Recombinant IL-4 and IFN-γ activate locomotor capacity in human B lymphocytes.

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]