鸡贫血病雏鸡ND免疫后免疫器官抗体生成细胞动态变化

对感染鸡传染性贫血病毒（ＣＩＡＶ）雏鸡新城疫（ＮＤ）免疫及其强毒攻击后，其免疫器官ｋｋ法氏囊、脾脏和胸腺的ＩｇＧ、ＩｇＭ和ＩｇＡ抗体生成细胞的动态变化进行了检测。结果发现，感染雏鸡ＩｇＧ抗体生成细胞于免疫后７～２８ｄ，在法氏囊和胸腺髓质及脾脏红髓和白髓区明显低于未感染的免疫对照雏鸡；ＩｇＭ生成细胞分别于免疫后７～２８ｄ、７ｄ或１４ｄ明显降低；而ＩｇＡ生成细胞于免疫后２８ｄ，仅在法氏囊髓质区明显减少，表明ＣＩＡＶ感染雏鸡免疫器官对ＮＤ免疫的体液免疫应答降低。ＮＤ强毒攻击后，ＣＩＡＶ感染ＮＤ免疫雏鸡法氏囊、脾脏、胸腺的三种抗体生成细胞均程度不同地低于对照雏鸡，其中ＩｇＧ生成细胞减少最为明显。ＣＩＡＶ感染雏鸡免疫器官抗体生成细胞减少与免疫保护率降低密切相关     

鸡传染性贫血病毒感染胸腺集落刺激因子对骨髓粒单系祖细胞增殖功…

本文研究了鸡传染性盆血病毒感染鸡胸腺ＣＳＦ对正常鸡骨髓粒单系祖细胞增殖功能的影响。结果表明，雏鸡感染ＣＩＡＶ后１４天胸腺ＣＳＦ对ＣＦＵ－ＧＭ刺激作用与对照鸡比较未见明显异常。感染后２１天，刺激作用较对照鸡明显增强；感染２８天以后，其刺激作用达正常鸡水平。结果证明，ＣＩＡＶ感染引起的骨髓造血机能障碍与胸腺ＣＳＦ活性无关。     

鸡传染性贫血病毒感染胸腺集落刺激因子对骨髓粒单系祖细胞增殖功能的影响

本文研究了鸡传染性贫血病毒感染鸡胸腺ＣＳＦ对正常鸡骨髓粒单系祖细胞（ＣＦＵ—ＧＭ）增殖功能的影响．结果表明，雏鸡感染ＣＩＡＶ后１４天胸腺ＣＳＦ对ＣＦＵ—ＧＭ刺激作用与对照鸡比较未见明显异常．感染后２１天，刺激作用较对照鸡明显增强（ｐ＜０．０１）；感染２８天以后，其刺激作用达正常成水平．结果证明，ＣＩＡＶ感染引起的骨髓造血机能障碍与胸腺ＣＳＦ活性无关．     

鸡传染性贫血病骨髓造血细胞分化发育功能变化

本文采用鸡骨髓切片造血细胞分类计数和造血细胞糖类化学等方法检测了鸡传染性贫血病（ＣＩＡ）骨髓造血细胞分化发育功能变化。结果显示，１日龄雏鸡ＣＩＡＶ感染后１４、２１天骨髓红系、粒系、淋巴系和血栓系细胞总数均减少，且各系各阶段发育的幼稚和成熟细胞亦减少，并与外周血细胞的数量变化相一致，表明感染鸡骨髓造血细胞的增殖和分化功能降低与其贫血和全血细胞减少密切相关     

感染鸡传染性贫血病毒（CIAV）雏鸡免疫器官抗体生成细胞的动态变化

对１日龄雏鸡感染鸡传染性贫血病毒（ＣＩＡＶ）后免疫器官法氏囊、脾脏和胸腺的ＩｇＧ、ＩｇＭ、ＩｇＡ抗体生成细胞数量的动态变化进行了检测。结果发现,感染雏鸡法氏囊、脾脏和胸腺的３种抗体生成细胞数量均程度不同地低于未感染对照雏鸡,其中法氏囊的ＩｇＧ、ＩｇＭ抗体生成细胞和ＩｇＡ抗体生成细胞分别在感染后７～３５ｄ和１４～３５ｄ明显减少;脾脏红髓、白髓和淋巴小结的ＩｇＧ抗体生成细胞分别于７～３５ｄ、１４～３５ｄ和１４～２１ｄ明显减少,ＩｇＭ抗体生成细胞分别在７～４２ｄ、２８～３５ｄ和１４ｄ时明显减少,ＩｇＡ抗体生成细胞仅在红髓中（７～２８ｄ）明显减少;胸腺髓质的ＩｇＧ、ＩｇＭ、ＩｇＡ抗体生成细胞分别在１４～２８ｄ、７～２１ｄ和２１ｄ时明显减少。结果表明,ＣＩＡＶ感染雏鸡免疫器官的体液免疫功能明显降低。     

