Neutralization of sensitized virus by the fourth component of complement

Herpes simplex virus which had been sensitized with IgM antibody was not neutralized by the addition of the purified activated first component of complement. In the presence of an optimum concentration of the first component of complement, however, the sensitized virus was neutralized by the addition of a high concentration of the purified fourth component of complement. Under these conditions, the addition of the purified second and third components of complement failed to enhance virus neutralization. With low concentrations of the fourth component of complement, the addition of the second and third components enhanced virus neutralization.     

Evidence for in vivo reaction of antibody and complement to surface antigens of human cancer cells

The immune adherence test was used to determine whether antibody and complement in cancer patients are fixed in vivo to tumor cells. Human erythrocytes adhered in vitro to the surface of human cancer cells obtained from autopsy and biopsy. Adherence was enhanced by further addition of the C2 and C3 components of complement, and was diminished by preliminary treatment with antibody to C3 (that is, to beta1C-globulin). The results suggest that tumor associated membrane antigens form complexes in vivo with antibodies and complement.     

Inhibition of the complement cascade by the major secretory protein of vaccinia virus

The complement system contributes to host defenses against invasion by infectious agents. A 35-kilodalton protein, encoded by vaccinia virus and secreted from infected cells, has sequence similarities to members of a gene family that includes complement control proteins. Biochemical and genetic studies showed that the viral protein binds to derivatives of the fourth component of complement and inhibits the classical complement cascade, suggesting that it serves as a defense molecule to help the virus evade the consequences of complement activation.     

Complement: substitution of the terminal component in immune hemolysis by 1,10-phenanthroline

The participation of metal ions in the terminal step of immune cytolysis was investigated with chelating agents. 1,10-Phenanthroline induced lysis of sensitized sheep erythrocytes which had reacted with the first eight components of human complement. Hemolysis caused by 1,10-phenanthroline resembled lysis produced by the ninth component of complement in dependence on cell-bound eighth component and on temperature and in inhibition by 0.09M ethylenediaminetetraacetic acid. Bivalent metal ions reduced the hemolytic capacity of 1,10-phenanthroline, and Fe(++) inhibited the activity of the ninth component. Since trivalent iron had no such effects, it is postulated that the hemolytic activity of 1,10-phenanthroline and the ninth component of complement is a function of their affinity for Fe(++).     

Biosynthesis of C4 (fourth component of complement) by hybrids of C4-deficient guinea pig cells and HeLa cells

Peritoneal exudate cells from guinea pigs homozygous for a genetic deficiency of the fourth component of complement (C4) were fused in vitro with a cell line of human origin (HeLa). The resulting hybrid cells, derived from cell lines each incapable of C4 synthesis by themselves, synthesized functionally active human C4.     

Genetic defect in biosynthesis of the precursor form of the fourth component of complement

Under cell-free conditions, liver polysomes from guinea pigs genetically deficient in the fourth component of complement (C4) did not synthesize pro-C4 (the precursor of C4), but did synthesize nascent C4 polypeptides which remained polysome bound. The defect was specific for pro-C4 synthesis since the amounts of total protein and albumin synthesis and release from C4-deficient polysomes were similar to that in normal guinea pig liver polysomes.     

硬骨鱼补体系统的研究进展

综述了各种硬骨鱼物种具体的补体成分的特点,以及鱼类补体在调理、吞噬、免疫应答、炎症介导及病原体的防御和清除中的作用,并从生理角度评估了影响补体活性水平及其组分的因子,此外,笔者还提出了一些硬骨鱼补体系统未来的研究方向。     

Structure of C8alpha-MACPF reveals mechanism of membrane attack in complement immune defense

Membrane attack is important for mammalian immune defense against invading microorganisms and infected host cells. Proteins of the complement membrane attack complex (MAC) and the protein perforin share a common MACPF domain that is responsible for membrane insertion and pore formation. We determined the crystal structure of the MACPF domain of complement component C8alpha at 2.5 angstrom resolution and show that it is structurally homologous to the bacterial, pore-forming, cholesterol-dependent cytolysins. The structure displays two regions that (in the bacterial cytolysins) refold into transmembrane beta hairpins, forming the lining of a barrel pore. Local hydrophobicity explains why C8alpha is the first complement protein to insert into the membrane. The size of the MACPF domain is consistent with known C9 pore sizes. These data imply that these mammalian and bacterial cytolytic proteins share a common mechanism of membrane insertion.     

