4. Monoclonal antibodies

Question 1

what is the structure of the antibody?

Answer 1

see pic

Question 2

what is FAB?

Answer 2

antibody binding fragment - contains hypervariable regions that allow for recognition for lots of different antigens

Question 3

what is FC region?

Answer 3

responsible for binding to the immune effector cells to elicit the immune response

Question 4

what do monoclonal antibodies recognise?

Answer 4

one epitope - they are monovalent and produced from a single B lymphocyte clone which will produce an antibody specific for one particular antigen

Question 5

how was this tested in the past?

Answer 5

mouse injected with an antigen to elicit a specific immune response. the spleen was then removed and B cells isolated. these were then fused with myeloma cell line (hybridoma) which then produced the antibody the mouse B cell was specific for, which is screened and purified for use

Question 6

what was the first monoclonal antibody used in clinical treatment?

Answer 6

100% murine (omab) - recognised aas foriegn by immmune system reducing half life…so less immunogenic antibodies develop… chimeric antibodies (ximab)

Question 7

how are monoclonal antibodes produced today?

Answer 7

transgenic mice are used to produce fully human anitibodies (umab) which are recognized as self and low immungenicity

Question 8

how are monoclonal antibodies used as treatment?

Answer 8

antibody drug conjugates to target treatment to a specific cell type to avoid off target cytotoxic off target effects
bispecific monoclonal antibodies which target bows own immune system (t cells) ti kill B cells by bringing to both

Question 9

when the antibody binds with the cell surface receptor, what is the effect?

Answer 9

can activate or inhibit cell signalling resulting in - cell death induction, antibody dependent cell mediated cytotoxicity activation and complement dependent cytotoxicity activation

Question 10

how can monoclonal antibodies be used in diagnositics?

Answer 10

the use of emission of light (flourescent tag) or an enzymatic reaction to identify specific cells using immunohistochemistry and flow cytometry

Question 11

in what areas are monoclonal antibodies used today?

Answer 11

lymphoma
solid cancers
autoimmune disease
cardiology
endocrine

Question 12

how are blood cancers divided?

Answer 12

into B and T cell lymphomas due to clonal proliferations of lymphoid cells
b cell most common esp diffuse large B cell lymphoma

Question 13

how can lymphomas be diagnosed?

Answer 13

via structure and use of CD20 immunohistochemistry to diagnose B cell lymphoma

Question 14

what types of treatment are available for lymphoma?

Answer 14

chemo
radiotherapy
monoclonal antibody therapy
emerging targeted therapy
stem cell transplantation

Question 15

what adverse reactions can result from monoclonal antibody treatment?

Answer 15

due to immune activation - patients pre dosed with paracetamol, antihistamines and steroids to prevent hypersensitivity reaction and infusion reactions must be treated promptly

Question 16

define conjugated monoclonal antibodies

Answer 16

monoclonal antibody linked to a potent drug delivering anti cancer agents to tumour cell
the antibody targets antigen expressed on the surface of cancer cells and enter via receptor mediated endocytosis and lysosomal degradation and release of cytotoxic agent

Question 17

define bispecific monoclonal antibodies

Answer 17

simultaneously anti CD3 and anti CD20 simultaneously cause activation of T cells and B cells