Page 472 - Veterinary Immunology, 10th Edition

region but reduces their biological activities. It is possible, however,
VetBooks.ir to join this fragment to the Fc region of the target species to produce

a chimeric molecule. For example, mouse myeloma variable regions
can be attached to dog constant regions to make a canine

monoclonal antibody for use in that species. By subsequently
modifying the sequence in the V region framework regions, the
monoclonal antibody may be fully “caninized.” For example, a
caninized monoclonal antibody directed against interleukin-31 is

used to prevent itch in dogs with atopic dermatitis (Chapter 30).
Alternatively, it is possible to produce monoclonal antibodies of the
desired species using “display technologies” such as phage
displays. In these cases, huge libraries of antibody fragments are

generated from the species of interest and then screened for their
antigen-binding abilities.
Monoclonal antibodies are the preferred source of antibodies for
much immunological research. They are absolutely specific for

single epitopes and are available in large amounts. Because of their
purity, they are used in clinical diagnostic tests in which large
quantities of antibodies of consistent quality are required. Although
mouse cells have been the preferred source, studies have shown

that cattle and goats can be genetically engineered to produce
monoclonal antibodies in their milk. It has even proved possible to
incorporate antibody genes into plants such as soy, corn, and
tobacco. These “plantibodies” are produced in very large quantities

and appear to be functional. “Humanized” monoclonal antibodies
are being employed to treat cancers and suppress inflammatory
and autoimmune diseases. Similar species-modified monoclonal
antibodies are being increasingly employed in veterinary medicine

(Chapter 41).

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