Homograft target cells: contact destruction in vitro by immune macrophages

Specific adherence of immune macrophages to monolayers of target cells is a passive phenomenon which represents only the first step in the mutually destructive interaction of immune macrophages and target cells. A specific hemagglutinin, responsible for specific adherence, was eluted from well-washed immune macrophages by heat treatment. The nature of the events in the interaction subsequent to adherence are unknown, but apparently demand the biosynthetic activities of the immune macrophage.     

Mouse complement: influence of sex hormones on its activity

Sex hormones influence the hemolytic of one or more of the late-acting components of complement measured in the presence of trisodium ethylenediaminetetraacetate. The titers of the serums of male mice, normally tenfold higher than those of females, fell after castration, becoming about the same as those of females. The titers of the serums from females rose after these mice were castrated, but castration did not affect the activities of the first, second, and fourth components of complement. Serums of normal and castrated mice of both sexes treated with testosterone showed increased late-acting component activity, whereas the estrogen caused decreased activity. Treatment in vitro of mouse serum with these hormones had no effect on the activity of late-acting components.     

Anaphylatoxin in its relation to the complement system

The fifth component of complement that reacts hemolytically in the guinea pig or rat complement system, C'3b, is intimately associated with the generation of anaphylatoxin. Anaphylatoxin was formed (i) if this purified component reacted with a washed, intermediate complex consisting of antigen, antibody, and the first four components of complement; (ii) if the component was treated with trypsin; or (iii) if the component was incubated with a material isolated from cobra venom together with a fraction from serum other than complement. The significance of this fifth component as anaphylatoxinogen is discussed, and a common mechanism is proposed for the generation of anaphylatoxin in whole serum.     

中药对隐性乳房炎奶牛红细胞免疫粘附功能的影响

用黄芪、白芍、当归、川芎、蒲公英、王不留行、益母草等中药组方 ,对患隐性乳房炎泌乳黑白花奶牛进行阶段性添加试验 ,于试验前后测试红细胞 C3 b花环、红细胞免疫复合物花环及红细胞 C3 b花环促进率和抑制率 ,并检测隐性乳房炎转阴情况。结果表明 ,隐性乳房炎患牛红细胞免疫功能较低 ,用药后红细胞免疫功能明显提高。中药治疗隐性乳房炎的有效率达 83%。     

Host immunoglobulin G and complement deposits in the choroid plexus during spontaneous immune complex disease

Hybrid (NZB x W)F(1) mice spontaneously develop antibodies to nuclear antigens (ANA) and DNA (ADNA) and are an animal model of human systemic lupus erythematosus. Immunofluorescent and electron microscopic observations of the choroid plexus and renal glomeruli of (NZB x W)F(1) mice reveal deposits of host immunoglobulin G (IgG) and the third complement component which appear shortly after the development of ANA and ADNA in the circulation. Additionally, enhancement of ADNA responses accelerates the appearance and severity of IgG deposits in the choroid plexus. The choroid plexus may be a favored site for the deposition of immune complexes and the neuropsychiatric findings in patients with systemic lupus erythematosus and some patients with acute or chronic infections may be related in part to immune complex disease of the choroid plexus.     

Fc and C3b receptors on pulmonary endothelial cells: induction by injury

Receptors for the activated third component of complement and for the Fc portion of immunoglobulin G are not expressed by apparently normal bovine pulmonary endothelial cells, but are expressed when the cells are exposed to white cell lysates or are infected with influenza or cytomegalovirus. The unmasking of these latent receptors may contribute to the pulmonary inflammatory response characteristic of, for example, anaphylaxis and to those lung diseases characterized by the deposition of immune complexes.     

雏鸡感染vMDV后红细胞免疫功能的变化

1日龄AA肉用雏鸡马立克氏病强毒(vMDV)人工感染后,马立克氏病(MD)发病率4875%,MD死亡率为1645%,红细胞EC3bR花环率、EIC花环率呈现先升高后降低的变化。     

鹅源H5N1禽流感病毒感染对雏鸭红细胞免疫功能的影响

将100只21日龄雏鸭随机分为AIV感染组(I)和对照组(C),应用免疫学和细胞培养及MTT等方法动态检测AIV感染雏鸭血液红细胞免疫黏附能力、红细胞免疫自身调控能力以及红细胞促外周血淋巴细胞增殖能力。结果表明,雏鸭感染AIV后1～14 d,红细胞C_(3b)受体花环(E-CRR)率明显低于对照组,而红细胞免疫复合物花环(E-ICR)率明显高于对照组;AIV感染雏鸭后3～21 d,红细胞C_(3b)受体花环促进率(RFER)显著低于对照组,且红细胞C_(3b)受体花环抑制(RFIR)率显著高于对照组;AIV感染雏鸭的红细胞对血液T、B淋巴细胞增殖促进能力明显低于对照组。表明AIV感染引起的雏鸭红细胞免疫黏附功能、自身调控能力和T、B淋巴细胞增殖能力下降,与AIV感染导致雏鸭外周血免疫功能降低密切相关。     

