Separation and characterization of macrophage precursors and of interleukin 2-responding cells from nylon wool-nonadherent murine spleen cells by using Bauhinia purpurea agglutinin.
Precursors of macrophages were found to be enriched in nylon wool-nonadherent cells which are often used as purified T cells. By using a 2-step agglutination sedimentation method with Bauhinia purpurea agglutinin (BPA), the precursors of macrophages which were enabled to proliferate and differentiate by the addition of colony-stimulating factor (CSF) or high concentrations of concanavalin A (Con A) were exclusively separated into a nylon wool-nonadherent, BPA-agglutinated (bottom) fraction. Cells responsive to some kind of factor(s) other than CSF in Con A supernatants (Con A-Sup) were also fractionated into the bottom fraction. Under these conditions, T cells were separated into both BPA-nonagglutinated (top) and agglutinated (bottom) fractions. The proliferative response of the cells in the top fraction was higher than that in the bottom fraction when they were stimulated with an optimal concentration of Con A (3 micrograms/ml). As assessed by the Con A pulse experiments, T cells in the bottom fraction required larger amounts of interleukin 2 (I1-2) than those in the top fraction for proliferation and the growth of T cells in both fractions was completely dependent upon I1-2.