IFN-λ1-induced chemokines production by human PBMC and dose-relationship of IFN-λ1- induced chemokines by PBMC. Human PBMC were cultured for 72 h in the presence of recombinant IFN-λ1 and supernatants were examined for levels of IP-10, MIG and IL-8 using ELISA. The chemokines' response to LPS was also examined as a positive control. In SLE patients, IFN-λ1-stimulated PBMC displayed higher levels of chemokines IP-10 (a) and MIG (b) in comparison with positive control LPS. IFN-λ1 could induce more generation levels of chemokines IP-10 (a) and MIG (b) in SLE patients than normal controls, but the secretion levels of IL-8 were lower in SLE patients than normal controls (c). Meanwhile, in patients with SLE, IFN-λ1 induced less secretion of chemokine IL-8 than LPS, but it had the ability to stimulate more IL-8 production than medium (c). Then human PBMC were cultured over different IFN-λ1 concentrations for 72 h and supernatants were examined for IP-10 (d), MIG (e) and IL-8 (f) levels using ELISA. Both 10 ng/ml and 50 ng/ml IFN-λ1 had effects on the secretion of IP-10 (P = 0.033, 0.005) (d). IFN-λ1 displayed its effects at the three different concentration on MIG secretion with dose-dependent relation (P = 0.043, 0.016, 0.001) (e). Compared with other two concentration, 10 ng/ml IFN-λ1 had the most obvious effect in the secretion of IL-8 (P = 0.008) (f). *, P < 0.05, **, P < 0.01. means ± s.d. are shown. ELISA, enzyme-linked immunosorbent assay; LPS, lipopolysaccharide; IFNλ1, interferon λ1; IL-8, interleukin-8; IP-10, IFN-inducible protein-10; MIG, monokine induced by interferon-γ; NC, normal control; PBMC, peripheral blood mononuclear cells; SLE, systemic lupus erythematosus.