Natural Killer Cell Proliferation Mechanisms (ETF6976 )

Principal Investigator: Alar Aints
Duration of project: 1st January 2007 – 31st December 2010

NK (Natural Killer) cells are cellular effectors of the innate immune system. They comprise 5-15% of the peripheral blood mononuclear cells. Their functions include the primary elimination of virally infected cells, immune activation via cytokines, immune regulation via killing of immature dendritic cells, and tumour control and inhibition of metastatic spread. NK cells can be used in immunotherapy for malignant diseases, and for reducing the risk of complications in haematopoietic stem cell transplantation. Unfortunately, the amount of cells available from one donor is not sufficient for effective therapy. The expansion of NK cells in culture using available knowledge results in highly variable yields. Also, many methods of NK cell expansion use tumour material as feeder cells, thus posing a risk for contamination and immune dysregulation. The aim of the current project is to elucidate the mechanisms of NK homeostatic proliferation in the absence of target cells. This allows for a better understanding of immune regulation processes and gives an opportunity for designing therapeutic interventions in the cases of autoimmune, malignant and infectious diseases.

The effect of novel growth factors to productivity of therapeutic proteins in mammalian cells (ETF7652)

Principal Investigator: Monika Drews
Duration of project: 1st January 2008 – 31st December 2011

The novel idea of the current project is to study the effect of yeast extracts (YE) containing organic form of selenium (Se) and glutathione (GSH) as well as functional fractions and growth factors derived from these extracts to growth characteristics of mammalian cells - producers (CHO, 293, hybridomas, SP2/0 etc.) and to productivity of potential anticancer therapeutic proteins in serum-free suspension cultures. The investigation will include the study of the effect of Se-YE, GSH-YE, fractions and growth factors of them to producer cells: 1) growth parameters (growth rate, maximal cell density); 2) viability, cell cycle and apoptosis; 3) transfectability (efficiency, toxicity) and 4) expression efficiency and productivity of potential therapeutic proteins - recombinant proteins (incl. CD44-3MUT) and monoclonal antibodies (incl. 5E1). For the study of the effect of fractions and growth factors derived from Se-YE and GSH-YE on mammalian cells, the simple and rapid test-system on mammalian cells will be developed. Components of fractions will be analysed with ultraperformance liquid chromatography – mass-spectometer (UPLC-MS). For determination and sequencing of bioactive peptide components MS/MS will be used. Se-YE and GSH-YE or fractions or bioactive compounds derived from them could be novel growth enhancing, antioxidant, antiapoptotic and cell stress reducing growth factors for serum-free suspension cultures of producer mammalian cells.