Question

Describe the cell-surface events leading to neutrphil movement to site of infection.

Answer 1

Answer:

Neutrophils help fight infections because they ingest microorganisms and secrete enzymes that destroy them. A neutrophil is a type of white blood cell, a type of granulocyte and a type of phagocyte.

Explanation:

Neutrophils display adhesion glycoproteins on their surface to bind endothelial and subendothelial structures. They move randomly until they find a damaged site. Unless neutrophils are activated, endothelial cells do not tend to adhere. When inflammation mediators (IL-1, FNT) activate endothelial cells, they express P-selectin and E-selectin on the surface. The expression of glycoproteins and L-selectin cause the initial adhesion of the non-stimulated neutrophil to the activated endothelium, slowing it down by rolling it over the endothelium. Activated endothelial cells, opsonized particles, immune complexes, FEC-G, FEC-GM and chemoattractants produce factors that stimulate neutrophil activation. Expressing β2 integrin (endothelium adhesion molecule) Neutrophils expand and form pseudopods. Neutrophil activation also promotes degranulation, superoxide generation, and arachidonate metabolite production.