Bactericidal and Tumoricidal Activities of Synthetic Peptides Derived from Granulysin

Abstract

Granulysin, a 9-kDa protein localized to human CTL and NK cell granules, is cytolytic against tumor cells and microbes. Molecular modeling predicts that granulysin is composed of five α-helices separated by short loop regions. In this report, synthetic peptides corresponding to the linear granulysin sequence were characterized for lytic activity. Peptides corresponding to the central region of granulysin lyse bacteria, human cells, and synthetic liposomes, while peptides corresponding to the amino or carboxyl regions are not lytic. Peptides corresponding to either helix 2 or helix 3 lyse bacteria, while lysis of human cells and liposomes is dependent on the helix 3 sequence. Peptides in which positively charged arginine residues are substituted with neutral glutamine exhibit reduced lysis of all three targets. While reduction of recombinant 9-kDa granulysin increases lysis of Jurkat cells, reduction of cysteine-containing granulysin peptides decreases lysis of Jurkat cells. In contrast, lysis of bacteria by recombinant granulysin or by cysteine-containing granulysin peptides is unaffected by reducing conditions. Jurkat cells transfected with either CrmA or Bcl-2 are protected from lysis by recombinant granulysin or the peptides. Differential activity of granulysin peptides against tumor cells and bacteria may be exploited to develop specific antibiotics without toxicity for mammalian cells.

Spring viraemia of carp virus: recent advances

“…They are stored in cytoplasmic granules and released upon target cell recognition via MHC class I to induce apoptosis in the infected cells (Trapani & Smyth, 2002). The inhibitory role of NK-lysins against bacterial, fungal and parasitic infections has been well established (Wang et al, 2000;Jacobs et al, 2003;Hirono et al, 2007), but their role in protection against viral infections is relatively unknown. Recently, NK-lysin genes were characterized in zebrafish and their expression was investigated in SVCV-infected zebrafish (Pereiro et al, 2015).…”

Granulysin Induces Cathepsin B Release from Lysosomes of Target Tumor Cells to Attack Mitochondria through Processing of Bid Leading to Necroptosis

“…Lysis of Salmonella was measured as previously described (24). Briefly, a log-phase culture of Salmonella (OD 600 ϭ 0.5) was diluted to 2 ϫ 10 5 /ml in 10 mM sodium phosphate buffer (pH7.4) containing 0.03% Luria-Bertani broth.…”

The Relevance of Structural Biology in Studying Molecules Involved in Parasite–Host Interactions: Potential for Designing New Interventions

“…Interestingly, a number of human Sap domain-containing proteins, including granulysin, NK-lysin and surfactant protein B, have activity against a range of targets, such as tumor cells, bacteria, fungi and parasites, [38][39][40] and, accordingly, are considered components of the innate (not antibody provided) immune system.…”

“…[34][35][36] Moreover, sera from experimental mice infected with S. mansoni reacted to Fh-SLP-2 in vitro, thus showing crossreactivity [37] and suggesting that helminth SAPLIPs might be able to protect against trematodes more broadly. Interestingly, a number of human Sap domain-containing proteins, including granulysin, NK-lysin and surfactant protein B, have activity against a range of targets, such as tumor cells, bacteria, fungi and parasites, [38][39][40] and, accordingly, are considered components of the innate (not antibody provided) immune system. Despite the conservation of the Sap domain, the fold of individual SAPLIPs is adapted to carry out particular and diverse functions at biological membranes ranging from cytolytic properties of amoebapores, [28] granulysin [41] and NK-lysin [42] to plant aspartic proteases [43] and neurotrophic factors.…”