鸡脾脏中T淋巴细胞及其亚群的发育

利用免疫组化法结合计算机图像分析技术研究鸡不同生长发育阶段T淋巴细胞及其亚群在脾脏中的发育过程。研究发现,CD3+和CD8+T淋巴细胞最早出现在18日龄鸡胚,CD4+细胞出现在20日龄鸡胚。随着日龄增长,CD3+、CD4+和CD8+T淋巴细胞的数量均呈上升趋势,在21日龄雏鸡脾脏中达到稳定。CD3+和CD8+细胞在动脉周围淋巴鞘和红髓中大量分布,而CD4+细胞主要分布在动脉周围淋巴鞘中。脾小体中也存在CD4+细胞,但不存在CD8+细胞。CD4+细胞数量始终少于CD8+细胞,两者的比值基本维持在0.3～0.5。结果表明,鸡出壳后初期,脾脏的细胞免疫功能迅速增强,并在21日龄时达到成熟水平。     

鸡回肠中T淋巴细胞及其亚群发育的试验

为探寻鸡回肠中T淋巴细胞及其亚群的发育规律,本试验通过免疫组织化学方法,应用CD3、CD4和CD8单克隆抗体研究鸡回肠中T淋巴细胞及其亚群出现、迁移、定位分布及数量变化过程.结果显示,CD3+、CD8+T淋巴细胞最初于18胚龄时出现,CD4+T淋巴细胞于出壳后1日龄时出现.在定位分布上,CD3+细胞在黏膜上皮内以及固有层中均匀分布,CD4+细胞以固有层中的分布为主,黏膜上皮内的分布较少.CD8+细胞最初主要分布在黏膜固有层中;随后,CD8+细胞逐渐向上皮内迁移;最终,黏膜上皮内出现广泛的CD8+细胞浸润.在数量变化上,CD3+、CD4+及CD8+整体呈逐渐增加趋势,第2周时阳性细胞数量稍有下降,21日龄时显著增加到达较高水平后保持稳定.结果表明,鸡出壳后,回肠的细胞免疫功能逐渐增强,并在21日龄时到达成熟水平.     

Characterization of two monoclonal antibodies which recognize different subpopulations of chicken T lymphocytes

Distribution among peripheral T lymphocyte subpopulations and biochemical properties of the chicken lymphocyte surface antigens defined by monoclonal antibodies (mAbs) Lc-4 and Lc-6 were examined. Two-color immunofluorescence analysis revealed that Lc-4 and Lc-6 antigens were expressed on mutually exclusive subpopulations of peripheral T lymphocytes but not on B lymphocytes. Lc-4 mAb precipitated a polypeptide with apparent molecular mass of 35 and 65 kilodalton under reducing and non-reducing conditions, respectively. These results indicated that the antigen recognized with Lc-4 was closely similar in tissue distribution and biochemical property to mammalian CD8 antigen.     

Presence of natural suppressor cells in the chicken embryo spleen and the effect of virus infection of the embryo on suppressor cell activity

Spleen cells but not the thymus or the bursa cells of chicken embryos suppressed the in vitro mitogenesis of spleen cells of adult syngeneic or allogeneic chickens. The natural suppressor cell activity of embryo spleen was present at embryonation day 16, reached peak levels at embryonation day 18 and disappeared at hatch. The embryo spleen cells did not by themselves respond to phytohemagglutinin stimulation in vitro. The suppressive effect of embryonic spleen cells on adult spleen cells was present when the embryonic cells were added at the time of or after initiation of the adult spleen mitogenic cultures. When the embryonic cells were added to the cultures of adult spleen cells after the blastogenic response of the adult cells had peaked, the embryonic cells inhibited the incorporation of the label into adult spleen cell blasts. The suppressive activity of the embryonic spleen cells was mediated by soluble suppressor product(s) secreted by these cells, and direct cell-to-cell contact between embryonic and adult spleen cells was not necessary for suppression to occur. Infection of embryos with turkey herpesvirus and Marek's disease virus reduced the suppressor cell activity of embryonic spleen, although substantial residual suppressor cell activity remained in virus-infected embryos. Several pathogenic or non-pathogenic isolates of infectious bursal disease virus did not appreciably alter the suppressor cell activity of embryonic spleen cells.     

