The authors do so by demonstrating differences in Blimp-1 expression between T lymphocytes isolated from patients with chronic active HIV versus those from long-term nonprogressors and showing that this is matched by differences in the cells’ capacity to produce IL-2 and the level of expression of the inhibitory receptor PD-1.

The data presented here suggest that this may relate to differential regulation of Blimp-1 by the micro RNA, mIR-9. These findings complement current murine work and fit squarely within the research priorities, as outlined by the International AIDS Society, for determining a cure for AIDS. The International AIDS Society Scientific Working Group on HIV Cure promoted seven key research goals, including the need to ‘determine host mechanisms that control HIV replication in check details the absence of therapy’ [1]. This research goal hinges on the fact that HIV infection affects humans in a heterogeneous manner. In most individuals, primary inoculation

is followed by rapid viral replication leading to a high viral load, measured as levels of virus detectable in the blood. Following the development of the adaptive immune response the viral load decreases. In the majority of individuals, in the absence of therapy, this is followed by a finite period, termed asymptomatic HIV infection, during which the viral load remains detectable and is accompanied by a steady decrease in the CD4+ T-cell numbers of the host. The CD4+ cell count shows Racecadotril an inexorable fall and eventually crosses a critical threshold beyond which the patient suffers the clinical features of defective cell-mediated immunity, BGB324 order culminating in AIDS. For certain individuals, this usual disease progression differs favorably. In those termed long-term nonprogressors (LNTPs), following primary infection the viral load is unusually reduced and

the loss of CD4+ T cells occurs at a vastly diminished rate. These individuals, although initially thought to show no disease progression, are in fact now known to be at risk of disease progression although developing with greatly reduced kinetics [2]. The recommendation from the International AIDS society is, therefore, that we seek to understand how HIV replication is controlled in this patient group in order to reach an understanding of how to modulate immunity to better control HIV infection for all patients. The host control of viral infection depends on the T-cell adaptive immune response and this response differs between those with progressive chronic HIV infection (CHI) and termed long-term nonprogressors. The T cells from individuals with CHI have significantly fewer polyfunctional T cells (i.e. T cells that secrete multiple cytokines), and these cells express higher numbers and levels of inhibitory receptors such as PD-1 and CTLA-4 [3]. This T-cell phenotype of expression of inhibitory receptors and diminished ability to secrete cytokines has been termed T-cell ‘exhaustion’.