The interaction of macrophage and non-macrophage tropic isolates of HIV-1 with thymic and tonsillar dendritic cells in vitro

Dendritic cells isolated from thymus and tonsil were tested for susceptibility to HIV-1 strains that are tropic for macrophages or for T cell lines. DCs were purified by cell sorting and before infection expressed high levels of CD4 and HLA-DR and lacked markers for T, B, NK cells, or macrophages. Viral entry and reverse transcription was found after pulsing with strains of HIV-1 that could infect macrophages. During the first 36 h the PCR signals for gag sequences increased in DCs and macrophages. In contrast little if any viral DNA was found after pulsing macrophages or DCs with HIV-1 that was able to infect T cell lines. DCs pulsed with HIV-1 were able to transmit infection to responding T cells during an allogeneic or superantigen response. Selection for virus able to infect lymphoid DCs and other DCs expressing CD4 and its transfer to T cells during subsequent immune responses may provide a mechanism for the observed predominance of macrophage-tropic HIV-1 after in vivo transmission

In vitro analysis of the TAT protein transduction domain as a drug delivery vehicle in protozoan parasites

The present study was undertaken to analyse the capability of HIV-1 derived TAT protein transduction domain (PTD) fused with Green Fluorescent Protein (TAT-GFP) as a delivery vehicle into a range of protozoan parasites. Successful transduction of native purified TAT-GFP was observed by fluorescent microscopy in Cryptosporidium parvum, Giardia duodenalis, and Neospora caninum. The ability to transduce peptides and other cargo into protozoan parasites, will greatly assist in the delivery of future peptide-based drugs and target validation peptides