Transcriptomic effects of combined AZD4573 and SMAP-2 treatment in resting and anti-CD3/CD28-activated primary human CD4+ T cells

This study characterized the effects of combined CDK9 inhibition and PP2A activation on host gene expression in primary human CD4+ T cells. In the broader study, the CDK9 inhibitor AZD4573 and the PP2A activator SMAP-2 cooperatively suppressed HIV transcription and promoted durable transcriptional silencing. The RNA-seq experiment was performed to determine whether this drug combination caused broad or selective host-transcriptome changes in uninfected primary CD4+ T cells under resting and T-cell receptor-activated conditions. Primary CD4+ T cells from three independent HIV-negative donors were either maintained without stimulation or activated for 48 h with plate-bound anti-CD3 and anti-CD28 antibodies. Resting and activated cells were subsequently treated for 24 h with either 0.1% DMSO or a combination of 5 nM AZD4573 and 5 μM SMAP-2. Within each activation state, drug-treated samples were compared with donor-matched DMSO controls. The transcriptional response to AZD4573 plus SMAP-2 was dependent on T-cell activation state. Resting CD4+ T cells exhibited a larger number of differentially expressed transcripts, many corresponding to unannotated protein-coding loci or long non-coding RNAs, with the P-TEFb-responsive gene MYC among the annotated downregulated genes. Activated CD4+ T cells exhibited fewer transcriptional changes; among these, HEXIM1 was downregulated and the transcriptional corepressor SLFN5 was upregulated. These data define the host-transcriptome effects of combined AZD4573 and SMAP-2 treatment in resting and activated primary human CD4+ T cells.