Abstract
In this paper, we propose an alternative strategy to the ones proposed before (Oh et al., 1993; Øyaas et al., 1994a) to get real increases of global final antibody titer and production at hyperosmotic stress, by reducing the detrimental effect of such a stress on cell growth, and conserving the stimulating effect on antibody production. It consists of cultivating the cells in continuous culture and increasing the osmolality stepwise. In this way, the cells could progressively adapt to the higher osmolality at each step and antibody titers could be nearly doubled at 370 and 400 mOsm kg-1, compared to the standard osmolality of 335 mOsm kg-1. Surprisingly, the stimulation of antibody production was not confirmed for higher osmolalities, 425 and 450 mOsm kg- 1, despite the minor negative effect on cell growth. Intracellular IgG analysis by flow cytometry revealed at these osmolalities a significant population of non-producing cells. However, even when taking into account this non-producing population, a stimulating effect on antibody production could not be shown at these highest osmolalities. It seems to us that osmolality has a significant effect on the appearance of these non-producing cells, since they were not observed in continuous cultures at standard osmolality, of comparable duration and at an even higher dilution rate. The appearance of the non-producing cells coincides furthermore with modifications of the synthesised antibody, as shown by electrophoretic techniques. It is however not really clear if these two observations reflect actually the same phenomenon. Hyperosmolality affects the cell behaviour in continuous culture in multiple ways, independently of the growth rate, counting all at least partially for the observed stimulation of antibody production: acceleration of the amino acid, and in particular the glutamine metabolism, increase of the cell volume, increase of the intracellular pH and accumulation of cells in the G1 cell cycle phase.
Keywords: bioreactor, continuous culture, hybridoma cells, hyperosmolality, monoclonal antibody production, non-producing subpopulation
Full Text
The Full Text of this article is available as a PDF (184.9 KB).
References
- Al-Habori M. Minireview: Cell volume and ion transport regulation. Int J Biochem. 1994;26:319–334. doi: 10.1016/0020-711x(94)90052-3. [DOI] [PubMed] [Google Scholar]
- Altschuler GL, Dilwith R, Sowek J, Belfort G. Hybridoma analysis at cellular level. Biotechnol Bioeng Symp. 1986;17:725–736. [Google Scholar]
- Cherlet M. De l'intérêt de la cytométrie en flux pour l'étude de cultures d'hybridomes en bioréacteurs: Cinétiques de croissance et décès cellulaires, de production d'anticorps et d'évolution du pH intracellulaire. Nancy, France: INPL; 1995. [Google Scholar]
- Cherlet M, Kromenaker SJ, Srienc F. Surface IgG content of murine hybridomas: direct evidence for variation of antibody secretion rates during the cell cycle. Biotechnol Bioeng. 1995;47:535–540. doi: 10.1002/bit.260470505. [DOI] [PubMed] [Google Scholar]
- Chevalot I, Dardenne M, Cherlet M, Engasser JM, Marc A. Effect of sodium butyrate on protein production in different culture systems. In: Spier RE, Griffiths JB, Beuvery EC, editors. Animal Cell Technology: Developments towards the 21st Century. Dordrecht: Kluwer Academic Publishers; 1995. pp. 143–147. [Google Scholar]
- Chua FKF, Yap MGS, Oh SKW. Hyper-stimulation of monoclonal antibody production by high osmolarity stress in eRDF medium. J Biotechn. 1994;37:265–275. doi: 10.1016/0168-1656(94)90133-3. [DOI] [PubMed] [Google Scholar]
- Demaurex N, Grinstein S. Na+/H+ antiport: Modulation by ATP and role in cell volume regulation. J Exp Biol. 1994;196:389–404. doi: 10.1242/jeb.196.1.389. [DOI] [PubMed] [Google Scholar]
- Flickinger MC, Goebel NK, Bibila T, Boyce-Jacino S. Evidence for posttranscriptional stimulation of monoclonal antibody secretion by L-glutamine during slow hybridoma growth. J Biotechn. 1992;22:201–226. doi: 10.1016/0168-1656(92)90142-v. [DOI] [PubMed] [Google Scholar]
- Fong W, Zhang Y, Yung P. Optimization of monoclonal antibody production: combined effects of potassium acetate and perfusion in a stirred tank bioreactor. Cytotechnology. 1997;24:47–54. doi: 10.1023/A:1007914004727. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Frame KK, Hu WS. Kinetic study of hybridoma cell growth in continuous culture: II. Behaviour of producers and comparison to nonproducers. Biotechn Bioeng. 1991;38:1020–1028. doi: 10.1002/bit.260380910. [DOI] [PubMed] [Google Scholar]
- Grainger JL, Winkler MM, Shen SS, Steinhardt RA. Intracellular pH controls protein synthesis rate in the sea urchin egg and early embryo. Devel Biol. 1979;68:396–406. doi: 10.1016/0012-1606(79)90213-6. [DOI] [PubMed] [Google Scholar]
- Kromenaker SJ, Srienc F. Cell-cycle-dependent protein accumulation by producer and nonproducer murine hybridoma cell lines: a population analysis. Biotechn Bioeng. 1991;38:665–677. doi: 10.1002/bit.260380612. [DOI] [PubMed] [Google Scholar]
- Kromenaker SJ, Srienc F. Cell cycle kinetics of the accumulation of heavy and light chain immunoglobulin proteins in a mouse hybridoma cell line. Cytotechnology. 1994;14:205–218. doi: 10.1007/BF00749617. [DOI] [PubMed] [Google Scholar]
- Kromenaker SJ, Srienc F. Stability of producer hybridoma cell lines after cell sorting: a case study. Biotechnol Prog. 1994;10:299–307. doi: 10.1021/bp00027a010. [DOI] [PubMed] [Google Scholar]
- Lee GM, Varma A, Palsson BO. Application of population balance model to the loss of hybridoma antibody productivity. Biotechnol Prog. 1991;7:72–75. doi: 10.1021/bp00007a013. [DOI] [PubMed] [Google Scholar]
- Maiorella B, Inlow D and Howarth W (1989) Method of increasing product expression through solute stress. International Patent Publication Number W089/04867.
