title: [Studies on the core functional region of antimicrobial peptide LL-37 for inhibition of RSV replication].
abstract: OBJECTIVE
  To investigate the core functional region of antimicrobial peptide LL-37, which inhibites RSV replication and could be developed for theraputic aplication.
  
  
  METHODS
  A panel of 6 partial LL-37 peptides (referred to as P1 to P6) was synthesized according to LL-37 amino acide sequence. Hep-2 cells were infected with RSV, treated with LL-37 or partial peptides respectively. Cells were collected after 24 hours incubation at 37 degrees C, CO2 5%. Total RNA was obtained from the cells. Expression level of RSV N gene was quantified by real-time PCR. Meanwhile enzyme-linked immunosorbent assay (ELISA) was used to quantify the chemokines RANTES, IL-8, MCP1 in the supernatants of Hep-2 cultures after 24 h incubation with or without LL-37 and partial peptide P6.
  
  
  RESULTS
  N-terminal partial LL-37 peptide (corresponding to residues 1-12 of LL-37) had no significant effects on RSV replication (P > 0.05). In contrast, C-terminal (corresponding to residues 13-37) and a panel of 4 overlapping 22-mer partial peptides (from the peptide incorporating aa 13-34 through that spanning aa 16-37) showed significant inhibitory effect on RSV replication to some extent (P < 0.05 or P < 0.01). LL-37 induced significant expression of chemokine RANTES, IL-8 and MCP-1 in Hep-2 cells. In contrast, partial peptide P6 had no significant effect on expression of the chemokines in Hep-2 cells.
  
  
  CONCLUSIONS
  The LL-37 C-terminal 22-mer partial peptide P6 was putative core functional region for inhibition of RSV replication. The partial peptide didn't induce significant expression of chemokine RANTES, IL-8 and MCP-1.
authors.affiliation: Department of Respiratory Medicine, Affiliated Nanjing Children's Hospital of NJMU, Nanjing 210008, China.
authors.forename: Man
authors.initials: M
authors.lastname: Tian
authors.forename: De-Yu
authors.initials: DY
authors.lastname: Zhao
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Wang
mesh_terms: D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins / Q000494:pharmacology*; D002460:Cell Line; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D006801:Humans; D018357:Respiratory Syncytial Virus Infections / Q000235:genetics / Q000276:immunology / Q000821:virology*; D012136:Respiratory Syncytial Viruses / Q000187:drug effects* / Q000502:physiology; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D016207:Cytokines