Transcriptomic Profiling Identifies TALAM1 and LINC00702 as HIV-1-Responsive lncRNAs in Microglia

Microglia, the resident macrophages of the central nervous system (CNS), serve as the primary reservoir of HIV-1 in the brain and play a crucial role in the development of HIV-1-associated neurocognitive disorders (HAND). While long non-coding RNAs (lncRNAs) have emerged as essential regulators of HIV-1 replication in T cells and macrophages, their role in microglia remains poorly understood. Here, we performed RNA sequencing of polyadenylated transcripts from a human microglial cell line exposed to HIV-1 infection or TNF-α stimulation to investigate transcriptional responses and identify lncRNAs with potential regulatory functions. Gene set enrichment analysis revealed broad overlap between viral and inflammatory responses, reflecting convergence on common molecular pathways. Among differentially expressed lncRNAs, we focused on TALAM1, which was specifically induced by HIV-1, and LINC00702, which responded to both HIV-1 and TNF-α. Validation by RT-qPCR confirmed the upregulation of TALAM1 and LINC00702 at 24 h post-infection. Furthermore, knockdown of either lncRNA affected viral genomic RNA levels, while only LINC00702 knockdown affected p55 production. Given that subcellular localization informs lncRNA function, we assessed the distribution of TALAM1 and LINC00702. TALAM1 was predominantly cytoplasmic under basal conditions but shifted toward nuclear enrichment upon HIV-1 infection, whereas LINC00702 remained primarily nuclear regardless of infection status. Consistent with their genomic context, protein interaction predictions, and pathway enrichment analyses suggested that TALAM1 may influence RNA processing and splicing, whereas LINC00702 may contribute to translational regulation and is associated with proteins involved in immune responses. Together, these findings provide an initial characterization of lncRNA responses to HIV-1 infection in a human microglial cell line and identify TALAM1 and LINC00702 as candidates for future functional studies in the context of viral infection and neuroinflammation.