胸腺制剂对鸡马立克氏病疫苗免疫增强作用的研究

STUDIES ON THE THYMUS EXTRACT AS AN IMMUNOLOGIC ENHANCER AGAINST MAREK'S DISEASE IN CHICKEN

将一日龄ＳＰＦ来航鸡分成４组，饲养在隔离器中。第１组１日龄接种ＭＤ疫苗，同时皮下注射０．５ｍＬ胸腺制剂；第２组１日龄接种ＭＤ疫苗时不加免疫增强剂；第３组、第４组均不接种ＭＤ疫苗，也不注射免疫增强剂。第１、２、３组于１３日龄时用ＢＪＭＤＶ－１强毒株攻毒。结果显示：第１组、第２组、第３组分别于攻毒后２８、２４、１７ｄ开始出现死亡，第４组没有死亡。第１组的攻毒保护率为４０．０％，比第２组保护率１５．０％有明显提高。此外，于１１、２８、５６日龄时检测了外周血液中Ｔ淋巴细胞百分率。２８日龄和５６日龄时第１组的外周血Ｔ淋巴细胞活性高于第２组。试验结果表明胸腺制剂对鸡马立克氏病疫苗有免疫增强作用。

Day-old SPF leghorn chicks were divided into four groups and raised separately in isolators.Group 1 chicks were inoculated s.c,with 0.2 mL M D vaeeine and 0.5 mL thymus extract in .the neck,group 2 chicks were inoculated with 0.2 mL MD vaccine(immunized control)only,group 3 and 4 chicks were not injected with any vaccine or other substanee.Group l to 3 birds were challenged with the virulent BJMDV-1 strain on day 13. Death occurred on day 17 and 24 post-infection for groups 3 and 2 birds respectively.For the groups that reeeived thymus extract,death occurred on 28 days P.I.,No death occurred in group 4.Group 1 showed 40% protection rate against MDV whereas the protection rate in group 2 was only 15.0% In addition,the group that reeeived immunengancement, had higher T lymphocyte level in the peripheral blood than group 2.Results of this experiment indicated that the thymus extract had the potential for improving immunizaton against MD.