Production of recombinant immunoglobulin g1 monoclonal antibodyusing Kluyveromyces lactis yeast expression system

Monoclonal antibodies that exhibit high affinity towards their targets play a crucial role in the treatment of numerous diseases. Advances in recombinant DNA technology have enabled the production of monoclonal antibodies without the requirement of animal vaccination in recent years. Apart from widely used platforms like mammalian cells, yeast species such as K. lactis have gained prominence in recombinant protein production. In this thesis, full-length trastuzumab which is approximately 150 kDa was produced using safthe K.lactis yeast expression system and secreted out of the cell. The light and heavy chain sequences were effectively cloned into the pKLAC2 vector and then introduced into K. lactis cells through electroporation. Expression of both light and heavy chain transcripts was confirmed through the induction of cultures in BMLY medium containing lactose. Ammonium sulfate precipitation and hydrophobic interaction chromatography methods were used for the purification of trastuzumab. Successful production and extracellular secretion of full-size trastuzumab was confirmed by SDS-PAGE and western blot analysis. Furthermore, using MCF7 cell lysate it has been demonstrated that purified trastuzumab can effectively bind to the HER2 receptor