Virosome-bound antigen enhances DC-dependent specific CD4+ T cell stimulation, inducing a Th1 and Treg profile in vitro

Virosomes and liposomes are spherical unilamellar structures comprised of phosphilipids. Virosomes additionally contain fractions from the influenza virus envelope, hemagglutinin (HA) and neuraminidase (NA). To study the interaction of such nanocarriers with dendritic cells (DCs), we fluorescently labeled and coupled them with ovalbumin (OVA). Murine bone marrow-derived dendritic cells (BMDCs) were treated with virosomes or liposomes prior to determining OVA-specific CD4+ T cell proliferation in an in vitro co-culture of BMDCs and T cells. BMDCs treated with OVA-coupled virosomes induced enhanced antigen-specific CD4+ T cell proliferation compared to treatment with empty virosomes and soluble OVA protein or OVA-coupled liposomes.158