鸡传染性贫血病骨髓造血微环境的研究

对１日龄雏鸡感染ＣＩＡＶ后骨髓造血微环境的变化进行了动态观察。结果显示，ＣＩＡＶ感染后７～２１天，骨髓基质中性粘多糖减少、酸性粘多糖增多，表明造血微环境基质粘多糖对红系造血细胞的增殖、分化和成熟具有一定的抑制作用。骨髓成纤维祖细胞体外增殖功能，成纤维细胞，内皮细胞等基质细胞的形态学均未见明显异常，表明骨髓造血微环境的细胞不是ＣＩＡＶ作用的靶细胞，这对鸡感染后期造血功能的恢复具有重要意义     

鸡传染性贫血病骨髓造血微环境的研究

对１日龄雏鸡感染ＣＩＡＶ后骨髓造血微环境的变化进行动态观察，结果显示，ＣＩＡＶ感染后７～２１天，骨髓基质中性粘多糖减少，酸性粘多糖增多，表明造血微环境基质粘多糖对红系造血细胞的增殖，分化和成熟具有一定的抑制作用，骨髓成纤维祖细胞代体外增殖功能，成纤维细胞，内皮细胞等基质细胞的均形态学均未见明显异常，表明骨髓造血微环境的细胞不是ＣＩＡＶ作用的靶细胞，这对鸡感染后期造血功能的恢复具有重要意义。     

鸡贫血因子病全身免疫功能变化的研究

用鸡贫血病毒（ＣＡＶ）感染１日龄ＡＡ雏鸡,以未感染同龄ＡＡ雏鸡为对照,感染后不同时间检测其外周血液Ｔ、Ｂ细胞数量和ＩｇＧ,ＩｇＭ,ＩｇＡ含量,胸腺,法氏囊,脾脏ＩｇＧ,ＩｇＭ,ＩｇＡ抗体生成细胞和Ｔ细胞数量以及Ｔ、Ｂ细胞增殖功能;胸腺和脾脏白细胞介素２（ＩＬ－２）和干扰素（ＩＦＮ）诱生活性等的动态变化。     

鸡贫轿病雏鸡ND免疫后免疫器官抗体生成细胞动态变化

对感染染鸡传染性贫血病毒（ＣＩＡＶ）雏鸡新城疫（ＮＤ）免疫及其强毒攻击后，其免疫器官－－法氏囊、脾脏和胸腺和ＩｇＧ、ＩｇＭ和ＩｇＡ抗体生成细胞的动态变化进行了检测。结果发现，感染雏鸡ＩｇＧ抗体生成细胞于免疫后７～２８ｄ、在法氏囊和胸腺髓质及脾脏红髓和白髓区明显低于未感染的免疫对照雏鸡；ＩｇＭ生成细胞分别于免疫后７～２８ｄ、７ｄ或１４ｄ明显降低；而ＬｇＡ生成细胞于免疫后２８ｄ，公在法氏囊髓质区明显减     

感染CIAV雏鸡岛免疫器官对ND疫苗的细胞免疫应答

对１日龄感染ＣＩＡＶ雏鸡接种ＮＤ疫苗后，其免疫器官组织Ｔ细胞数量的动态变化研究，结果，感染ＣＩＡＶ雏鸡ＮＤ疫苗免疫后，其胸腺和脾脏以及盲肠桃体和哈德尔腺的Ｔ细胞数量，于接种ＮＤ疫苗后较未感染ＣＩＡＶ免疫对照雏鸡明显减少，表明感染雏鸡的中枢和外周免疫器官及局部免疫组织对ＮＤ疫苗的细胞免疫应答功能降低，ＮＤ强毒攻击后，感染免疫鸡的免疫保护率明显低于未感染免疫对照鸡。     

