Characterization of immunoglobulin classes of human antibodies to cryptococcus neoformans

Immunoglobulin G (IgG), immunoglobulin M (IgM) and immunoglobulin A (IgA) levels were determined by radial immunodiffusion techniques in sera from 11 patients with cryptococcosis. Most specimens showed increased levels of IgM. Studies with fluorescein-labeled monospecific antihuman IgG and IgM, however, indicated that IgG was the immunoglobulin reactive in the indirect fluorescent antibody (IFA) test. In addition, cross-reacting sera from mycotic infections other than cryptococcosis were also shown to contain IFA antibodies of the IgG class. Sera treated with 2-mercaptoethanol continued to react in both the IFA test and the tube agglutination test. No correlation could be established between IgG and IgM concentrations and serological reactivity in the sera evaluated in this study.     

Segmental flexibility and complement fixation of genetically engineered chimeric human, rabbit and mouse antibodies.

We generated a family of chimeric immunoglobulin G (IgG) molecules having identical antigen-combining sites for the dansyl (DNS) hapten, in conjunction with nine heavy chain constant (CH) regions. This family of antibody molecules allows comparison of CH dependent properties independent of possible variable region contributions to IgG function. The segmental flexibility and complement fixation activity were measured of six genetically engineered molecules (the four human IgG isotypes, mouse IgG3 and rabbit IgG) and the remaining three mouse IgG isotypes, (IgG1, IgG2a and IgG2b), isolated previously by somatic cell genetic techniques. These properties of antibody molecules each correlate with the length of the immunoglobulin hinge region which separate the first and second CH (CH1 and CH2) domains. These results attribute a structural basis for two critical properties of antibody molecules.     

Self-association of bovine immunoglobulin G1.

The self-association properties of bovine serum immunoglobulin G1 and colostral immunoglobulin G1 (IgG1) in 0.32 M-NaCl/0.01 M-Tris/HCl, pH 8.0, were investigated by analysing sedimentation data according to a monomer-dimer association model. The self-association was characterized by an equilibrium constant of 5.3 X 10(4) +/- 3.5 X 10(4) M-1 for serum IgG1 and 1.6 X 10(3) +/- 0.69 X 10(3) M-1 for colostral IgG1. The removal of the Fc portion of IgG1 by pepsin digestion abolished its property of self-aggregation. At high total protein concentrations of serum IgG1, low concentrations of the ostensible trimer species were observed. However, no self-aggregation was evident when 0.14 M-NaCl/0.01 M-sodium phosphate. pH 6.0, was used as a solvent, thus confirming results published previously [Tewari & Mukkur (1975) Immunochemistry 12, 925--930].     

Affinity chromatography of antibodies directed against soybean lipoxygenase-1 and -2 and an enzyme-linked immunosorbent assay (ELISA) for antibodies and lipoxygenases

Crude immunoglobulin G (IgG) fractions of antisera directed against soybean lipoxygenase-1 and -2 were purified by being passed through an immunoadsorbent column containing lipoxygenase coupled to CNBr-activated Sepharose 4B. Bound immunoglobulin was desorbed with pulses of 2 M or 3 M ammonium thiocyanate or 0.1 M glycine-HCl buffer (pH 2.5). The total column recoveries of anti-lipoxygenase-1 IgG and anti-lipoxygenase-2 IgG were 45% and 58%, respectively. The affinity for lipoxygenase of immunospecific antibodies was determined in an enzyme-linked immunosorbent assay (ELISA). In a reaction with lipoxygenase-1, anti-lipoxygenase-1 IgG, which was eluted with glycine-HCl buffer (pH 2.5) with recovery of 24%, had a 6.5-times higher affinity than the whole IgG fraction of antiserum. The affinity of anti-lipoxygenase-2 IgG for lipoxygenase-2 increased 2.2-times after chromatography of IgG over an immunoadsorbent column using 2 M ammonium thiocyanate as eluent (recovery 21%).     

