流感疫苗脂质体干粉制备方法对其免疫原性影响研究

A study on immunogenicity of influenza vaccine lyophilized liposome prepared by different methods

目的:考察薄膜分散及冻融冻干法制备H1N1单价流感疫苗脂质体呼吸道免疫效果,为减毒活疫苗脂质体的制备奠定基础。方法:将实验小鼠分为4个实验组(脂质体疫苗干粉肺部免疫组、腹腔免疫组,非脂质体疫苗原液肺部免疫组、腹腔免疫组),和1个阴性对照组。实验组以每只4μg和6μg血凝素含量(H1N1亚型)肺部免疫或腹腔免疫,以未免疫小鼠(PBS给药)为阴性对照。免疫7、14、28 d,血凝抑制试验(HI)检测免疫后小鼠血清抗HA抗体水平,ELISA检测血清中细胞因子含量。结果:两种方法制备的脂质体组6μg剂量肺部免疫抗体滴度高于4μg剂量肺部免疫(P<0.05);两种方法制备脂质体肺部免疫抗HA抗体滴度高于非脂质体肺部免疫(P<0.05)。脂质体组肺部免疫抗HA抗体滴度高于非脂质体组腹腔免疫(P<0.01);薄膜分散法优于冻融冻干法组;两种方法制备的脂质体肺部免疫产生的白细胞介素(IL)-2与干扰素(IFN)-γ水平高于疫苗原液腹腔免疫,均高于阴性对照组。结论:两种方法制备流感疫苗脂质体肺部给药均能有效诱发体液免疫及细胞免疫,薄膜分散法优于冻融冻干法,均高于疫苗原液组;冻融冻干法肺部免疫14 d即产生免疫应答,而原液腹腔免疫抗体滴度比仅为1.8。冻融冻干法组脂质体肺部免疫产生的细胞因子水平也明显高于疫苗原液腹腔免疫组。说明冻融冻干法在疫苗脂质体制备中具有可行性。

Objective：To evaluate the immunity effect of H1N1 influenza vaccine prepared by film-dispersion and freeze-thawing method,and to provide expermental foundation for attenuated live vaccine liposome preparation.Methods：Experimental mice were divided into the influenza vaccine non-liposome group,the film-dispersion prepared H1N1 influenza vaccine liposome group,the freeze-thawing lyophilized prepared H1N1 influenza vaccine liposome group,the positive control group and the negative control group（n=5）.4 μg and 6 μg hemagglutinin of H1N1 subtype per mouse were tracheally delivered to the mice for the non-liposome group and the lyophilized liposome groups,with the same dose intraperitoneally delivered groups as the positive control,and the PBS intraperotoneal injection group as the negative control.After 7,14 and 28 d of immunization,serum levels of HA antibodies were measured by the hemagglutination-inhibition method,and serum cytokine levels were measured by the ELISA method.Results：By pulmonary injection of the two liposome groups,the antibody titers of 6 μg dose groups were higher than those of 4 μg dose groups（P 0.05）.HA antibody titers of the two pulmonarily delivered liposome groups were higher than those of the pulmonarily（P 0.05） and intraperitoneally（P 0.01） injected non-liposome group.Antibody titers of the film-dispersion liposome group for both doses were higher than those of the freeze-thawing lyophilized liposome group.IL-2 and IFN-γ produced by the pulmonary injected liposome groups were higher than those of the intraperitoneally delivered non-liposome group.Conclusion：The humeral and cellular immunities could be effectively induced by pulmonarily delivered vaccine liposomes;The film-dispersion method group is better than the freeze-thawing lyophilized group in terms of immunity strength.For the freeze-thawing lyophilized prepared H1N1 influenza vaccine liposome group,the immune response occurs at 14 d after vaccination,while the titer ratio is only 1.8 for normal vaccinated flu vaccine.The freeze-thawing lyophilized liposome vaccine also stimulates higher levels of cytokines.