This ppt is based on the antibody mediated immunotherapy

1. 12/25/2017 1Dept. of Plant Biotechnology

2. ANTIBODY MEDIATED
IMMUNOTHERAPY
Submitted By
UPASANA MOHAPATRA
PALB 6290

3. CONTENTS
• Specificity of mAbs to tumors
• Tumor therapy with antibodies alone
• Tumor therapy with immunotoxins (Its)
• Tumor therapy with bispecific antibodies
(BsAbs)
• Purging of bone marrow for analogous
transplants
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4. Specificity of
mAbs to tumors
• Anti-ideotype antibody is specifically used
against tumor.
• DNA coding ideotype is a potential way to
immunize patients against their own B cell
tumor and also T cell based on expression of
unique binding site.
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5. Continued..
• Mutant form of epidermal growth factor
receptor acts as antigen and is uniquely
expressed on tumors to induce the cytotoxic T
cell response.
• Also by using the information on mutations
and translocation of various tumors, identified
gene products are used as tumor specific
antigen for the activation of antibodies against
the tumor.
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6. Failure
Due to the following reasons it may fail
1. Lack ofspecificity
2. Interference of soluble antigen present in serum
with antibody iteraction
3. Modulation and loss of Ab-Ag complex from
tumor cell surface before Ab mediated killing
4. Tumorcell not expressing antigen
5. Mouse mAb do not interface well with human
complement, NK celll,macrophage,PMNs.
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7. Useful
This may be useful if
• They are human or humanised to permit long
term use.
• The Ag to which they react is expressed at
high level on tumor.
• mAbs are used to treat minimal disease.
• The patient’s immune system is fully
functional.
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8. Tumor therapy with immunotoxins
(Its)
• Immunotoxin (mAbs+toxin/rdo isotopes) when
injected don’t activate patient effector
mechanism.It would seek out and bind to
TCA, and mediate their own cell.
• Ex:mAb(to CD 33) +
CalicheamicinMylotarg
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9. RADIO ISOTOPES COUPLED
mAbS
• It causes DNA damage by high energy particle.
• But it kills normal cells but also tumor cells
not expressing antigen.
• Demerits-Some compound have toxic effect.
• CD 20 + YttriumZevalin
For B cell lymphoma
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10. Tumor therapy with BsAbs
• Covalently linked two different antibodies
having two specificities
1) To a TAA(tumor associated antigen)
2) To trigger molecule on a killer cell to kill
the cells
• When it is injectedIt binds to immune
effector cells arming it to seek out and killl
tumor cells.
• Ex.For ovarian cancer
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11. Antibody-based tumor therapy. (a) antibody alone; (b) antibody
toxin/radionuclides constructions; (c) bispecific antibodies;
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12. Purging of bone marrow for
analogous transplants
• Use of cytotoxic drugs,irradiation,or both of
which target dividing cells do not cure
significant no. of tumor cells.
• Because irradiation amount is limited by
toxicity of these to normal cells and HSC cells.
• To increase dosage bone marrow transplant +
chemotherapy is used.
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13. Purging of tumor cells from bone-marrow or stem cell populations.
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14. Conclusion
• Using any one of the immunotherapy methods
tumor can be cured by using antibodies.
• It gives a better option to cure this deadly
diasease and can save lot of human lives.
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15. References
• P.M. Lydyard, A. Whelan, M.W. Fanger
,Instant notes Immunology,
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16. 12/25/2017 16Dept. of Plant Biotechnology