The chemiluminescence response of normal human leukocytes to chlamydia trachomatis

The aim of the present study was to investigate the phagocytic response of normal human polymorphonuclear leukocytes (PMN) and monocytes (MN) to eight serotypes of C trachomatis (B,C,D,E,F,I,J, and L2) using a chemiluminescence (CL) assay, with luminal and lucigenin as amplifiers. The magnitude of the phagocytic cell CL response was proportional to the phagocyte-to-chlamydiae ratio, with a poor CL response detected at a ratio of 1:125 and progressively larger CL responses up to ratios of 1:50,000. The durations of the CL responses to all chlamydiae serotypes tested were considerably longer than that for zymosan. The PMN demonstrated a relatively greater CL response to all chlamydiae serotypes tested when compared with MN. The PMN and MN CL responses to "genital serotypes" (D,E,F,I, and J) (as well as lymphogranuloma venereum serotype L2) were greater than that for "ocular" serotypes (B and C). Inactivation of serum complement and specific chlamydial antibody absorption reduced the CL responses of both PMN and MN. This is the first study to characterize the CL responses of normal human PMN and MN cells to C trachomatis, and it indicates the important role of oxygen dependent antimicrobial systems in the phagocytosis of this common human pathogen.