Animals cell culture systems

Historically, the development of animal cell culture systems has been dependent upon the development of new types of tissue culture media. Mouse L cells and HeLa cells were developed using a balanced salt solution supplemented with blood plasma, an embryonic tissue extract, and/or serum. In 1955 Eagle developed a nutritionally defined medium, containing all of the essential amino acids, vitamins, cofactors, carbohydrates, salts, and small amounts of dialyzed serum (Table 1). He demonstrated that this minimal essential medium (MEM) supported the long-term growth of mouse L and HeLa ceils. Eagle s MEM was so well defined that the omission of a single essential nutrient eventually resulted in the death of these animal cells in culture. 

Plaques may be obtained for animal viruses by using animal cell-culture systems as hosts. A monolayer of cultured animals cells is prepared on a plate or flat bottle and the virus suspension overlayed. Plaques are revealed by zones of destruction of the animal cells. 

Expression of recombinant proteins in animal cell culture systems... 

Although capable of glycosylating heterologous human proteins, the glycosylation pattern usually varies from the pattern observed on the native glycoprotein (when isolated from its natural source, or when expressed in recombinant animal cell culture systems). 

Viral particles destined for use as vaccines are generally propagated in a suitable animal cell culture system. Although true cell culture systems are sometimes employed, many viral particles are grown in fertilized eggs or cultures of chick embryo tissue (Table 13.7). 

The genetic manipulation of animal cells allows the production of therapeutic proteins in animal cell culture systems. Mammalian cells such as Chinese hamster ovarian cells and baby hamster kidney cells are commonly used. These mammalian hosts produce recombinant proteins that have almost identical properties to those made by human cells. However, the use of mammalian cells does have disadvantages. As noted earlier, they are expensive to use. This is influenced by their more complex nutritional requirements, their slower growth, and their increased susceptibility to physical damage (Walsh, 2003). 

Sanderson CS, Jang JD, Barford JP, Barton GW (1999), A structured, dynamic model for animal cell culture systems application to murine hybridoma, Biochem. Eng. J. 3 213-218. 

Animal cell culture systems all require at least two substrates as carbon and/or nitrogen sources, and electron donors [1] and usually require more [2], as illustrated by reference [3]. Higher plant cell culture systems are equally complex [4]. This complicates efforts to understand what is the source of energy that enters into... 

When sufficiently high levels of expression and protein accumulation are achieved, efficient downstream processing protocols must be developed to insure product quality and the economic feasibility of production. As the demand for safe, recombinant pharmaceutical proteins continues to expand, the market potential of plant-produced recombinant proteins is considerable. Molecular farming can produce recombinant proteins at a lower cost than traditional expression systems based on microbial or animal cell culture, and without the risk of contamination with human pathogens. 

Animal cell culture (particularly CHO and BHK cell lines) Transgenic animals (focus thus far is upon sheep and goats) Plant-based expression systems (various)... 

Over half of all biopharmaceuticals thus far approved are produced in recombinant E. coli or S. cerevisiae. Industrial-scale bacterial and yeast fermentation systems share many common features, an overview of which is provided below. Most remaining biopharmaceuticals are produced using animal cell culture, mainly by recombinant BHK or CHO cells (or hybridoma cells in... 

A variety of cell culture systems for the modelling of the tracheo-bronchial epithelium are available. These include primary cultures and cell lines of human and animal origins, plus airway cells with characteristics of lung disease such as CF. The advantages and limitations of using a simple culture system compared to one that recreates to a greater extent the epithelial structure and function in vitro should be considered according to the pre-clinical application required. However, this choice is complicated by the lack of comparative data, both between the different cell systems and for in vitro-in vivo correlation, upon which to base such decisions. 

We have chosen animal cell cultures for that purpose, bearing in mind the following advantages of such system (i) the action of peptide results in a limited number of integral responses, when a variety of biochemical mechanisms gives rise to uniform effects, such as cell death or stimulation/inhibition of cell proliferation rate (ii) the test requires low, picomolar amounts of peptides (iii) the results are treated by simple and reliable statistic methods. 

Recently, monoclonal antibodies were attached to gas-filled microbubbles using this spacer coupHng technology. Testing in vitro, in a cell culture system, demonstrated selective accumulation of decafluorobutane-based lipid shell MP1950 microbubbles with covalently attached anti-lCAM-1 antibodies, onto the surface of activated endotheUum [8]. Anti-P-selectin antibodies attached to such microbubbles via an avidin-biotin scheme showed selective accumulation in the areas of inflammation and ischemia/reperfusion injury in an animal model [93]. In the latter example, biotin was also connected to the microbubble surface via a flexible polymer spacer arm. 

Over half of all biopharmacuticals thus far approved are produced in recombinant E. coli or S. cerevisiae. Industrial-scale bacterial and yeast fermentation systems share many common features, an overview of which is provided below. Most remaining biopharmaceuticals are produced using animal cell culture, mainly by recombinant BFIK or CFiO cells (or hybridoma cells in the case of some monoclonal antibodies Appendix 1). While industrial-scale animal cell culture shares many common principles with microbial fermentation systems, it also differs in several respects, as subsequently described. Microbial fermentation/animal cell culture is a vast speciality area in its own right. As such, only a summary overview can be provided below and the interested reader is referred to the Further Reading section. 

---