A comparative study between the adsorption of IgY and IgG on latex particles

The use of egg yolk antibodies (IgY) instead of IgG from mammalian species may present several advantages in the development of routine diagnostic immunoassays. On the one hand, the animal suffering is reduced, as antibodies are obtained directly from the egg. On the other hand, the use of IgY avoids the rheumatoid factor interference. The rheumatoid factor interacts with IgG molecules in many immunoassays causing false positive results. Despite these advantages, IgY antibodies are scarcely used. As part of an aim to develop a diagnostic test based on IgY-latex agglutination, a preliminary study on some characteristics of the IgY-latex complexes is carried out. In this work, protein adsorption and desorption, isoelectric point, electrokinetic mobility, and colloidal stability are analysed. Results are compared to those obtained by IgG. Interesting differences are observed (which mainly arise from the difference in molecular structure between IgY and IgG), suggesting that IgY is a more hydrophobic molecule than IgG. In addition, colloidal dispersions of IgY-covered latex particles are more stable (at pH 8) than those sensitized by IgG.     

Use of chicken immunoglobulin Y in general virology

Immunoglobulin Y (IgY), an antibody present in birds, reptiles, and amphibians, is actively transported from the serum to egg yolks, where it is stored in large quantities. The use of chicken polyclonal IgY instead of mammalian IgG antibodies for biomedical applications has ethical and economic advantages, such as the lack of a need for animal bleeding because the antibodies are extracted from eggs after hen immunization and the low cost of the production and purification methods. This article reviews the latest IgY applications in diagnostic virology and the therapeutic use of IgY in viral gastroenteritis.     

Immunoglobulin Y Levels in Egg Yolk From Three Chicken Genotypes

Laying hens are very efficient producers of antibodies and provide an interesting alternative for large-scale production of specific antibodies. These antibodies also have biochemical advantages over mammalian antibodies (e.g. rabbit antibodies) that can be used to improve immunoassays where antibodies are used. The concentration of IgY in egg yolk is an important production parameter. The purpose of this study was to investigate the genetic variation of IgY levels in egg yolk. We have compared IgY concentrations in egg yolks from two lines, selected for egg production traits at the Swedish University for Agricultural Sciences (Single Comb White Leghorn and Rhode Island Red) and a cross between the two lines (SLU-1392). Single Comb White Leghorns have the highest mean concentration of yolk IgY, 2.21 mg ml^-1 compared to SLU-1392 1.95 mg ml^-1 and Rhode Island Red 1.68 mg ml^-1. The cross thus had an intermediate IgY concentration in relation two the two other lines. There were great differences between individual animals within each line. Our results indicate that it should be possible to increase yolk antibody production by using a high producing chicken line and by genetic selection within the line. We found three individuals with very low yolk IgY concentrations among the Rhode Island Red hens. Newly hatched chickens with limited amounts of IgY from the hen may be more susceptible to infections.     

Production of IgY anti-mouse IgG antibodies from chicken eggs

IgY technology offers several advantages over antibody production in mammals. In this study, we applied IgY technology for the production of anti-mouse IgG polyclonal antibodies and developed a FITC conjugate reagent. Two hens were immunized 3 times with mouse IgG, one via the pectoralis and the other via the calf muscles. Specific antibodies could be detected in the sera two weeks after the immunization, and maximum levels were reached at week 10. The hen which was immunized via the pectoralis muscle produced a much higher antibody response than the hen immunized via the calf muscle. In egg yolk, specific antibodies appeared 2 weeks after the first immunization, reached a plateau after week 11 and remained high until week 20. IgY were extracted from egg yolk by sodium sulfate precipitation. Approximately 40 mg of IgY could be extracted from a single egg. The extracted IgY was labeled with FITC. The so-produced antibody-FITC conjugate reacted to all mouse IgG isotypes and could be used to determine leukocyte sub-populations in blood samples by flow cytometry.     

