马立克强毒MDV-GA对BWEL-SPF鸡的感染试验

Infection of MDV-GA in BWEL-SPF chickens

134只1日龄BWEL-SPF鸡随机分成2组,攻毒组84只腹腔注射2 000 PFU的MDV-GA细胞毒0.2 mL,对照组50只注射同等剂量的病毒稀释液。结果显示,攻毒后27 d攻毒组鸡只开始发病并持续到攻毒后51 d,发病高峰期在攻毒后28~42 d。经过60 d的观察发现,该毒株可以引起很高的肿瘤发生率（61.90%）,死亡率为75.00%。肿瘤主要出现在肾脏、心脏、肝脏、性腺、脾脏、肺、胸腺、皮肤、腺胃等组织,其中以肾脏、心脏、肝脏、性腺、脾脏肿瘤发生率较高,分别为：36.90%,28.75%,25.00%,21.43%,17.86%。其中2个以上组织发生肿瘤的个体占44.08%;3个以上组织发生肿瘤的个体占27.38%。多数肿瘤个体同时伴有胸腺、法氏囊萎缩,脾脏、性腺肿大等症状。经过对发病鸡的肾脏作组织切片观察,发现其基本结构已经消失,伴随大量的淋巴细胞和浆细胞浸润,呈现典型的马立克症状。结果表明,利用2 000 PFU的MDV-GA毒株感染BWEL-SPF鸡可以得到大量的肿瘤样本,可用于探讨马立克淋巴瘤内部的基因变化。

One hundred and thirty four 1-day-old birds were divided randomly into two groups.Challege group included 84 chicks which were injected intraperitoneally with MDV-GA and the rest 50 birds were injected with the same dose of diluent as controls.During sixty-day observation,we found this strain could cause higher incidence of tumor（61.90%） and mortality was 75.00%.Clinical signs occurred from 27 day after infection（27 d.p.i.） to 51 d.p.i.and death appeared during these days,peaking from 28 to 42 d.p.i..Neoplasm mostly occurred in kidney,heart,liver,gonad,spleen,lung,thymus,skin,and proventriculus.The first five tissues had higher incidence of lymphomas and the percentage was 36.90%,28.75%,25.00%,21.43%,and 17.86%,respectively.Moreover,many birds presented lymphoid infiltration in more than one tissue.The birds suffering from lymphoid in more than two or three organs accounted for 44.08% and 27.38%,respectively.Simultaneously,these birds showed intumescence in spleen and gnoad besides atrophy in thyms and bursa of fabricius.To observe histological lesions,we chose kidneys of infected chickens for tissue pathological slices.It showed that basical structure of kidney was lost.Instead,massive lymphocytes and plasmatocytes infiltrated,which were typical MD symptoms.The results showed that many tumor samples could be obtained by inoculating MDV-GA（2 000 PFU） into BWEL-SPF chickens,which could be used to analyse gene expression in lymphomas.