A novel vaccine targeting glypican-3 as a treatment for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has high morbidity and mortality rate worldwide, 38 with limited treatment options. Glypican-3 (GPC3) is a glycosylphosphatidylinositol- 39 anchored glycoprotein that is overexpressed in most HCC tissues but not in the 40 normal tissues. GPC3-targeting antibody therapy shows limited response in a clinical 41 trial due to the lack of tumor specific cytotoxic T lymphocyte (CTL) response. Here, 42 in C57/B6 mice, we demonstrated that intravenous infusion of GPC3-coupled 43 lymphocytes (LC/GPC3+) elicited robust GPC3-specific antibody and CTL responses, 44 which effectively restricted proliferation and lysed cultured-HCC cells. Treatment 45 with LC/GPC3+ induced durable tumor regression in HCC-bearing C57/B6 mice. 46 Administration of LC/GPC3+ induced elevated levels of the cytotoxic T cell bioactive 47 factors TNF-α, IFN-γ, granzyme B and perforin, and substantially increased the 48 number of infiltrating CD8+ T cells in tumor tissues. Moreover, immune responses 49 elicited by LC/GPC3+ selectively suppressed GPC3-positive tumors, but didn’t affect 50 the GPC3-negative tumors in BALB/c mice. Our findings provide the first preclinical 51 evidence that intravenous infusion of the LC/GPC3+ complex can induce strong anti- 52 HCC effect through regulating systemic and local immune responses. These results 53 indicate that LC/GPC3+ complex could be developed as precision therapeutics for HCC patients in future.