Course: Immunology
Lecturer: Dr. Weam Saad
Lecture: Monoclonal Antibodies
Monoclonal Antibodies
Principles for Monoclonal and polyclonal Abs production
Monoclonal Antibodies are made by immunizing animals
(mouse, rabbit, goat, horse, etc.) with purified Ag. The animal
responds by producing Abs that specifically recognize
and bind to the
Ag (single specificity). Polyclonal Abs are produced in multiple
animal species e.g. rabbit, horse, goat, and chicken and wide reactivity
but lower specificity when compared with monoclonal Abs.
Polyclonal Abs have the advantage (comparing with
monoclonal antibodies) in that they can react to multiple epitopes of
the target protein. The disadvantage is the cross-reactivity with similar
epitopes in other proteins and give false positives.
Monoclonal Abs are produced mostly in mice. Köhler and
Milstein developed the technology of monoclonal Ab production.
Mice are injected with purified immunogen (Ag). After an immune
response has been achieved, the B lymphocytes (Ab-producing cells)
are harvested from the spleen. Because isolated B-cells have a limited
life span, they are fused with mouse myeloma cells.
The hybrid cell produced (hybridoma) is an immortal cell that
produces Igs specific for a single epitope (monoclonal Abs). The
advantage of monoclonal Abs is their higher specificity when
compared with polyclonal Abs. Hybridomas can be kept in cell
cultures (highly pure Ab but at low concentration). The commercial
catalogs usually includes the host (animal in which the Ab was
produced e.g., mouse, rabbit).
Some vaccines that use monoclonal Abs:
1. Tetanus
2. Rabies
Some Immunological techniques and that use
monoclonal Abs:
1- ELISA, all types.
2- Immunohistochemistry.
3- Immunotherapy.
4- Flow Cytometry.
5- Biosensors.
6- Affinity chromatography.
7- Immunological Tests for infections like Salmonellosis and
Brucellosis.