LAUSR

Agents that safely induce, enhance, or sustain multiple innate immune signaling pathways could be developed as potent vaccine adjuvants or co-adjuvants. Using high-throughput screens with cell-based nuclear factor kappa B (NF-κB) and interferon stimulating response element (ISRE) reporter assays, we identified a bis-aryl sulfonamide bearing compound 1 that demonstrated sustained NF-κB and ISRE activation after a primary stimulus with lipopolysaccharide or interferon-α, respectively. Here, we present systematic structure-activity relationship (SAR) studies on the two phenyl rings and amide nitrogen of the sulfonamide group of compound 1 focused towards identification of affinity probes. The murine vaccination studies showed that compounds 1 and 33 when used as co-adjuvants with monophosphoryl lipid A (MPLA) showed significant enhancement in antigen ovalbumin-specific immunoglobulin responses compared to MPLA alone. SAR studies pointed to the sites on the scaffold that can tolerate the introduction of aryl azide, biotin and fluorescent rhodamine substituents to obtain several affinity and photoaffinity probes which will be utilized in concert for future target identification and mechanism of action studies.