Fabry's disease: Heterozygote detection by hair root analysis

Summary Serum concentrations of immunoglobulin G (IgG), immunoglobulin M (IgM) and immunoglobulin A (IgA) were determined in 15 women with a lack of X chromosome material (Turner's syndrome), and compared with the immunoglobulin concentrations in normal men and women. Further, the investigation is supplemented by a comparison of normal women and the Turner group matched according to age.The serum concentrations of IgG and IgA in women with Turner's syndrome were very close to the concentration in serum from normal men, whereas the concentration of IgM was significantly lower. Compared to normal women the concentrations of IgG and IgM were significantly lower, and the concentration of IgA significantly higher in the Turner group.Whether these differences in serum immunoglobulins are determined by hormonal factors or under direct genetic control linked to the X chromosomes, is discussed.     

Trypanosoma cruzi: immunoglobulin isotype profiles during the acute phase of canine experimental infection with metacyclic or blood trypomastigotes

A detailed investigation has been carried out about the serological profiles of groups of dogs experimentally infected with metacyclic (MT) or blood (BT) trypomastigotes of Berenice-78 Trypanosoma cruzi strain. Peripheral blood was collected from infected dogs and uninfected controls, weekly during 35 days following the acute phase of infection, and immunoglobulin profiles were determined by ELISA. Dogs infected with BT exhibited unaltered levels of IgG2, increases in IgM, IgE, IgA, IgG and IgG1. In contrast, dogs infected with MT presented unaltered levels of IgE and IgG1 and an increase in IgM, IgA, IgG and IgG2 levels. Compared with the MT group, animals infected with BT showed significant increases in IgM on days 7, 14 and 28, in IgA on days 7, 14 and 21, in IgE on days 7 and 14, in IgG on days 14 and 28, and in IgG1 on days 7, 14 and 21. Parasitemia levels of the infected animals were measured over the same time period. No correlations were found between the immunoglobulin profiles and the parasitemia levels. The results demonstrated that the inoculum source (BT or MT) influence the immunoglobulin isotype profile that may drive distinct outcome of acute canine Chagas disease.     

Induction of surface IgG receptors in cytomegalovirus-infected human fibroblasts

Binding studies on diploid human fibroblasts with human immunoglobulin G (IgG) demonstrate the existence of a specific receptor for this class of immunoglobulin. The receptor preferentially binds aggregated human IgG and recognizes these complexes via the Fc portion of the molecule. Cytomegalovirus infection of diploid human fibroblasts results in a more than 100-fold increase in the number of IgG-receptors present on the cell surface. The binding of aggregated IgG by these newly expressed receptors exhibits the characteristics of the binding mediated by the receptors detectable in uninfected cells.     

Binding of subclasses of rat immunoglobulin G to detergent-isolated Fc receptor from neonatal rat intestine

Brush borders of cells lining the proximal small intestine of neonatal rats express a receptor specific for the Fc portion of IgG that mediates transport of IgG from gut lumen to blood. We have investigated the interaction of subclasses of rat IgG with this receptor, extracted in Triton X-114 solution, using phase separation to separate receptor-immunoglobulin complexes from free immunoglobulin. Binding of immunoglobulin showed the same pH dependence as is found in vivo, being active at pH 6 and reversibly inhibited at pH 8. The numbers of binding sites for each IgG subclass were similar, but polyclonal IgG2a was bound with higher affinity (1.2 X 10(8) M-1) than monoclonal IgG1 or IgG2b (2-3 X 10(7) M-1). Radiolabeled monoclonal IgG2c did not show specific binding, apparently as a result of the iodination process. Competition studies showed cross-inhibition between all IgG subclasses. IgG2a being approximately 10-fold more effective at competing for receptor than other isotypes, in the order IgG2a much greater than IgG1 greater than IgG2b greater than or equal to IgG2c. These data suggest that a single receptor capable of binding all subclasses of IgG is active in the detergent extract. However, investigation of radiolabeled immunoglobulins that were bound to isolated gut cells before detergent extraction showed evidence for other types of interaction in vivo.     

