SUMMARY HIV cure efforts are hampered by limited characterization of the cells supporting HIV replication in vivo and inadequate methods for quantifying the latent viral reservoir in patients receiving antiretroviral therapy. We combine fluorescent in situ RNA hybridization with detection of HIV protein and flow cytometry, enabling detection of 0.5–1 gag-pol mRNA+/Gag protein+ infected cells per million. In the peripheral blood of untreated persons, active HIV replication correlated with viremia, and occurred in CD4 T cells expressing T follicular helper cell markers and inhibitory co-receptors. In virally-suppressed subjects, the approach identified latently infected cells capable of producing HIV mRNA and protein after stimulation with PMA/ionomycin and latency-reversing agents (LRAs). While ingenol-induced reactivation mirrored the effector and central/transitional memory CD4 T cell contribution to the pool of integrated HIV DNA, bryostatin-induced reactivation occurred predominantly in cells expressing effector memory markers. This indicates that CD4 T cell differentiation status differentially affects LRA effectiveness.

Purpose: CD73 is an adenosine-generating ecto-enzyme that suppresses antitumor immunity in mouse models of cancer, including prostate cancer. Although high levels of CD73 are associated with poor prognosis in various types of cancer, the clinical impact of CD73 in prostate cancer remains unclear.Experimental Design: We evaluated the prognostic value of CD73 protein expression and CD8 þ cell density in 285 cases of prostate cancer on tissue microarray (TMA). Normal adjacent and tumor tissues were evaluated in duplicates.Results: Univariate and multivariate analyses revealed that high levels of CD73 in normal adjacent prostate epithelium were significantly associated with shorter biochemical recurrence (BCR)-free survival. Notably, CD73 expression in normal epithelium conferred a negative prognostic value to prostate-infiltrating CD8 þ cells. Surprisingly, high levels of CD73 in the tumor stroma were associated with longer BCR-free survival in univariate analysis. In vitro studies revealed that adenosine signaling inhibited NF-kB activity in human prostate cancer cells via A2B adenosine receptors. Consistent with these results, CD73 expression in the prostate tumor stroma negatively correlated with p65 expression in the nuclei of prostate tumor cells. Conclusions: Our study revealed that CD73 is an independent prognostic factor in prostate cancer. Our data support a model in which CD73 expression in the prostate epithelium suppresses immunosurveillance by CD8 þ T cells, whereas CD73 expression in the tumor stroma reduces NF-kB signaling in tumor cells via A2B adenosine receptor signaling. CD73 expression, including in normal adjacent prostate epithelium, can thus effectively discriminate between aggressive and indolent forms of prostate cancer.

Dysfunction of virus-specific CD4 + T cells in chronic human infections is poorly understood. We performed genome-wide transcriptional analyses and functional assays of CD4 + T cells specific for human immunodeficiency virus (HIV) from HIV-infected people prior and after initiation of antiretroviral therapy (ART). A follicular helper T cell (T FH cell)–like profile characterized HIV-specific CD4 + T cells in viraemic infection. HIV-specific CD4 + T cells from people spontaneously controlling the virus (elite controllers) robustly expressed genes associated with the T H 1, T H 17 and T H 22 subsets of helper T cells. Viral suppression by ART resulted in a distinct transcriptional landscape, with a reduction in the expression of genes associated with T FH cells but persistently low expression of genes associated with T H 1, T H 17 and T H 22 cells compared to the elite controller profile. Thus, altered differentiation is central to the impairment of HIV-specific CD4 + T cells and involves both gain of function and loss of function.

Recent analysis of HIV-1 envelope glycoproteins (Env) dynamics showed that the unliganded Env trimer can potentially sample three conformations: a metastable "closed" conformation (State 1), an "open" CD4-bound conformation (State 3), and an intermediate "partially open" conformation (State 2). HIV-1 evolved several mechanisms to avoid "opening" its Env in order to evade immune responses such as antibody-dependent cellular cytotoxicity (ADCC), which preferentially targets Envs in the CD4-bound conformation on the surface of infected cells. Here we took advantage of a well-characterized single-residue change in the gp120 trimer association domain to modify Env conformation and evaluate its impact on ADCC responses. We found that cells infected with viruses expressing Env stabilized in States 2/3 become highly susceptible to ADCC responses by sera from HIV-1-infected individuals. Our results indicate that the conformations spontaneously sampled by the Env trimer at the surface of infected cells has a significant impact on ADCC responses.