Cholera toxin (choleragen)-polymorphonuclear leukocyte interactions: effect on migration in vitro and Fc gamma R-dependent phagocytic and bactericidal activity.

PMNL leukocytosis is a feature common to many types of infectious and inflammatory diseases. How PMNL are recruited to tissues is not yet clear although it is a question that has considerable clinical importance. We investigated the function of PMNL which migrated through an artificial barrier (Chinese hamster ovary (CHO) cells, collagen and nylon cloth membrane) subjected to CT or choleragenoid treatment toward plain medium (the same RPMI in the upper and lower chamber) or medium containing chemotactic factor (fMLP or LPS or ZAS). CT treatment significantly (P < 0.01) reduced the Fc gamma R expression on the surface of PMNL. The PMNL functions, namely, migration, phagocytic activity and intracellular killing of staphylococci, also have been reduced significantly (P < 0.01). Fc gamma R expression and some functions of PMNL that migrate to chemoattractants were reduced, irrespective of the presence or absence of CT; however, the inhibitory effect of CT on PMNL function was observed only when PMNL migrate to the lower chamber without chemotactic factor. On the other hand choleragenoid treatment of CHO cells did not have any significant influence on PMNL function and Fc gamma R expression. In conclusion, our experiments demonstrate that CT reduces EAFc rosetting and the Fc gamma R-dependent phagocytic and bactericidal activity of bovine blood PMNL.