An engineered non-toxic superantigen increases cross presentation of hepatitis B virus nucleocapsids by human dendritic cells.

Virus like particles (VLPs) are potent immunogens capable of priming strong protective antibody responses due to their repetitive structural arrangement and affinity for specific B cell receptors. By contrast, T cell responses to VLPs can be weak due to inefficient uptake and processing by antigen presenting cells. We report here a novel strategy for increasing the T cell reactivity of a VLP, the nucleocapsid of hepatitis B virus, through covalent coupling of M1, an engineered form of the Streptococcal superantigen SMEZ2, that binds MHC II with high affinity but lacks its T cell mitogenic capability.

Rotavirus NSP4 Triggers Secretion of Proinflammatory Cytokines from Macrophages via Toll-Like Receptor 2.

Nonstructural protein 4 (NSP4), encoded by rotavirus, exhibits various properties linked to viral pathogenesis, including enterotoxic activity. A recent study (O. V.

Targeting antigen to MHC class II molecules promotes efficient cross-presentation and enhances immunotherapy.

An efficient pathway of cross-presentation common to a range of dendritic cell (DC) populations was identified by targeting Ag to MHC class II molecules. This finding was achieved by conjugating Ag to M1, which is a modified version of the superantigen streptococcal mitogenic exotoxin Z-2 that binds to MHC class II molecules but cannot directly stimulate T cells. M1 conjugates were efficiently presented to CD4(+) and CD8(+) T cells by bone marrow-derived DC and Langerhans cells in vitro.