APPLICATIONS OF ANIMAL CELL CULTURE

The animal cell cultures are used for a diverse range of research and development. These areas are:
a) production of antiviral vaccines, which requires the standardization of cell lines for the multiplication and assay of viruses.

b) Cancer research, which requires the study of uncontrolled cell division in cultures.
c) Cell fusion techniques.

d) Genetic manipulation, which is easy to carry out in cells or organ cultures.

e) Production of monoclonal antibodies requires cell lines in culture.

f) Production of pharmaceutical drugs using cell lines.

g) Chromosome analysis of cells derived from womb.

h) Study of the effects of toxins and pollutants using cell lines.

i) Use of artificial skin.

j) Study the function of the nerve cells.

Many commercial proteins have been produced by animal cell culture and there medical application is being evaluated.
Tissue Plasminogen activator (t-PA) was the first drug that was produced by the mammalian cell culture by using rDNA technology. The recombinant t-PA is safe and effective for dissolving blood clots in patients with heart diseases and thrombotic disorders.

Fig showing the production of t-PA

rDNA technology has been used to produce Factor VIII  which causes blood clotting. This factor VIII is absent in the people suffering from genetic disorder called Haemophilia A.

Amgen Inc. holds US patent for preparation of, eErythropoietin, by recombinant method using Chinese Hamster Ovary cell lines. Erythropoietin (EPO) is a hormone-like substance released by the kidney under hypoxic or anoxic conditions caused by anaemia. r-HUEPO- recombinant human erythro- protein has been effectively used to treat anemia associated with AIDS, renal failure etc.

The production of Monoclonal Antibodies using hybridoma technology

Hybridoma are obtained by using an antibody producing lymphocytes cell and a single myeloma cell. Monoclonal antibodies bind very specifically to an epitope (specific domains) on an antigen and by using them it is possible to detect the presence of specific antigens. The Monoclonal antibodies are used for the treatment of patients with malignant leukaemia cells, B cell lymphomas and allograft rejection after transplantation. OKT3 is a monoclonal antibody which has been licensed for clinical use for the treatment of acute renal allograft rejection. OKT3 removes antigen bearing cells from circulation thereby helps in accepting the graft.

 

Fig showing the steps involved in the production of monoclonal antibodies

When Monoclonal antibodies are used as enzymes using the technique of enzyme engineering, then they are called abzymes.

Using animal cell cultures, it is also possible to produce Polyclonal Antibodies. Polyclonal antisera are derived from many cells therefore contains heterogeneous antibodies that are specific for several epitopes or an antigen.

SCALE-UP OF ANIMAL CELL CULTURE

Modifying a laboratory procedure, so that it can be used on an industrial scale is called scaling up. Laboratory procedures are normally scaled up via intermediate models of increasing size. The larger the plant, the greater the running costs, as skilled people are required to monitor and maintain the machinery.
Mainly Roller Bottles with Micro Carrier Beads are used in Scale-up of animal cell culture process.

Roller Bottles

The Roller bottles provide total curved surface area of the micro carrier beads for growth. The continuous rotation of the bottles in the CO2 incubators helps to provide medium to the entire cell monolayer in culture.

Micro Carrier Beads

Micro Carrier beads, increase the number of adherent cells per flask. The beads are either dextran or glass-based and come in a range of densities and sizes. The cells grow at a very high density which rapidly exhausts the medium and therefore the medium has to be replaced for the optimum cell growth.

Spinner cultures

Spinner cultures are used for scaling up the production of suspension cells. The flat surface glass flask is fitted with a Teflon paddle that continuously turns and agitates the medium. This stirring of the medium improves gas exchange in the cells in culture.