Altered Neutrophil Migration during Bacterial Infection Associated with a Serum Modulator of Cellular Motility

The motility of polymorphonuclear leukocytes (PMNLs) from 25 patients with bacterial infection was assessed by using the migration-under-agarose assay. A spectrum of responses was observed. Random and directional motility stimulated by C5a or pressed in parallel. These responses contrasted with those of normal PMNLs preincubated with either FMLP or C5a; preincubation with one chemotaxin inhibited a subsequent response to the same stimulus but did not inhibit the response to the other. The parallel responses of patient PMNLs to C5a and FMLP suggest that the altered motility reflects a perturbation independent of a specific chemotactic receptor. Heat-inactivated serum from patients with bacterial infection, when preincubated with normal PMNLs, resulted in significant enhancement of both random and directional migration. The data indicate that bacterial infection is associated with appearance of a modulator of neutrophil motility.