Plant-derived EpCAM-Fc fusion proteins induce in vivo immune response to produce IgGs inhibiting invasion and migration of colorectal cancer cells

초록

Transgenic tobacco plant expressed EpCAM-Fc fusion proteins to induce in vivo immune responses producing anti-EpCAM antibodies inhibiting human colorectal cancer cell invasion and migration. Plant is emerging as a promising alternative to produce valuable immunotherapeutic vaccines. In this study, we examined the in vivo anti-cancer efficacy of epidermal cell adhesion molecule (EpCAM)-Fc and EpCAM-FcK fusion proteins produced in transgenic plants as colorectal cancer vaccine candidates. Mice were injected with plant-derived EpCAM-Fc (EpCAM-FcP) and EpCAM-FcP tagged with KDEL (ER retention signal) (EpCAM-FcKP), using mammalian-derived EpCAM-Fc (EpCAM-FcM) as positive control. Total IgGs from the immunized mice were used to assess immune responses. ELISA tests revealed that IgGs from mice immunized with EpCAM-FcKP (EpCAM-FcKP IgG) exhibited the highest absorbance value for binding affinity to recombinant EpCAM-FcM compared to IgGs from mice immunized with EpCAM-FcP (EpCAM-FcP IgG) and EpCAM-FcM (EpCAM-FcM IgG). Bio-layer interferometry revealed that EpCAM-FcKP IgG had a higher affinity value than EpCAM-FcM IgG and EpCAM-FcP IgG. Cell ELISA revealed that EpCAM-FcKP IgG exhibited the highest binding activity to EpCAM-positive cells SW480 and SW620 compared to EpCAM-FcP IgG, EpCAM-FcM IgG, and anti-EpCAM mAb. In the transwell invasion assay, EpCAM-FcKP IgG significantly decreased the numbers of invaded SW480 and SW620 cells compared to EpCAM-FcP IgG, whereas EpCAM-FcM IgG had similar numbers. In the wound healing assay, EpCAM-FcKP IgG showed higher migration inhibition compared to EpCAM-FcP IgG in both cell types, with similar results to EpCAM-FcM IgG in SW620 cells. These results confirm the applicability of plant systems to produce EpCAM-Fc vaccine candidates, inducing the production of anti-EpCAM IgGs against colorectal cancer cells. © 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

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