Human immunodeficiency virus type-1 (HIV-1) is a complex retrovirus that relies on alternative splicing, translational, and post-translational mechanisms to produce over 15 functional proteins from its single ~10 kb transcriptional unit. Using ribosome profiling, nascent protein labeling, RNA sequencing, and whole-proteomics of infected CD4 + T lymphocytes, we characterized the transcriptional, translational, and post-translational landscape during infection. While viral infection exerts a significant impact on host transcript abundance, global translation rates are only modestly affected. Proteomics data reveal extensive transcriptional and post-translational regulation, with many genes showing opposing trends between transcript/ribosome profiling and protein abundance. These findings highlight a complex regulatory network orchestrating gene expression at multiple levels. Viral ribosome profiling further uncovered extensive non-AUG translation of small peptides from upstream open reading frames (uORFs) within the 5’ long terminal repeat, which elicit specific T cell responses in people living with HIV. Conservation of uORF translation among retroviruses, along with TAR sequences, shapes DDX3 dependency for efficient translation of the main viral open reading frames.
HIV-1 is a single-stranded, positive-sense, diploid and enveloped RNA virus that belongs to the Retroviridae family. Upon infection, the genomic RNA is reverse-transcribed into a double-stranded DNA molecule that is then integrated into the host cell genome as a provirus or in some instances remains unintegrated in a circular form. The provirus DNA (integrated or circular) is transcribed