Nucleic acid (NA)-containing damage- and pathogen-associated molecular patterns (DAMPs and PAMPs, respectively) are implicated in numerous pathological conditions from infectious diseases to autoimmune disorders. Nucleic acid-binding polymers, including polyamidoamine (PAMAM) dendrimers, have demonstrated anti-inflammatory properties when administered to neutralize DAMPs/PAMPs. The PAMAM G3 variant has been shown to have beneficial effects in a cutaneous lupus erythematosus (CLE) murine model and improve survival of mice challenged with influenza. Unfortunately, the narrow therapeutic window of cationic PAMAM dendrimers makes their clinical development challenging. An alternative nucleic acid-binding polymer that has been evaluated in humans is a linear β-cyclodextrin-containing polymer (CDP). CDP's characteristics prompted us to evaluate its anti-inflammatory potential in CLE autoimmune and influenza infectious disease mouse models. We report that CDP effectively inhibits NA-containing DAMP-mediated activation of Toll-like receptors (TLRs) in cell culture, improves healing in lupus mice, and does not immunocompromise treated animals upon influenza infection but improves survival even when administered 3 days after infection. Finally, as anticipated, we observe limited toxicity in animals treated with CDP compared with PAMAM G3. Thus, CDP is a new anti-inflammatory agent that may be readily translated to the clinic to combat diseases associated with pathological NA-containing DAMPs/PAMPs.