The role of immunoglobulins in immunity to Trypanosoma brucei gambiense

The effects of IgM and IgG antibody molecules were compared on a weight basis by both agglutination and in vitro protection tests. It was shown that IgM is a better agglutinating antibody and in the presence of complement is also a better neutralizing antibody. However, when IgM and IgG were tested for their ability to passively protect infected animals, it was noted that the IgG fraction appeared to give greater protection. Based on differences in diffusion coefficients (and size) of the molecules, it is hypothesized that IgM is the antibody class responsible for the relapse phenomena observed in the blood, while, it is the IgG antibody molecule which is more active in extravascular locations.     

Neuron-derived IgG Protects Neurons from Complement-dependent Cytotoxicity

Passive immunity of the nervous system has traditionally been thought to be predominantly due to the blood-brain barrier. This concept must now be revisited based on the existence of neuron-derived IgG. The conventional concept is that IgG is produced solely by mature B lymphocytes, but it has now been found to be synthesized by murine and human neurons. However, the function of this endogenous IgG is poorly understood. In this study, we confirm IgG production by rat cortical neurons at the protein and mRNA levels, with 69.0 ± 5.8% of cortical neurons IgG-positive. Injury to primary-culture neurons was induced by complement leading to increases in IgG production. Blockage of neuron-derived IgG resulted in more neuronal death and early apoptosis in the presence of complement. In addition, FcγRI was found in microglia and astrocytes. Expression of FcγR I in microglia was increased by exposure to neuron-derived IgG. Release of NO from microglia triggered by complement was attenuated by neuron-derived IgG, and this attenuation could be reversed by IgG neutralization. These data demonstrate that neuron-derived IgG is protective of neurons against injury induced by complement and microglial activation. IgG appears to play an important role in maintaining the stability of the nervous system.     

Maternal Immunization Confers Protection to the Offspring against an Attaching and Effacing Pathogen through Delivery of IgG in Breast Milk

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E.tenella感染雏鸡特异性抗体的动态变化和母源免疫的研究

本实验用斑点酶联免疫试验 (Dot ELISA)检测了E .tenella感染雏鸡特异性抗体、免疫母鸡卵黄和后代血清中特异性母源抗体的动态变化及不同日龄雏鸡的抗球虫水平。结果表明 :(1)雏鸡感染E .tenella后第 6d即可在循环血液中检测到特异性IgG ,于第 18天达到峰值 ,第 30天降至感染后第 7天时的水平。 (2 )母鸡二次免疫后第 5天卵黄中即有高水平的母源抗体 ,免疫母鸡后代 1日龄时母源抗体滴度高达 9.83,与未免疫对照组差异极显著 (P <0 .0 1) ,二者都随着日龄增长降低 ,但免疫组下降幅度很小 ,2 9日龄时仍和对照组 18日龄水平相当。 (3)免疫母鸡后代对再感染的抵抗力显著增强 ,卵囊减少率高达 93%,抗球虫指数和相对增重率都与对照组差异极显著 (P <0 .0 1) ,雏鸡的抗球虫水平随着日龄增长逐渐降低 ;母源抗体、抗球虫指数和相对增重率三者之间两两呈现明显的正相关 ,而这三者又都与卵囊产量呈明显的负相关。     

猪流行性腹泻病毒诱导的猪肠道-乳腺-sIgA轴以及免疫机制探讨

猪的“肠道-乳腺-sIgA轴”免疫通路是指侵染猪的胃肠道病原通过胃肠道免疫可以激发乳腺产生sIgA;sIgA被初生仔猪摄取可以获得针对胃肠道病原的被动免疫保护。该免疫通路的反应动力模式涉及病原侵染、抗原提呈、淋巴细胞活化、淋巴细胞的肠道和乳腺归巢以及抗体分泌等诸多环节,受到病原毒力、母猪的妊娠阶段及免疫生理状态等众多因素影响。目前,猪流行性腹泻病毒（Porcine Epidemic Diarrhea Virus,PEDV）诱发的“肠道-乳腺-sIgA轴”的理论可以解释自然感染状态下哺乳仔猪获得的被动免疫保护,但根据这一概念所设计的疫苗和免疫方案并未取得满意效果。本文综述了PEDV感染和宿主免疫各个环节的研究现状,分析了影响PEDV免疫和肠道-乳腺-sIgA轴系反应的关键病原和宿主因素,提出了在轴系理论基础上应重视PEDV灭活疫苗以及特异IgG作用的建议。     

IgG and IgM levels in dairy cows during the periparturient period

In dairy cows, the incidence of infectious diseases during the periparturient period is high. The most common diseases ante partum (a.p.) and post partum (p.p.) are mastitis and puerperal toxicaemia, puerperal septicaemia, and chronic endometritis, respectively. Studies suggest that this is related to an immunosuppressed status during this period.Therefore, the aim of this study was to determine the periparturient immune status characterized by concentrations of IgG and IgM in peripheral blood and colostrum samples of dairy cows and to assess in detail whether variations in immunoglobulin levels may be related to age and status of productivity. In addition, a possible correlation between the course of immunoglobulin levels and lymphocyte concentrations was assessed.Eighteen clinically healthy German Holstein and Red Holstein dams were selected for this study and sampled regularly between the 8^th week a.p. and the 4^th week p.p. IgG and IgM levels were determined using two novel competitive ELISAs.Results demonstrated a dramatic decrease of serum IgG and IgM levels beginning at the 8^th week and 4^th week a.p., respectively, both reaching trough at parturition. The IgG level recovered by the 4^th week p.p., while IgM concentrations remained low. The extent of IgG reduction seemed to be dependent on the initial IgG concentration when the cow was dried-off (8^th week a.p.). In contrast to IgM, the degree of IgG reduction correlated significantly with the IgG concentrations in the colostrum. Furthermore, a cross-correlation between the IgG levels and the lymphocyte counts was detectable (P < 0.01).In conclusion, the antepartal decline of blood IgG and IgM levels as well as the low periparturient IgG levels could reflect a “physiological phenomenon” of dairy cattle. If the phenomenon is associated with an unstable immune system, it must be assessed in future studies. Nonetheless, a sensitive immune system could explain the high incidence for infectious diseases during this period.     

