HETEROGENEITY OF HUMAN PERIPHERAL-BLOOD EOSINOPHIL-TYPE COLONIES - EVIDENCE FOR A COMMON BASOPHIL-EOSINOPHIL PROGENITOR

  • 1 January 1985
    • journal article
    • research article
    • Vol. 66  (2) , 312-318
Abstract
A proportion of previously designated human eosinophil (Eo)-type colonies in methylcellulose contain basophils and histamine. Individual Eo-type colonies were analyzed by cell morphology as well as by biochemical assays for histamine, Charcot-Leyden crystal protein (CLC), and eosinophil granule major basic protein (MBP). Clonal origin of single Eo-type colonies was confirmed by G6PD [glucose-6-phosphate dehydrogenase] isoenzyme analysis. Morphological observations of such colonies revealed the existence of 2 distinct colony types: Eo type containing 100% basophils and Eo type containing mixtures of basophils and eosinophils, including cells with mixed basophileosinophil granulation. Histamine was not detected in pure, mature peripheral blood eosinophils. Immunofluorescent studies demonstrated bright staining for CLC and MBP in 95% .+-. 3% of cells in Eo-type colonies but only in 5% .+-. 4% of cells in GM-type colonies. Radioimmunoassay for MBP was positive in 5/9 Eo-type and 0/10 neutrophilmacrophage (GM-type) colonies, with a mean level (nanogram/colony) of 11.6 .+-. 4.2 per Eo-type colony; 4 of the latter colonies were doubly positive for both histamine and MBP. These and previous findings point out the morphological and biochemical heterogeneity of peripheral blood Eo-type colonies and provide direct evidence for the existence of a common, circulating basophil-eosinophil progenitor.