Immunoglobulin Y
Immunoglobulin Y (abbreviated as IgY) is a type of
IgY is often mislabelled as Immunoglobulin G (IgG) in older literature, and sometimes even in commercial product catalogues, due to its functional similarity to mammalian IgG and Immunoglobulin E (IgE). However, this older nomenclature is obsolete, since IgY differs both structurally and functionally from mammalian IgG,[1] and does not cross-react with antibodies raised against mammalian IgG.[2]
Since chickens can lay eggs almost every day, and the yolk of an immunised hen's egg contains a high concentration of IgY, chickens are gradually becoming popular as a source of customised antibodies for research. (Usually, mammals such as rabbits or goats are injected with the antigen of interest by the researcher or a contract laboratory.)[3]
IgY has also been analyzed in the Chinese soft-shelled turtle,
Characteristics
In chickens, immunoglobulin Y is the functional equivalent to
Functionally, IgY is partially comparable to Immunoglobulin E (IgE), as well as to IgG. However, in contrast to IgG, IgY does not bind to Protein A, to Protein G, or to cellular Fc receptors. Furthermore, IgY does not activate the complement system. The name Immunoglobulin Y was suggested in 1969 by G.A. Leslie and L.W. Clem, after they were able to show differences between the immunoglobulins found in chicken eggs, and immunoglobulin G. Other synonymous names are Chicken IgG, Egg Yolk IgG, and 7S-IgG.
Bioanalytic applications
As compared to mammalian antibodies, IgY offers various advantages for the targeted extraction of antibodies and their application in bioanalysis. Since the antibodies are extracted from the yolks of laid eggs, the method of antibody production is non-invasive. Thus, no blood must be taken from the animals for the extraction of blood serum.
The available quantity of a given antibody is considerably increased through repeated egg laying from the same hen. The cross-reactivity of IgY with proteins from mammals is also markedly less than that of IgG. Furthermore, the immune response against certain antigens in chickens is more strongly expressed than in rabbits or other mammals.
Of the immunoglobulins arising during the immune response, only IgY is found in chicken eggs. Thus, in preparations from chicken eggs, there is no contamination with Immunoglobulin A (IgA) or Immunoglobulin M (IgM). The yield of IgY from a chicken egg is comparable to that of IgG from rabbit serum.
One disadvantage of IgY, as compared to mammalian antibodies, is that the isolation of IgY from egg yolk is more difficult than the isolation of IgG from blood serum. This is due in large part to the fact that IgY cannot be bound with Protein A and Protein G. Thus, it cannot be separated from other components of the assay, for example from other proteins. Additionally, the egg yolk's rich store of lipids and lipoproteins must be removed.[7] Antibody-containing blood serums, on the other hand, can sometimes be directly used in bioanalysis, i.e., without complicated isolation steps.
Utilization in foods
Particularly in
Anti-Fel d1 egg IgY immunoglobulin has been successfully tested to reduce active
Literature
- Rüdiger Schade, Irene Behn, Michael Erhard: Chicken Egg Yolk Antibodies, Production and Application. Springer-Verlag, Berlin 2001, ISBN 3-540-66679-6
- G.A. Leslie, L.W. Clem: Phylogeny of immunoglobulin structure and function. 3. Immunoglobulins of the chicken. In: Journal of Experimental Medicine. 130(6)/1969. Rockefeller University Press, S. 1337-1352, ISSN 0022-1007
- A. Polson, M.B. von Wechmar, M.H. van Regenmortel: Isolation of viral IgY antibodies from yolks of immunized hens. In: Immunological Communications. 9(5)/1980. Dekker New York, S. 475-493, ISSN 0090-0877
- A. Polson, M.B. von Wechmar, G. Fazakerley: Antibodies to proteins from yolk of immunized hens. In: Immunological Communications. 9(5)/1980. Dekker New York, S. 495-514, ISSN 0090-0877
References
- Table comparing mammalian IgG and IgE with avian IgY and duck truncated IgY. Gallus Immunotech, accessed 28 October 2010.
- ^ Larsson A, Bålöw RM, Lindahl TL, Forsberg PO. Poult Sci. 1993 Oct;72(10):1807-12.Chicken antibodies: taking advantage of evolution--a review.
- ^ Structure, Function and Physicochemical Properties of IgY Archived 2014-05-21 at the Wayback Machine, Gallus Immunotech. Accessed 28 October 2010.
- ^ REVIEW - Chicken Antibodies- IgY - http://www.oramune.com/custom.aspx?id=7 Archived 2009-06-03 at the Wayback Machine
- ISBN 978-0-12-370634-8.
- PMID 16150486.
- ^ Zhen Xu, Gai L Wang, P Nie. Mol Immunol. 2009 vol. 46 (10) pp. 2124-32. IgM, IgD and IgY and their expression pattern in the Chinese soft-shelled turtle Pelodiscus sinensis.
- ISBN 3-527-30078-3
- S2CID 19455348.
- PMID 15545368.
- PMID 22052727. Retrieved 19 February 2015.
- PMID 30851084.