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Efavirenz (EFV) is one of the preferred components of first-line antiretroviral treatment. EFV is characterized by a long plasma half-life (40–55 hours) with large interpatient variability, which raises the potential for individualization of therapy. Analyses of EFV levels in plasma require specialized facilities (cold storagetransport) which, in resource-limited settings, can be problematic; dried blood spots (DBS)-EFV measurements thus provide a cheap easy alternative for therapeutic drug monitoring. Our aim was to develop and validate a liquid chromatography–mass spectrometry method to quantify EFV in DBS collected as part of clinical trials in resource-limited settings.

NCHECR is funded by the Australian Government Department of Health & Ageing and is affiliated with the Faculty of Medicine, The University of New South Wales. The vaccines were designed with the assistance of NIH-NIAID-DAIDS HVDDT Award N01-AI-05395. The authors would like to thank Wadchara Pumpradit for his assistance in the preparation and initial drafting of trial protocols and regulatory documents. We also wish to thank members of the Australia Thai HIV Vaccine Consortium including the CSIRO, Australian National University, University of Melbourne, Australian Federation of AIDS Organisations, National Centre in HIV Social Research, University of New South Wales for the design and manufacture of vaccines and assistance with study protocol drafting and initiation. We would like to acknowledge Ormrudee Rit-im, Wendy Lee, Noorul Absar, Charles Tran, Pitch Boonrak and Ekkasit Thodsanit for database and statistical assistance, Nounpen Sangthong, Narumon Subsri, Kanitta Pussadee and Peeraporn Keaw-on for clinical care, Parinya Sutheerasak for pharmacy expertise and Meeling Munier, Kate Merlin, Supranee Buranapraditkun, Pornsupa Chatkulkawin for their laboratory input. Salaries for those working in the Vaccine and Cellular Immunology Laboratory were kindly supported in part by grants from the National Center for Genetic Engineering and Biotechnology, Thailand.

Although effective in reducing mortality, current antiretroviral therapy for HIV infection involves complex and expensive drug regimens that are toxic and difficult to take. Eradication of HIV reservoirs is not possible with existing therapies. The concept of therapeutic vaccination has been investigated to increase the potency and breadth of anti-HIV immune responses in order to delay or reduce antiretroviral therapy use. A variety of approaches targeted to both cell- and antibody-mediated immunity have been developed, including whole inactivated HIV-1, protein subunits and synthetic peptides, DNA vaccines and a number of viral vectors expressing HIV-1. These investigations have occurred in the absence of a clear understanding of disease pathogenesis or the correlates of protective immunity. At this time, there is no licensed therapeutic vaccine for any viral disease, including HIV; however, this review will consider recent progress in the field and summarize the challenges faced in the development of a therapeutic HIV vaccine.

Interleukin 12 (IL-12) production is believed to be impaired in individuals with HIV infection and this impairment manifests early in disease, when the CD4+ cell counts are within normal values. The reduced antigen-specific and mitogen-stimulated T cell-proliferative responses that occur in HIV infection can be corrected by the addition of recombinant human interleukin 12 (rhIL-12). As the IL-12 receptor (IL-12R) is central to the IL-12 signaling pathway, we examined whether the augmentation of antigen-specific proliferation of HIV+ peripheral blood mononuclear cells (PBMCs) related to altered IL-12R expression. rhIL-12 augmented antigen-specific proliferation of HIV+ PBMCs but not of HIV- PBMCs. Examination of resting PBMCs from HIV+ and HIV- donors showed that neither of these populations expressed IL-12Rβ1 or IL-12Rβ2 chains on their cell surface as detected by flow cytometry. However, examination of mRNA showed that both IL-12Rβ1 and IL-12Rβ2 mRNAs were markedly reduced in HIV+ PBMCs when compared with HIV- PBMCs. After mitogen activation there was an increase in IL-12Rβ1 expression on the cell surface of HIV+ and HIV- PBMCs and this level was not altered by coculture with rhIL-12 or interferon γ (IFN-γ). However, coculture of phytohemagglutinin (PHA)-activated HIV+ or HIV- PBMCs with rhIL-12 (but not IFN-γ) increased IL-12Rβ2 expression on the cell surface of both populations. Examination at the message level showed a correction of IL-12Rβ1 to normal levels with activation that was further enhanced by rhIL-12 coculture for both the HIV+ and HIV- PBMCs. However, although the level of IL-12Rβ2 for the HIV+ PBMCs was normalized by PHA, rhIL-12 caused a further augmentation. This information provides a strong link between IL-12R upregulation, and the significant improvement in antigen-specific HIV-proliferative responses seen with the addition of rhIL-12. It also reveals that the dysfunction in IL-12R expression seen in cells from HIV+ patients occurs at the transcriptional level. In addition, we provide further evidence that IL-12Rβ1 and IL-12Rβ2 regulation in human PBMCs is independent of IFN-γ.