Download Powerpoint Presentation: The Monoclonal Antibodies

MONOCLONAL
ANTIBODIES
mAbs
© 2016 Paul Billiet ODWS
Antibodies
• Antibodies are specific in their binding with
antigens
• Developing specific antibodies would be useful in
fighting particular diseases
• Diagnosing infections
• Identifying molecules with antigenic properties.
© 2016 Paul Billiet ODWS
Polyclonal antibodies
• The response of the immune system to an
infection is polyclonal
• We produce a whole range of antibodies each
time we are infected
• If it were possible to isolate single antibody
secreting cells they would die within a few
generations.
© 2016 Paul Billiet ODWS
Monoclonal antibodies
• To produce specific antibodies requires a
monoclonal system
• This must keep producing antibody for a long
period of time.
© 2016 Paul Billiet ODWS
Immunise a mouse with
antigen Y
Extract the spleen cells from mouse
Some cells will be B-cells making
antibody against antigen Y
B-cell tumour
(myeloma) will grow
cells indefinitely
Fusion of B-cells from mouse spleen with
cancerous B-cells = HYBRIDOMAS
Selection: Grow cells in culture medium in
which only fused cells can grow
Producing
monoclonal
antibodies
© 2016 Paul Billiet ODWS
Separate the hybridomas and test each
one for antibody Y production
Multiply up the cells and collect the
antibody they produce
The uses of monoclonal antibodies
Diagnosing and identifying molecules
• Preparations can be made to identify tissue types
with a high degree of accuracy
• The preparation of pregnancy testing kits using
anti HCG antibody linked to a coloured indicator
• The identification and localisation of molecules in
cells or on the surface of cells
• The antibodies can be combined with a
fluorescent dye so that under UV light they glow.
© 2016 Paul Billiet ODWS
Fluorescent monoclonal antibodies used to identify and study
the behaviour of molecules in the cytoskeleton
The uses of monoclonal antibodies
Medical therapy
• The location and destruction of cancerous cells
• Herceptin binds to a growth factor receptor on
some tumour cells (e.g. breast cancer) blocking
their development
• Omalizumab binds to IgE and helps to control
asthma
• OKT3 binds to the surface of T-cells to prevent
rejection in transplant patients.
© 2016 Paul Billiet ODWS
Problems with monoclonal therapy
• The mouse immunoglobulins will be identified by
the human immune system of the patient
• Human anti-mouse antibodies (HAMA) will
appear
• This reduces their effectiveness and also can
cause kidney damage
• The solution?
Use transgenic mice that produce human
immunoglobulins.
© 2016 Paul Billiet ODWS