IAb-restricted PADRE

Pan DR-binding epitope (PADRE) is a universal synthetic peptide binding Major Histocompatibility Complex (MHC)-II receptors, of which H2 complex (mouse MHC), present on specific immune cells. 4 class II loci exist in the region I of the H2 complex gene, known as Aa & Ea loci (α encoded) and Ab & Eb loci (β encoded), that are similar to the DR, DP and DQ loci of the Human Leukocyte Antigen (HLA) complex. I-Ab restricted PADRE peptide interacts specifically with mouse H2-I-Ab receptors that activate antigen specific CD4+ T-cells in the same way as PADRE peptide’s interaction with HLA-DR receptors. This feature places I-Ab restricted PADRE as promising adjuvant for immunotherapeutic vaccines against chronicle diseases such as infections, Alzheimer or cancer. Similarly to the original PADRE peptide, the restricted version also acts as a Toll-like receptor (TLR) agonist and was described as alternative carrier, such as KLH/BSA or OVA, for prophylaxis and therapeutic vaccines. An aminocaproic acid (Ahx) linker, attached to an additional C-terminal Cysteine, was added to the sequence to allow both the peptide and its loading to interact independently and freely with molecules exposed to them. This modification is used for the loading of antigenic determinants in solution in order to enhance the immune response against a specific antigen (AG).