Vero cells

Production of the vims in a bioreactor reactor, using a continuous cell line, has also been studied (85,86). This will reduce production costs and side effects. Both Madin-Darby canine kedney (MDCK) and Vero cell lines are being developed for production of the vaccine. 

The incorporation of acyclovir triphosphate into calf thymus DNA primer template has been shown to be much more rapid and extensive with HSV-1 DNA polymerase than with vero cell DNA polymerase a. This incorporation of acyclovir ceased after 15 min since the template is chain terminated by the acyclovir incorporation, as there is no 3 -hydroxyl group on which to continue elongation. The viral DNA polymerase is also inactivated by tight binding to the terminated template. 

Vero Cells Grown on Microcarriers (Contact Inhibition)... 

Hawboldt et al. (1994) have also reported data on anchorage dependent Vero cells grown on Cytodex I microcarriers in 250 mL spinner flasks and they are reproduced here in Table 17.14. 

Table 17.14 Growth of Vero Cells Cell Density versus Time for Vero Cells Grown on Cytodex I Microcarriers in 250 mL Spinner Flasks at Two Inoculation Levels (2.00 and 9.72 cells/bead).

In addition to the aforementioned effects on paracellular drug transport, Ca2+ also plays an important role in the transcytosis of macromolecules. The entry of the plant lectins abrin, modeccin, and viscumin into Vero cells was inhibited in a Ca2+-free medium a well as in a Ca2+-containing medium containing verapamil and Co2+, both inhibitors of Ca2+ [217], Ca2+ is therefore required at a stage after the binding of the above lectins, perhaps in the fusion and exocytosis of membrane vesicles. 

The entry of CL into cells may be essential for the cellular entry [232] or secretion [233] of some macromolecules such as diphtheria toxin and modeccin. Sandvig and Olsnes [232] studied the entry of diphtheria toxin and modeccin into Vero cells in pH 7.2 media containing 20 mM Hepes, 1 mM Ca(OH)2, 5 mM glucose,a sufficient amount of mannitol to ensure isotonicity, and varying concentrations of NaCl. The cellular uptake of 0.1 nM diphtheria toxin at the end of 50 min was strongly dependent on CL concentration. It was 0% at 0 mM NaCl, 25% of the 140 mM NaCl control at 2 mM NaCl, and 60% of the control at 70 mM NaCl. A similar trend was observed for modeccin, i.e., no transport at 0 mM NaCl, 20% of control at 0.05 mM NaCl, 60% of control at 0.1 mM NaCl, 80% of control at 0.5 mM NaCl, and 100% of control at 2 mM NaCl. 

The use of CL-free media required 100 times higher concentrations of the toxins for any cellular uptake. Furthermore, the entry of both toxins was denied when Vero cells were incubated in normal medium with inhibitors of CL entry, including 4-acetamido-4 -isothiocyanostilbene-2,2 -disulfonate (SITS), pyridoxal... 

Hata, Y., Kita, T., and Murakami, M. (1999). Bovine milk inhibits both adhesion of Helicobacter pylori to sulfatide and Helicobacter pylori-induced vacuolation of vero cells. Dig. Dis. Sci 44,1696-1702. 

Tumor cells T11 and Vero cells viability after 72 hours of treatment with red onion extract... 

Umata T, Moriyama Y, Futai M, Mekada E. The cytotoxic action of diphtheria toxin and its degradation in intact Vero cells are inhibited by bafilo-mycin Al, a specific inhibitor of vacuolar-type H(+)-ATPase. J Biol Chem 1990 265(35) 21940-21945. 

In a recent investigation of phenolic compounds tested, using herpes simplex virus type 1 (HSV-1) infected Vero cells, caffeic acid has been reported to inhibit virus replication [91], In a related study [92], chlorogenic acid significantly inhibited acyclovir-resistant HSV-1 replication without any cytotoxicity. However, flavonoids have exhibited cytotoxicity at the same concentration [92],... 

In one of our recent studies, we examined antimicrobial and antiviral activities of four flavonoid derivatives, namely, scandenone (5), tiliro-side (6), quercetin-3,7-O-a-L-dirhamnoside (7), and kaempferol 3,7-O-a-L-dirhamnoside (8) as shown in Fig. 2. These were tested against E. coli, P. aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter bau-mannii, S. aureus, B. subtilis, and Enterococcus faecalis, as well as the fungus Candida albicans by the microdilution method [26]. In addition, both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza (PI-3) were employed for antiviral assessment of the compounds using Madin-Darby bovine kidney (MDBK) and Vero cell lines. 

After this period, there was an accelerated use of animal cells. Namalwa cells (Finter et al., 1991) were used to produce alpha-interferon by Wellcome in 1986. Vero cells (a cell line derived from monkey) were used for anti-rabies vaccine. Hybridomas were considered acceptable for mAb production and the use of genetically modified CHO (Chinese hamster ovary) cells was authorized for the production of tissue plasminogen activator (tPA) by Genentech in 1986. 

The cell lines most commonly employed for production of biopharmaceuticals include CHO-K1, BHK-21, and Vero cells, besides various antibody-secreting hybridomas. Other cell lines, such as NSO, HEK-293 and PER.C6, have also been employed for recombinant protein production. 

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