IMG 03 (3)

Characteristic	Mast Cells	Basophils	fosmophils
Origin of precursor Major site of maturation Matura cells in circulation Matura cells recruitad into tis-sues from circulation	C034’ hematopoietic progenitor cells Connective tissue No No	C034' hematopoietic progenitor cells Bona marrow Yes (0.5% of blood leukocytes) Yes	C034* hematopoietic progom- 1 tor cells 1 Bona marrow Yes (2.7% of blood leufco-cytasj Yes
Maturo cells residmg in connac-tive tissue	Yes	No	Yes
Prolrterative abHrty of matura cells	Yes	No	No
| Life span	Weeks to months	Days	Days to wtoki
Major devełopmental factor (cytokine)	Stern celi factor	IL-3	IL-5
j Eupression of FcrRI	High levels	High lavals	Low levels
Major granule contents	Histamina, heparin and/or chon-droitin sulfate, proteases	Histaminę, chondroitin sulfate, proteasa	Major basie prom, eosmo pM cebomc protein, panu- 1 idases, hydroiasas. łyso-phosphokpase
Abbrewations: FcrRI. Fcr receptor type 1; IL-3, interłeukin-1 i Modified from Costa JJ, PW Wolier, and SJ Galii. The cells of the allergic response JAMA 27W15-1I& Copyright 1994. Amancan Mofcal Associetion.