Inhibition of Chemotaxis by Human Leukocytes Following Incubation in Homologous Serum Devoid of Chemotactic Activity

Incubation of rabbit polymorphonuclear leukocytes (PMNS) with chemotactic factors has been shown to lead to a progressive decrease, or “deactivation,” in the chemotactic responsiveness of the PMNS (Ward and Becker). In these studies, we report that human PMNS can be similarly “deactivated” by humoral materials lacking chemotactic activity. Suspensions of human, peripheral blood PMNS (5 × 106 PMNS/ml) were incubated with equal volumes of undiluted homologous sera at 4, 23, or 37°C, or with serum that had first been incubated at 37°C for 10 min followed by 56°C for 20 min, or with heat-inactivated serum (56°C for 60 min), or with serum from which chemotactic activity had first been generated by the addition of pre-formed antigen-antibody complexes. After 30 min incubation, the cell suspensions were washed and tested for chemotactic response. Cell suspensions which had been incubated with materials having significant chemotactic activity had been “deactivated”—they failed to chemotax.