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Treating Disease
What are monoclonal antibodies?
Polyclonal antibodies are naturally produced in an immune
response. Different plasma cells secrete antibodies, resulting
in a variety of different antibodies against a specific antigen.
Monoclonal antibodies (mAbs) are antibodies produced
from clones of a single plasma cell and are therefore all
identical. They have many important uses, such as:

the treatment of cancer
and other diseases

drug screening

home pregnancy kits

scientific research.
Production of monoclonal antibodies
Large quantities of mAbs can be produced using mice or
rabbits.
A specific antigen is injected into
the animal, stimulating the
production of plasma cells.
The plasma cells are removed
from the animal and fused
with cancerous myeloma
cells from normal mice.
These form immortal
hybridoma cells, which can
produce a single type of
antibody indefinitely.
Exam question – monoclonal antibodies
Remember:
- Antigen injected into animal
- Plasma cells produced
- Plasma cell fused with myeloma (cancer)
cell
- Hybridoma cell formed – multiplies quickly
and indefinitely to produce many identical
antibodies (for the original antigen).
Artificial immunity
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Vaccines, lymphocytes and the secondary response
Primary Response
Secondary Response
The first time a new antigen is The second time the antigen
encountered, it takes time for is encountered, there are
already a number of memory
B- and T-cells to respond.
cells present.
Antibodies are produced fairly
The immune response is
slowly as plasma cells are
quicker.
produced by mitosis of Bcells.
More antibodies are produced
more quickly than in the
Memory cells (B and T)
primary response.
remain in the blood for a
period of time after the initial
infection.
Immunological memory
Now try the questions on the back of the
sheet.
Influenza vaccines
New strains of the influenza virus are constantly emerging.
This is because antigens displayed on the virus change due
to mutation. This causes antigenic variation.
Antigenic variation makes it
hard to immunize a patient
against the influenza virus for
life with just a single vaccine.
The government works with other
organizations to identify current
strains of influenza. An effective
vaccine is developed each year.
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What is vaccination?
Vaccines stimulate the production of antibodies and memory
cells against the target pathogen without causing illness.
Why don’t vaccines cause illness?

They may contain an inactivated
form of the pathogen, killed by heat
treatment (which leaves the
immune-stimulating antigens intact).

They may contain an attenuated
(less virulent) form of the pathogen.

They may contain isolated antigens,
such as cell surface proteins, from
the pathogen.
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The MMR controversy
In 1998, a scientific paper was published in the medical
journal The Lancet, speculating that the MMR vaccine could
cause autism.
The authors thought that the MMR vaccine could damage
the bowel, allowing toxins that are normally destroyed in
digestion to move into the blood. If these toxins travelled to
the brain they might cause autism.
The authors did not prove
that this was the case but still
recommended that doctors
stop administering the MMR
vaccine until more research
was done.
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The media’s role in the MMR controversy
Many studies have concluded that the MMR vaccine is safe
and only a few studies claim that it isn’t. However, this was
not reflected by the media coverage.
The majority of coverage centred on the possibility of
a link between the MMR vaccine and autism, while the
government insisted that the vaccine was safe.
This mixed message caused confusion among the general
public, leading to a drop in the number of children being given
the combined vaccine.
Should scientists be more careful about how they present
their research or should the media be responsible for how
they present controversial topics to society?
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