Utility of a Recombinant HSV-1 Vaccine Vector for Personalized Cancer Vaccines

Area of Science:

• Oncology
• Immunology
• Virology

Background:

• Current cancer immunotherapies like checkpoint inhibitors and vaccines show limited efficacy.
• Oncolytic virotherapy (OVT) offers a promising approach, with oncolytic viruses (OVs) capable of delivering tumor antigens to enhance immune responses.
• Talimogene laherparepvec (T-VEC), an oncolytic herpes simplex virus type 1 (HSV-1), is FDA-approved for melanoma treatment.

Purpose of the Study:

• To engineer a recombinant oncolytic HSV-1 (oHSV) expressing ovalbumin (OVA) as a fusion protein.
• To evaluate the capacity of the engineered oHSV (VC2-OVA) to stimulate potent, specific antitumor immunity.
• To assess the therapeutic efficacy of VC2-OVA in a syngeneic murine melanoma model.

Main Methods:

• Engineered recombinant oHSV (VC2-OVA) expressing OVA fused to VP26.
• Tested VC2-OVA's ability to induce antitumor immunity in a syngeneic murine melanoma model.
• Evaluated tumor colonization reduction and survival rates in mice challenged with B16cOVA cells.

Main Results:

• Therapeutic vaccination with VC2-OVA significantly reduced lung tumor cell colonization in mice.
• VC2-OVA induced a potent prophylactic antitumor response.
• VC2-OVA significantly extended survival in mice with established B16cOVA tumors.

Conclusions:

• Engineered oHSV VC2-OVA effectively stimulates specific antitumor immunity.
• VC2-OVA demonstrates potential as a novel cancer immunotherapy vector.
• This approach warrants further investigation for melanoma and other cancers.