[Preparation of monoclonal antibodies against enterovirus type 71 with an epitope-incorporated adenovirus type 3 vector].

Objective To develop the monoclonal antibodies (mAbs) against enterovirus type 71 (EV71). Methods Two neutralization epitopes, SP70 and SP55, from EV71 were cloned into the hexon gene of adenovirus type 3 to generate a recombinant adenovirus type 3 (R1R2A3) presenting SP70 and SP55 antigens. BALB/c mice were immunized with the R1R2A3. The mAbs were developed with hybridoma technology and were analyzed with microneutralizing assay, indirect ELISA, Western blotting and direct immunofluorescence assay (DFA). Results The study obtained four hybridoma cell clones, 2C4, D2C9, I2G2 and I12C3. ELISA showed that the titer of D2C9 against EV71 was 1:8 000 000 and the titers of 2C4, I2G2, and I12C3 all were 1:500 000. ELISA and Western blotting demonstrated that all mAbs could specifically recognize the VP1 of EV71. In addition, D2C9 recognized the SP70 epitope, and 2C4, I12C3 and I2G2 all recognized the SP55 epitope. DFA revealed that all mAbs could react with EV71, but not with Coxsackie virus A16 (CoxA16). Conclusion Four mAbs against EV71 have been developed successfully, and all of them could react with EV71 rather than CoxA16.