title: An alpha-helical cationic antimicrobial peptide selectively modulates macrophage responses to lipopolysaccharide and directly alters macrophage gene expression.
abstract: Certain cationic antimicrobial peptides block the binding of LPS to LPS-binding protein and reduce the ability of LPS to induce the production of inflammatory mediators by macrophages. To gain a more complete understanding of how LPS activates macrophages and how cationic peptides influence this process, we have used gene array technology to profile gene expression patterns in macrophages treated with LPS in the presence or the absence of the insect-derived cationic antimicrobial peptide CEMA (cecropin-melittin hybrid). We found that CEMA selectively blocked LPS-induced gene expression in the RAW 264.7 macrophage cell line. The ability of LPS to induce the expression of >40 genes was strongly inhibited by CEMA, while LPS-induced expression of another 16 genes was relatively unaffected. In addition, CEMA itself induced the expression of a distinct set of 35 genes, including genes involved in cell adhesion and apoptosis. Thus, CEMA, a synthetic alpha-helical peptide, selectively modulates the transcriptional response of macrophages to LPS and can alter gene expression in macrophages.
authors.affiliation: Department of Microbiology and Immunology, and Biotechnology Laboratory, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: M G
authors.initials: MG
authors.lastname: Scott
authors.forename: C M
authors.initials: CM
authors.lastname: Rosenberger
authors.forename: M R
authors.initials: MR
authors.lastname: Gold
authors.forename: B B
authors.initials: BB
authors.lastname: Finlay
authors.forename: R E
authors.initials: RE
authors.lastname: Hancock
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects / Q000235:genetics*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000276:immunology
chemical_list: D000890:Anti-Infective Agents; C091741:CEMA protein, recombinant; D002352:Carrier Proteins; D016207:Cytokines; D007166:Immunosuppressive Agents; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D011994:Recombinant Proteins