Determination of IgG and IgM levels in serum by rocket immunoelectrophoresis using yolk antibodies from immunized chickens

Polyclonal IgY Antibodies from Chicken Egg Yolk — an Alternative to the Production of Mammalian IgG Type Antibodies in Rabbits

Based on a physiological process, antibodies are concentrated in the yolk of chicken eggs, and can be used as a convenient source of polyclonal antibodies. Hens were immunised with a BSA-cholecystokinin octapeptide conjugate (CCK-8) to obtain antibodies against CCK-8. A simple method is described for extracting the antibodies from egg yolk, which can then successfully be used in immunocytochemical studies. Using these antibodies, CCK-like immunoreactivity was found in brain sections of rats, both by fluorescein isothiocyanate and peroxidase staining. The specificities of these antibodies were different from those of rabbit antibodies against the C-terminal part of CCK-8.

The applicability of egg yolk antibodies in immunological investigations is reviewed and discussed in detail. The properties of avian egg yolk antibodies are compared with those of polyclonal antibodies obtained from mammals (e.g. the rabbit). The more general use of avian antibodies is emphasised as a real alternative, taking into consideration the reduction in animal suffering involved in comparison with the classical immunisation techniques used on rabbits.

Study on development of Vipera lebetina snake anti-venom in chicken egg yolk for passive immunization

Chicken egg yolk antibodies against Vipera lebetina venom were evaluated for their antivenom potential. White leghorn hens were immunized with detoxified V. lebetina venom (γ-irradiated venom). The detoxified venom (200 μg) was mixed with an equal volume of complete Freund's adjuvant and was injected intramuscularly into the hens. The antibodies showed high activity (1.6 LD50/mL) in egg yolks after 12 d of venom injection. The eggs were collected after 12 days, and the egg yolks were removed and washed with purified water to remove any contamination with egg whites. The purification was performed using a method described by Maya Devi et al., followed by gel filtration (Sephadex G-50). The purity and molecular weight of antivenom antibodies (IgY) were determined using electrophoresis, and the molecular weight was found to be approximately 185 kDa. The potency of IgY was 6 LD50/mL (mice), i.e., 1 mL of IgY could neutralize 43.8 μg of standard V. lebetina venom). Our results showed that chicken egg yolk antibodies were effective in neutralizing the lethality and several pharmacological effects of V. lebetina venom and could be used for developing effective antivenom.

Monitoring of laying capacity, immunoglobulin Y concentration, and antibody titer development in chickens immunized with ricin and botulinum toxins over a two-year period

One of the key benefits in using chickens for immunization is the high yield of antibodies obtainable. It is known that egg production decreases over time, while animal maintenance costs remain stable. It would, however, be desirable to keep hens as long as possible to obtain maximal amounts of antibodies. To identify a suitable length of time that animals can be kept and to optimize the cost:yield ratio, we monitored the number of eggs laid, the total amount of chicken IgY, and the specific antibody titer from individually prepared eggs over a 2-yr period. The plant toxin ricin and the Clostridium botulinum neurotoxins type A and B were used to immunize 4 chickens. The number of eggs laid in 2 yr was approximately 600 per hen (about 80% of the maximum egg number), yielding about 20 to 40 g of total IgY per hen. A stable antibody titer of 1:100,000 to 1:1,000,000, as measured by ELISA, was obtained following up to 11 injections of 10 to 20 microg of immobilized native toxin. Laying capacities were found to decrease, on average, from 7 eggs/wk at the point of first immunization to 2 eggs/wk after more than 2 yr. In parallel, the yield of total and specific IgY increased over time, so that the antibody recovery remained high, even after prolonged immunization times. Using purified IgY preparations, classical immunological assays such as ELISA and Western blotting were performed. Furthermore, the IgY showed neutralizing capacity when used to block the functional activity of the toxins both in vitro and in vivo. Analysis of the total IgY content over time demonstrated a complex biological oscillation (and the antigen-specific titer), with a shorter time period of around 7 d (circaseptan rhythm). In summary, we successfully immunized chickens with ricin and botulinum neurotoxins and monitored laying capacity, IgY concentration, and specific antibody titer over an extended period of 2 yr.

