Antibody Development

Antibodies are glycoproteins belonging to the immunoglobulin superfamily. Generally, antibodies can be divided into 4 major types based upon their origin and clonality:


1. IgG polyclonal and monoclonal antibodies

Their origin is mammalian B-cells and they are present in blood circulation and lymph nodes.

2. IgY polyclonal and monoclonal antibodies

These are the antibodies also produced by B-cells, but they are secreted into egg yolk.

GenWay's core technology can generate libraries of gene-specific and domain-targeted antibodies, which can be either polyclonal or monoclonal, based upon gene-expression or formulated protein/peptide immunization. GenWay specializes in polyclonal chicken antibodies, which are isolated from the egg yolk of the immunized chickens, and are called IgY (Immunoglobulin Yolk). GenWay also has the know-how and technology to produce mammalian IgG antibodies from rabbit and mouse host systems, in both polyclone and monoclone formats. The antibodies can be directly used for research and diagnostic applications. In meeting the needs of therapeutics or in human application, GenWay has also developed technology and know-how for producing humanized or fully human antibodies.

IgG and IgY are common in many aspects as immunoglobulin. However, they also have definitive differences with associated advantages and
disadvantages (Table 1).


Table 1. Comparison of Antigens
Features of
Comparison

IgG

IgY

References

Overview  Relatively matured in technology
 development and application
 Relatively new in product development
 and application
 Larsson et al., 1993
 Warr et al., 1995
 Schade and Hlinak 1996
 Zhang, 2003
Animal  Mammal  Birds, Reptiles, Amphibia  Klemperer, 1893
 Warr et al., 1995
Sources  Serum  Egg Yolk  Patterson et al., 1962
 Leslie and Clem, 1969
 Du Pasquier et al., 1989
Molecular Weight
(by SDS-PAGE)
 Whole: 150 kDa
 Light chains: 22 kDa x 2
 Heavy chains: 50 kDa x 2
 Whole: 180 kDa
 Light chains: 21 kDa x 2
 Heavy chains: 70 kDa x 2
 Hatta et al., 1993
Molecular Weight
(by MALDI-TOF MS)
 Whole: 150 kDa
 Light chains: 23 kDa x 2
 Heavy chains: 50 kDa x 2
 Whole: 167 kDa
 Light chains: 19 kDa x 2
 Heavy chains: 65 kDa x 2
 Sun et al., 2001
Basic Structure
Differences
 Flexible hinge region, shorter Fc stem
 with 1 pairs of carbohydrate groups
 Shorter and less flexible hinge, longer
 Fc region with 2 pairs of carbohydrate
 groups
 Warr et al., 1995
Immune Response
to Mammalian Antigens
 Adversely affected by phylogenetic homology  Enhanced by phylogenetic differences  Gassmann et al., 1990
Affinity Maturation
Mechanism
 Somatic hypermutation  Pseudo-V gene conversion  Bezzubova and Buerstedde 1994
 Warr et al., 1995
Affinity or Avidity  Moderate  High  Ikemori et al., 1993
 Lemamy et al., 1999
 Lin et al., 2001
Quantity (Yield per
month per animal)
 Milligrams with 0.1-5% specific
 antibodies (rabbit)
 Grams with 0.1-10% specific antibodies  Schade et al., 1994
Cross Reactivity  High to human (antibody)  Low to human (antibody)  Hadge et al., 1984
 Tini et al., 2002
Non-Affinity
Isolation
 Relatively more complicated and slow  Fast and simple  Polson et al., 1980
 Akita and Nakai, 1993
 Schwarzkopf and Thiele, 1996
 Bizhanov and Vyshniauskis, 2000
 Stalberg and Larsson, 2001
 Devi et al., 2002
Affinity
Purification
 Proteins A or G, or antigen-based
 purification
 Protein L or antigen-based purification  Lin et al., 2001
Stability  Good, Stable at pH 3-10, up to 700C  Good, Stable at pH 4-9, up to 650C  Shimizu et al., 1992
 Hatta et al., 1993
 Lee et al., 2002
Hydrophobicity  Less hydrophobic than IgY  Fc region is hydrophobic  Davalos-Pantoja et al., 2000
Immunoaffinity
Fractionation
 IgG microbeads are shown having
 less binding capacity and higher non-specific
 binding
 IgY microbeads are highly specific with
 high capacity in capturing and removal
 of highly-abundant proteins. Less
 non-specific binding
 Fang et al., 2004
 Hinerfeld et al., 2004
 Huang et al., 2005
 Qian et al., 2006
 Liu et al., 2006
Productivity  Limited in quantity and duration  High with greater quantity and long duration  Gassmann et al., 1990
 Hatta et al., 1993
Scalability  Difficult  Feasible and practical  Mine and Kovacs-Nolan, 2002
Monoclonal
Antibodies
 Have been well developed  Several cases reported, technology
 development is rapidly progressing
 Sasai et al.,1996
 Michael et al., 1998
 Greunke et al., 2006
 Miyamoto et al., 2007
Immune
Suppression
 Several products are under development  May be useful for xenotransplantation  Fryer et al., 1999
Diagnosis  Widely used, especially monoclonal antibodies  Useful and practical for various applications  Erhard et al., 2000
 Carlander et al., 1999
Therapeutics  Well developed  To be further developed, such as in
 antibiotic-alternative therapy
 Carlander et al., 2000
 Mine and Kovacs-Nolan, 2002
 Tsurushita et al., 2004



For further information on the features and applications of IgY and IgG antibodies, as well as the related products such as secondary antibodies and antibody conjugates, please visit the pages:


GenWay offers extensive custom services in antibody development and applications. For more detailed information, please see the specific description pages in Custom Antibodies,and Immunoaffinity Separation.