鸡贫血病毒实验感染雏鸡胸腺与骨髓的超微结构观察

用鸡贫血病毒 Ｃｕｘ １ 毒株接种于 １ 日龄 Ｓ Ｐ Ｆ 雏鸡，在确认感染成功的基础上，对感染雏鸡胸腺和骨髓的超微结构进行了观察。电镜观察表明，感染鸡骨髓和胸腺细胞的形态变化具有较典型的凋亡特征，如细胞膜出泡、核染色质凝结边集、细胞核裂解、出现凋亡小体等，此外还见有可能由病毒粒子形成的环状物。本试验为证明鸡贫血病毒能引起细胞凋亡提供了依据。     

一株鸡传染性贫血病毒对不同日龄SPF鸡的致病性研究

为评价鸡传染性贫血病毒AV1550株的致病性,取1日龄、7日龄和14日龄SPF鸡分别经胸部肌肉注射不同病毒含量的病毒液,同时设置正常对照,隔离饲养观察21日。感染后14日采血测定红细胞压积,21日统计死亡率、体重变化以及胸腺、骨髓、法氏囊病变情况并测定1日龄SPF鸡感染后不同组织中的病毒载量。结果表明,1日龄SPF鸡感染AV1550株后,表现出精神沉郁、增重减缓、贫血等明显的临床症状,死亡率为53.9%;死亡鸡或观察期结束时存活鸡剖检,可见胸腺萎缩,骨髓变成淡黄色;不同剂量感染后14日,均能引起红细胞压积显著下降;21日时,胸腺病毒载量最高,可达106.7copies/mg 。7日龄SPF鸡感染后,出现增重减缓,高感染剂量（100000EID50）出现贫血,部分鸡出现胸腺萎缩和骨髓病变,但病变率低于30%。14日龄SPF鸡感染后,不引起明显临床症状。研究证实,CAV对SPF鸡的致病性具有明显的日龄依赖性,红细胞压积降低、骨髓病变、胸腺萎缩以及胸腺病毒载量测定可作为评价CAV致病的指标。     

Pathogenesis of chicken anemia virus: comparison of the oral and the intramuscular routes of infection

The events during the pathogenesis of chicken anemia virus (CAV) infection following intramuscular (IM) and oral inoculation were further elucidated and compared by sequential clinical, pathologic, and morphometric histopathologic evaluations, and by sequential determination of CAV genome concentrations in different organs. Specific-pathogen-free chickens were inoculated by IM or oral routes with the same dose (2 x 10(6) mean tissue culture infective dose [TCID50]) of CAV isolate 03-4876 at 1 day of age. Weights and hematocrits were obtained at 7, 10, 14, 18, 21, 25, and 28 days postinoculation (DPI). Seven birds from each group were necropsied at 7, 10, 14, and 28 DPI, and samples of thymus, Harderian gland, and cecal tonsils (CT) were obtained for histopathologic examination and CAV genome quantification by real-time polymerase chain reaction. Peak CAV genome concentrations were detected in the thymus at 10 and 14 DPI in the IM and orally infected chickens, respectively. High CAV DNA concentrations were maintained throughout the experimental period until 28 DPI, despite specific seroconversion occurring by 14 DPI in the IM-inoculated chickens. CAV was isolated from both orally and IM-infected chickens 28 DPI. Peak CAV genomes in the thymuses of IM and orally infected chickens coincided with peak lymphocyte depletion in these organs. Lymphocyte repopulation of the thymus occurred by 28 DPI in spite of the presence of the virus in the organs of both infected chicken groups. CAV genomes were detected in the CT, but histopathologic changes were not observed. Compared with the IM route of infection, orally infected chickens did not show apparent signs of illness. Clinical parameters, including reduction of weight gains and hematocrits, and gross and histopathologic changes were delayed and less severe in the orally inoculated chickens. This was concurrent with a delay in accumulation of CAV genomes in the thymus of these chickens.     

