Applications of the fourier transform path integral method /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1993.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy Link to ProQuest copy Link to OAKTrust copy Link to ProQuest copy http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=744947601&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Abstract: | The goal of this project was to investigate the kinetics of baculovirus-infected .insect cell cultures. The cell death process of baculovirus-infected insect cells was divided into two phases: a constant viability (or delay) phase characterized by a delay time ( tj and a first-order death phase characterized by a half-life (t1/2). These two parameters were used in conjunction with the n-target theory to classify the baculovirus-induced cell death. Based on these analyses, Spodoptera frugiperda Sf9 cells infected by the wild-type Autographa californica nuclear polyhedrosis virus, polyhedrin deletion mutant, and recombinant viruses encoding E. coli P-galactosidase, human T-cell leukemia virus type (HTLV-I) p40 and human interleukin 2 (IL-2) were found to exhibit a constant extrapolation number (n = 10 to 11). In contrast, cells infected by a human tissue-type plasminogen activator (t-PA) encoding virus showed a lower extrapolation number (n = 4). The low extrapolation number in the latter case was restored to the normal value (n = 10 to 11) when the signal peptide and prosequences of t-PA were deleted. Therefore, it was concluded that the t-PA processing in insect secretory pathways retarded the cell death process. The effect of process variables on recombinant protein production was also investigated using both recombinant baculoviruses yielding normal extrapolation number (P-galactosidase) and low extrapolation number (t-PA). Two groups of variables were found. The first group did not change the extrapolation number, and it includes MOI, serum concentration, and host cell lines. The second group caused a decrease in the extrapolation number, and it includes environmental variables, such as incubation volume, cell density, extracellular L(+)-lactate and ammonium concentrations. If the extrapolation number remains constant, prolonged cell life gives increased recombinant protein production. If the extrapolation number is reduced, prolonged cell life gives decreased recombinant protein production. Although the underlying mechanisms of these effects are as yet unknown, the death kinetics of infected cells significantly affects the recombinant protein production. |
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| Item Description: | Vita. "Major subject: Electrical Engineering." |
| Physical Description: | xi, 92 leaves : illustrations ; 28 cm |
| Bibliography: | Includes bibliographical references. |