Studies on the mechanism of macrophage aggregation induced by lymphokines

Macrophage aggregation (measured by a light-scattering technique) induced by unpurified lymphokine preparations has been investigated. This has been shown to be Ca2+ or Mg2+ dependent and to be inhibited by a number of agents known to affect cellular physiology and biochemistry. The divalent cation ionophore A23187 causes a macrophage aggregation superficially similar to that induced by lymphokines, although differences were found. It is suggested that a biochemical response by the macrophage is required for aggregation induced by lymphokines, and thus measurements of macrophage aggregation allow a study of the early events in the response of macrophages to lymphokines.