Journal Article

Application of a small molecule calcium influx inducer as a vaccine adjuvant: enhancing Th2-biased immune responses

Chan, Michael, Carson, Dennis A., Hayashi, Tomoko, Mclaughlin, Ian, Yao, Shiyin, Anguiano Quiroz, Paola, Cozza, Renna, Sako, Yukiya, Shukla, Nikunj M., Jin, Jasmine, Brown, Tyler, Gil, Fernando, Yokoyama, Yumi, Corr, Maripat

2026

Overview

Vaccines are highly effective in preventing the spread of communicable diseases and are critical to overall public health. As immune stimulants vaccine adjuvants augment the level and longevity of these protective responses. Seeking novel adjuvants using parallel high throughput screens and subsequent systematic structure-activity relationship studies we identified an analogue of a hit compound, , that in screening assays retained induction of calcium (Ca ) influx, tetraspanin CD63 EV reporter activity and cell viability. Here, we further our analyses of the biological activity of related its potential use as a vaccine adjuvant. was tested for activation of murine bone marrow-derived dendritic cells (mBMDC) by flow cytometry for Ca entry, levels of CD80 and CD86 expression, and stimulation of antigen-specific T cell proliferation. Cytokines and IgG responses from BALB/c mice injected with as a single agent or as an adjuvant with ovalbumen were measured by ELISA. triggered store-operated Ca entry in mBMDC as well as increases in CD80 and CD86 surface expression. In co-culture experiments, this compound amplified the stimulation of cognate T cell proliferation. Intramuscular injection of elicited minimal systemic cytokine and chemokine release. When used as an adjuvant with ovalbumen, generated a significant antigen-specific IgG1 response with a higher splenocyte T helper 2 (Th2) cytokine response. activated mBMDCs associated with EV release and a store-operated calcium entry response. Enhanced cognate T cell proliferation was mediated either through direct engagement with compound-stimulated mBMDCs or indirectly via immunostimulatory extracellular vesicles released by -activated mBMDCs. elicited minimal systemic cytokine and chemokine release, demonstrating a promising safety profile. When used as an adjuvant in a murine vaccination model, enhanced the IgG1 response with an associated T helper 2 cytokine profile. Hence this compound shows promise as an adjuvant if a Th2 response is beneficial or in combination with other agents to provide a balanced immune response in vaccines.

• Publisher: Frontiers Media SA,Frontiers Media S.A
• Subject: adjuvant / Adjuvants / Adjuvants, Immunologic - pharmacology / Adjuvants, Vaccine - pharmacology / Animals / Antibodies / Antigens / Biological activity / Bone marrow / Ca2+ influx / Calcium - metabolism / Calcium influx / CD63 antigen / CD80 antigen / CD86 antigen / Cell culture / Cell proliferation / Cell viability / Chemokines / Cytokines / Cytokines - metabolism / dendritic cell / Dendritic cells / Dendritic Cells - drug effects / Dendritic Cells - immunology / Dendritic Cells - metabolism / Electrons / Enzyme-linked immunosorbent assay / extracellular vesicle / FDA approval / Female / Flow cytometry / Immune response / Immunity (Disease) / Immunoglobulin G / Immunostimulation / Laboratories / Lymphocyte Activation - drug effects / Lymphocytes / Lymphocytes T / Mice / Mice, Inbred BALB C / Original Research / Proteins / Public health / Reagents / Stimulants / T cell receptors / T helper 2 / Th2 Cells - drug effects / Th2 Cells - immunology / Th2 Cells - metabolism / Transmission electron microscopy / vaccine / Vaccines