Study on purification and immunologic effect of 42KD protein from group B Streptococcus / 中华微生物学和免疫学杂志

ABSTRACT

Objective To look for a vaccine on the base of surface protein which can elicit protective immunity.Methods Purification of 42KD protein from Streptococcus serotype Ⅲ was used one-step chromatography.Antibody response was evaluated in mice immunized by 42KD protein with different immunization dose and by the different immunization procedure.After immunizing the mice in the optimum procedure,we challenge the mice in intradermal with Streptococcus to observe the active and passive protection.Results The molecular weight(Mr)of the protein was 42.33×103 and its point isoelectric(pI)was 6.6.Its property might be a glycoprotein which could be released to supernatant.The highest titer of antibody against 42KD protein Was 1:24576.Which indicated that 42KD protein had good immunogenicity.The immunity exponent of NIH mice was 100 in test group and infant mice was 40.Conclusion The data suggests that 42KD protein may elicit protective immunity to adult and infant mice.Through protecting test with different immunizing doses,the findings indicate that protecting capability is relative to the titer of IgG specificantibody.