Defensin-related peptide 1 (Defr1) is allelic to Defb8 and chemoattracts immature DC and CD4+ T cells independently of CCR6.
Beta-defensins comprise a family of cationic, antimicrobial and chemoattractant peptides. The six cysteine canonical motif is retained throughout evolution and the disulphide connectivities stabilise the conserved monomer structure. A murine beta-defensin gene (Defr1) present in the main defensin cluster of C57B1/6 mice, encodes a peptide with only five of the canonical six cysteine residues. In other inbred strains of mice, the allele encodes Defb8, which has the six cysteine motif. We show here that in common with six cysteine beta-defensins, defensin-related peptide 1 (Defr1) displays chemoattractant activity for CD4(+) T cells and immature DC (iDC), but not mature DC cells or neutrophils. Murine Defb2 replicates this pattern of attraction. Defb8 is also able to attract iDC but not mature DC. Synthetic analogues of Defr1 with the six cysteines restored (Defr1 Y5C) or with only a single cysteine (Defr1-1c(V)) chemoattract CD4(+) T cells with reduced activity, but do not chemoattract DC. Beta-defensins have previously been shown to attract iDC through CC receptor 6 (CCR6) but neither Defr1 or its related peptides nor Defb8, chemoattract cells overexpressing CCR6. Thus, we demonstrate that the canonical six cysteines of beta-defensins are not required for the chemoattractant activity of Defr1 and that neither Defr1 nor the six cysteine polymorphic variant allele Defb8, act through CCR6.
Taylor
Karen
K
MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine Western General Hospital, Edinburgh, Scotland, UK.
Rolfe
Mark
M
Reynolds
Natalie
N
Kilanowski
Fiona
F
Pathania
Uday
U
Clarke
Dave
D
Yang
De
D
Oppenheim
Joost
J
Samuel
Kay
K
Howie
Sarah
S
Barran
Perdita
P
Macmillan
Derek
D
Campopiano
Dominic
D
Dorin
Julia
J
D000483:Alleles; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002633:Chemotaxis / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D054399:Receptors, CCR6 / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023083:beta-Defensins / Q000235:genetics / Q000276:immunology*
C498126:CCR6 protein, mouse; C446439:Defb8 protein, mouse; C472072:Defr1 protein, mouse; D054399:Receptors, CCR6; D023083:beta-Defensins