5: Tumor Immunology

Question 1

what do NK cells do?

Answer 1

• Recognize and kill infected cells
• produce IFN g and TNF a
• can kill Via ADCC

Question 2

How can NK recognize and kill infected cells?

Answer 2

• Down regulation of MHCI by virussen
• DAMPS en virus - infected cells
• Direct cytolisis through perforin- granzyme or TRAIL - DR4/5

Question 3

how do Nk cells kill through ADCC?

Answer 3

• antibody dependent cell-mediated cytotoxicity
• Via fcyRIII binding to IgG

Question 4

how does phagocytesis of tumor cell work?

Answer 4

• Tumor cell surrounded with plasma Membrane
• enclosed vesicles formed → phagesome or endosome
• phagascom fuses with lysesome → phagolysosome
• Degradation/ killing

Question 5

Where is MHCI presented?

Answer 5

• Intracellular antigens (peptides)
• on all nuelated cells

Question 6

Where is MHC II presented?

Answer 6

• only extracellular antigens (peptides)
• only on antigen presenting cells → macrophages,dendritic cells,B cells

Question 7

features CD8 + T cells?

Answer 7

• Cyto toxic T-cells
• kill infected cells ( perforin, granzyme )
• Trigger apoptosis
• soluble factors

Question 8

features CD4 + T-cells?

Answer 8

helps DCS to stimulate an effective CD8 T cell response & help production of IFN g
help B- cells to produce antibodies

Question 9

secondary lymphaid organs?

Answer 9

• lymph nodes → filters tissue
• spleen → filters blood
• MALT → filters gastrointestinal tract t airways + uregenital tract

Question 10

Activation of T- cells?

Answer 10

Tumor cell gets iptaken by macrophages and transports to the secondain lympheid organs and presents antigen
- Naive CD4 and CD8 recognize antigen
- T cell activated / secretion il-2
- proliferatie and produce CD4 and Cd8 Memory T cells
- in tissue Tcells differentiate into effector and helper T cells /cytotoxic T- cells

Question 11

After activation the cytotoxic T cells hill via?

Answer 11

Extrinsic pathway(fas/fasI )
intrinsic pathway ( perforin / granzyme B )

Question 12

What is the immune Surveillance hypothesis?

Answer 12

Elimination - Equilibrium - escape

Question 13

what is Elimination in the immune Surveillance hypothesis?

Answer 13

when a tumor is in a tissue, multiple immune cells can recognize and eliminatie them

Question 14

Equilibrium in the immune Surveillance hypothesis?

Answer 14

Variant tumor cells arise that are More resistant → Over time a variety of different tumor variants develop

Question 15

Escape in the immune Surveillance hypothesis?

Answer 15

1 variant may escape the killing mechanisms or recruit tregs te protect them