Serum IgG4 concentrations and allergen-specific IgG4 antibodies compared in adults and children with asthma and nonallergic subjects

We describe the development of specific immunoassays for IgG4 protein and for allergen-specific IgG4 antibodies. We also measured the concentrations of IgG4 protein and determined the frequencies of detectable IgG4 antibodies to several common allergens in sera from adults and children with asthma and from nonallergic subjects. Serum concentrations of IgG4 protein increase with age but are not different in children with asthma and nonallergic children, nor does a raised serum concentration predict a severe clinical course in childhood asthma. IgG4 antibodies to milk and egg are common in children and adults and are more common in children with asthma than in nonallergic children less than 3 years of age. The presence of detectable IgG4 antibodies or a raised concentration of IgG4 protein in serum is not useful empirically as a diagnostic indicator of asthma but more likely results from antigen exposure occurring at mucosal surfaces.     

Limited Day to Day Variation of IgY Levels in Eggs from Individual Laying Hens

Laying hens are highly efficient producers of polyclonal antibodies (PAbs). These antibodies are transported to the egg yolk in large quantities from the blood of laying hens. The IgY concentration in the egg yolk is important to protect the newly hatched chick against infections and it is also an important factor for the production of yolk antibodies for commercial purposes. A single egg yolk contains approximately the same amount of IgY as 30 ml of blood. This is a significant loss of antibodies for an animal the size of a hen. We have studied the IgY levels in egg yolk. We found low day to day variability. There was no decrease in IgY levels at the end of the egg laying cycle and there was no correlation between IgY concentration and egg production.     

抗日本血吸虫SEA特异性IgY应用于循环抗原检测的研究

本研究应用抗日本血吸虫可溶性虫卵抗原(SEA)的鸡卵黄免疫球蛋白(IgY)建立敏感、特异的检测循环抗原的双抗体夹心酶联免疫吸附试验( ELISA).用SEA皮下多点注射法免疫海蓝鸡,水稀释法制备IgY抗体,以辣根过氧化物酶标记纯化的IgY抗体(IgY-E)和兔抗IgG抗体(IgG-E)分别作为检测抗体,IgY抗体和兔抗...     

A novel, cost-effective and efficient chicken egg IgY purification procedure

Chicken IgY antibodies have been touted to be a superior alternative to mammalian antibodies for use in various immunological, molecular biology and proteomics applications for several reasons. These include, but are not limited to, improved specificity due to maximum phylogenetic distance between host and recipient, cost effectiveness in maintaining commercial numbers of hens, IgY yield and the use of non-invasive methods used to isolate IgY from eggs as opposed to blood. Despite this, the routine use of IgY-based methodologies in the laboratory is not widespread. One reason for this reluctance may be derived from the difficulties and expense of isolating IgY antibodies from egg yolk in sufficient yield, with high purity at a realistic reasonable price. Here, we describe an extremely cost-effective ($5USD per egg), rapid (within 5 h), efficient and optimised technique to isolate high yields (60 mg) of high purity (~80%) chicken IgY from egg yolks using the common plant gums pectin and κ-carrageenan in the presence of calcium chloride to delipidate egg yolk mixtures whilst maintaining IgY in solution and then ammonium sulphate to subsequently precipitate the resulting IgY antibodies to higher purity. Our data demonstrates that this technique results in a high yield and purity of IgY that is comparable (if not superior to) existing commercial IgY isolation kits. The method also allows the isolation of immunologically active IgY which can be used for further downstream immunotechnological processes. Furthermore, it can also be easily implemented in a standard well equipped laboratory, and may be scaled up to commercial quantities (i.e., thousands of eggs).     

