猪脾转移因子提高LaSota株鸡新城疫弱毒疫苗的免疫保护率

旨在了解猪脾转移因子（TF）对新城疫病毒（NDV）弱毒疫苗LaSota株的免疫增强效果及机制。本研究分别采用不同剂量（10^-2、10^-3、10^-4、10^-5羽份） LaSota疫苗株单独（单独免疫组）、LaSota疫苗株与TF联合（联合免疫组）免疫SPF鸡，14 d后以NDV F₄₈E₉强毒攻毒，同时设立对照组（非免疫攻毒）和空白组（非免疫非攻毒），并采用ELISA方法与蛋白质芯片技术分别测定外周血IL-4、IFN-γ与IL-12 P40浓度。结果显示，鸡免疫10^-2、10^-3、10^-4、10^-5羽份时疫苗攻毒保护率和半数保护量（PD₅₀）如下：单独免疫组分别为100%、55%、0%、0%和0.000 8羽份，联合免疫组分别为100%、75%、0%、0%和0.000 5羽份，对照组和空白组死亡率分别为100%和0%。免疫10^-3羽份疫苗后，联合免疫组IL-4和IFN-γ含量均高于其他组，并于第7、14天差异极显著（P<0.01）；攻毒后，联合免疫组IL-4、IFN-γ和IL-12 P40含量均高于其他组，IL-4于第1、14天，IFN-γ于第1、3天，IL-12 P40于第1天差异极显著（P<0.01）。综上表明，TF可增强IFN-γ、IL-12介导的细胞免疫和IL-4介导的体液免疫，提高LaSota株弱毒疫苗的免疫保护率，降低疫苗PD₅₀；在抵抗NDV F₄₈E₉强毒攻击时，联合免疫组的免疫保护率明显高于单独免疫组。

Improvement of the Immune Protection Rate on Newcastle Disease Virus Attenuated Vaccine LaSota Strain by Pig Spleen Transfer Factor

This study was conducted to evaluate the immune enhancement effect and mechanism of pig spleen transfer factor(TF) on Newcastle disease virus(NDV) attenuated vaccine LaSota strain. Specific pathogen free(SPF) chickens were inoculated with different doses(10^-2, 10^-3,10^-4, 10^-5) of NDV strain LaSota(vaccination group without TF), NDV strain LaSota combined with TF(vaccination group with TF), respectively, and challenged with virulent NDV strain F₄₈E₉ on 14 days post vaccination(dpv). The control group(non-immunized but challenged) and blank group(non-immunized and non-challenged) were set up simultaneously. In addition, the change of IL-4, IFN-γ and IL-12 P40 in peripheral blood were analyzed by ELISA and protein chip technology. The protection rate of different doses and median protective dose(PD₅₀) were 100%, 55%, 0%, 0%, 0.000 8 doses in the plume in vaccination group without TF, respectively, and 100%, 75%, 0%, 0%, 0.000 5 doses in the plume in vaccination group with TF. In contrast, the mortality of control group and blank group were 100% and 0%. After immunization with 10^-3 dose of vaccine, the levels of IL-4 and IFN-γ in vaccination group with TF were higher than in other groups and the difference was extremely significant on 7 and 14 dpv(P<0.01). After challenge, the levels of IL-4, IFN-γ and IL-12 P40 in vaccination group with TF were higher than in other groups. The differences of IL-4 on 1 and 14 days post challenge (dpc), IFN-γ on 1 and 3 dpc, IL-12 P40 on 1 dpc were extremely significant(P<0.01). These findings indicated that TF could reinforce cellular immunity by IFN-γ, IL-12 and humoral immunity by IL-4, improve the immune protection rate of NDV attenuated vaccine LaSota strain and reduce the PD₅₀. Vaccination group with TF was more effective than vaccination group without TF against virulent NDV strain F₄₈E₉.