IgY-Based Immunotherapy Development

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Introduction of IgY

In contrast to mammalian serum, egg yolk contains only one class of antibodies: egg yolk immunoglobulin (IgY) is a functional homolog and evolutionary ancestor of the mammalian IgG, however, it is structurally different. IgY is considered a typical low-molecular-weight (i.e., non-IgM) serum antibody of birds, reptiles, amphibians, and lungfish. The general structure of the IgY molecule is similar to that of IgG. IgY has two heavy and two light chains; the heavy chains have one variable and four constant regions. Chicken IgY has a molecular weight (MW) of 180kDa. Duck IgY is smaller, with MW=120kDa, and represents a truncated version of IgY, IgY(ΔFc) lacking the two C-terminal domains of the H chains; it is therefore considered a structural equivalent of an F(ab')₂ fragment.

Fig. 1 Basic structure of IgY. (Rahman, 2013)

IgY-Based Immunotherapy

Because IgY is resistant to the gastric barrier, the oral administration of yolk purified IgY can be used for passive immunotherapy against bacterial and viral gastrointestinal (GI) tract infections. Thus IgY is an alternative for antibiotics in the treatment of enteric antibiotic-resistant pathogens. Oral administration of IgY obtained by chicken immunization with the purified proteins has proved successful for the treatment of a variety of GI infections, such as bovine and human rotaviruses, bovine coronavirus, Yersinia ruckeri, enterotoxigenic Escherichia coli, Edwardsiella tarda, Staphylococcus, Pseudomonas, and H. pylori Urease B. In another research, following DNA immunization of laying ducks with a plasmid expressing H. pylori UreB (large subunit of urease), anti-UreB IgY antibodies were generated from egg yolk. These polyclonal and monospecific IgY antibodies are of high titer and specifically recognize recombinant H. pylori urease purified from Escherichia coli.

Fig. 2 The antibody diversification in chicken by gene conversion. (Dias da Silva, 2010)

Advantages of IgY-Based Immunotherapy

IgY lacks reactivity with the human complement system and human Fc-receptors, thus preventing non-specific inflammation.
IgY is prepared from egg yolks thus avoiding the use of toxic compounds or additives.
Control egg cholesterols and triglycerides in low levels.
Together with other egg proteins, IgY exerts beneficial antibacterial and immune-stimulating effects.

Advantages of IgY-Based Immunotherapy Compared with Vaccine

The rapid and local onset of action
The broader age range of patients
High specific activity
Nontoxic

In general, the role of IgY is intended to be achieved in specific local sites along the digestive tract. This process has a high degree of target specificity and relies on a largely predictable and usually effective antigen-antibody interaction. Several mechanisms of action are proposed in host protection:

Inhibit the adhesion of microorganisms to the cell surface.
Prevent virus colonization by preventing cell-to-cell transmission,
Bacteria agglutination leads to the fixation and death of microorganisms or is easily flushed into the intestinal tract.
Inhibit enzyme activity.
Neutralize toxin activity.

Services at Creative Biolabs

IgY-based immunotherapy is an important application of non-IgG antibodies. Creative Biolabs has been focusing on non-IgG antibodies over years and provides comprehensive relevant services. We have an advanced technology platform offering services including but not limited to:

If you are interested in non-IgG antibodies, please feel free to contact us for more information

References

Rahman, S.; et al. Oral passive IgY-based immunotherapeutics: a novel solution for prevention and treatment of alimentary tract diseases. Hum Vaccin Immunother. 2013, 9(5): 1039-48.
Dias da Silva, W. and Tambourgi, D. V. IgY: a promising antibody for use in immunodiagnostic and in immunotherapy. Vet Immunol Immunopathol. 2010, 135(3-4): 173-80.

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!! For Research Use Only. Our products and services are NOT intended for diagnostic or therapeutic applications.

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