Abrin toxin (AT) consisting of an A chain and a B chain is a potential agent for bioterrorism and an effective vaccine against AT poisoning is urgently required. In this study, AT B chain (ATB) was successfully expressed in the Escherichia coli (E. coli) and assessed the protection capacity against AT intoxication. The recombinant ATB (rATB) subunit induces a good immune response after 4 immunizations. All BALB/c mice immunized intraperitoneally (i.p.) with the purified rATB protein survived after challenged with 5 × LD50 of AT. Transfusion of sera from immunized mice provided passive protection in naive mice. Furthermore, histological findings showed that immunization with rATB decreased the severity of toxin-related tissue damage. This work indicates that the rATB protein may be a promising vaccine candidate against human exposure to AT.
Keywords: AT, abrin toxin; ATB, abrin toxin B chain; B chain; E. coli, Escherichia coli; ELISA, enzyme-linked immunosorbent assay; LD50, 50% lethal dose; PBS, phosphate-buffered saline solution; RT, ricin toxin; RTB, ricin toxin B chain; SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis; abrin toxin; bioterrorism; i.p, intraperitoneal or intraperitoneally; immunogen; pAb, polyclonal antibody; vaccine candidate.