Identification and Validation of New Interleukin-2 Ligands Using DNA-Encoded Libraries

Abstract

Interleukin-2 (IL2) is a pro-inflammatory cytokine that plays a crucial role in immunity, which is increasingly being used for therapeutic applications. There is growing interest in developing IL2-based therapeutics which do not interact with the alpha subunit of the IL2 receptor (CD25) as this protein is primarily found on immunosuppressive regulatory T cells (Tregs). Screenings of a new DNA-encoded library, comprising 669,240 members, provided a novel series of IL2 ligands, subsequently optimized by medicinal chemistry. One of these molecules (compound 18) bound to IL2 with a dissociation constant of 0.34 μM was able to form a kinetically stable complex with IL2 in size-exclusion chromatography and recognized the CD25-binding site as evidenced by competition experiments with the NARA1 antibody. Compound 18 and other members of the series may represent the starting point for the discovery of potent small-molecule modulators of IL2 activity, abrogating the binding to CD25.

Isolation of a Natural Killer Group 2D Small‐Molecule Ligand from DNA‐Encoded Chemical Libraries

“…Dissociation constant of the carboxylic acid 16 was determined via competitive fluorescence polarization [K D =(5±1) μM, Supporting Information Figure S24] by measuring the displacement of compound 17 in complex with hNKG2D (Supporting Information, section 8). A stable hNKG2D‐compound 17 complex was isolated by gel filtration using NAP5 columns (Figure 3d) [29] . The selectivity of compound 17 was assessed by repeating affinity measurements by fluorescence polarization against a panel of unrelated proteins, such as serum albumins (of mouse, bovine and human origin), hen egg lysozyme, as well as certain tumor associated antigens (fibroblast activation protein, mucin 16, extra domain A of fibronectin, extra domain B of fibronectin and human tenascin C), immuno‐modulators [CD16, Natural cytotoxicity triggering receptor 1 (NKp46), 41bb, L19‐interleukin‐12, L19‐interferon gamma, tumor necrosis factor receptor 1 (TNF‐R1), interleukin‐15, tumor necrosis factor (TNF)] and immunoglobulins (bF8‐IL9, F8‐IgG).…”

Discovery of TIGIT inhibitors based on DEL and machine learning

“…To our knowledge, the number of small-molecule inhibitors identified by DEL screening of PPI targets in the past decade is relatively few, mainly including LFA-1, TEAD, Bcl-xL, and IL-2. ( Buller et al, 2009 ; Kollmann et al, 2014 ; Kunig et al, 2020 ; Gironda-Martínez et al, 2021 ; Wang et al, 2022 ). On the other hand, the PPI targets is much challenging for DEL screening, due to the lack of information on existing scaffolds from other sources.…”

On-DNA Synthesis of Multisubstituted Indoles

“…Since its inception 3 decades ago, the pool of DNA-compatible chemical transformations has been significantly extended, facilitating the on-DNA synthesis of numerous heterocycles. − The indole scaffold is a privileged structure as a result of its appearance in many natural products, synthetic ligands, and drugs. − On the basis of the substitutional pattern of U.S. Food and Drug Administration (FDA)-approved drugs, synthetic options for functionalization at the second and third positions are preferred . Lately, a handful of on-DNA methods were reported for the selenylation, sulfenylation, and sulfonylation of indoles at the second and third positions. − Also, multistep condensation with aldehydes and indole–styrene couplings or cross-dehydrogenative couplings at the second and third positions may lead to alkylated derivatives. − Despite the growing interest in indole-containing DELs, no method for on-DNA indole synthesis has been reported thus far. − …”

“… 14 − 17 Despite the growing interest in indole-containing DELs, no method for on-DNA indole synthesis has been reported thus far. 18 − 20 …”