Enhancing monoclonal antibodies and hybridoma cell lines

Abstract

We are interested in determining the range of variants present in a cell population that can actually be isolated. We have used subcloning and sublining to search for variants with increased antibody stability, increased cell line stability to freezing and defrosting, increased cell population viability, increased antibody production and the ability to grow in simpler media. This paper presents the case histories of several different hybridoma cell lines which required some property changed before they became production ready clones. We found that switching the class of an antibody from IgG3 to IgG1 did increase its stability, decrease its tendency to aggregate and allowed it to be used in a commercial diagnostic kit. We could isolate subclones that produced twice the level of antibody with a frequency of 1-3%. It was straight forward to isolate clones that were stable to freezing and defrosting or grew in a simpler media. We were not successful in increasing the maximum viability of a cell line. In conclusion, we have found that any population of hybridoma cells has natural variants with significantly enhanced properties that can be isolated.