人巨细胞病毒IgG 抗体标准品研究进展

人巨细胞病毒(CMV)是威胁人类健康的最重要病原之一。高CMV抗体效价的免疫球蛋白G(IgG)制剂,为临床医生在预防和治疗用药上提供了一个有价值的选择。而CMV免疫球蛋白标准品对于制品的CMV抗体效价测定以及高效价血浆的筛选都至关重要。该标准品对于器官移植/输血安全测试,以及临床诊断都是不可或缺。本综述提供了一种人巨细胞病毒IgG标准品制剂方法以及目前研究进展的概述。此外,本文还关注应用于不同领域的不同CMV IgG抗体效价单位。故本文为人巨细胞病毒免疫球蛋白的开发,人巨细胞病毒IgG抗体诊断试剂的标准化,以及为其质量控制提供参考。     

Immunoelectron microscopic localization of idiotypes and allotypes on immunoglobulin molecules

We have developed a novel approach to the analysis of antigenic (allotypic and idiotypic) determinants on intact immunoglobulin molecules. Immune complexes composed of IgG in combination with anti-idiotype or anti-allotype antibody were "visualized" by transmission electron microscopy. Individual Fab fragments of anti-idiotype or anti-allotype antibody, when bound to the IgG, altered the "Y" configuration in a reproducible and interpretable manner. Anti-idiotype antibody (either as Fab or IgG) bound to the terminus of the presumed V region of the IgG molecule, thus extending the apparent length of the Fab arms. Analysis of a rabbit VH framework allotype (a1) revealed that the determinant(s) is (are) located on the lateral portion of the V region of IgG. Binding of the anti-a1 Fab fragments was always at approximately right angles to the axis of the Fab arms of IgG. Fab antibody to the rabbit kappa light chain (b4) allotype bound to the lateral portion of the terminal half of the IgG Fab arms. This technique should be of value in localizing less well defined immunoglobulin determinants.     

An ellipsometric study of the antigen-antibody interaction in the interphase solid/solution area]

Ellipsometric studies have proved that monoclonal immunoglobulin G(IgG) against gamma-interferon (gamma-INF) and immunoglobulin fraction (Ig-fraction) of rabbit blood serum against human serum albumin (HSA) are adsorbed according to the Langmuir model on the surfaces of mirror plates of covalently modified gamma-INF or HSA, respectively. The maximum surface concentrations (Tmax) and equilibrium adsorption constants (K) for IgG and Ig-fraction are equal to 2.57 pmol/cm2 and 2 x 10(7) M-1, 3.3 mg/m2 and 0.1 cm3/micrograms, respectively. The additional treatment of gamma-INF modified surfaces with Tween-20 leads to an increase of K IgG ut to 2.7 x 10(-7) M-1 while Tmax decreases up to 1.12 pmol/cm2 which is conditioned by the blocking of protein non-specific binding sites. The role of specific and non-specific interactions of IgG and Ig-fraction with covalently immobilized antigens was studied at antibody-antigen mixture adsorption. The necessity to apply this method to quantitative determination of gamma-IHF and HSA in solutions was proved.     

Antibody/antigen affinity behavior in liquid environment with electrical impedance analysis of quartz crystal microbalances

Electrical impedance analysis has been used to study anti-human immunoglobulin G (anti-h IgG) adsorption and the subsequent human immunoglobulin G (hIgG) or rabbit immunoglobulin G (rIgG) affinity reaction in aqueous liquids on a polystyrene (PS)-modified quartz crystal microbalance (QCM) surface. Time-dependent adsorption data of both the frequency shift and the electrical equivalent parameters (motional resistance, shunt capacitance, quality factor, etc) are monitored. It was found that the motional resistance, R, increases while the resonance frequency, f, decreases during both the anti-h IgG immobilization and the subsequent affinity process. Decreasing f primarily arises from the increased mass loading. Increasing R indicates more power dissipation (increased losses) in the system. The change in motional resistance, delta R, in the affinity reaction is considerably larger than that in anti-h IgG immobilization adsorption process, although the resonant frequency shifts, delta f, are very close in these two processes. Specifically, for a saturated solution, the ratio of delta R/delta f is 9.45 x 10 (-3) Omega/Hz for anti-h IgG adsorption and 28.1 x 10 (-3) omega/Hz for anti-h IgG/hIgG binding respectively, indicating the increased power dissipation with the increasing binding molecules. The shunt capacitance changes little in the hIgG binding process ( approximately 0.01 pF).     

