Short amyloid-beta immunogens show strong immunogenicity and avoid stimulating pro-inflammatory pathways in bone marrow-derived dendritic cells from C57BL/6J mice in vitro.

Amyloid beta peptide 1-15 (Aβ1-15) and its derivatives have attracted the attention of the scientific community as candidate vaccines for Alzheimer's disease (AD) immunotherapy. Recent studies suggested that Aβ1-42 modulated the immune system by inducing pro-inflammatory dendritic cells (DCs) with reduced antigen-presenting function. However, it remains elusive how Aβ1-15 impacts DCs function. We therefore investigated the modulation by short Aβ peptides of DCs from C57Bl/6J mice. Two new immunogens, a tandem repeat of two-lysine-linked Aβ1-15 sequences with or without an addition of a RGD motif, were tested. Chemotaxis, endocytosis, antigen presenting function and producing cytokines were measured. Both peptides increased migration/endocytosis of immature DCs and MHC II molecule expression/alloreactive T cell activation in TNF-α-matured DCs. In addition, they exhibited decreased production of Th1/Th2 cytokines and pro-inflammatory cytokines. Overall, the two peptides demonstrated strong immunogenicity but did not stimulate pro-inflammatory pathways. These results support the use of short Aβ immunogens in AD immunotherapy.