Lecture 14 Flashcards
(22 cards)
What is a tumour
Cells that become altered that they grow uncontrollably
What can trigger the development of tumours
Viruses, chemicals or other factors
Do the proteins on the surface of cells differ differ from those found on a tumour
Yes
What are tumours from epithelial cells called
Carcinomas
What are tumours from mesenchymal origin called
Sarcomas
What are secondary tumours refereed to as
Metastases
When do tumours become unable to present an antigen
When the lose the MHC I antigen normal present on the nucleated cells in the body
What do tumours express when introduced by viruses
Viral non-structural antigens
What do tumours express when introduced by a single chemical
Unrelated antigens
What are tumour rejection antigen specific to
Individual tumours
What can tumours expressed as antigenic peptides become targets for
Specific T cells
What are the 3 phases in tumour surveillance
- Elimination phase
- Equilibrium phase - mutations that aid survival as a result of selection pressure
- Escape phase - accumulate sufficient mutations to elude the attention of the immune system
What do NK cells play a crucial role in
Immune surveillance against tumours
What can NK cells bind to and kill
Target cells
What are NK cells activated by
Cytokines
What do activated NK cells release
Proteolytic enzymes, granzyme A and B
What do NK cells secrete
Cytokines TNF-a anf IFN-y
What does IFN-y enhance
NK activity by promoting the rapid differentiation of the pre-NL cells and activated macrophages
What cells are of the greatest importance in destruction of tumours
T cells
What can activated macrophages may be able to destroy
Some tumour cells
What do activated macrophages produce
IL-1 and TNF-a
What can antibodies been used to increase
Antibody mediated immune responses
