Discovery of Self‐Assembling Small Molecules as Vaccine Adjuvants

Abstract

Immune potentiators,termed adjuvants,trigger early innate immune responses to ensure the generation of robust and long-lasting adaptive immune responses of vaccines. Presented here is as tudy that takes advantage of as elfassembling small-molecule library for the development of an ovel vaccine adjuvant. Cell-based screening of the library and subsequent structural optimization led to the discovery of as imple,c hemically tractable deoxycholate derivative (molecule 6,a lso named cholicamide) whose well-defined nanoassembly potently elicits innate immune responses in macrophages and dendritic cells.F unctional and mechanistic analyses indicate that the virus-like assembly enters the cells and stimulates the innate immune response through Toll-like receptor 7(TLR7), an endosomal TLR that detects singlestranded viral RNA. As an influenza vaccine adjuvant in mice, molecule 6 was as potent as Alum, ac linically used adjuvant. The studies described here pave the way for anew approachto discovering and designing self-assembling small-molecule adjuvants against pathogens,i ncluding emerging viruses.

Discovery of a phase-separating small molecule that selectively sequesters tubulin in cells

“…In order to search for phase-separating small molecules that specifically interact with cellular proteins, we exploited our previously reported chemical library of self-assembling small molecules. 20 Each of the compounds in our library form particles detectable by one of two environment-sensitive fluorescent probes, namely Nile Red and 8-anilinonaphthalene-1-sulfonic acid (ANS), in PBS buffer, and display a variety of particle morphologies such as micelle, fibers, crystals, and colloid aggregates. 20 Each of the library compounds (20 μM) was incubated with human cell lysates.…”

“…20 Each of the compounds in our library form particles detectable by one of two environment-sensitive fluorescent probes, namely Nile Red and 8-anilinonaphthalene-1-sulfonic acid (ANS), in PBS buffer, and display a variety of particle morphologies such as micelle, fibers, crystals, and colloid aggregates. 20 Each of the library compounds (20 μM) was incubated with human cell lysates. After this incubation period, the lysates were subjected to centrifugation (Fig.…”

“…The huezole assemblies were visualized by Nile Red (100 nM), a typical environment-sensitive fluorescent probe for molecular condensates. 20,21 R -huezole demixed in an aqueous solution and formed liquid-like spherical droplets, which can fuse with one another to generate larger spherical units in vitro (Fig. 3A).…”

Amino acid sequence determines the adjuvant potency of ad-tetra-peptide hydrogel

“…Proinflammatory cytokines, such as IFN-γ, IL-6 and TNF-α, play essential roles in shaping or mediating vaccine-induced protective immunity against viruses and tumors. [43][44][45][46][47] Therefore, we measured the production of these cytokines in the supernatant of ex vivo cultured splenocytes isolated from vaccine-immunized mice (Fig. 5a).…”

Self-assembling small-molecule adjuvants as antigen nano-carriers

“…We previously discovered a small molecule vaccine adjuvant, cholicamide (molecule 1 ), which self-assembles to form a nanoparticle approximately 150 nm in size and stimulates APCs through the activation of TLR7, an endosomal Toll-like receptor. 14 Activation of TLR7 has been demonstrated to induce highly potent humoral and cell-mediated immune responses. Taking advantage of the self-assembling property of cholicamide ( 1 ), we postulated that cholicamide ( 1 ), when covalently conjugated with peptides, serves simultaneously as a nano-carrier and an adjuvant for peptide antigens (Fig.…”