BT PHARMA’s PepTel® vector system consists of 2500 kDalton particles to which up to a 100 peptides can be covalently coupled via a hetero-bifunctional linker. The carrier consists of intact 70S E.coli ribosomes purified on pilot scale (100 liter Fermentor) and to crystallographic purity.

Bacterial ribosomes have been shown to be recognized by peripheral and mucosal B cells. Experiments have shown that preparations carrying similar particles are selected by lymphoid epithelial M-like cells, which transport the particles by endocytosis to the sub-epithelial space, where antigen presenting cells such as macrophages and dendritic cells can recruit and process the antigen.

BT PHARMA’s PepTel® vector exerts a non-specific immuno-stimulatory effect associated with its ability to strongly induce interferon-gamma by cells in contact with PepTel®. This is likely due to the presence of double-stranded RNA in the intact ribosomes that has been shown to lead to maturation and activation of dendritic cells responsible for professional antigen presentation to T lymphocytes.

As most peptides can be coupled to PepTel® via a universal 15 Å bi-functional linker, this particulate vector system is suited for targeting peptides to antigen-recruiting cells in the mucosa of respiratory, gastro-intestinal and uro-genital tracts. Two patent families protect PepTel®.