Immature dendritic cell-derived exosomes can mediate HIV-1 trans infection.

Immature dendritic cells (DCs) capture HIV type 1 (HIV-1) and can transmit captured virus particles to T cells. In this report, we show that HIV-1 particles captured by DCs can be transmitted to T cells by exocytosis without de novo infection. Captured HIV-1 particles were rapidly endocytosed to tetraspan protein (CD9, CD63)-positive endocytic compartments that were reminiscent of multivesicular endosomal bodies.

Cellular immune responses to helper-free HSV-1 amplicon particles encoding HIV-1 gp120 are enhanced by DNA priming.

A single inoculation of herpes simplex virus type-1 (HSV-1) amplicon vectors encoding human immunodeficiency virus type-1 gp120 (HSV:gp120) results in robust, specific immune responses to gp120. To explore further the utility of this novel vaccine delivery system, we examined the kinetics of the cellular immune response by tetramer staining, following a single intramuscular administration of HSV:gp120 particles, and found that it peaks at 9-28 days post-immunization, before declining to a stable memory response. We also examined the utility of prime-boost regimens using packaged amplicon particles and naked amplicon plasmid DNA (DNA:gp120).

Expression of human immunodeficiency virus type 1 gp120 from herpes simplex virus type 1-derived amplicons results in potent, specific, and durable cellular and humoral immune responses.

Herpes simplex virus type 1 (HSV-1) infects a wide range of cells, including dendritic cells. Consequently, HSV-1 vectors may be capable of eliciting strong immune responses to vectored antigens. To test this hypothesis, an HSV-1 amplicon plasmid encoding human immunodeficiency virus type 1 gp120 was constructed, and murine immune responses to helper virus-free amplicon preparations derived from this construct were evaluated.