Studies on the mode of action of anticoccidial drugs in the chicken and chicken embryo

Delayed treatment has been used to investigate the activity of anticoccidials against the Houghton strain and an embryo-adapted strain of E. tenella. The results show that in chicken embryos the effect of the quinolones and clopidol depends upon the concentration of drug employed. The earlier stages in the life cycle appear to be intrinsically more vulnerable to the action of these drugs. In the chicken, the activity of amprolium was restricted to early stages in the life cycle, but in the chicken embryo, where development is restricted to the thin chorioallantoic membrane, all stages present up to 72 h after inoculation were equally affected. Absorption and distribution may, therefore, limit the action of amprolium in the chicken. Robenidine and sulphaquinoxaline were equally active up to 72 h post inoculation in chickens and chicken embryos, suggesting that absorption and distribution do not limit the activity of these drugs.     

鸡胚成纤维细胞的冷冻保存

试验研究了不同的冷冻保护液、不同的平衡方法对鸡胚成纤维细胞活力的影响及细胞复苏后的培养情况。结果表明,冷冻保护液Ⅰ和冷冻保护液Ⅱ对细胞的保护效果差异不显著(P>0 05),冷冻保护液Ⅲ对细胞的保护效果优于冷冻保护液Ⅰ和冷冻保护液Ⅱ,并且差异极显著(P<0 01);平衡方法Ⅰ和平衡方法Ⅱ对细胞的存活率影响差异不显著(P>0 05)。复苏后的鸡胚成纤维细胞于体外培养时存在贴壁迟缓,前期生长速度较慢等现象。     

IBDV B87株不同鸡胚代次毒力和细胞嗜性差异的比较研究

对IBDV疫苗株:B87的鸡胚传代毒E2和E6的VP2片段进行测序和分析,发现两个代次毒株VP2序列存在7个氨基酸的差异,即S76G、L217S、Q253H、D279N、A284T、I294.L、S330R。将E2和E6接种CEF细胞,E2不能在CEF'上增殖,而接种E6的CEF细胞可以产生明显的CPE,说明两个毒株对CEF的嗜性不同。分别将E2和E6接种3周龄SPF鸡,对鸡的毒力进行比较,接种后第7天开始,E2出现囊体比下降,BB指数明显低于E6,相应的法氏囊切片经HE染色后,接种E2的法氏囊滤泡萎缩严重,结构松散,E6只有部分滤泡出现萎缩,滤泡间隔基本正常,说明E2,E6对SPF'鸡法氏囊毒力存在明显差异。根据两个毒株的VP2序列差异以及相关研究,推测Q253H/D279N/A284T三个位点突变可能是IBDV毒力和细胞嗜性差异的分子基础,但另外4个位点也可能对IBDV毒力差异产生影响。     

鹅副粘病毒对鸡胚及雏鸡致病性的初步研究

鹅副粘病毒是一种引起多种家禽疾病的病毒,通过人工感染鸡胚和雏鸡试验,其结果表明本病毒主要以呼吸系统、消化系统病变为主要临床症状和特征,并且可导致10日龄的鸡胚100％死亡,对雏鸡的致死率为85％。因此,可见其致死率高,广大养殖户应重视鹅副粘病毒的预防。     

镉致鸡胚胫骨软骨发育不良的研究

为了研究镉对鸡胚胫骨软骨发育的影响,选取体重相近的SPF鸡胚120枚随机分为4组,每组30枚,孵化6 d后在鸡胚气室打孔,其中对照组向卵黄囊注射PBS50μL,其他3组分别向卵黄囊注射0.05、0.1和0.2 mg/mL醋酸镉50 μL,处理10d,通过石蜡切片HE染色、阿利新蓝染色观察胫骨软骨发育情况;扫描电镜观察软...     

