试验Ⅰ:免疫应答试验:取450只雏鸡随机均分为9组,在14日龄用新城疫Ⅳ系疫苗免疫,同时分别肌肉注射高、低剂量的3种硫酸化香菇多糖(sLNT_1、sLNT_2、sLNT_3)和香菇多糖(LNT)。分别于首免前和首免后连续6周检测血清HI抗体效价和外周血T淋巴细胞增殖的动态变化。试验Ⅱ:免疫保护试验:取350只雏鸡随机均分为7组,除非免疫组外其余组用新城疫Ⅳ系疫苗免疫,同时3个sLNT组和LNT组分别注射sLNT_1、sLNT_2、sLNT_3和LNT。于免疫后第21天,除无佐剂对照组第2组外各组鸡均肌肉注射NDV强毒攻毒,观察保护效果,并分别于攻毒前和攻毒后第3、6、9、12和15天测定血清HI抗体效价和外周血T淋巴细胞增殖的动态变化。结果表明:3种sLNT在首免后28 d内比LNT显著提高血清抗体效价最高2个滴度(高剂量的效果优于低剂量),促进淋巴细胞增殖(低剂量的效果强于高剂量);攻毒鸡发病率和死亡率降低,保护率提高最多达17.5%,加速攻毒后血清抗体生成和T淋巴细胞增殖,病鸡最快可以在攻毒后6 d恢复正常。综合评价以sLNT_2的效果最好。揭示:硫酸化修饰能显著提高LNT的免疫增强活性,增强新城疫疫苗的免疫效果。
Ⅰ) Immune response test:450 14-day-old chickens were randomly divided into 9 groups and vaccinated with Newcastle disease vaccine,and at the same time of vaccination,the chickens in 6 sLNT and 2 lentinan(LNT) control groups were intramuscularly injected respectively with sLNT_1,sLNT_2,sLNT_3 and LNT at high and low dose.Before and on days continuous 6 weeks after vaccination,the dynamic change of serum HI antibody and peripheral T lymphocyte proliferation were determined.Ⅱ) Immune protective test:350 14-day-old chickens were divided randomly into 7 groups and vaccinated with Newcastle disease vaccine except for non-vaccinated(NV) group.At the same time,the chickens in 3 sLNT and LNT control groups were injected respectively with sLNT_1,sLNT_2,sLNT_3 and LNT.On day 21 after vaccination,the chickens except for no-adjuvant second (NA_2) group were challenged with injection of NDV.The protective effect of chickens was observed.Before and on days 3,6, 9,12 and 15 after challenge,the dynamic change of serum HI antibody and peripheral T lymphocyte proliferation were measured. The results showed that as compared with LNT,three sLNTs could significantly enhance antibody titer to 2 titres at most(high dose being better than low dose) and promote lymphocyte proliferation(low dose being better than high dose) especcially in 28 d after first vaccination,reduce morbidity and mortality,promote the protective rate to 17.5%at most,accelerate the antibody production and lymphocyte proliferation,and recover to normal in 6 d in challenged chickens.The effect of sLNT_2 was the best in general evaluation.This indicated that sulfated modification could increase the adjuvant activity of LNT,and sLNT could strengthen the immune effect of ND vaccine.