An Inflammatory Polypeptide Complex from Staphylococcus epidermidis: Isolation and Characterization

Abstract

Staphylococcus epidermidis releases factors that activate the HIV-1 long terminal repeat, induce cytokine release, and activate nuclear factor κB in cells of macrophage lineage. The active material had a mass of 34,500 daltons, was inactivated by proteases and partitioned into the phenol layer on hot aqueous phenol extraction, and thus was termed phenol-soluble modulin (PSM). High performance liquid chromatography (HPLC) of crude PSM yielded two peaks of activity designated PSM peak 1 and peak 2. MALDI-TOF (matrix-assisted laser desorption ionization-time of flight) mass spectroscopy indicated the presence of two components in peak 1, which were designated PSMα and PSMβ. Peak 2 contained a single component, designated PSMγ. Separation of PSMα and PSMβ in peak 1 could be achieved by a second HPLC procedure. The structure of each component was determined by amino acid sequence analysis and identification and sequencing of their genes. PSMα, PSMβ, and PSMγ were 22-, 44-, and 25-amino acid, respectively, strongly hydrophobic polypeptides. PSMγ was identified as Staphylococcus epidermidis delta toxin, whereas PSMα and PSMβ exhibited more distant homology to previously described staphylococcal toxins. They appeared to exist as a complex or aggregate with activity greater than the component parts. The properties of the S. epidermidis PSMs suggest that they may contribute to the systemic manifestations of Gram-positive sepsis.

Mastoparan, a G Protein Agonist Peptide, Differentially Modulates TLR4- and TLR2-Mediated Signaling in Human Endothelial Cells and Murine Macrophages

“…The TLR2 ligand S-(2,3-bispalmitoyloxypropyl)-Cys-Gly-Asp-Pro-Lys-HisPro-Lys-Ser-Phe, Pam(2)CGDPKHPKSF (FSL-1) was purchased from InvivoGen. Phenol-soluble modulin (PSM), derived from Staphylococcus epidermidis, was prepared as described elsewhere (42)(43)(44). FBS and other tissue culture media were obtained from HyClone and BioWhittaker.…”

Toll-Like Receptor 2 (TLR2) and TLR9 Signaling Results in HIV-Long Terminal RepeatTrans-Activation and HIV Replication in HIV-1 Transgenic Mouse Spleen Cells: Implications of Simultaneous Activation of TLRs on HIV Replication

“…Since THP-1 cells do not express CD14, they were differentiated by 36-h stimulation with vitamin D 3 (0.1 M) before LPS treatment. Phenolsoluble modulin (PSM), a complex of three small secreted polypeptides purified by phenol extraction of supernatants of stationary Staphylococcus epidermidis (26), was obtained from S. Klebanoff (University of Washington). A protein-free, heat-stable, Mycobacterium tuberculosis-conditioned culture supernatant, soluble tuberculosis factor (STF), was obtained from M. J. Fenton (Boston University, Boston, MA).…”

Regulated expression of pathogen-associated molecular pattern molecules in Staphylococcus epidermidis: quorum-sensing determines pro-inflammatory capacity and production of phenol-soluble modulins

“…Recently, it has been shown that S. epidermidis produces a pro-inflammatory complex of peptides named phenolsoluble modulin (PSM) based on their partition into the phenol layer on hot phenol extraction (Mehlin et al ., 1999). Phenol-soluble modulin is a stronger inducer of cytokine release from monocytes and THP-1 cells than LTA (Mehlin et al ., 1999), activates the HIV-1 LTR in cells of macrophage lineage, and induces NF-k B production by these cells (Mehlin et al ., 1999). Phenol-soluble modulin also causes degranulation, primes for an enhanced respiratory burst, and inhibits spontaneous apoptosis in human neutrophils (Liles et al ., 2001).…”

“…As a result of its diverse and strong pro-inflammatory properties, PSM may contribute significantly to sepsis caused by S. epidermidis . Phenol-soluble modulin consists of at least three amphipathic peptides, PSM a , PSM b and PSM g (Mehlin et al ., 1999). PSM g is identical and PSM a similar to S. epidermidis delta toxin.…”