Monoclonal antibodies hybridoma technique

Monoclonal antibodies can be produced not only in a cell culture but also in live animals. When injected into mice (in the peritoneal cavity, the gut), the hybridoma cells produce tumors containing an antibody-rich fluid called ascites fluid. Production in cell culture is usually preferred, as the ascites technique may be very painful to the animal and if replacement techniques exist, may be considered unethical. The process of producing monoclonal antibodies described above was invented by Georges Kohler. Cesar Milstein, and Niels Kaj Jeme in 1975 they shared the Nobel Prize in Physiology or Medicine in 1984 for the discovery (http //en.wikipedia.org/ wiki/Antibody). 

Hybridoma Cell produced by the fusion of antibody-producing plasma cells with myeloma/carcinoma cells. The resultant hybrids have then the capacity to produce antibody (as determined by the properties of the plasma cells), and can be grown in continuous culture indefinitely owing to the immortality of the myeloma fusion partner. This technique enabled the first continuous supply of monoclonal antibodies to be produced. 

The next development was the production of monoclonal antibodies (MAbs) in the mid-1970s. This uses hybridoma technology, which involves the fusion of antibody-producing B cells to immortal myeloma cells. Figure 4.4 shows the preparation of MAbs using hybridoma techniques. A more detailed discussion of biopharmaceuticals production is presented in Section 10.5. 

A rat anti-mouse VEGFR2 (Flkl) monoclonal antibody (DClOl) was developed by ImClone Systems (New York, NY, www.imclone.com) using conventional hybridoma technique [194] to conduct proof-of-concept studies. 

Catalytic antibodies, like enzymes, must be isolated and purified to homogeneity before they can be studied. Initially this was done by using the hybridoma technique for isolation of monoclonal antibodies (Box 31-A). After induction of antibody formation by injecting a selected hapten into a mouse, large numbers of monoclonal antibodies had to be tested for catalytic activity. Even if several thousand different monoclonal antibodies were tested, only a few with catalytic properties could be found.1 Newer methods have incorporated recombinant DNA techniques (Box 31-A) and use of combinatorial libraries and phage display.) Incorporation of acidic or basic groups into the haptens used to induce antibody formation may yield antibodies capable of mimicking the acid-base catalysis employed by natural enzymes. 0... 

The mammalian cell culture technique can be employed to produce clinically important biochemicals such as human growth hormones, interferon, plasminogen activator, viral vaccines, and monoclonal antibodies. Traditionally, these biochemicals had been produced using living animals or extracted from human cadavers. As examples, monoclonal antibodies can be produced by cultivating hybridoma cells in the peritoneal cavity of mice, and the human growth hormone to cure dwarfism can be extracted from human cadavers. However, the quantity obtained from these methods is quite limited for the wide clinical usages of the products. 

Volume 121. Immunochemical Techniques (Part I Hybridoma Technology and Monoclonal Antibodies)... 

The most commonly used technique to produce bispecific antibodies from two monoclonal antibodies is by fusing two hybridoma cell lines by conventional cell fusion procedure (Staerz and Bevan, 1986). These cells produce all possible combinations of the heavy and light chains of both antibodies, including the desired bispecific antibody. A limitation is that only part of the antibodies is the desired bispecific monoclonal antibody therefore, further purification is necessary (Van Ravenswaay et al., 1993). 

Fig. 3.2 Hybridoma technique for the production of monoclonal antibodies. Spleen (milt) cells, which have been taken from mice (being immunized with an antigen X) contain anti-X-antibody-producing B cells. These cells are fused with myeloma cells in the presence of polyethylene glycol (PEG) and then taken to the HAT (hypoxanthine-aminopterin-thymi-dine) medium. HAT will induce death to myeloma cells because of the absence of the enzyme hypoxanthine-guanine-phosphoribosyl-transferase (HGPRT). Hybridoma cells, how-...

The problem of multiple epitopes in an antigen can be overcome by using monoclonal antibodies produced in vitro, a technique first described in 1975 by Milstein and Kohler [6] who received the Nobel Prize for their revolutionary achievement. Antibody-secreting hybridoma cell colonies are cloned by means of limiting dilution, so that only one antibody-producing cell (clone) remains in each well. From this single parental cell, all the progeny secrete the same... 

---