Serum and urinary immunoglobulin in the rat model of acute urinary tract infection

Total levels of urine and serum immunoglobulin IgM, IgG and IgA, and the E. coli-specific bacterial immunoglobulin response were determined by enzyme-linked immunosorbent assay (ELISA) in a rat model of acute urinary tract infection. High levels of urinary IgM were detected as early as day 3 post infection and then decreased to statistically insignificant levels. Peak levels of IgG occurred in the serum and urine on day 14. Urine and serum IgA levels remained low throughout the study period. The results demonstrate that in the rat model of acute urinary tract infection, IgM appears first in the urine and serum, and rapidly decreases. IgG then appears in the serum and urine followed by a late E. coli-specific immunoglobulin serum and urine response. Also, a non-specific component of the immunoglobulin response was noted in both the serum and urine. In the rat, IgA appears to play little or no role in the urine or in the serum response to the infection.     

糖皮质激素联合吗替麦考酚酯分散片对系统性红斑狼疮患者的疗效及对免疫功能的影响

目的:研究糖皮质激素联合吗替麦考酚酯分散片治疗系统性红斑狼疮患者的临床疗效及对免疫功能的影响。方法:选取2014年9月至2015年8月本院收治的84例系统性红斑狼疮患者,根据投硬币法分为观察组和对照组,42例每组。对照组使用单纯的糖皮质激素,观察组在此基础上使用吗替麦考酚酯分散片。比较两组患者临床疗效,治疗前后免疫球蛋白A(IgA)、免疫球蛋白(IgG)、免疫球蛋白(IgM)、C反应蛋白(CRP)、血沉(ESR)的变化及不良反应的发生情况。结果:治疗后,观察组临床总有效率显著高于对照组(P0.05)。治疗前,两组患免疫球蛋白A(IgA)、免疫球蛋白(IgG)、免疫球蛋白(IgM)、C反应蛋白(CRP)、血沉(ESR)水平比较差异均无统计学意义(P0.05);治疗后,两组患者IgA、IgG、IgM、CRP、ESR水平均较治疗前显著降低(P0.05),与对照相比,观察组的IgA、IgG、IgM、CRP、ESR明显降低(P0.05)。两组组的不良反应率比较差异无统计学意义(P0.05)。结论:糖皮质激素联合吗替麦考酚酯分散片能有效改善系统性红斑狼疮患者的免疫功能,临床疗效良好,安全性高。     

The Influence of Sow Colostrum Trypsin Inhibitor on the Immunoglobulin Absorption in Newborn Piglets

The influence of sow colostrum trypsin inhibitor (SCTI) on the immunoglobulin absorption from the gut of 16 newborn colostrum-deprived piglets was investigated in a paired feeding experiment. Three times at 1 h intervals the piglets were fed an experimental diet consisting of sow milk, purified swine serum immunoglobulins containing agglutinins against Bordetella bronchiseptica, and purified SGTI (diet I) or saline (diet II). The serum concentrations of IgG, IgM, IgA, and antibodies for B. bronchiseptica were measured by single radial immunodiffusion and by a tube agglutination procedure and used to evaluate the immunoglobulin absorption. Four and 6 h after the first experimental meal, blood samples from the piglets given SGTI in their diet had a generally higher level of IgG, IgA and aggutinins against B. bronchiseptica than blood samples from the piglets d no SGTI. No real differences were found in the IgM levels. Although the piglets fed no SGTI all showed a considerable immunoglobulin absorption, the SCTI was found to have a statistically significant positive influence on the IgG and IgA absorption.     