鸽新城疫病毒在鸡胚上的增殖动态

采用红细胞凝集试验（HA），通过对鸽新城疫病毒（NDV）在鸡胚上增殖动态的研究表明，ND－gs01病毒经尿囊腔接种9－10日龄鸡胚、24h内病毒处于“掩蔽期”，24h后开始增殖，72h左右鸡胚死亡。新城疫病毒在尿囊膜、羊膜、尿囊液、羊水中含量较高，增殖动态趋于一致。卵黄、胚体中含量较低。上述结果，为该病毒的进一步研究和应用提供了科学依据。     

新城疫病毒在鸡胚中增殖特性的研究

本研究将接种到9～10日龄鸡胚中的鸡新城疫病毒(NDV)La Sota或V4株弱毒培养24h,病毒滴度可增加106以上,培养108 h,病毒滴度则增加至10 10倍以上.NDV在有NDV母源抗体的普通鸡胚与无抗体的SPF鸡胚中的增殖无显著差异;盲传对于检验NDV没有意义.La Sota或V4株病毒悬液在理论上稀释至每胚接种量只有数个或1个病毒时,仍可引起鸡胚感染.低毒量条件下固定病毒的数量,随着接种胚数的增加,感染率随之下降,但感染数在一定范围内波动,没有减少趋势.以上结果证实数个甚至1个活的NDV粒子即可引起鸡胚感染,这对现地检测NDV具有重要意义.     

Strain differences in whole-body protein turnover in the chicken embryo.

1. Whether or not there is a strain difference in embryonic whole-body protein turnover rates was tested using the chicken embryos of Rhode Island Red carrying a sex-linked dwarf gene (dwarf), White Leghorn (layer), and White Cornish X White Plymouth Rock (broiler) strains on day 12 of incubation. 2. Whole-body protein synthesis was estimated by injecting L-[15N]-phenylalanine either intraperitoneally or intravenously on day 12 of incubation in order to investigate the effect of the route of isotope administration. The results showed that the values for fractional and absolute synthesis rates were approximately 13% higher by intravenous injection than by intraperitoneal injection. 3. Whole-body protein turnover, both in terms of fractional and absolute rates, was significantly faster in dwarf than in broiler embryos, with intermediate values in layer embryos, although no growth differences were observed on day 12. 4. Difference in egg weight, measured before incubation, did not affect protein turnover. 5. It was concluded that the strain difference manifested in whole-body protein turnover of the chicken embryo would probably be a reflection of differences in genetic background.     

The chicken pituitary expresses an ovoinhibitor-like protein in subpopulations of some, but not all, hormone-producing cell types

Ovoinhibitor is a serine protease-inhibiting protein that was originally purified from egg whites. It is secreted by the oviduct under the control of estrogen and progesterone and it specifically inhibits serine proteinases such as trypsin and chymotrypsin. During recent attempts to raise monoclonal antibodies (Mabs) against chicken bursa of Fabricius proteins, one Mab was produced that specifically recognized chicken ovoinhibitor. This was the first demonstration of ovoinhibitor in an avian immune organ. We presently report on the expression of an ovoinhibitor-like molecule by the pituitary of the chicken as revealed by immunocytochemistry and RT-PCR. Immunofluorescent dual staining experiments using the mouse anti-ovoinhibitor Mab in conjunction with polyclonal antibodies against various hypophysial hormones revealed partial co-localization of an ovoinhibitor-like molecule with growth hormone (GH), luteinizing hormone (LH), and pro-opiomelanocortin (POMC), in a subset of the respective hormone producing cells. By contrast, no co-localization with prolactin (PRL) could be reliably demonstrated. RT-PCR of hypophysial mRNA using ovoinhibitor gene-specific primers yielded an amplicon that was 20% shorter than predicted on the basis of the published ovoinhibitor sequence. Sequencing revealed that of the represented exons only the central portion was expressed in the pituitary and that both 5′ and 3′ ends of each exon had been truncated. While expression of ovalbumin-like serine protease inhibitors (serpins) has been previously reported in the rat pituitary, to our knowledge, this is the first report of a Kazal-type serine protease inhibitor in the vertebrate neuroendocrine system.