Strategy for the production of monoclonal antibodies

Lymphocytes, activated in vivo or in vitro to produce antibodies, do not have the ability to grow in vitro. Essentially this problem may be overcome by two different methods (i) transformation of B cells in vitro, e.g. by oncogenic viruses or, (ii) fusion of antibody-producing cells with myeloma cells to confer immortality to the B cells. 

Direct transformation of human B lymphocytes with Epstein Barr virus seems to hold great promise since a high percentage of the cells may be transformed. This method met also with some success for rabbit cells, using SV40 virus, but less with murine cells (Zurawski et al., 1978 Steinitz et al., 1980 Reading, 1982). 

Most current protocols use the approach of fusion with mutant myeloma cells according to a strategy in which the mutant cells are rescued from death by hybridization with lymphocytes in a medium otherwise lethal for this mutant (Littlefield, 1964 Ephrussi and Weiss, 1969) in which only the hybrids survive. Usually only a few hybrids produce the desired antibodies. 

The two most popular myeloma cell lines used for this purpose are those lacking hypoxanthine-guanine phosphoribosyl transferase (HGPRT) or thymidine kinase (TK). Other kinds of mutants can be used as well, such as those resistant to ouabain (in combination with HGPRT- Baker et al., 1974). Myeloma cells treated with biochemical inhibitors can also be rescued by fusion with untreated lymphocytes (Wright, 1978). 

For the production of stable hybridomas, ontogenetically related cells should be used (Kohler, 1981) from the same species (Yarmush et al., 1980) and at a similar stage of differentiation (Ringertz and Savage, 1976). 

---