Immunoglobulin receptors of group A Streptococcus]

It was shown in the gel precipitation tests that absorption of human and rabbit IgG or Fc-fragments obtained from human IgG group A streptococcal cultures results in inhibition of the reactions of these preparations with immunoglobulin sera. The reactions of F(ab')2-fragments with the corresponding sera are not inhibited during their absorption by the same cultures. The results obtained support the presence in a number of group A streptococcal cultures of immunoglobulin receptors (Ig-receptors) capable of reacting with Fc-parts of human and rabbit IgG. Pepsin treatment destroys Ig-receptors. These receptors could not be found by the method used in hydrochloric acid extracts prepared from streptococci containing the receptors. The method can be applied for determination of Ig-receptors in streptococcal cultures.     

Immunoglobulin M and immunoglobulin G secretion by human B cells exposed to RU 41.740, a glycoprotein extract from Klebsiella pneumoniae

RU 41.740, a glycoprotein extract from Klebsiella pneumoniae, was seen to activate human B cells to immunoglobulin secretion in vitro. The effects of RU 41.740 on human B cells were compared to those induced by pokeweed mitogen, a T-cell-dependent polyclonal B-cell activator, and Epstein-Barr virus, a T-cell-independent polyclonal B-cell activator. Exposure of human B cells to all of these agents resulted in increased immunoglobulin M (IgM) and immunoglobulin G (IgG) secretion. IgM and IgG secretion induced by RU 41.740 appeared to be T cell dependent when B cells were isolated from human peripheral blood. However, this activity may have been T cell independent when B cells were isolated from human spleen. RU 41.740-induced IgM secretion by peripheral blood B cells was seen to peak after 6 days in culture; IgG secretion peaked after 7 days in culture. The optimal concentration of RU 41.740 for the induction of IgM and IgG secretion by human B cells in vitro was seen to be 200 micrograms/ml.     

Physicochemical and biological properties of poly(ethylene glycol)-coupled immunoglobulin G

In order to develop a new intravenous immunoglobulin G (IgG), IgG was covalently coupled to poly(ethylene glycol) previously activated by cyanuric chloride. The poly(ethylene glycol) coupled IgG obtained was studied for physicochemical and biological properties such as molecular structure, size-exclusion chromatographic behaviour, surface activity, interfacial aggregability, heat aggregability inducing nonspecific complement activation, and antigen-binding activity. The poly(ethylene glycol) coupling to IgG increased the apparent Stokes' radius and the surface activity of IgG and stabilized IgG on heating and/or on exposure to interface, while no structural denaturation of IgG was observed. The suppressed nonspecific aggregability was interpreted mainly by difficulty in association between the modified IgG molecules. These results indicated the use of the poly(ethylene glycol)-coupled IgG as an intravenous preparation and also as an additive stabilizing intact IgG for intravenous use.     

F(ab')2 reagents are not required if goat, rather than rabbit, antibodies are used to detect human surface immunoglobulin.

The present report provides evidence that whole goat anti-human immunoglobulin, unlike similar reagents produced in the rabbit, binds both to the same number of and the same individual cells as the F(ab')2 fragments of rabbit or goat anti-human immunoglobulin. These results suggest that goat IgG has a lower affinity for the Fc receptors of human lymphocytes and monocytes than rabbit IgG. Because of this property, whole goat antibodies against human immunoglobulin can be used as simple, convenient relatively inexpensive reagents for the routine detection of immunoglobulin on cell surfaces by immunofluorescence microscopy. The preparation of F(ab')2 fragments of anti-immunoglobulin, which are necessary when rabbit antibodies are used, does not appear to -e required if goat antibodies can be empolyed. This observation has multiple practival applications in cellular immunology.     

The development by cytomegalovirus-infected cells of binding affinity for normal human immunoglobulin.

After infection with human cytomegalovirus (CMV), cells develop an affinity for normal human immunoglobulin G (IgG). This was demonstrated using 125iodine-labeled purified IgG. It was further demonstrated that the immunoglobulin molecule binds to CMV-infected cells via its Fc portion, and competition for binding to infected cells occurred between purified preparations of human IgG and the Fc fragment of human IgG. Whole sera from individuals with or without a high titer of anti-CMV antibody were labeled with 125iodine and it was demonstrated that serum from individuals with no anti-CMV antibody had an affinity for CMV-infected cells which probably reflected binding of IgG via its Fc fragment. The possible significance of these results in immunologic studies of human CMV is considered.