Commerson's dolphin (Cephalorhynchus commersonii): A discussion of the first live birth within a marine zoological park

Six adult Commerson's dolphins (Cephalorhynchus commersonii) have been housed at Sea World, San Diego, since 1983. Details of their husbandry at Sea World are briefly presented. Pregnancy was determined in one of the females by means of radioimmunoassay, following observations of copulation. Food consumption of the pregnant female decreased beginning 5 days prior to parturition and ceased entirely 6 hours prior to delivery. A single male calf, 55–65 cm in length and weighing 4.5–5.5 kg, was delivered after 35 minutes of labor. Details of the delivery, calf's appearance, suckling behavior, and early respiratory pattern are presented. Similarities between the birth of the Commerson's dolphin calf and previous births of bottlenosed dolphin (Tursiops truncatus) calves are discussed. The successful propagation of new species, such as Commerson's dolphins, permits documentation of the event with greater detail and accuracy than is possible in the wild. Details of growth and reproduction thus gained may provide information applicable to the natural history and proper management of the species in question.     

两步法提纯猪血清IgG得率分析

采用改进的饱和硫酸铵盐析和DEAE-52纤维素层析两步法提纯猪血清IgG,并分析了IgG得率低的可能原因。利用Bradford蛋白浓度测定法、SDS—PAGE测得盐析粗提蛋白得率为12．96mg／mL血清,纯度为61．4％;DEAE层析第一峰蛋白纯度达95．7％,得率为3．9mg／mL血清。结果表明两步法能获得免疫实验要求电泳纯IgG,也发现明显分开的两个层析峰含有相同分子量成分IgG,这是纯化得率低的主因。     

Fasciola hepatica: IgG and IgA levels in the serum and bile of infected cattle

Bile and serum samples were collected from calves with an implanted cannula throughout a 20-week period of infection with Fasciola hepatica. Using indirect fluorescent antibody labelling and plastic-embedded sections of juvenile and adult flukes as antigens, estimates were made of the relative concentrations of IgG and IgA specific for fluke tegumental and gut antigens in the samples of serum and bile. In serum, antibodies against juvenile (t1) tegument and gut antigens reached peak concentrations 4–6 weeks postinfection and declined slowly thereafter as flukes became established in the bile ducts. IgG against adult tegument (t2) antigens appeared in the serum 6 weeks after infection, but no IgA against t2 was detected. In the bile, both IgG and IgA titres against t1 and gut antigens rose to peak values at 4–6 weeks after infection, but there was no activity against t2 antigen. The Ig levels in bile were considerably lower than in serum. Much more IgA relative to IgG occurred in bile as compared to serum (IgG/IgA ratio in serum was 16–32, in bile 1–2) suggesting a role for IgA in defence at mucosal surfaces. Comparison of the antibody profiles in bile and serum suggested that IgG in the bile was derived from circulating IgG whereas IgA may have been preferentially concentrated in the bile.     

血清抗体早期诊断侵袭性念珠菌病的研究进展

近年来,研究者已经评价的大量具有潜在诊断价值标志物,尤其是应用念珠菌特异性抗原的血清抗体早期诊断侵袭性念珠菌病有了长足进展。如HWP1、ENO1等IgG抗体的单个或多个组合快速准确地诊断早期念珠菌病,不仅适用于免疫正常患者,而且适用于免疫受损患者,因此,在临床上具有潜在的巨大的应用价值。     

卵泡液蛋白质组学2-DE体系的构建与应用

卵泡液是在卵泡形成过程中生成的,作为卵母细胞生长和分化的培养基,直接或间接影响卵母细胞的生育力和发育潜能,其成分非常复杂。本研究通过调整,优化2-DE技术条件,建立了相对稳定的卵泡液蛋白质2-DE技术,获得了卵泡液蛋白质组表达图谱,并用PDQuest软件进行了图像分析,用MALDI-TOF MS鉴定了9个蛋白点,其中有四种为新鉴定的在卵泡液中表达的蛋白质。结果表明,该体系稳定性、重复性好,为进一步开展卵泡液蛋白质组学的相关研究奠定了基础。     

断奶仔猪肠道菌群的研究

研究断奶仔猪在不同生理状况下的肠道菌群,结果表明：健康仔猪肠道内容物中,从十二指肠到结肠,所测定的８种细胞数量都随肠段后移而逐渐增加,４３日龄仔猪肠道内容物中以乳杆菌、肠球菌和梭菌占绝对优势,双歧杆菌次之;与健康仔猪相比,下痢仔猪肠道中肠球菌、梭菌和乳杆菌等优势菌群的数量明显低于对照组;饲喂了含肠球菌的活菌制剂的仔猪肠道中双歧杆菌和类杆菌的数量比对照组明显增加,但肠球菌数量却无显著改变。