0000000000082132
AUTHOR
F Leoni
Effect of partially modified retro-inverso analogues derived from C-reactive protein on the induction of nitric oxide synthesis in peritoneal macrophages
The ability of three modified tetrapeptides, representing fragments of the C-reactive protein (CRP) sequence and stabilized in the first peptide bond by retro-inverso modification, to affect the secretion of nitric oxide (NO) was studied in macrophages of BALB/c mice. These tetrapeptides, resembling the aminoacid sequence of tuftsin (CRP I, H-gThr-(R,S)mLys-Pro-Leu-OH, ITF 1192; CRP II, H-gGly-(R, S)mLys-Pro-Arg-OH, ITF 1127; CRP III, H-gThr-(R,S)mLys-Pro-Gln-OH, ITF 1193), were able to induce NO synthesis by peritoneal macrophages in a dose-dependent manner; the most stimulating dose was 1000 ng ml−1 for CRP II and 100 ng ml−1 for CRP I and CRP III. NO synthesis was not strictly dependent …
The macrophage-activating tetrapeptide tuftsin induces nitric oxide synthesis and stimulates murine macrophages to kill Leishmania parasites in vitro.
The macrophage-activating tetrapeptide tuftsin was able to activate, in a dose-dependent manner, murine macrophages to express nitric oxide (NO) synthase and to produce NO. Tuftsin required lipopolysaccharides for the optimal induction of NO production and synergized with gamma interferon in the induction of NO synthesis. Tuftsin-dependent NO production was sensitive to inhibition by dexamethasone and the NO synthase specific inhibitor LGN-monomethylarginine (L-NMMA). Murine peritoneal macrophages activated by tuftsin were able to kill the amastigotes of the intracellular protozoan parasite Leishmania major in vitro.