Study on immune mechanism of a recombinant ricin B chain protein against ricin intoxication in BALB/c mice / 中国免疫学杂志

ABSTRACT

Objective:To explore the immunity provided to BALB/c mice by immunization with the recombinant ricin B chain protein (rRTB). Methods:Female BALB/c mice were randomly selected into rRTB-vaccinated group and PBS group. Mice were subcu-taneously (s. c. ) injected four times with 14 days immunization time interval. Changes of antibodies (IgG,IgG1and IgG2a) in serum were detected by ELISA. Meanwhile,the expression of IL-4 and IFN-γ were detected by flow cytometry. Results:The mean IgG titers reached 106 after the fourth immunization and a strong secondary response was induced in vaccinated mice when challenged with toxin. There was significant difference between rRTB-vaccinated group and PBS group ( P<0. 05 ) . The same result was shown in IgG1. However,no changed was detected in IgG2a. Meanwhile,there was significant difference for IL-4 between two groups (P<0. 05), while no significant difference for IFN-γwas observed. Conclusion:rRTB can produce higher levels of antigen-specific antibodies ( IgG and IgG1),and cytokine (IL-4) of splenocytes,which means the recombinant protein can induce the Th2-type immune response and trigger a good immune response. rRTB may be a potentially valuable vaccine candidate against human exposure to AT.