Figure 1.

hBD3 down-regulates cytokine production in response to the TLR4 agonist LPS in human and mouse Mφ. (A) THP-1 monocyte cell line, (B) human monocyte-derived Mφ, (C and D) RAW264.7 mouse Mφ cell line and (E) BMDM from CBA mice were exposed to β-defensin or control peptides at 5 μg/mL, in the presence or absence of LPS for 18 h in serum-free media. TNF-α (or IL-6) in the supernatant was measured by ELISA, n=6 donors for the human primary cells, n=3 THP-1, n=3 RAW264.7 and n=3 mouse BMDM (from three separate mice). Figure shows means±SEM, significance assessed by two-way ANOVA, ^***p<0.001, ^**p<0.01 was calculated by comparing LPS plus peptide to LPS alone. (F) TNF-α levels in supernatant in BMDM from different mouse strains, treated with hBD3 or LL37 at indicated concentrations, with and without LPS for 18 h, n=3. Statistical comparisons are between LPS alone versus LPS with peptide in each strain, ^***p<0.001, ^**p<0.01, ^*p<0.05.