Transcriptional Changes in CD8(+) T Cells During Antiretroviral Therapy Intensified With Raltegravir

Metabolic pathway activation distinguishes transcriptional signatures of CD8+ T cells from HIV-1 elite controllers

OBJECTIVE

Elite controllers, defined as persons maintaining undetectable levels of HIV-1 replication in the absence of antiretroviral therapy, represent living evidence that sustained, natural control of HIV-1 is possible, at least in relatively rare instances. Understanding the complex immunologic and virologic characteristics of these specific patients holds promise for inducing drug-free control of HIV-1 in broader populations of HIV-1 infected patients.

DESIGN

We used an unbiased transcriptional profiling approach to characterize CD8+ T cells, the strongest correlate of HIV-1 immune control identified thus far, in a large cohort of elite controllers (n = 51); highly active antiretrovial therapy (HAART)-treated patients (n = 32) and HIV-1 negative (n = 10) served as reference cohorts.

METHODS

We isolated mRNA from total CD8+ T cells isolated from peripheral blood mononuclear cell (PBMC) of each individual followed by microarray analysis of the transcriptional signatures.

RESULTS

We observed profound transcriptional differences [590 transcripts, false discovery rate (FDR)-adjusted P < 0.05] between elite controller and HAART-treated patients. Interestingly, metabolic and signalling pathways governed by mammalian target of rapamycin (mTOR) and eIF2, known for their key roles in regulating cellular growth, proliferation and metabolism, were among the top functions enriched in the differentially expressed genes, suggesting a therapeutically actionable target as a distinguishing feature of spontaneous HIV-1 immune control. A subsequent bootstrapping approach distinguished five different subgroups of elite controller, each characterized by distinct transcriptional signatures. However, despite this marked heterogeneity, differential regulation of mTOR and eIF2 signalling remained the dominant functional pathway in three of these elite controller subgroups.

CONCLUSION

These studies suggest that mTOR and eIF2 signalling may play a remarkably universal role for regulating CD8 T-cell function from elite controllers.

Transcriptome profiling of alphaherpesvirus-infected cells treated with the HIV-integrase inhibitor raltegravir reveals profound and specific alterations in host transcription

Anti-microbial compounds typically exert their action by directly interfering with one or more stages of the pathogen's life cycle. However, some compounds also have secondary effects on the host that aid in pathogen clearance. Raltegravir is a human immunodeficiency virus (HIV)-integrase inhibitor that has been shown to alter the host immune response to HIV in addition to its direct antiviral effect. Interestingly, raltegravir can also directly inhibit the replication of various herpesviruses. However, the host-targeted effects of this drug in the context of a herpesvirus infection have not been explored. Here, we used felid alphaherpesvirus 1 (FHV-1), a close relative of human alphaherpesvirus 1 (HHV-1) that similarly causes ocular herpes, to characterize the host-targeted effects of raltegravir on corneal epithelial cells during an alphaherpesvirus infection. Using RNA deep sequencing, we found that raltegravir specifically boosts the expression of anti-angiogenic factors and promotes metabolic homeostasis in FHV-1-infected cells. In contrast, few changes in host gene transcription were found in uninfected cells. Importantly, we were able to demonstrate that these effects were specific to raltegravir and independent of the direct-acting antiviral effect of the drug, since treatment with the DNA polymerase inhibitor phosphonoacetic acid did not induce these host-targeted effects. Taken together, these results indicate that raltegravir has profound and specific effects on the host transcription profile of herpesvirus-infected cells that may contribute to the overall antiviral activity of the drug and could provide therapeutic benefits in vivo. Furthermore, this study provides a framework for future efforts evaluating the host-targeted effects of anti-microbial compounds.