Monoclonal antibodies generation process

Fig. 25 The monoclonal antibody 26D9, generated to the jV-oxide hapten [67], catalysed the 6-exo-tet ring closure of [65] regioselectively to yield the disfavoured tetrahydropyran product [68]. This is a formal violation of Baldwin s rules, which predicts a 5-exo-tet spontaneous process to generate tetrahydrofuran derivative [66].

The aim of most technologies is to generate a population of cells each of which secretes a desired product into the medium. For this to occur the cells do not need to be actively dividing and, in fact, this is sometimes counterproductive. Cells can remain viable at high cell densities using perfusion systems (Chapter 3) and the product purified from the spent medium (Spier, 1988). Furthermore, the simpler the growth medium (i.e. the fewer protein factors required) then the easier is the downstream processing and this is one reason for the development of serum-free media especially for the culture of hybridoma cells used for monoclonal antibody production ( 5.8). 

SFD is a combination of the two previously described drying techniques in which the microdispersed liquid particles are generated through the jet nozzle in the absence of heat, then collected and frozen in liquid nitrogen before sublimation occurs. The frozen particles are then lyophilized. SFD is used in place of SD when the protein cannot withstand the temperatures in the SD process. Preparation of SFD powders of DNase and an anti-IgE monoclonal antibody were found to be superior to those prepared by SD. ... 

After biological reactions have generated a product of interest, it is necessary to recover this product from a liquid mixture that typically contains several undesirable components. The treatment of any culture broth after bioreactor cultivation is known as downstream processing. Downstream processing can account for 60-80%) of the total production cost, particularly in the production of modern recombinant proteins and monoclonal antibodies. A typical downstream process requires several steps in the areas of solid-liquid separation, cell rupture, product recovery, and product purification. It is important to minimize the number of downstream processing steps required because significant product losses inevitably occur during each step.f ... 

Therapeutic antibodies, especially the latest generation platforms (humanized and fully human), have a potentially superior specificity due, for example, to the high number of variants in the selection process (more than 10 °) that cannot be matched by small-molecule libraries that show diversities in the range of 10 (see also Part V, Chapter 2). This often leads to better side-effect profiles shown in the better overall clinical survival rates, especially for humanized and fully human antibodies (e.g. [23]) (see also Part IV, Chapter 3). In addition, monoclonal antibodies have specific capabilities that are entirely unique (e.g., activation of immune response). 

Much work is required to generate a successful monoclonal antibody, especially in the cloning and selection process. 

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