- Oh SKW, Vig P, Chua F, Teo WK, Yap MGS. Substantial overproduction of antibodies by applying osmotic pressure and sodium butyrate. Biotechnol Bioeng. 1993;42:601–610. doi: 10.1002/bit.260420508. [DOI] [PubMed] [Google Scholar]
- Oh SKW, Chua FKF, Choo ABH. Intracellular responses of productive hybridomas subjected to high osmotic pressure. Biotechnol Bioeng. 1995;46:525–535. doi: 10.1002/bit.260460605. [DOI] [PubMed] [Google Scholar]
- Ozturk SS, Palsson BO. Effect of medium osmolarity on hybridoma growth, metabolism, and antibody production. Biotechnol Bioeng. 1991;37:989–993. doi: 10.1002/bit.260371015. [DOI] [PubMed] [Google Scholar]
- Øyaas K, Berg TM, Bakke O, Levine DW. Hybridoma growth and antibody production under conditions of hyperosmotic stress. In: Spier RE, Griffiths JB, Stephenne J, Crooy PJ, editors. Advances in Animal Cell Biology and Technology for Bioprocesses. Oxford: Butterworth-Heinemann; 1989. pp. 212–218. [Google Scholar]
- Øyaas K, Ellingsen TE, Dyrset N, Levine DW. Hyperosmotic hybridoma cell cultures: increased monoclonal antibody production with addition of glycine betaine. Biotechnol Bioeng. 1994;44:991–998. doi: 10.1002/bit.260440816. [DOI] [PubMed] [Google Scholar]
- Øyaas K, Ellingsen TE, Dyrset N, Levine DW. Utilization of osmoprotective compounds by hybridoma cells exposed to hyperosmotic stress. Biotechnol Bioeng. 1994;43:77–89. doi: 10.1002/bit.260430111. [DOI] [PubMed] [Google Scholar]
- Pauly H, Cherlet M, Marc A, Franck P, Nabet P, et al. Influence of mass culture operating conditions on the apoptosis of OKT3 hybridoma cells. In: Carrondo MJT, et al., editors. Animal Cell Technology: From Vaccines to Genetic Medicine. Dordrecht: Kluwer Academic Publishers; 1997. pp. 331–336. [Google Scholar]
- Pellicciari C, Filippini C, De Grada L, Fuhrman Conti AM, Manfredi Romanini MG. Cell cycle effects of hypertonic stress on various human cells in culture. Cell Biochem Funct. 1995;13:1–8. doi: 10.1002/cbf.290130103. [DOI] [PubMed] [Google Scholar]
- Reddy S, Miller WM. Effects of abrupt and gradual osmotic stress on antibody production and content in hybridoma cells that differ in production kinetics. Biotechnol Prog. 1994;10:165–173. doi: 10.1021/bp00026a006. [DOI] [PubMed] [Google Scholar]
- Renard JM, Spagnoli R, Mazier C, Salles MF, Mandine E. Evidence that monoclonal antibody production kinetics is related to the integral of the viable cells curve in batch systems. Biotechnol Lett. 1988;10:91–96. [Google Scholar]
- Thomas JE and Roberts RS (1989) Effect of hyperosmotic pressure on growth of L5178Y cells. Proc Biochem October 1989: 179-182.
- Wentz D, Schügerl K. Influence of lactate, ammonia, and osmotic stress on adherent and suspension BHK cells. Enz Microbiol Technol. 1992;14:68–75. doi: 10.1016/0141-0229(92)90029-n. [DOI] [PubMed] [Google Scholar]