Page 149 - Academic Press Encyclopedia of Physical Science and Technology 3rd BioTechnology

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Encyclopedia of Physical Science and Technology EN009G-399 July 6, 2001 20:4

34 Mammalian Cell Culture

TABLE II Examples of Commonly Used Mammalian Cell Lines
Cell Source Morphology Application
Finite cell lines
MRC-5 Human lung Fibroblastic Virus studies, vaccine production,
and aging studies
WI-38
Continuous cell lines
HeLa Human cervical carcinoma Epithelial Virology
L929 Mouse connective tissue Fibroblastic General studies
Vero Monkey kidney Fibroblastic Virology and vaccines
BHK21 Syrian hamster Fibroblastic FMDV vaccine
CHO, CHO dhfr– Chinese hamster ovary Epithelial Genetics, recombinant proteins
MDCK Dog kidney Epithelial Virology
3T3 Mouse embryo Fibroblastic IGF-1 production
COS African green monkey kidney Fibroblastic SV40 viruses
NS0, Sp2/0 Mouse myeloma Spherical Fusion partners to form hybridomas
for monoclonal antibodies
J558L Mouse BALB/C myeloma Spherical IgA secretion
Hybridoma Hybrid of myeloma and Spherical Mab production
plasma cell partner
Namalwa Human tumor Spherical Interferon production
C6 Rat brain glial tumor Epithelial Neurotoxicity studies
GH3 Rat pituitary tumor Epithelial Hormone studies
293 Adenovirus transformed HEK Epithelial Gene therapy
X CRE/Y, CRIP Mouse NIH3/Moloney leukemia
Spherical Retrovirus packaging

fibroblasts) and lifespan (typically 50 to 60 population one is the feature of the continual production of a spe-
doublings for MRC-5 cells). Continuous cell lines are the cific antibody (monoclonal) by an individual B-cell de-
most widely used cell materials but the cell is usually rived from an immunized animal (mouse, rat, or human).
dedifferentiated. The second is the feature of unlimited life span, a char-
A cell line is perpetuated by the subculture technique. acteristic of tumor cells. Hybridomas are created by the
For anchorage-dependent cells attached to a substrate, this fusion, through a number of techniques, of a tumor cell
entails detachment from the substrate by an enzyme (usu- line, usually of mouse origin with B-lymphocytes derived
ally 0.25% trypsin) followed by dilution in fresh medium from an immunized mouse. The original experiment by
in a 1:2 to 1:20 ratio, depending upon cell type. Cells Koehler and Milstein in 1975 demonstrated that differ-
growing in free suspension are concentrated (by gentle entiated mouse B-cells producing a specific type of an-
centrifugation) and redistributed into fresh medium. tibody constitutively could be coerced to grow in vitro
and scaled-up when fused with cells from an immortal
tumor cell line (myeloma). Originally, the fusion partner
B. Cell Lines for mouse B-lymphocytes was a mouse myeloma cell line,
P3X63AG8, but today more popular as a fusion partner is
A very wide selection of cell lines is available from culture
the cell line SP2/0, which is a recloned product of a fusion
collections (e.g., ATCC, ECACC, Riken) and examples
are given in Table II of the more widely used ones. For experiment between P3X63AG8 and mouse spleen cell.
more information, see culture collection catalogs. The fusion of cells of the two populations can be induced
by the treatment with a high concentration of polyethylene
glycol (PEG) solution (in medium). PEG causes aggrega-
C. Hybrid Cell Lines tion of membrane-bound proteins, resulting in the outer
cell membranes being reduced in proteins—membrane-
1. Hybridomas
bound proteins interfere with the fusion of lipid bilayers.
Hybridoma cell lines are biologically unique, since they Two cell membranes that come into close contact with
have their origin in an experimental setup that sets out each other will fuse into one, eventually creating a single
to unify two cellular characteristics into one. The first cell containing the two individual genomes.