IMM2022 Study Guide - Final Guide: Polyethylene Glycol, Tumor Antigen, Rheumatoid Arthritis
4 May 2018
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Department
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Immunotherapy and alternative medicine
Immunotherapy is a process or procedure
that is designed to target the immune
response or even use aspects of immunity for
an outcome.
MONOCLONAL ANTIBODIES
• Highly specific
• High affinity
• Large quantities
Generating monoclonals
1. Inject antigen of interest (can add
adjuvant)
2. Isolate spleen want B cells
Note that these B cells are short lived
3. An immortal myeloma cell line (needs
special media to survive) added
these do not produce Ab
4. Cells mixed and shocked with
polyethylene glycol to promote
fusion
Note that this step is inefficient and most cells
will die
5. Cells grow in HAT medium (only fused
cells will survive)
6. Screen closed for antibody production
7. Select clone with appropriate
antibody specificity
8. Expand identified clone to produce
large quantities of monoclonal
antibody
How HAT media is selective
Unfused myeloma cells cannot grow because
they lack the enzyme HGPRT to duplicate their
DNA in HAT media.
Unfused B cells have HGPRT but cannot grow
indefinitely because of their limited lifespan.
Humanising MAbs
OMAB = fully mouse
XIMAB = mouse binding domains, Fc human
domain (chimeric)
ZUMABS = human with mouse CDR
UMABS = human made by replacing the
mouse Ig gene locus with human Ig locus i.e
made in a mouse using human genes.
Human and humanised antibodies are less
immunogenic than mouse and chimeric
Monoclonal Abs are used in research as
markers, for diagnosis and as treatment. Can
be used for isolation of specific cell
populations for functional analysis flow
cytometry or SPECT – single photon emission
computed tomography.
In SPECT antibodies specific for tumour
antigens can be liked to a radioactive
substance. If a tumour is present Abs will stick
reveal tumour location.
Monoclonal examples
Infliximab – chimeric against TNF-a
(inflammatory cytokine) treatment of
autoIMM eg Crohns disease, psoriasis,
rheumatoid arthritics.
Rituximab – antiCD20 eliminated B cells eg
in Non-hogkins lymphoma (chimeric)
Adalimumab – anti TNF-a (fully human)
Rheumatoid arthritis
CHECKPOINT INHIBITORS
The immune response is shut down using
CTLA-4 and PD1 (inhibitory molecules)
CTLA-4
Expressed on activated T cells, both CD28
AND CTLA-4 bind to B& CTLA-4 with higher
affinity inhibitory
PD-1
Linked to ITIM – expressed on CD4 and CD8
following stimulation. Binds to PDL-1 on APCs
Some tumours express PDL1 and CTLA4 to
turn off the immune response Checkpoint
inhibitors block the inhibitors enable
immune system to do its job. A side effect of
this can be autoimmunity.
DENDRITIC CELL BASED THERAPY
Document Summary
Immunotherapy is a process or procedure that is designed to target the immune. Umabs = human made by replacing the mouse ig gene locus with human ig locus i. e made in a mouse using human genes. response or even use aspects of immunity for. Human and humanised antibodies are less an outcome. immunogenic than mouse and chimeric. Monoclonal abs are used in research as: highly specific, high affinity. Isolate spleen want b cells markers, for diagnosis and as treatment. Can be used for isolation of specific cell populations for functional analysis flow cytometry or spect single photon emission computed tomography. In spect antibodies specific for tumour antigens can be liked to a radioactive substance. If a tumour is present abs will stick. Note that these b cells are short lived. Monoclonal examples: an immortal myeloma cell line (needs special media to survive) added these do not produce ab, cells mixed and shocked with polyethylene glycol to promote fusion.
