Chemotactic activity of lymphotoxin and tumour necrosis factor alpha for human neutrophils

Lymphotoxin (TNF beta) and tumour necrosis factor alpha (TNF alpha) stimulate locomotion and chemotaxis of human blood neutrophils as measured in three assays. Both cytokines stimulate morphological polarization of neutrophils in suspension; both stimulate locomotion of neutrophils into micropore filters; both cause orientation of neutrophils towards a gradient source. Orientation in a gradient suggests a chemotactic effect. The action of both cytokines is similar but is not as strong as that of formyl peptide used as a positive control. Myelomonocytic cell lines (U937 and HL-60) develop responsiveness to formyl peptides on maturation but not to TNF alpha or beta.