Fig. 4.

NBS1 is dispensable for intracellular DNA-mediated type I IFN induction. (A) Schematic representation of the series of human MRE11 mutants and their proposed properties. (B and C) Immunoblot analysis of MRE11 (B) and qPCR analysis of mouse Ifnb1 (C) in MEFs stimulated with 1 μg⋅mL⁻¹ of ISD for 6 h. (D) Immunoblot analysis of NBS1 in GM7166 and complemented cells. (E) Immunofluorescence staining of MRE11 in GM7166 cells treated as in Fig. 3A and endogenous MRE11 was observed by immunofluorescence staining. Data are from one experiment representative of two. (F) qPCR analysis of human IFNB1 in GM7166 cells transfected with 1 μg⋅mL⁻¹ of ISD or poly (I:C) for 8 h. Results for mRNA are represented relative to those of control samples. Data are from three independent experiments in triplicate (mean and SD in C and F). *P < 0.05 and **P < 0.005 compared with controls.