MAB production
Early production methods to isolate the right antibody involved injecting an animal, typically a mouse or rat, with the target antigen. Spleen cells would then be harvested, and the specific B cell extracted.1
However, this can mean that a lot of proteins from the source species are present, increasing the risk of sensitisation. If an immune reaction occurs, the patient may then be unable to have further doses of any MAB with a similar source species component.
Genetic engineering with recombinant DNA is used to make the animal proteins more closely resemble human-type proteins, reducing exposure to animal protein allergens. ‘Humanised’ mice produce human-like immunoglobulins, thus reducing sensitisation.
Another method used to isolate an antibody for cloning is to identify a specific antibody from a patient. This method is used particularly in treating cancers. A third method is using an in vitro screening library of antibodies to identify sequences which will bind with a target antigen.
Most mass production is done cell cultures, often using CHO cells, but developments using yeast cells could speed up production. The mixture also needs purifying to remove unwanted remnants from the host cell.