Two chemically linked fragments antigen-binding form an artificial
antibody that binds to two different
antigens
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...
, making it a type of
bispecific antibody. They are
fragments antigen-binding (Fab or Fab') of two different
monoclonal antibodies
A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell Lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell.
Monoclonal antibodies ca ...
and are linked by chemical means like a
thioether. Typically, one of the Fabs binds to a
tumour antigen (such as
CD30) and the other to a protein on the surface of an
immune cell, for example an
Fc receptor on a
macrophage
Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cel ...
. In this way, tumour cells are attached to immune cells, which destroy them.
In the late 1990s and early 2000s,
clinical trials with chemically linked Fabs were conducted for the treatment of various types of
cancer. Early results were promising,
but the concept was dropped because of high production costs.
s employ a similar mechanism of action while being cheaper.
References
Monoclonal antibodies
Antineoplastic drugs
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