鸡卵黄免疫球蛋白的研究进展

卵黄免疫球蛋白(IgY)类似于哺乳动物的IgG,但又有其独特的优点。本文对IgY的结构、提取纯化以及在免疫 检测、免疫治疗等方面的应用进行了较详细的论述。     

Selective reactivity of antibodies to human immunoglobulins G, M, and A with rubella virus proteins

Proteins of purified rubella virus were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to nitrocellulose, and immunoblotted with human sera and immunoglobulin class heavy-chain-specific peroxidase conjugates. The levels of rubella antibodies in these sera were predetermined by the radial hemolysis test, the density gradient centrifugation method for immunoglobulin M (IgM) antibodies, and IgG-, IgM-, and IgA-specific enzyme immunoassays. In immunoblotting, rubella-specific IgG antibodies reacted with both envelope glycoproteins (E1 and E2) and the capsid protein (C). In contrast, rubella IgM antibodies reacted predominantly with E1, whereas the specific reactivity of IgA antibodies was directed mainly to the capsid protein. Purified IgM rheumatoid factor added to IgG-positive, IgM-negative serum did not give false-positive reactivity in the immunoblotting test as it did in solid-phase enzyme immunoassays. The immunoglobulin class-specific reactivities with the different viral proteins are expected to have diagnostic applications.     

Determination of human IgG and IgM class antibodies to West Nile virus by enzyme linked immunosorbent assay (ELISA)

An enzyme-linked immunosorbent assay (ELISA) was developed and used for the detection of IgG and IgM antibodies to West Nile virus in human sera. Thirteen paired sera of clinical cases and 24 control sera taken randomly from a blood bank repository were tested. The sera were reacted in microtiter plates coated with PEG-treated WNV antigen. IgG or IgM antibodies were quantitated by the use of alkaline-phosphatase-conjugated anti-human IgG or IgM antibodies. Of the 24 randomly collected serum samples, 7 were positive in the IgG-ELISA test. One positive by the IgM-ELISA was found to contain rheumatoid factor. In 12 of 13 paired sera of clinical cases, IgM as well as IgG antibodies were detected in the second serum sample taken about 3 wk after the onset of clinical signs. The IgM positive sera were screened for rheumatoid factor (RF) on IgG-coated plates. None of them contained RF. Antibody titers obtained by ELISA showed a good correlation with titers obtained by hemagglutination inhibition, complement fixation, and neutralization tests. The ELISA tests for detection of IgM and IgG antibodies to WNV therefore can replace the other serological methods for epidemiological surveillance and diagnostic purposes.     

Structure of IgG and IgY molecules in ribosome—Antibody complexes as studied by electron microscopy

The overall shape and dimensions of IgG (rabbit) and IgY (chicken) antibodies against ribosomal proteins have been studied in electron micrographs of ribosome—antibody complexes. The antibodies appear as Y-shaped molecules with an angle of about 90° between their Fab arms. The length of one Fab arm amounts to about 10 nm. No differences between the IgG and IgY molecules could be detected electron microscopically. The data obtained on the shape of IgG and IgY correlate with those of earlier electron microscopic studies while the determined size of the Fab arms is in the range found by scattering methods.     

Solid-phase enzyme immunoassay for determination of antibodies to cytomegalovirus.

A solid-phase enzyme immunoassay for the determination of immunoglobulin H (IgG) and IgM antibodies to cytomegalovirus is described. The enzyme immunoassay gave reliable and consistent results which were in concordance with those obtained by the complement fixation test and the indirect immunofluorescence test. Antibodies to herpes simplex and varicella-zoster viruses did not interfere in the enzyme immunoassay for cytomegalovirus IgM antibodies. In a few patients with IgM antibodies to Epstein-Barr virus, cytomegalovirus IgM antibodies were also detected. False-positive cytomegalovirus IgM antibody results were observed in sera containing both the rheumatoid factor and cytomegalovirus IgG antibodies. This rheumatoid factor interference was overcome by the absorption of sera with polymerized human gamma globulin. The absorption did not affect true cytomegalovirus IgM antibody titers. Also described is a simple enzyme immunoassay that makes possible a more sensitive detection of the rheumatoid factor than the latex agglutination test.     

