Immune response of a recombinant abrin B chain protein against abrin intoxication in BALB/c mice / 中国免疫学杂志

ABSTRACT

Objective:To evaluate the immune response efficiency of the recombinant abrin B chain protein (rATB) in BALB/c mice.Methods:BALB/c mice were vaccinated intraperitoneally (i.p.) with the purified rATB protein.ELISA was used to detect the IgG,IgG1 and IgG2a.Meanwhile,the expression of IL-4 and IFN-γwere detected by flow cytometry.Then the protein neutralization assay and efficacy of passive protection were done .Results:The anti-rATB antibody was detected by ELISA after vaccinated the rATB in the mice and results showed that the highest titer reached 106 ,which was acquired after the last vaccination .Meanwhile,a strong secondary response was triggered in mice when challenged with toxin .In contrast ,the antibody response of the PBS-vaccinated mice was less than 1:10 and P<0.05 indicated obvious difference between test group and control group .The result of IgG 1 was the same as the IgG ,while the result of IgG2a had not changed.There was significant difference for IL-4 between two groups (P<0.05),while no significant difference for IFN-γwas observed.All BALB/c mice survived after challenged with 5×LD50 of AT.Transfusion of sera from immunized mice provided passive protection in naive mice.Furthermore, the rATB could induce specific neutralizing antibodies against abrin toxin.Conclusion: The recombinant protein can induce the Th 2-type immune response and trigger a good immune response and protective efficacy,which means it may be a promising vaccine candidate against human exposure to AT .