FIG 1.

(A) (Top) Schematic representation of fractionation of yeast strain S. cerevisiae JC7. Cell lysis followed by differential centrifugation generated SN, a suspension of yeast microsomes. Phenol extraction of SN removed lipids and proteins and resulted in a nucleic acid solution (NA). (Bottom) Next, NA was fractionated by electrophoresis in a native 1% agarose gel. The first and second bands were isolated from the gel and digested in the presence of high-dose RNase A (50 ng/μl). NAB1 was RNase A resistant, while NAB2 and the lower-molecular-mass molecules appearing as smears were digested. Arrow, NAB2; asterisk, lower-molecular-mass molecules. (B) NA, NAB1, and NAB2 were treated with RNase A or not and tested on the HEK-hTLR3-luc cell lines. NAB2, like NA, increased the fold induction of luciferase activity. NAB1 had no effect. Treatment with RNase A abolished TLR3 activation by NA and NAB2. The means ± SEMs of two independent experiments are shown.