Enzyme immunoassays for IgG and IgM antibodies to Toxoplasma gondii based on enhanced chemiluminescence.

AIMS--To evaluate the clinical performance of enzyme immunoassays for IgG and IgM antibodies to Toxoplasma gondii based on enhanced chemiluminescence. METHODS--Classification of routine clinical samples from the originating laboratories was compared with that obtained using the chemiluminescence based assays. Resolution of discordant results was achieved by testing in alternative enzyme immunoassays (IgM) or by an independent laboratory using the dye test (IgG). RESULTS--Compared with resolved data, the IgM assay was found to be highly specific (100%) with a cut off selected to give optimal performance with respect to both the early detection of specific IgM and the detection of persistent levels of specific IgM (sensitivity 98%). Compared with resolved data, the IgG assay was shown to have a sensitivity and a specificity of 99.4%. CONCLUSIONS--The Amerlite Toxo IgM assay possesses high levels of sensitivity and specificity. Assay interference due to rheumatoid factor like substances is not a problem. The Amerlite Toxo IgG assay possesses good sensitivity and specificity, but is less sensitive for the detection of seroconversion than methods detecting both IgG and IgM.     

Comparison of four purification methods for the production of immunoglobulins from eggs laid by hens immunized with an enterotoxigenic E. coli strain

The importance of eggs as a source of specific antibodies is well recognized. Egg yolk contains 8–20 mg of immunoglobulins (IgY) per ml. However, the major problem in isolation is removal of lipids which are present in high concentrations. A method had been developed by employing water dilution to separate the yolk plasma proteins from the granules and lipids. Further purification of IgY from plasma proteins was achieved by a protocol involving salt precipitation and ultrafiltration. The water dilution method (WD) was compared with three other methods, namely, polyethylene glycol (PEG), dextran sulphate (DS) and xanthan gum (Xan) in terms of yield, purity, ease of use, potential scaling up and immunoactivity of IgY. The WD method gave the highest yield, followed by DS, Xan and PEG methods in that order. 9.8 mg IgY / ml egg yolk was routinely obtained from the WD method compared to 4.9 mg IgY / ml egg yolk with the popular PEG method with purities of 94% and 89% respectively. Purification methods had no adverse effect on the immunoactivities of IgY. WD was also found superior in terms of ease of use and large scale production of IgY. WD method therefore provides a simple, rapid and efficient means of purifying IgY with high activity.     

Quantification of antibody (IgY) titers in hen eggs following immunization and their use in detecting cell surface molecules on nitrocellulose membranes

HLA-A*0201 alpha chain and beta2m were expressed from a prokaryotic system, and after refolding and purification, the alpha chain and beta2m were used to immunize eight laying hens. The titer of egg yolk antibody against alpha chain increased from 10(2) to 10(5.3) The titer of egg yolk antibody against beta2m increased from 10(1) to 10(4.7). The extent of titer increase is similar between the two antigens. An average of 135 mg purified polyclonal antibody (IgY) can be easily obtained from one egg yolk. The use of egg collection rather than serum collection is compatible with modern animal protection regulations. An average of 28 eggs were obtained from a laying hen every month, with a total amount of 3780 mg immunoglobulin extracted from one immunized hen every month, which would be equivalent to 630 mL of serum or 1260 mL of blood per month. Chickens are an optimal host for the production of polyclonal antibodies with high titer and high yield. Purified IgY was labeled with horseradish peroxidase and reacted with PBMC on nitrocellulose membranes indicating that the antibody can bind to the native conformation of class I HLA molecule on PBMC.     