PCR和斑点杂交检测鸡传染性贫血病毒

通过聚合酶链反应（ｐｃＲ）扩增鸡传染性贫血病毒（ｃＡＶ）ＤＮＡ特定片段，将此ｐｃＲ产物用Ｄｉｇｏｘｉｇｅｎｉｎ标记后作为探针进行斑点杂交，以此检测ＣＡＶ并作流行病学调查。对从江苏省不同地市随机采集的２月龄左右不同疾病的病鸡ＤＮＡ样品进行检测，在被检的５２个不同鸡群来源的病料中，有３６个鸡群来源的病料ＤＮＡ显示ＣＡＶ阳性（群阳性率为６９．２％）；备组织中ＣＡＶＤＮＡ含量有所差异，依次为胸腺＞脾、骨髓、肝＞肾、法氏囊、脑。用ＰＣＲ检测得到的阳性鸡的组织病料感染ＳＰＦ鸡，在感染后第２４天检查，出现贫血症状。初步调查表明，在江苏一些地区ＣＡＶ感染已相当普遍，但它与发病的关系还有待于进一步研究。     

Studies on the pathogenesis of chicken infectious anaemia virus infection in six-week-old SPF chickens

The pathogenesis of chicken infectious anaemia virus (CAV) infection was studied in 6-week-old and one-day-old SPF chickens inoculated intramuscularly with graded doses of Cux-1 strain (10(6)-10(2) TCID50/chicken). Viraemia, virus shedding, development of virus neutralizing (VN) antibodies and CAV distribution in the thymus were studied by virus isolation, polymerase chain reaction (PCR), immunocytochemistry (IP) and in situ hybridization until postinfection day (PID) 28. In 6-week-old chickens infected with high doses of CAV, viraemia and VN antibodies could be detected 4 PID and onward without virus shedding or contact transmission to sentinel birds. However, virus shedding and contact transmission were demonstrated in one-day-old infected chickens. In the 6-week-old groups infected with lower doses, VN antibodies developed by PID 14, transient viraemia and virus shedding were detected. The thymus cortex of all 1-day-old inoculated chickens stained with VP3-specific mAb. Cells with positive in situ hybridization signal were fewer and scattered throughout the thymus tissue of the one-day-old inoculated chickens as compared to IP-positive cells. These results suggest that early immune response induced by high doses of CAV in 6-week-old chickens curtails viral replication and prevents virus shedding.     

Isolation and preliminary characterization of chicken anemia virus from chickens in Nigeria

Chicken anemia virus (CAV) was isolated for the first time from the Nigerian chicken population. The virus was recovered from necropsied birds from broiler and pullet flocks that suffered disease outbreaks tentatively diagnosed as infectious bursal disease. A sensitive polymerase chain reaction (PCR) assay detected CAV DNA in tissues of necropsied birds. Restriction endonuclease analysis performed with the 733-bp PCR product and the Cfo I enzyme indicated at least two different CAVs were circulating among the Nigerian chicken population. Four isolates were obtained from pooled liver and thymus tissues using the MDCC-MSB1 cell line. These isolates were found to be antigenically closely related to the Cuxhaven-1 (Cux-1) reference strain of CAV when reacted with four monoclonal antibodies prepared against the Cux-1 virus. One of the isolates (isolate A) induced thymus atrophy, bone marrow aplasia, and low hematocrit values when inoculated into 1-day-old specific-pathogen-free chickens. These findings not only demonstrate that CAV is present in Nigeria, but they also likely represent the first cell culture isolation of the virus in Africa.     

Pathological and immunohistochemical studies of subclinical infection of chicken anemia virus in 4-week-old chickens

Subclinical infection of chicken anemia virus (CAV) at 4 to 6 weeks of age, after maternal antibodies have waned, is implicated in several field problems in broiler flocks. In order to understand the pathogenesis of subclinical infection with CAV, an immunopathological study of CAV-inoculated 4-week-old SPF chickens was performed. Sixty 4-week-old SPF chickens were equally divided into CAV and control groups. The CAV group was inoculated intramuscularly with the MSB1-TK5803 strain of CAV. Neither mortality nor anemia was detected in the CAV and control groups. In the CAV group, no signs were observed, except that some chickens were grossly smaller compared with the control group. Sporadic thymus lobes appeared to be reddening and atrophied. Within the first two weeks p.i. of CAV, there was a mild to moderate depletion of lymphocytes in the thymus cortex and spleen in some chickens. Moreover, lymphoid depletion of the bursa of Fabricius, proventriculus and cecal tonsils was observed. Hyperplastic lymphoid foci were observed in the liver, lungs, kidneys and heart at the 4th week p.i. of CAV. Immunohistochemically, a moderate lymphoid depletion of CD4(+)and CD8(+) T cells in the thymus cortex and spleen was observed in some chickens within two weeks p.i. of CAV. CAV inclusions and antigens were detected infrequently in the thymus cortex and spleen. It could be concluded that the immunosuppression in subclinical infection with CAV occurs as a result of reduction of cellular immunity.     

