Antigen-presenting cells activated by aluminum hydroxide

Antigen-presenting cells (APCs) activated by aluminum hydroxide represent a specific cellular state essential for the efficacy of many human vaccines. Aluminum hydroxide, commonly referred to as alum, is the most widely used vaccine adjuvant and functions by enhancing the body's immune response to co-administered antigens (Marrack et al., 2009, Nature Reviews Immunology). When injected, alum forms a local depot that facilitates the recruitment and uptake of antigens by APCs, such as dendritic cells and macrophages. Inside these cells, alum particles cause lysosomal destabilization and cellular stress, which triggers the activation of the NLRP3 inflammasome (Eisenbarth et al., 2008, Nature). This activation leads to the maturation of the APCs and the secretion of pro-inflammatory cytokines like IL-1β and IL-18, which are critical for priming T-helper 2 (Th2) cell responses and subsequent B-cell antibody production. While highly effective for inducing humoral immunity, this entity is a complex cellular population rather than a single molecular target, and its activation is a multifaceted process involving various intracellular signaling pathways (Kool et al., 2008, JEM).

Other names

Alum-activated APCsAlum-stimulated antigen-presenting cellsAlum-primed dendritic cellsAlum-activated macrophages

Aluminum hydroxide acts as an adjuvant by creating a depot effect for antigens, promoting the recruitment of immune cells, and triggering the NLRP3 inflammasome within antigen-presenting cells to induce pro-inflammatory cytokine release (e.g., IL-1β) and enhance adaptive immunity.