Transcient cell interaction

Question 1

Define Transcient cell adhesion

Answer 1

Transcient cell adhesion allows for cells to resist any external forces eg) Blood flow while remaining dynamic and reversible

• White blood cells need to leave the bloodtsream but the the epithelial cells expeprience a lot external force while flowing.

Question 2

What are the proteins involved
1) Selectins
- describe and list the types of selectins

Answer 2

1) Selectins
- These are ca 2* dependent proteins
- They bind to carbohydrate ligands
- Form weak bonds quickly
- They mediate rolling adhesions

• L- selectin : Leukocytes
• E - selectin : activated endothelial cells
• P - selectin : Platlets

Question 3

Intergrins

Answer 3

• They mediate firm adhesions
• Activated after roling

Question 4

Ig Superfamily

Answer 4

• These are Ca 2+ independent proteins
  1) ICAMs : Intracellular adhesion molecules
  2) VCAMs: Vascular cell adhesion molecular
• They act as ligands for intergrins

Question 5

where and when does transcient cell adhesion happen ?

Answer 5

• It happens in the bloodstream ‘during
  1) Immune response
  2) inflammation

Question 6

describe the process

Answer 6

1) Rolling
- This is mediated by selectins
- cell slows down but keeps moving

2) Firm- adhesion
- The intergrins switch to a high affinity state
- Cell binds to ICAMs and VCAMs
- Cell stops

3) Transmigration
- Cell squeezes through epithelial cells