屎肠球菌对仔猪生长性能、免疫和抗氧化功能的影响

试验旨在研究屎肠球菌(Enterococcus faecium, E. faecium)对仔猪生长性能、免疫和抗氧化功能的影响。选用平均体重19.7 kg左右的杜长金仔猪120头,随机分为对照组和试验组,每组设3个重复,每个重复20头仔猪(公母各半)。对照组仅饲喂基础日粮,试验组饲喂添加屎肠球菌(菌含量为1×10⁶ CFU·g-1饲料)的基础日粮。结果表明：日粮中添加屎肠球菌能改善动物的生产性能,其中日增重提高了11.46% (P<0.05),料肉比降低了6.20% (P<0.05);屎肠球菌能提高仔猪免疫和抗氧化功能,其中仔猪血清中白蛋白,IgA,IgG,C3,C4水平和溶菌酶活性分别提高了28.06%(P<0.05),16.48%(P<0.05),25.43%(P<0.05),37.84%(P<0.05),25.00%(P<0.05)和76.08%(P<005);血清中谷胱甘肽含量提高了46.80%(P<0.01),但总超氧化物歧化酶活力降低了10.38%(P<0.05)。另外,日粮中添加屎肠球菌使仔猪粪中沙门氏菌和大肠杆菌数量分别降低了15.37% (P<0.01) 和11.79% (P<0.05),乳酸菌数量增加了18.78% (P<0.05),细菌总数无明显变化。结果还表明,在断奶仔猪日粮中添加屎肠球菌能够显著促进断奶仔猪的生长,其机理可能在于屎肠球菌作为益生菌,其添加能够显著提高仔猪的特异性免疫和非特异免疫功能,并改善断奶仔猪肠道菌群结构。     

Effect of Astragalus polysaccharides on Erythrocyte Immune Adherence of Chickens Inoculated with Infectious Bursal Disease Virus

Two hundred and forty specific pathogen free leghorn chickens were randomly divided into four groups and reared in isolated pens. The tested chickens were negative to infectious bursal disease virus （IBDV） at 25 d old. Group 1 was treated with saline, whereas Groups 2, 3, and 4 were inoculated with 0.3 mL IBDV suspension intranasally the next day. Groups 3 and 4 were also administered with Astragalus polysaccharides （APS） intramuscularly twice daily at 5 or 10 mg kg-1 BW, respectively, until 31 d old. The erythrocyte-C3b receptor rosette rate （E-C3bRR） and the erythrocyte-C3b immune complex rosette rate （E-ICRR） were measured at 25, 29, 32, 35, and 38 d old. The results showed that IBDV significantly reduced E-C3bRR and E-ICRR when compared with the control group （P 〈 0.05）, while simultaneous administration of APS with 1BDV maintained E-C3bRR at similar levels to the control group （P 〉 0.05） and increased E-ICRR when compared with the control group and the group non-treated with APS （P 〈 0.05）. APS treatment reduced the morbidity and mortality of chickens inoculated with IBDV （P 〈 0.05）. The results suggest that APS may enhance the immune adherence of chickens erythrocytes by affecting the activity and/or the number of complement receptors on the erythrocyte membrane. These findings can be beneficial in providing an understanding of the basic mechanisms required for the rational application of APS in modern medicine.     

C'3 synthesis in the human fetus and lack of transplacental passage

Allotypic differences in the third component of complement between mothers and their newborns provided evidence for synthesis of this complement component by the fetus. There was no indication that this protein traversed the placenta. The known low level of C'3 in the neonate was confirmed, and the maternal concentration was found to be significantly elevated.     

精制玉屏风散对仔猪免疫功能和生长性能的影响

在饲料中添加精制玉屏风散观察其对断奶仔猪的免疫功能和生长性能的影响.结果表明,添加高剂量(质量分数为0.8%)玉屏风散组仔猪的日增重、补体(C3、C4)和免疫球蛋白(IgA、IgM、IgG)含量均比其他组有显著提高(P<0.05);血清中淋巴细胞阳性率、白介素(IL-2)和γ-干扰素含量、T淋巴细胞亚群(CD3、CD4、CD8)数量均比对照组有显著提高(P<0.05),而CD4/CD8值有极显著提高(P<0.01).表明玉屏风散在一定程度上可以改善仔猪的生产性能,提高机体的免疫功能,是一个较为理想的免疫增强剂.