Purification of carboxymethylcellulose decreases toxicity of poly ICLC in mice

The interferon inducer poly ICLC has toxic side effects; the carboxymethylcellulose (CMC) component is a possible source of this toxicity. We have purified CMC by ethanol extraction, and found that poly ICLC made with purified CMC is not significantly different in its effectiveness as an interferon inducer in mice than poly ICLC made with unpurified CMC, but is less toxic.