[Monoclonal antibody mNI-58 inducing morphological changes in a human monocyte-like cell line, U937, stimulated with phorbol myristate acetate (PMA)].

A mouse monoclonal antibody (mAb), designated mNI-58, was produced. The mNI-58 markedly induced spread formation of the phorbol myristate acetate (PMA)-stimulated U937 cells (referred to as PMA-U937 cells) but not that of the resting U937 cells. This spread formation was completely blocked in the presence of cytochalasin D or cycloheximide. It was partially blocked by an mAb against CD18 (lymphocyte function-associated antigen-1 beta). These results suggest that mNI-58 is capable of transducing a signal for spread formation of the PMA-U937 cells.