Mortal and immortal cell lines

1. Introduction
Immortalised cell lines are widely used as a
simple model for more complex biological
systems.
for example for the analysis of the
biochemistry and cell biology of mammalian
(including human) cells.
The main advantage of using an immortal cell
line for research is its immortality

2. Introduction
Immortal cell lines are a very important tool
for research into the biochemistry and cell
biology of multicellular organisms.
Immortalised cell lines have also found uses in
biotechnology.
Immortal mean living forever; never dying or
decaying.

3. Introduction
Senescence from Latin: senescere, meaning
"to grow old,"
Or biological aging (also spelled biological
ageing).
Grown for Pronlonged Period in vitro.
Prolonged =continuing for a long time or
longer than usual; lengthy.

4. Introduction
The mutations required for immortality can
occur naturally or be intentionally induced for
experimental purposes.
Immortal cell lines are a very important tool
for research into the biochemistry and cell
biology of multicellular organisms.

5. Introduction
An immortalised cell line should not be
confused with stem cells
Which can also divide indefinitely
But form a normal part of the development of
a multicellular organism.
Stem cell mean an undifferentiated cell of a
multicellular organism which is capable of
giving rise to indefinitely more cells of the
same type.

6. Introduction
Immortalised cell lines can also be cloned .
Giving rise to a clonal population which can, in
turn, be propagated indefinitely.
Immortalised cell lines find use in
biotechnology where they are a cost-effective
way of growing cells similar to those found in
a multicellular organism in vitro.

7. Introduction
There are several methods for generating
immortalised cell lines which are described by
other nembers but some methods names are
below..
1-Isolation from a naturally occurring cancer.
2-Spontaneous or induced random
mutagenesis

8. Introduction
Mutagenesis in the laboratory is an important
technique whereby DNA mutations are
engineered to produce mutant genes,
proteins, strains of bacteria, or other
genetically modified organisms.

9. EXAMPLES
• There are several examples of immortalised
cell lines, each with different properties.
Most immortalised cell lines are classified
by the cell type they originated from or
are most similar to biologically.
• A549 cells – derived from the tumor of a
cancer patient
• HeLa cells – an extremely widely used
human cell line isolated from a cervical
cancer, probably derived from epithelial cells

10. • HEK 293 cells – derived from aborted
human fetal cells and a virus
• Jurkat – a human T lymphocyte cell line
isolated from a case of leukemia
• 3T3 – a mouse fibroblast cell line derived
from a spontaneous mutation in cultured
mouse embryo tissue
• Vero cells – a monkey cell line
• F11 Cells - a line of neurons from the
dorsal root ganglia of rats.

11. HeLa CELLS
• HELA CELL is a cell type in an
immortal cell line used in scientific
research. It is the oldest and most
commonly used human cell line.The
line was derived from cervical cancer
cells taken on February 8, 1951 from
Henrietta Lacks, a patient who died
of her cancer on October 4, 1951.

12. • In 1955, HeLa cells were
the first human cells
successfully cloned.
• hela cells are human
epithelial cells of a strain
maintained in tissue culture
and used in research,
especially in virology.

13. Vero cell
• Vero cells are lineages of cells used in cell
cultures.The 'Vero' lineage was isolated
from kidney epithelial cells extracted from
an African green monkey.
• The lineage was developed on 27 March
1962, by Yasumura and Kawakita at the
Chiba University in Chiba, Japan.

14. Vero cells are used for many
purposes, including:
• screening for the toxin of
Escherichia coli
• as host cells for growing virus
• as host cells for eukaryotic
parasites

15. Relation to natural biology and
pathology

16. • There are various immortal cell lines. Some of
them are normal cell lines - e.g. derived from
stem cells
• Other immortalised cell lines are the in
vitro equivalent of cancerous cells.
• The culture history of normal cells were divided
into 3phases
• Phase I represented initial culture,phase II, the
period of exponential cell increase and phase III,
the death of cells

17. • Phase III was not due to the inadequate nutrition
or other failures in techniques for death of
cultured cells.
• Moorhead and Hayflick demonstrated that death
of cultured normal or untransformed cells is an
inherent property of cells themselves.
• That observation has now been confirmed in
hundreds of laboratories .
• They interpreted the phase III to be aging at cell
level.

18. • Cancer occurs when a somatic cell which
normally cannot divide undergoes mutations
which cause de-regulation of the normal cell
cycle controls leading to uncontrolled
proliferation
• Immortalised cell lines have undergone
similar mutations allowing a cell type which
would normally not be able to divide to be
proliferated in vitro.

19. Spontaneously Immortalized Cells
• The best example of this would be cancer cells, which
may have undergone genetic changes to resist
senescence and are immortal.
• However, many cancer cell lines may not have these
changes, in fact, George Gey, the scientist who created
the first immortalized and arguably the most famous
cell line: HeLa cells, had to test hundreds of cancer
lines before stumbling upon the highly metaplastic
ovarian cells of Henrietta Lacks.
• Thus, other methodologies may be required to help
even cancer cells become immortal.

20. How to Introduce Immortality to a
Primary Cell Line
• As many primary cells lines are frustratingly difficult to
transfect, the easiest and most effective way to introduce
genetic changes into a primary cell line is through viral
infection.
• The most popular method is through replication-deficient
lentiviruses, since they are relatively safer then
adenoviruses which have the ability to re-infect cells and
thus contain live virus for a much longer period of time
• Retroviruses can also be used to transfect cells, however,
they can only infect actively dividing cells, thus reducing the
number of cells that may be transduced with virus.

21. Words of Caution: Immortality May
Not be the Best Route!
• By introducing genetic changes into cells, one may be
profoundly altering the phenotype of your cell line.
Although this does make your cell line more useful in
some ways: it may make your cells more homogeneous
allowing for replication of results, you can create large
stocks of cells for future use and they may be easier to
experimentally, there is still many benefits to using
primary cell lines.
• As primary lines adapt to being culture and being
immortalized, cell populations and cellular mechanisms
are altered. This may lead to results. In addition, there
is much debate about how accurately immortalized
cells model real tissue