Search

Recombinant human intcrlcukin-4 (IL-4) or interferon-gamma (IFN-γ) were added to cultures of B-enriched human lymphocytes from normal blood, or to the lymphocytes from live patients with chronic lymphocytic leukaemia (CLL), IL-4 and IFN-γ caused the B lymphocytes to acquire locomotor capacity, as judged by morphological polarization and invasion of collagen gels. This was detectable in normal B cells within a few hours of culture and fully developed by 24–48 hr. It was inhibited by the presence of cyclosporin A. The responding, motile cells also increased in size. These findings suggest that B lymphocytes acquire locomotor capacity early in growth, as the cells move from G0 to G1, IL-4 or IFN-γ had no direct effect in polarizing lymphocytes in a short-term (30-min) assay, thus they do not behave like chemotactic factors. They slowly increase the proportion of locomotor cells in B-lymphocyte populations, and these motile cells respond by polarization to factors released by the growing cells into the medium. [ABSTRACT FROM AUTHOR]

The locomotor response of human blood monocytes to chemotactic factors was studied using a polarization assay on cells in suspension and by filming locomotion on albumin-coated glass. Cells in optimal (5 × l0-9 m) but uniform concentrations of N-formyl-methionyl-leucyl-phenylalanine (FMLP) polarized well and showed a 'persistent random walk' type of locomotion, whereas in supraoptimal concentrations (10-7M), the cells took erratic paths and polarized poorly, suggesting that monocytes cannot develop an anteroposterior polarity if hit by ligand molecules at many points on the cell surface simultaneously. Monocyte polarization in chemotactic factors at 37° was transient and was gradually lost after 15-20 min. Likewise, the ability to form Fc rosettes after this time was gradually lost, suggesting loss of functional receptors from the cell surface with time. In optimally polarized cells, Fc rosettes were frequently localized at the head of the cell. This localization also was lost with time. Using pure chemotactic factors (FMLP, C5a, leukotriene B4) we found, as reported earlier (Cianciolo & Snyderman 1981), that polarization was restricted to a subpopulation (approximately 60% of cells) that responded to multiple attractants. However, 80-90% of monocytes polarized in response to combinations of any of the above pure attractants with candidatactivated serum. This suggests that the subpopulation that lacks receptors for classical chemotactic factors nevertheless has locomotor capacity and can respond to undefined factors in activated serum, and that the great majority of blood monocytes is motile if appropriately stimulated. [ABSTRACT FROM AUTHOR]

Recombinant human interleukin-4 (IL-4) or interferon-gamma (IFN-gamma) were added to cultures of B-enriched human lymphocytes from normal blood, or to the lymphocytes from five patients with chronic lymphocytic leukaemia (CLL). IL-4 and IFN-gamma caused the B lymphocytes to acquire locomotor capacity, as judged by morphological polarization and invasion of collagen gels. This was detectable in normal B cells within a few hours of culture and fully developed by 24-48 hr. It was inhibited by the presence of cyclosporin A. The responding, motile cells also increased in size. These findings suggest that B lymphocytes acquire locomotor capacity early in growth, as the cells move from G0 to G1. IL-4 or IFN-gamma had no direct effect in polarizing lymphocytes in a short-term (30-min) assay, thus they do not behave like chemotactic factors. They slowly increase the proportion of locomotor cells in B-lymphocyte populations, and these motile cells respond by polarization to factors released by the growing cells into the medium.