DC immunotherapy in HIV-1 infection induces a major blood transcriptome shift

Abstract

ObjectiveThis study aimed to evaluate the effect of dendritic cell (DC) vaccination against HIV-1 on host gene expression profiles. DesignLongitudinal PBMC samples were collected from participants of the DC-TRN trial for immunotherapy against HIV. Microarray-assisted gene expression profiling was performed to evaluate the effects of vaccination and subsequent interruption of antiretroviral therapy on host genome expression. Data from the DC-TRN trial were compared with results from other vaccination trials. MethodsWe used Affymetrix GeneChips for microarray gene expression analysis. Data were analyzed by principal component analysis and differential gene expression was assessed using linear modeling. Gene ontology enrichment and gene set analysis were used to characterize differentially expressed genes. Transcriptome analysis included comparison with PBMCs obtained from DC-vaccinated melanoma patients and of healthy individuals who received seasonal influenza vaccination. ResultsDC-TRN immunotherapy in HIV-infected individuals resulted in a major shift in the transcriptome. Longitudinal analysis demonstrated that changes in the transcriptome sustained also during interruption of antiretroviral therapy. After DC-vaccination, the transcriptome was enriched for cellular immunity associated genes that were also induced in healthy adults who received live attenuated influenza virus vaccination. These beneficial responses were accompanied by detrimental signals of general immune activation. ConclusionsThe DC-TRN induced changes in the transcriptome were profound, lasting, and consisted of both protective signals and signatures of inflammation and immune exhaustion, with a net result of decreased viral load, without clinical benefit. Thus transcriptome analysis provides useful information, dissecting both positive and negative effects, for the evaluation of safety and efficacy of immunotherapeutic strategies.