Production of chicken yolk IgY to sulfamethazine: comparison with rabbit antiserum IgG

Sulfamethazine was used as target analyte to produce IgY from chicken aiming to compare the performance of these two antibodies in term of yield, titer, sensitivity, selectivity and matrix effect under parallel conditions. The results showed that the total yield of IgY produced by one chicken during 43 weeks' experimental period was about 15 g. This output is much more than IgG (150 mg from one rabbit). Besides, IgY titers increased during 10 weeks and remained stable over 30 weeks. The peak titer of IgY was 1:2¹⁸. As the antibody titer rose, the sensitivity was increased. For IgG, the maximum titer was observed to be 1:2²³. In addition, both IgY and IgG were highly sensitive. The limits of detection were 0.54 ng/mL for IgY and 0.24 ng/mL for IgG. These results indicated that the IgY potentially provides a practical and ethical alternative to IgG in veterinary drug residue immunoanalysis.     

鸡卵黄抗体的制备以及金磁微粒为载体去除人血浆部分高丰度蛋白的研究

目的:以人血浆白蛋白(HSA)和IgG为免疫原,制备特异性鸡卵黄抗体IgY(Egg yolk immunoglobulin),并将其固定于金磁微粒表面,用于HSA和IgG的去除研究.方法:用HSA、IgG以及混合成分分别作免疫原免疫Roman母鸡.制备抗HSA和IgG鸡卵黄抗体IgY,并对IgY的分离提取条件进行优化.SDS-PAGE和间接ELISA检测IgY的纯度和效价.将高效价IgY固定于金磁颗粒表面进行血浆高丰度蛋白去除研究.结果:免疫后60～120 d内,鸡血清抗体效价可达1∶15 000～1∶25 000;收获鸡蛋,提取得到的卵黄抗体IgY效价可达1∶10000～1∶25000,纯度98%以上;采用金磁微粒载体固定IgY,可对血浆中的HSA,IgG进行特异性的去除.结论:人血浆中的高丰度蛋白成分HSA和IgG免疫产蛋母鸡后,可从鸡卵黄中分离提取到高效价、高纯度的卵黄抗体IgY;IgY偶联于金磁微粒表面可特异性的去除人血浆中的HSA和IgG,作为血浆蛋白质组学研究的一种新方法,有较好的应用前景.     

Anti-horse globulin antibodies in human sera

Organ transplant patients who had received ALG, patients with rheumatoid arthritis and normal persons were studied for serum antibodies to horse globulins. Although normal individuals rarely show the presence of anti-horse antibody, rheumatoid patients with high titres of rheumatoid factor usually show anti-horse globulin agglutinins in their IgM globulins and these agglutinins are considered to be a manifestation of their `rheumatoid factors'. These agglutinins are readily absorbable with aggregated human γ-globulin. On the other hand, although most transplant patients administered ALG produce anti-horse antibody, it is usually produced as an IgG globulin and it is not absorbable with aggregated human γ-globulin.     

Clinical significance of IgG4 antibody determination in children against egg white, milk, soybean and Dermatophagoides farinae]

The measurement of IgE and IgG4 antibodies against egg white, milk, soybean and Dermatophagoides farinae was performed by FAST (fluorescence allergosorbent test) using 21 serum samples obtained from non-allergic children and 160 serum samples from atopic children with bronchial asthma and/or atopic dermatitis. Their antibody levels were evaluated for any association with disease severity and for clinical significance in establishing diagnosis. It was found that children with bronchial asthma showed lower levels of IgE antibodies against egg white, milk and soybean and higher levels of IgE antibodies against Dermatophagoides farinae compared with those of children with atopic dermatitis, while both groups showed higher levels of egg white and milk-specific IgG4 antibodies compared with non-allergic children. These IgE and IgG4 antibody levels revealed a tendency to correlate with disease severity in patients with atopic dermatitis, while this was not observed in patients with bronchial asthma. The contribution percentages of IgG4 antibody determination, together with IgE antibody determination, in retrieving causal allergens were 71% for egg white, 70% for milk and 48% for soybean allergy, implying their diagnostic value in establishing clinical diagnosis.