The latest Technology of Cell Engineering
Cell Engineering Research Centre, the Fourth Military Medical University
Li Mi Xianhui Wang Ling Li Zhinan Chen

Cell engineering refers to heredity operation and recombination of cell structure to change the biological structures and functions, thus to achieve a practically useful outcome by employing the molecular and cellular theory and technique of modern subjects, such as modern cell biology, development biology, genetics and molecular biology. Namely, the aim of bioengineering technology was to rapidly proliferate and cultivate new cell species that was obtained by cell fusion, karyolymph transplantation, chromosomes or genes transplantation. The advantage of cell engineering lies in that it can raise gene transfer efficiency by transfering cell genetic material in receptor cell to form hybrid cell, with the avoidance of some genetic manipulation, such as separation, purification, digestion and recombination. Generally, cell engineering is the operation on cell level and also named cell operation techniques including cell fusion technique, organelle transplantation, chromosome engineering and tissue culture technique. New species may be cultivated through cell fusion technique, which breaks through the traditional limitation that only the homolotous organism can cross-fertilize, but actualizes cross-fertilization between species. The techniques may fuse not only plant cells or animal cells in different species and source but also animal cells with plant cells, which have great significance to create new variety of animal, plant and microorganism.

1. Cell Fusion

Cell fusion is also named cell hybrid, which refers to the technique of combining artificially two categories or more than two categories of body cell into one cell to obtain hybrid cell without the process of sexual reproduction. In natural condition, fusion happens between cells cultured in vivo or in vitro which is named natural fusion. While the fusion is urged between the same or different cells in vitro by artificial method named artificial induction fusion.

In 1975, Milstein and Konler used Hybrid cell fused and formed by using mouse lymphocyte that was immunized by mouse myeloma cell and sheep’s red blood cell, which can secrete antibody aginst sheep’s red blood cell, to make monoclonal antibody. Because of the innovative work, they won Nobel physiological and medical prize in 1984.

2. Clone techniques

At Feb. 23rd, 1997, a lamb named Dolly was born in the Lab of British Institute. The birth of Dolly means that human may utilize one histocyte of animal to make identical life bodies in mass like photocopying or recording, which is one breakthrough in genetic engineering research domain undoubtedly. People shears branches of plants and plants them in earth, the branches germinate soon and grow the new plants that have completely identical heredity substances. This is“clone”, namely independent cell breeding series, which means that offspring is duplicated by one cell and have completely. Identical heredity substances

3. Chromosome engineering

Chromosome engineering is to add, preclud isotype or heterogeneity chromosome group to achieve the purpose of orientation alteration of organism heredity character according to artificial technical design.

4. Stem cell engineering

Stem cell engineering is new cell engineering that develops on the basis of cell culture technique. It utilizes cell’s proliferation, multi differentiation and high order to change their nature through culturing stem cell in vitro, inducing stem cell orientation differentiation or utilizing transgene technique to dispose stem cell, with the purpose of utilizing stem cell to serve human being.

One main aspect of the research is embryonic stem cell research, such as building ES cell line and utilizing pluripotency of ES cell growth, namely, the effect of environmental factor on cell differentiation and growth to orientation-induce cell differentiate into definite cells, as new source of cell transplantation, such as muscle cell, nerve cell and so on. Another aspect of research is adult stem cell, mainly including separation of adult stem cell cultured or implanted in vivo, renewal of lesion constitution apparatus to recover normal function, use of stem cell as target cells of gene therapy, and the technique of effectively activating constitution stem cell to reinforce its function.

5. large-scale cell culture techniques

Large-scale cell culture technique is the important part of cell engineering, which use animal, plant cell to produce biological products. Now the technique has been widely used in the research and production of modern bio-pharmaceuticals. Its application greatly reduces the experimental animals used in prevention, treatment and diagnosis of disease, and provides powerful tool for producing vaccine, cytokine and biological products as well as artificial products.

According to cell growth nature, the cultured cells can be divided into anchorage-dependent and anchorage-independent ones. The culturing method can be divided into suspension culture and fixation culture, the way of operation, it can be divided into batch, fed-batch and perfusion mode. Establishment of large-scale cell culture technique make the production of various of biological products develop greatly, such as monoclonal antibody, epoetin, vaccine, viral pesticide and so on.