Lena Häggström
lenah@biotech.kth.se
+46 8 5537 8308

Research profile

Since the beginning of 1990 my research group has focussed on animal cell technology, in particular on cell metabolism and physiology. Energy metabolism and formation of the inhibitory byproducts ammonia/ammonium and lactate has been studied in cultured mammalian, as well as in insect cells. Autocrine regulation of proliferation in serum-free media is another area of intrest currently in focus. Extracellular proteins are purified, identified and tested for activity. Gene expression by DNA-array technique is another tool used for understanding regulation of proliferation, as well as apoptosis. Currently NSO cells, CHO cells, Spodoptera frugiperda Sf9 cells, and Trichoplusia ni Hi5 cells are cultured in our laboratory. In parallel, E. coli metabolism with respect to amino aids and quorum sensing is investigated.

Some references

Förberg, C, Eliaeson, T and Häggström, L (1988) Correlation of theoretical and experimental yields of phenylalanine from non-growing cells of a rec Escherichia coli strain. J. Biotechnol. 7: 319-332

Förberg, C and Häggström, L (1988) Phenylalanine production from a rec Escherichia coli-strain in fed-batch culture. J. Biotechnol. 8: 291-300

Ljunggren, J and Häggström, L (1990) Glutamine limited fed-batch culture reduces ammonium ion production in animal cells. Biotechnol. Lett. 12: 705-710

Ljunggren, J and Häggström, L (1992) Glutamine limited fed-batch culture reduces overflow metabolism of amino acids in myeloma cells. Cytotechnology 8: 45-56

Martinelle, K and Häggström, L (1993) Mechanisms of ammonia and ammonium ion toxicity in animal cells: Transport across cell membranes. J. Biotechnol. 30: 339-350

Ljunggren, J and Häggström, L (1994) Catabolic control of hybridoma cells by glucose and glutamine limited fed batch cultures. Biotechnol. Bioeng. 44: 808-818

Öhman, L, Ljunggren, J and Häggström, L (1995) Induction of a metabolic switch in insect cells by substrate limited fed batch cultures. Appl. Microbiol. Biotechnol. 43: 1006-1013

Ljunggren J and Häggström, L (1995) Specific growth rate as a parameter for tracing growth limiting substances in animal cell cultures. J. Biotechnol. 42: 163-175

Martinelle K, Westlund A and Häggström L (1996) Ammonium ion transport - a cause of cell death. Cytotechnol. 22: 251-254

Öhman L, Alarcon M, Ljunggren J, Ramqvist A-K, Häggström L (1996) Glutamine is not an essential amino acid for Sf-9 insect cells. Biotechnol. Lett. 18: 765-770

Doverskog M, Han L, and Häggström L (1998) Cystine/cysteine metabolism in cultured Sf9 cells: Influence of cell physiology on biosynthesis, amino acid uptake and growth. Cytotechnol. 26: 91-102

Martinelle, K, Westlund, A and Häggström, L (1998) Saturable ammonium transport in myeloma and hybridoma cells is mediated by the Na+K+2Cl--cotransporter. Biotechnol. Lett. 20: 81-86

Martinelle, K, Doverskog, M, Jacobsson, U, Chapman, BE, Kuchel, PW, and Häggström, L (1998) Elevated glutamate dehydrogenase flux in glucose-deprived myeloma and hybridoma cells: evidence from 1H/15N NMR. Biotechnol. Bioeng. 60: 508-517

Westlund, A. and Häggström, L. (1998) Ammonium transport by the Na+K+2Cl--cotransporter induces apoptosis in hybridoma cells. Biotechnol. Lett. 20: 87-90

Doverskog, M, Tally, M, Häggström, L (1999) Constitutive secretion of an endogenous insulin-like peptide binding protein with high affinity for insulin in Spodoptera frugiperda (Sf9) cell cultures. Biochem. Biophys. Res. Com. 265: 674-679.

Drews, M, Doverskog, M, Öhman, L, Chapman, BE, Jacobsson, U, Kuchel, PE, and Häggström, L (2000) Pathways of glutamine metabolism in Spodoptera frugiperda (Sf9) insect cells: evidence for the presence of the nitrogen assimilation system, and a metabolic switch by 1H/15N NMR. J. Biotechnol. 78: 23-37

Doverskog, M, Jacobsson, U, Chapman, BE, Kuchel, PW, Häggström, L (2000) Determination of NADH-dependent glutamate synthase (GOGAT) in Spodoptera frugiperda (Sf9) insect cells by a selective 1H/15N NMR in vitro assay. J. Biotechnol. 79: 87-97

Doverskog, M, Bertram, E, Ljunggren, J, Öhman, L, Sennerstam, R, and Häggström, L (2000) Cell cycle progression in serum-free cultures of Sf9 cells: modulation by conditioned medium factors and implications for proliferation and productivity. Biotechnol. Prog. 16: 837-846

Han, L., Doverskog, M., Enfors, S.-O., and Häggström L. (2002) Effect of glycine on the cell yield and growth rate of Escherichia coli: evidence for cell-density-dependent glycine degradation as determined by ¹³C NMR spectroscopy, J. Biotechnol. 92:237-249