T-cell Mediated Tumor Response Flashcards
1
Q
What is a tumor antigen?
A
Molecules expressed by tumor cells that are not expressed in healthy cells.
2
Q
What are the 3 general types of tumor antigens?
A
- Products of oncogene or mutated tumor suppressor gene.
- Overexpressed self protein
- Oncogenic virus particles.
3
Q
Discuss the T-cell mediated response against tumors.
A
- Tumor antigen shown to DC
- Dendritic cells phagocytose the tumor cell.
- Cross-presentation (MHC 1 and 2)
- Activates tumor specific CD8 and CD4(Th1)
4
Q
Discuss the B-cell mediated response against tumors.
A
Production of anti-tumor antibodies
- Opsonization
- Activate NK cells
- Activate complement
- Block receptors on tumor cells needed for survival/growth
5
Q
What are the 5 ways tumor cells evade the immune system?
A
- Change the antigen the immune system is responding to.
- Downregulate MHC 1
- Secrete IL-10 & TGF-B (Supresses Th1 and attracts Tregs)
- Express CTLA-4 to inhibit co-stimulation
- Express Fas ligand
6
Q
Discuss monoclonal antibody treatment.
A
Tumor antigen specific T cells are removed from patient and expanded in vitro. Re-introduced to patient. Downside is there is no memory.