鸡贫血病毒感染鸡细胞凋亡研究

用TUNEL法检测了1 日龄SPF雏鸡感染鸡贫血病毒(CAV)后胸腺和骨髓细胞的凋亡情况。结果,接种CAV 后6、10、20 d,骨髓细胞的凋亡率分别达51% 、52% 、57% ;接种后6 d,胸腺细胞凋亡率为53% ,比对照鸡胸腺和骨髓细胞的凋亡率明显升高( P< 0.01)。用流式细胞仪对胸腺细胞悬液所作的细胞凋亡分析结果与TUNEL法检测结果一致。     

Chicken anemia virus in broilers: dynamics of the infection in two commercial broiler flocks

Chicken anemia virus (CAV) can cause a disease syndrome characterized by severe anemia, bone marrow atrophy, and severe immunosuppression in young chicks. Maternal antibodies prevent these clinical signs but do not prevent infection, transmission of the virus, or immunosuppression. The clinical disease is rare today because of the widespread practice of vaccinating breeders, but the subclinical form of the disease is ubiquitous. The dynamics of CAV infection, CAV antibody responses, relative lymphoid organ weights, and associated lesions were studied in two broiler flocks from a commercial producer. Both groups had detectable CAV antibodies at hatch, which waned over the first 3 wk of life. Both groups had detectable CAV DNA in both thymi and bursae over the same period. At 35 days of age, virus was detectable by polymerase chain reaction in 16 of 20 chickens, and 7 of 20 had detectable antibodies. By 42 days of age, virus was detectable in 18 of 20 chickens, and 18 of 20 had antibodies to CAV. We observed a decrease in relative thymic weights beginning at 35 days of age, coincidental withthe detection of CAV in the thymus. Bursal sizes began to decrease at 28 days of age, coincidental with a rise in antibody titers to infectious bursal disease virus. In this study, we demonstrated that under typical field conditions CAV infections in broilers have unique dynamics unlike those reported in egg laying strains of chickens managed under specific-pathogen-free conditions.     

Biological and molecular characterization of chicken anemia virus isolates from Slovenia

The presence of chicken anemia virus (CAV) in Slovenia was confirmed by inoculation of 1-day-old chickens without antibodies against CAV and isolation of the virus on the Marek's disease chicken cell-MSB1 line and by polymerase chain reaction (PCR). Experimental inoculation of 1-day-old chickens resulted in lower hematocrit values, atrophy of the thymus, and atrophy of bone marrow. CAV was confirmed by PCR in the thymus, bone marrow, bursa of Fabricius, liver, spleen, ileocecal tonsils, duodenum, and proventriculus. The nucleotide sequence of the whole viral protein (VP)1 gene was determined by direct sequencing. Alignment of VP1 nucleotide sequences of Slovenian CAV isolates (CAV-69/00, CAV-469/01, and CAV-130/03) showed 99.4% to 99.9% homology. The VP1 nucleotide sequence alignment of Slovenian isolates with 19 other CAV strains demonstrated 94.4% to 99.4% homology. Slovenian isolates shared highest homology with the BD-3 isolate from Bangladesh. Alignment of the deduced VP1 amino acids showed that the Slovenian isolates shared 100% homology and had an amino acid sequence most similar to the BD-3 strain from Bangladesh (99.6%) and were 99.1% similar to the G6 strain from Japan and the L-028 strain from the United States. The Slovenian isolates were least similar (96.6%) to the 82-2 strain from Japan. A phylogeneric analysis on the basis of the alignment of the VP1 amino acids showed that CAV isolates used in the study formed three groups that indicated the possible existence of genetic groups among CAV strains. The CAV isolates were grouped together independent of their geographic origin and pathogenicity.