INDUCIBLE NITRIC-OXIDE SYNTHASE IN HUMAN LYMPHOMONONUCLEAR CELLS ACTIVATED BY SYNTHETIC PEPTIDES DERIVED FROM EXTRACELLULAR-MATRIX PROTEINS

Synthetic peptides with sequences present in extracellular matrix prot eins are capable of causing the expression of the inducible form of ni tric oxide synthase (iNOS), detected by immunocytochemistry, and the r elease of NO by human lymphomononuclear cells incubated in their prese nce. Active peptides are 15-mers containing a characteristic 2-6-11 mo tif in which the amino acid residue at position 2 is Leu, Ile, Val, Gl y, Ala or Lys; the residue at position 6 is always Pro; and residue 11 is Glu or Asp. The induction of iNOS in human monocytes and macrophag es could be involved in the cytotoxicity against tumor cell lines also elicited by these peptides.