An insect antibacterial peptide-based drug delivery system.
The ability of the short, proline-rich native antibacterial peptides to penetrate bacterial and host cells suggests the utility of these transport systems in delivering peptidic cargo into cells. We studied the uptake of pyrrhocoricin and its most potent dimeric analogue by bacteria as well as human dendritic cells and fibroblasts. Native pyrrhocoricin entered the susceptible organism Escherichia coli very efficiently and the nonsusceptible bacterium Staphylococcus aureus to a significant degree. The antibacterial peptide also penetrated human monocyte-derived dendritic cells. It failed, however, to enter fibroblasts, whereas the designer analogue Pip-pyrr-MeArg dimer penetrated all the cell types that were studied. When glucoincretin hormone Glp-1 fragment 7-36 was cosynthesized with the dimer, the antibacterial peptide derivative lost its ability to cross the bacterial membrane layer. In contrast, a chimera of the Pip-pyrr-MeArg dimer and two copies of a shorter (nine residues) class I major histocompatibility complex epitope successfully entered bacterial and mammalian cells. While the Pip-pyrr-MeArg dimer was not immunogenic when inoculated into mice, the chimera elicited a strong cytotoxic T-cell response, indicating the maintenance of the antigenic integrity of the cargo in the peptide conjugate. The chimera when tested for its immunological properties activated human dendritic cells significantly more strongly than any of the two independent fragments alone, yet lacked mammalian cell toxicity. These results confirm the utility of designed pyrrhocoricin analogues for delivery of peptidic cargo across cell membranes in general, and their potential as carriers for epitope-based vaccines in particular.
Otvos
Laszlo
L
The Wistar Institute, Philadelphia, Pennsylvania 19104, USA. Otvos@wistar.upenn.edu
Cudic
Mare
M
Chua
Brendon Y
BY
Deliyannis
Georgia
G
Jackson
David C
DC
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003713:Dendritic Cells / Q000187:drug effects; D019281:Dimerization; D016503:Drug Delivery Systems; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts; D006801:Humans; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000378:metabolism
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D019476:Insect Proteins; D010446:Peptide Fragments; C087710:pyrrhocoricin protein, Pyrrhocoris apterus