title: Synthetic Toll like receptor-4 (TLR-4) agonist peptides as a novel class of adjuvants.
abstract: BACKGROUND
  Adjuvants serve as catalysts of the innate immune response by initiating a localized site of inflammation that is mitigated by the interactions between antigens and toll like receptor (TLR) proteins. Currently, the majority of vaccines are formulated with aluminum based adjuvants, which are associated with various side effects. In an effort to develop a new class of adjuvants, agonists of TLR proteins, such as bacterial products, would be natural candidates. Lipopolysaccharide (LPS), a major structural component of gram negative bacteria cell walls, induces the systemic inflammation observed in septic shock by interacting with TLR-4. The use of synthetic peptides of LPS or TLR-4 agonists, which mimic the interaction between TLR-4 and LPS, can potentially regulate cellular signal transduction pathways such that a localized inflammatory response is achieved similar to that generated by adjuvants.
  
  
  RESULTS
  We report the identification and activity of several peptides isolated using phage display combinatorial peptide technology, which functionally mimicked LPS. The activity of the LPS-TLR-4 interaction was assessed by NF-κB nuclear translocation analyses in HEK-BLUE™-4 cells, a cell culture model that expresses only TLR-4, and the murine macrophage cell line, RAW264.7. Furthermore, the LPS peptide mimics were capable of inducing inflammatory cytokine secretion from RAW264.7 cells. Lastly, ELISA analysis of serum from vaccinated BALB/c mice revealed that the LPS peptide mimics act as a functional adjuvant.
  
  
  CONCLUSIONS
  Our data demonstrate the identification of synthetic peptides that mimic LPS by interacting with TLR-4. This LPS mimotope-TLR-4 interaction will allow for the development and use of these peptides as a new class of adjuvants, namely TLR-4 agonists.
authors.affiliation: Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, United States of America.
authors.forename: Arulkumaran
authors.initials: A
authors.lastname: Shanmugam
authors.forename: Shilpi
authors.initials: S
authors.lastname: Rajoria
authors.forename: Andrea L
authors.initials: AL
authors.lastname: George
authors.forename: Abraham
authors.initials: A
authors.lastname: Mittelman
authors.forename: Robert
authors.initials: R
authors.lastname: Suriano
authors.forename: Raj K
authors.initials: RK
authors.lastname: Tiwari
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D021381:Protein Transport / Q000187:drug effects; D051197:Toll-Like Receptor 4 / Q000819:agonists* / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D016328:NF-kappa B; D010455:Peptides; D051197:Toll-Like Receptor 4