Hypersensitivity 4 Flashcards
(20 cards)
How can a tumour be made more immunogenic?
Tagged w/ antibodies
What is herceptin?
An antibody against HER2 receptor
HER2 and breast cancer?
Upregulated by ab 100 fold on breast cancer cells
How do antibodies to HER2 work?
Bind to HER2 and prevent it from binding to the receptor
Effect of CD28 binding to B7?
Costimulatory signal for t cells–> switches them on
Effect of CTLA4 binding to B7?
Switches t cells off again
What does ipilimumab do?
Block CTLA4–> reduces “switching off” of t cells
What kind of proteins are CTLA4 and PD1/PDL1?
Checkpoint proteins
Which agents are used against checkpoint proteins?
Checkpoint inhibitors
Effect of checkpoint inhibitor?
Blocks checkpoint protein (which would otherwise suppress t cells) meaning t cells are active for longer
Issue with a lot of tumour immunotherapy?
The targets are not tumour specific so it could affect wild type cells
How to make tumour immunotherapy specific?
Antibody Dependent Prodrug Therapy (ADEPT)
What is Antibody Dependent Prodrug Therapy (ADEPT)?
Antibody to tumour given has enzyme
add a prodrug which needs to be cleaved and activated by the enzyme
therefore the prodrug will only be activated in the vicinity of the tumour
What do most genetic immunodeficiency diseases cause?
Failure to produce antibodies
WHy is X-linked agammaglobulinemia more prevalent in males?
Only one copy of the x chromosome
What is Severe combined immunodeficiency (SCID)?
Failure to produce cytokine receptor chains
Ways to acquire immunodeficiency?
Infection, cancer, drug treatment
Why is chemotherapy immunosuppressive?
Chemo drugs target bone marrow which is rapidly proliferating–> no WBCs
What does HIV target?
CD4+ve Th cells
What causes patient death in HIV?
Opportunistic infections
