Secretolytin immunoreactivity.

Distribution of secretolytin immunoreactivity (A-D) and enkelytin immunoreactivity (E,F) in monocytes is shown. Cytocentrifuged monocytes were immunodetected for secretolytin or enkelytin content using Texas red–labeled secondary antibody. Confocal images were acquired as single midcellular optical sections at 32 scans/frame. (A) An intense secretolytin immunoreactivity is observed in monocytes. The labeling is preferentially located at the periphery of the cells. (B) Preabsorption of the antiserum with secretolytin totally abolishes the signal. (C) When cells are preincubated with IL-6 for 15 minutes, the labeling is no longer apparent. (D) After a 15-minute incubation in the presence of LPS, the distribution of secretolytin immunoreactivity is similar to that seen in panel A. (E) A strong enkelytin immunostaining is also detected in monocytes. The signal forms “hot spots” distributed throughout the cytoplasm. (F) Enkelytin immunostaining is not changed after incubation of the cells with IL-6. Original magnifications, × 40.