狂犬病病毒减毒株CTN-181的免疫原性

目的评价狂犬病病毒减毒株CTN-181的免疫原性。方法用不同病毒滴度的CTN-181株病毒对小鼠分别进行口腔或肌肉免疫,14 d后,分别用狂犬病病毒CVS株进行脑内或肌内攻毒,14 d后,计算小鼠的免疫保护力;同时于免疫后14、21和30 d,采用RFFIT法检测小鼠血清抗狂犬病病毒中和抗体水平。结果两种途径免疫的小鼠均产生了较强的保护作用和较高的中和抗体水平。口腔免疫后脑内和肌内攻毒的50%保护剂量分别为1.4×105和1.4×104PFU/ml;肌肉免疫后脑内和肌内攻毒的50%保护剂量分别为1.4×106和1.4×105PFU/ml。小鼠口腔免疫CTN-181病毒量≥1.4×105PFU/ml 14 d后,即可产生有效的保护,至30 d时,1.4×106和1.4×107PFU/ml剂量组中和抗体水平达20 IU/ml以上;肌内免疫产生的中和抗体水平较低。结论 CTN-181减毒株具有良好的免疫原性,以较低病毒量免疫小鼠即可产生高水平的中和抗体和保护作用。

Immunogenicity of attenuated rabies virus strain CTN-181

Objective To evaluate the immunogenicity of attenuated rabies virus strain CTN-181.Methods BALB / c mice were immunized with CTN-181 strain at various titers by oral and intramuscular routes respectively.Fourteen days after immunization,the mice in each group were challenged i.c.or i.m.with rabies virus CVS strain respectively.The immune protection rate was calculated 14 d after challenge,while the serum neutralizing antibody level was determined by RFFIT 14,21 and 30 d after immunization.Results Strong protection and high neutralizing antibody level against rabies virus challenge were induced by CTN-181 strain by both oral and intramuscular routes.The 50% effective doses(ED50)of CTN-181 strain by oral immunization against i.c.and i.m.challenge were 1.4 × 105 and 1.4 × 104 PFU / ml,while those by intramuscular immunization were 1.4 × 106 and 1.4 × 105 PFU / ml,respectively.Effective protection was induced 14 d,after oral immunization with CTN-181 strain at dosages of not less than 1.4 × 107 PFU / ml,while the neutralizing antibody level induced by the strain at dosages of 1.4 × 106and 1.4 × 107 PFU / ml reached more than 20 IU / ml 30 d.However,the neutralizing antibody level induced by intramuscular immunization with CTN-181 strain was relatively low.Conclusion CTN-181 strain showed high immunogenicity,which induced high neutralizing antibody level and strong protection only at a low dosage.