DENDRITIC CELL PROGENITOR IS TRANSFORMED BY A CONDITIONAL V-REL ESTROGEN-RECEPTOR FUSION PROTEIN V-REIER

A conditional v-Rel estrogen receptor fusion protein, v-RelER, causes estrogen-dependent but otherwise unaltered v-rel-specific transformati on of chicken bone marrow cells. Here, we demonstrate that such v-relE R-transformed cells exhibit B lymphoid determinants in line with earli er studies on v-rel-transformed cells. However, following inactivation of v-RelER oncoprotein activity by administration of an estrogen anta gonist, cells differentiate into antigen-presenting dendritic cells as judged by several morphological and functional criteria. Additionally , under yet different culture conditions, v-relER cells differentiate into cells resembling polymorphonuclear neutrophils. Our studies there fore suggest that the conditional v-RelER, and probably also the authe ntic v-Rel, transform a common progenitor for neutrophils and dendriti c cells.