapy delivered via electroporation into mouse tumor tissue.
• To elucidate the immune mechanisms underlying F gene therapy's anti-tumor effects, specifically examining the roles of IL-6 and RANTES.
• To assess the potential of F gene therapy as a novel cancer immunotherapy.

Main Methods:

• F gene was delivered into mouse tumor tissue using electroporation.
• Tumor growth, T-cell infiltration (CD4+ and CD8+), and IFN-γ T-cell response were assessed.
• The impact of neutralizing IL-6 receptor (IL-6R) and RANTES on F gene therapy's anti-tumor effects was evaluated.

Main Results:

• F gene therapy significantly retarded tumor growth in mice.
• Treatment increased CD4+ and CD8+ T-cell infiltration into tumors and induced a tumor-specific IFN-γ T-cell response.
• Neutralization of IL-6R signaling did not affect F gene therapy's efficacy; however, increased RANTES secretion by tumor-infiltrating T cells was observed. Neutralizing RANTES abolished the anti-tumor effect.

Conclusions:

• F gene therapy demonstrates significant anti-tumor activity by promoting T-cell infiltration and IFN-γ production.
• The anti-tumor mechanism of F gene therapy involves RANTES chemokine secretion rather than IL-6 signaling.
• F gene therapy holds promise as a potential novel therapeutic strategy for cancer immunotherapy, either alone or in combination with other treatments.