THE EFFECTS OF RECOMBINANT OVINE INTERLEUKIN-3 AND RECOMBINANT OVINE STEM-CELL FACTOR ON THE GROWTH AND MEDIATOR EXPRESSION OF CAPRINE AND OVINE BONE-MARROW-DERIVED MAST-CELLS

The growth of ovine and caprine mast cells in bone marrow cultures has been achieved using recombinant ovine interleukin-3 (rOvLL-3) and rec ombinant ovine stem cell factor (rOvSCF). After approximately 2-3 week s' growth in optimal concentrations of either rOvIL-3 alone or a combi nation of rOvIL-3 and rOvSCF, the majority of the cells produced in bo ne marrow culture from both species were mast cells. The significant i ncrease in the total numbers of cells and survival times of the cultur es when both cytokines were present compared to either alone, indicate d synergy between rOvIL-3 and rOvSCF on mast cell growth. Ovine and ca prine cells cultured in rOvIL-3 alone produced a four-fold increase in cell numbers compared with medium only controls. The resulting cultur es contained up to 52% mast cells by day 18 and had a lifespan of 3-4 weeks. In contrast, cells from both species grown in both rOvLL-3 and rOvSCF produced up to six times more cells than the equivalent rOvIL-3 stimulated cultures, contained up to 69% mast cells by day 21 and cou ld be maintained for at least 6 weeks. Ovine cells grown in rOvIL-3 al one or rOvIL-3 and rOvSCF contained significantly more aryl-sulfatase and serine protease but similar amounts of beta-hexosaminidase compare d with caprine cells during the second week of culture. There were no significant differences in the granule-associated mediator content of cells from either individual species grown in rOvIL-3 alone compared w ith those grown in rOvIL-3 and rOvSCF during the first 21 days of cult ure. (C) 1997 Elsevier Science B.V.