Monoclonal Antibodies

• Aims:

• Must be able to define the term monoclonal antibody.

• Should be able to outline the possible uses of monoclonal antibodies.

• Could be able to describe the process by which monoclonal antibodies are produced.

Monoclonal Antibodies• A monoclonal antibody is an artificially produced antibody that neutralises only

one specific protein (antigen).

– Monoclonal antibodies produced by stimulating the production of B-cells in mice injected with the antigen.

– These B-cells produce an antibody against the antigen.

– B-cells can be isolated and made to fuse with immortal tumor cells. They can then be cultured indefinitely in a suitable growing medium.

– Monoclonal antibodies are useful for 3 reasons:

• They are totally uniform (i.e. clones).

• They can be produced in large quantities.

• They are highly specific.

Making Monoclonal Antibodies

Hybridoma cells

Mouse cell and tumor cell fusingUnfused cell

Pure tumor cells are harvested from culture

A mouse is injected with a foreign protein (antigen).

The mouse’s B-cells produce an antibody to recognize the antigen.

A few days later, antibody-producing B-cells are taken from the mouse’s spleen.

The mouse cells and tumor cells are mixed together in suspension.

Some of the mouse cells fuse with tumor cells to make hybrid cells called hybridomas.

Hybridomas are screened for antibody production. They are then cultured to produce large numbers of monoclonal antibodies.

The mixture of cells is placed in a selective medium that allows only hybrid cells to grow.

Monoclonal Antibody Therapy

• Monoclonal antibodies have many therapeutic uses:

– Neutralizing endotoxins produced by bacteria in blood infections.

– Preventing organ rejection, e.g. in kidney transplants, by interfering with T cell activity.

– Treatment of some autoimmune disorders such as rheumatoid arthritis and allergic asthma.

– Immunodetection and immunotherapy of cancer. Newer methods specifically target tumor cells, shrinking solid tumors - no harmful side effects.

– Inhibition of platelet clumping to prevent reclogging of coronary arteries after angioplasty.

Diagnostic Uses

• Monoclonal antibodies have many diagnostic uses:

– Detecting the presence of pathogens such as Chlamidia and streptococcal bacteria, distinguishing between Herpesvirus I and II, and diagnosing AIDS.

– Measuring protein, toxin, or drug levels in serum.– Blood and tissue typing.– Detection of antibiotic residues in milk.– Detecting pregnancy.

Activity

• Complete the activities on page 159 in Biozone book.