The ability of human bispecific anti-idiotype antibody to elicit humoral and cellular immune responses in mice

Our goal is to compare the immunogenicity and the extent of immunologic reactivity between bispecific and mono anti-idiotype vaccines. We previously obtained two human anti-Id antibody fragments fuse5-G22, fuse5-I50 by phage display technology which were mimics of the antigens from nasopharyngeal carcinoma cell line (HNE2). In this study, we developed and characterized a bispecific anti-Id antibody vaccine G22–I50 and its parent monovalent antibody vaccines G22 and I50. The efficacy of G22–I50, G22, and I50 as tumor vaccines was evaluated in Balb/c mice with three injections of these vaccines adjuvanted with Freund's adjuvant. Mice immunized with G22–I50 exhibited comparable levels of antibody titers and stronger binding inhibition capabilities. Spleen cells from G22–I50-immunized mice gave a significant proliferative response and higher expression level of IFN-γ and IL-2.These results suggested that bispecific anti-Id antibody vaccine was able to induce more powerful humoral and cell-mediated immune responses, which might make it to be a potential vaccine candidate for the therapy of nasopharyngeal carcinoma.