Digoxin reveals a functional connection between HIV-1 integration preference and T-cell activation

Hiv-1 integrates more frequently into transcribed genes,however the biological significance of hiv-1 integration targeting has remained elusive. using a selective high-throughput chemical screen,we discovered that the cardiac glycoside digoxin inhibits wild-type hiv-1 infection more potently than hiv-1 bearing a single point mutation (n74d) in the capsid protein. we confirmed that digoxin repressed viral gene expression by targeting the cellular na+/k+atpase,but this did not explain its selectivity. parallel rnaseq and integration mapping in infected cells demonstrated that digoxin inhibited expression of genes involved in t-cell activation and cell metabolism. analysis of >400,000 unique integration sites showed that wt virus integrated more frequently than n74d mutant within or near genes susceptible to repression by digoxin and involved in t-cell activation and cell metabolism. two main gene networks down-regulated by the drug were cd40l and cd38. blocking cd40l by neutralizing antibodies selectively inhibited wt virus infection,phenocopying digoxin. thus the selectivity of digoxin depends on a combination of integration targeting and repression of specific gene networks. the drug unmasked a functional connection between hiv-1 integration and t-cell activation. our results suggest that hiv-1 evolved integration site selection to couple its early gene expression with the status of target cd4+ t-cells,which may affect latency and viral reactivation. © 2017 zhyvoloup et al.