Antibodies, also called immunoglobulins, are a key component of the immune system playing a central role in both recognizing foreign antigens, such as proteins, microorganisms or toxins, and stimulating an immune response against them.
They specifically bind to the antigen and signal other cells to eliminate the foreign matter. Some antibodies are autoantibodies and home in on our own tissues. It is not surprising therefore, that many immunotherapeutic approaches involve the use of antibodies.
An antibody is a large Y-shaped protein (+/- 150kDa) consisting of four polypeptides: two identical heavy chains and two identical light chains folded into constant and variable domains. The tips of the “Y” constitute the variable region giving the antibody its binding specificity for a given antigen. The constant tail region provides the structural framework of the antibody and directs the biological properties and its role in signaling to other immune cells (effector functions).
- Antigen binding fragment comprises one variable
and one constant region of both heavy and light chains
- Tail region
- Heavy chain with one variable domain, a constant domain, a hinge region, and two more constant domains
- Light chain with one variable and one constant domain
- Antigen binding site
- Hinge regions
Monoclonal antibody technology
The advent of monoclonal antibody technology has made it possible to raise antibodies against specific disease related antigens. The production of antibodies is a major function carried out by a type of white blood cell called B-cell or B lymphocyte. Monoclonal antibodies (mAb) are identical biomolecules, generated from a single B-cell clone that only recognize one unique binding site, or epitope, on a single antigen. Since specific monoclonal antibodies can be made against a virtually unlimited number of substances, these molecules have become an important tool in biochemical research as well as for medicinal diagnostic and therapeutic applications.
Trends in clinical development of monoclonal antibodies indicate that there is a nascent shift towards engineered antibody fragments, and it is likely that such fragments will become the next important class of protein-based therapeutics after monoclonal antibodies. Engineered antibody fragments retain full antigen-binding capacity with optimized properties for research, diagnostic and therapeutic applications. Fragments are particularly useful in therapeutic applications where epitope binding alone can produce the desired effect, for example in receptor blocking.
Through the acquisition of the Swiss biopharmaceutical Baliopharm AG in April 2018, Promethera Biosciences strengthened and diversified its technology base with innovative antibody engineering platforms. These platforms are dedicated to developing therapeutic options for chronic liver diseases, immune mediated inflammatory diseases and oncological indications. These antibody technologies are being developed in parallel to the cell based therapy to provide a complementary, holistic strategy for the treatment of liver diseases.