eosinophils and mast cells. eosinophil. Eosinophil : introduction. bone marrow derived granulocytes Myeloid lineage Paul Ehrlich 1879 red, eosinophilic basic granules nucleus divided into two tear-shaped lobes non-dividing - approx 13 hr in circulation usually less than 4% of WBC
Eosinophils need to move to sites of inflammation and adhere to and
cross pulmonary vascular epithelial cells. This involves :
Eosinophil chemotactic factors
eosinophil chemotactic factor of anaphylaxis (ECF-A) from mast cells
Val-Gly-Ser-Glu and Ala-Gly-Ser-Glu
N-formyl peptides (f-Met-Leu-Phe) bacteria
C5a complement activation
ecalectin T cell derived, 36-kDa protein
eotaxin CCR3 chemokine from lung and skin stromal cells
MIP-1, RANTES, MCP-3 monos,T cells, platelets, basophils
The cytoplasmic granules are membrane bound and contain a
crystalloid protein core. The granule and cell membranes fuse
on triggering and release the granule contents.
The granules contain four highly toxic arginine-rich proteins
with a high isoelectric point pH > 11.0
These bind the negatively charged surfaces of parasites.
ECP 21 kDa
EDN 18kDa (70% homology with ECP)
EPO 74 kDa
MBP 14 kDa
Reactive oxygen metabolites
Eosinophils kill the schistosomula (egg) stage of Schistosoma mansoni
Degree of protection against nematodes in guinea pigs and sheep correlates with eosinophilia.
Genetic determination - strain-dependent differences in eosinophilia following parasitic infection in mice. Possibly related to IL-5 or eotaxin polymorphism.
Mice infected with Trichonella spiralis treated with anti-eosinophil antibody cannot eliminate the worms and have more muscle cysts.