Fig 6.

Circulating CXCL9 and CXCL10 production correlate with IFNγ tissue activity in the model of TLR9-induced sHLH. (A, B) Mice (n = 7 mice per time-point) were injected with 50 μg of CpG-ODN on days 0, 2, 4, and 7 (gray filled triangles) and administered 100 mg/kg of the anti-IFNγ mAb, XMG1.2 (dotted line) or an isotype control mAb (solid line) at days 1, 3, and 6 (A and B, upper panels; black filled triangles) or at days 4 and 6 (A and B, lower panels; black filled triangles). mRNA quantification of cytokines from livers was obtained by qPCR, and serum concentrations of CXCL9 and CXCL10 were quantified in a multiplex assay using the Luminex technology. The samples from day 0 were collected before the CpG-ODN injection, whereas samples from day 4 and day 7 were collected 6 hours after CpG-ODN injection. Samples from the day of a mAb injection were collected before the injection. Values are the mean ± standard error of the mean. Data are representative of 2 experiments. Statistics were performed to compare the values at each time point between isotype control and XMG1.2-treated groups. ^∗P < 0.05, ^∗∗P < 0.01, ^∗∗∗P < 0.001, and ****P < 0.0001 were obtained using the 1-tailed nonparametric Mann–Whitney U t test. (C) Mice were injected with 50 μg of CpG-ODN at days 0, 2, 4, 7, and 9. Serum levels of IFNγ, CXCL9, and CXCL10 were quantified in a multiplex assay using the Luminex technology. Correlations were performed between CXCL9 and IFNγ or CXCL10 and IFNγ levels at different time point as HLH develops (depicted in Fig 1). Statistics were performed and P values were obtained using the Spearman test. The line of best fit was generated using the nonlinear regression analysis using GrapPad Prism software. IFNγ, interferon γ; mRNA, messenger RNA; qPCR, quantitative PCR; sHLH, secondary hemophagocytic lymphohistiocytosis; TLR9, Toll-like receptor 9.