Induction of protective and therapeutic anti-cancer immunity by using bispecific anti-idiotype antibody G22-I50 for nasopharyngeal carcinoma

• We firstly reported the protective efficacy of G22-I50 against human NPC using hu-PBL-SCID model.
• We firstly reported the therapeutic efficacy of G22-I50 against human NPC using hu-PBL-SCID model.
• We demonstrated that G22-I50 was able to induce more powerful humoral and cell-mediated immune responses.

Increasing evidence has suggested that bispecific and multivalent antibodies which have more antigen binding sites will improve their immunogenicity. The bispecific anti-idiotype antibody vaccine G22-I50 was obtained through genetic engineering to enhance the immunogenicity of anti-idiotype antibody vaccines G22 and I50. G22-I50 vaccination could induce anti-tumor immunity in the Balb/c mouse model. The protective and therapeutic efficacy of G22-I50 was also evaluated using the hu-PBL–SCID mouse model injected three times with G22-I50, G22, or I50 mixed with Freund's adjuvant. Results demonstrated that the protective anti-tumor effect of G22-I50 could be relevant with the production of Ab3 antibody and activation of CD8+ cytotoxic T-lymphocytes. In preventive and therapeutic experiments, G22-I50 could reduce tumor size and prolong the survival time of HNE2-bearing mice (p < 0.05). Human CD8+ T lymphocytes infiltrated the tumor sites, and high levels of human IFN-γ, TNF-α, and caspase-3 were also detected in the tumors from G22-I50-vaccinated and -treated mice. Therefore, the bispecific anti-idiotype antibody vaccine G22-I50 can induce strong humoral and cell-mediated immune responses. This vaccine can be potentially applied to prevent and treat nasopharyngeal carcinoma.