Skip to 0 minutes and 15 seconds Another very important technology, hybridoma technology. Hybridoma technology was invented by Milstein and Kohler in 1975. They shared the Nobel Prize in 1984. The technology is used to produce hybrid cell lines, hybridoma, and that’s why it’s called hybridoma technology. And the antibody produced by the technology are all from the same single source and that’s why they’re called monoclonal antibodies. In contrast with polyclonal antibodies. Let’s look at this sketch for monoclonal antibody production. Look at this poor mice, or mouse. He covered up his eyes with his right arm and extended his left arm for immunization. Now after immunization, the antibody-forming cells are produced. Those cells are fused with tumor cells to form hybridomas.
Skip to 1 minute and 28 seconds Another reason tumor cells are chosen is because of their speed growing and we want our hybridoma cells to grow quickly as well. The hybridoma cells are then cultured and reproduced. And we separate out those antibodies that have the potential to produce the antibodies and clone them again. Finally, we harvest the antibody. So this is the monoclonal antibody production procedure. Now there’re still problems with monoclonal antibody because they are derived from foreign source, from mouse. And because of that, patients developed antibody response to the monoclonal antibody. And the antibody is rapidly clear. So we have to do something about it and that’s called Chimerization.
Skip to 2 minutes and 32 seconds We chimerized the immunoglobin structure to humanize the antibody that is to make the antibody less foreign and more acceptable to the human body. And there are two implications of chimerization. Therapeutically, it reduces the immunogenic response and prolong the residence time in the body so that the antibody has more chance to work in the system. For diagnostic implication, it enhances tissue uptake for example the renal, biliary, or colonic uptake of that antibody which makes it an effective diagnostic agent. How to chimerize antibody? This is a regular structure of the antibody, the IgG structure. This is the constant region of the antibody.
Skip to 3 minutes and 32 seconds We can trim the constant region of the antibody or we can simply use one fragment of the antibody or we can use the variable region of the antibody. In essence, we reduce the size of the antibody, so that we make it less recognizable by our body system. so the antibody gets to stay in the system longer to exert its effect.
Hybridoma technology is a method for producing large amounts of identical antibodies, hence monoclonal antibodies, as opposed to the conventional polyclonal antibodies. Being foreign to human, the murine antibody is further chimerized via r-DNA technology to reduce its immunogenicity for therapeutic use.
Initially, a specific antigen is injected into a mouse Then, antibody-producing cells are collected from the mouse’s spleen The antibody-producing cells are fused with myeloma cells to form hybrid cells for rapid growth (thus the term hybridoma technology) The hybrid cells are used to produce antibodies in large amounts for therapeutic or diagnostic use. Since antibodies produced in the mouse are potentially immunogenic, they are subsequently chimerized (humanized) to improve human adaptation