Inhibition of Tumor Necrosis Factor mRNA Translation by a Rationally Designed Immunomodulatory Peptide

Abstract

Based on sequences of immunomodulatory peptides derived from the heavy chain of HLA Class I, novel immunomodulatory peptides with increased potency were developed by computer-aided rational design. Allotrap 1258 was characterized in detail and shown to inhibit cell-mediated immune responses in vitro and in vivo. Immunomodulatory activity was associated with the capability of the peptides to modulate heme oxygenase (HO) activity. In this study we analyzed the effect of Allotrap 1258 on cytokine expression. Allotrap 1258 inhibited concanavalin A-and lipopolysaccharide-induced human and mouse tumor necrosis factor (TNF) production in vitro and in vivo but had no effect on interleukin ( Peptides derived from the heavy chain of the HLA Class I molecule have been shown to modulate immune responses in vitro and in vivo (1-7). In vitro, these peptides inhibited cytotoxicity and differentiation of cytotoxic T cells (1). In vivo, they were shown to prolong allograft survival in rodents (2-7). Based on these HLA-derived peptide sequences, novel immunomodulatory peptides were developed by computer-aided rational design (8). Initially, the biological activity of a panel of 19 peptides derived from peptide 2702.75-84 (HLA-B2702, amino acids 75-84) as well as other major histocompatibility complex molecules was assessed in a heterotopic mouse allograft model. A rational drug design strategy based on these in vivo data resulted in a series of immunomodulatory peptides. One of these peptides, RDP1258 and its D-isomer, Allotrap 1258, showed enhanced efficacy in comparison with 2702.75-84 both in vivo when tested in rodent allograft models and in vitro in the inhibition of cytotoxicity in human and mouse T lymphocytes.The mechanism of immunomodulation mediated by these peptides is not fully understood. Observations in various in vivo models indicated that the peptides do not interact directly with T cell receptor or NK cell inhibitory receptors (4, 5, 9) The observation that both L-and D-isomers of peptide 2702.75-84 prolong graft survival indicates that the immunomodulatory activity of the peptides is not based on presentation by major histocompatibility complex molecules (5). Similarly, the recent hypothesis that these peptides modulate immune responses by binding to Hsc/Hsp70 can be excluded because the peptides D-enantiomers, while being immunomodulatory, do not bind to these proteins (10, 11). Affinity chromatography with one of these immunomodulatory peptides resulted in the identification of heme oxygenase-1 (HO-1) 1 as a potential target for these peptides (12). All of the biologically active peptides derived from 2702.75-84 were shown to inhibit HO activity in vitro. The original compounds, however, were 100-fold less potent than the rationally designed Allotrap 1258. Similar to what has been observed with other HO inhibitors, in vivo administration of the peptides to animals resulted in a rapid up-regulation of HO-1 protein expression (12). Subsequent studies with peptides and protoporphyrins specifically affecting HO ac...

von Hippel-Lindau Protein-Mediated Repression of Tumor Necrosis Factor Alpha Translation Revealed through Use of cDNA Arrays

“…Our studies show that the pVHL-dependent reduction in the association of TNF-␣ mRNA with the translationally active, polysome-bound fraction was linked to decreased TNF-␣ protein synthesis. In addition, we have provided evidence that the TNF-␣ 3ЈUTR, previously shown to participate in the translational regulation of TNF-␣ expression (20,27,41,52), was responsible for conferring translational repression upon a chimeric transcript. According to our unpublished results, neither the levels of several translational regulatory proteins examined (i.e., TIAR, TIA-1, EF-1␣) nor their association with in vitrosynthesized TNF-␣ 3ЈUTR transcripts appeared to be substantially influenced by the cell's pVHL status (results not shown).…”

Attenuation of aortic graft arteriosclerosis by systemic administration of Allotrap peptide RDP58

“…RDP58 has been shown to inhibit TNF in vitro in cultured monocytic cell lines as well as at the translational level in several in vivo animal models of inflammation [32]. Production of TNF during tissue injury may be responsible for the massive cell death observed in chronically rejected grafts.…”

Translational Control of Tumor Necrosis Factor-related Apoptosis-inducing Ligand Death Receptor Expression in Melanoma Cells

“…immunomodulatory peptides were reported to inhibit binding of proteins to the 3Ј-UTR mRNA for TNF-␣) (34). Inhibitors of signal pathways involved in regulation of the protein binding to the 3Ј-UTR may also up-regulate the TRAIL-R2 protein.…”