Vaccination with Antigen Combined with αβ-ATP as a Vaccine Adjuvant Enhances Antigen-Specific Antibody Production via Dendritic Cell Activation.

Abstract

Adjuvants are required to enhance antigen-specific immune responses by vaccines. Extracellular ATP serves as a danger signal to alert the immune system of tissue damage by acting on P2X and P2Y receptors and triggers the activation of dendritic cells (DCs). Here we investigated the in vivo adjuvant efficacy of α,β-methylene-ATP (αβ-ATP), a non-hydrolysable form of ATP. We found that intradermal injection of ovalbumin (OVA), as a model antigen, combined with αβ-ATP, as the adjuvant, enhanced OVA-specific immune responses more than OVA alone. Additionally, DCs in the skin of mice injected with OVA and αβ-ATP had increased expression of major histocompatibility complex class II and co-stimulator molecules, CD40, CD80, and CD86, suggesting that αβ-ATP activated DC. These findings indicate that αβ-ATP functions as a potent vaccine adjuvant.