Chicken Egg Yolk as an Excellent Source of Highly Specific Antibodies Against Cytochromes P450

Using chicken antibodies IgY (purified from egg yolks) against mammalian cytochromes P450 and by means of cytochrome P450 marker substrates, we found for the first time the presence of hepatopancreatic cytochrome P450 in crayfishOrconectes limosus(an inducible cytochrome P450 2B-like enzyme) and we were able to detect and quantify cytochrome P450 1A1 in microsomes of human livers. Expression levels of cytochrome P450 1A1 in human livers constituted less than 0.6% of the total hepatic cytochrome P450 complement. The results obtained in our study are clear examples that chicken IgY are suitable for cytochrome P450 detection and quantification. Due to the evolutionary distance, chicken IgY reacts with more epitopes on a mammalian antigen, which gives an amplification of the signal. Moreover, this approach offers many advantages over common mammalian antibody production since chicken egg is an abundant source of antibodies (about 100 mg IgY/yolk) and the egg collection is a non-invasive technique. In the case of antibodies against cytochrome P450 2B4, we documented fast and steady production of highly specific immunoglobulins. Thus, chicken antibodies should be considered as a good alternative to and/or superior substitute for conventional polyclonal antibody produced in mammals.

A comparison of three methods for extracting IgY from the egg yolk of hens immunized with Sendai virus

Hens were immunized with partially purified Sendai virus that had been grown on chicken embryos. The titres of specific antibodies to Sendai virus varied from log2 13.0 to 15.5 during the 4 months after immunization and the immunoglobulin Y (IgY) concentration varied from 2 to 10 mg per ml of egg yolk. A method has been developed employing dextran blue to isolate IgY from the egg yolk. The dextran blue method was compared with two other methods (poly(ethylene glycol) and chloroform) in terms of yield, total protein content, IgY concentration, specific activity of IgY and SDS-PAGE analysis. The specific activity and the IgY content obtained by these three methods proved to be identical, in the range log2 12.9-14.1, and 4.6-12.8 mg/egg, respectively. However, the total protein content when purified by chloroform was 2-fold to 4-fold higher than that of the others. The analysis of IgY by SDS-PAGE demonstrated that IgY purified with dextran blue contained three major protein components with molecular weights of 34.7 kDa, 41 kDa and 66 kDa and one minor protein of 45 kDa. IgY that was extracted with chloroform contained two major proteins of 45.7 kDa and 75.2 kDa and that extracted with PEG-6000 contained only one major protein of 66 kDa. The IgY obtained by these latter methods also contained several minor proteins in the range 41-80 kDa.

Chicken antibodies: taking advantage of evolution--a review

Laying hens are highly cost-effective as producers of antibodies compared with the mammals traditionally used for such production. Also, chicken antibodies have biochemical advantages over mammalian antibodies due to the phylogenetical differences between avian and mammalian species, resulting in increased sensitivity as well as decreased background in immunological assays. In contrast to mammalian antibodies, chicken antibodies do not activate the human complement system nor will they react with rheumatoid factors, human anti-mouse IgG antibodies, or bacterial and human Fc (fragment crystallizable)-receptors. Thus, chicken antibodies offer many advantages over mammalian antibodies and may replace such antibodies in the future.

Determination of circulating immune complexes by chicken anti-human C3 and anti-human C1q microELISA

The present study reports on an anti-human C1q and an anti-human C3 microELISA for measuring circulating immune complexes (CIC). Affinity-purified chicken anti-human C3 and anti-human C1q were used as capture antibodies and protein A-alkaline phosphatase conjugate for detection. Chicken antibodies do not activate mammalian complement, do not react with rheumatoid factor and are not bound to anti-mammalian IgG antibodies or protein A, which often are used for detection in ELISA. They are therefore suitable as capture antibodies in CIC assays. We have tested Bell's palsy patients and found an increase in both anti-C3- and anti-C1q-containing CIC in acute and convalescent sera compared with the normal.

Quantitation of rheumatoid factors by enzyme immunoassay using biotinylated human IgG

An enzyme-linked immunosorbent assay (ELISA) using biotinylated human IgG for the detection of rheumatoid factor (RF) in human sera has been developed. This assay avoids some of the problems encountered with earlier ELISA methods used for RF detection. Accurate RF titers of human sera were determined using a simple computer program developed for curve fitting of ELISA data.

Use of chicken and rabbit antibodies in a solid phase protein A radioimmunossay for virus detection

A new rapid indirect solid phase radioimmunoassay was developed for the detection of Sindbis virus. Chicken antibodies were adsorbed onto wells in microplates to serve as 'capture antibodies' and rabbit antibodies were used as the second antibody. 125I-labelled protein A that does not bind to chicken antibodies, but binds firmly to rabbit antibodies was used as the tracer. All the steps necessary for the development of the assay are described. The minimal amount of Sindbis virus detectable was around 3 x 10(5) PFU/ml and the interassay reproducibility was about +/- 30%.