Long-term non-progressors (LTNP) and elite controllers (EC) represent spontaneous natural models of efficient HIV-1 response in the absence of treatment. The main purposes of this work are to describe the miRNome of HIV-1 infected patients with different extreme phenotypes and identify potentially altered pathways regulated by differentially expressed (DE) miRNAs. The miRNomes from peripheral blood mononuclear cells (PBMCs) of dual phenotype EC-LTNP or LTNP with detectable viremia and HIV-infected patients with typical progression before and after treatment, were obtained through miRNA-Seq and compared among them. The administration of treatment produces 18 DE miRNAs in typical progressors. LTNP condition shows 14 DE miRNA when compared to typical progressors, allowing LTNP phenotype differentiation. A set of four miRNAs: miR-144-3p, miR-18a-5p, miR-451a, and miR-324 is strongly downregulated in LTNP and related to protein regulation as AKT, mTOR, ERK or IKK, involved in immune response pathways. Deregulation of 28 miRNA is observed between EC-LTNP and viremic-LTNP, including previously described anti-HIV miRNAs: miR-29a, associated with LTNP phenotype, and miR-155, targeting different pre-integration complexes such as ADAM10 and TNPO3. A holistic perspective of the changes observed in the miRNome of patients with different phenotypes of HIV-control and non-progression is provided.

Multiple sclerosis (MS) is the leading cause of neurologic disability in young adults worldwide. Despite the development of 20 disease-modifying treatments (DMTs) aimed at reducing disability, approximately 30% of patients experience therapeutic failure. Identifying early biomarkers for therapeutic response is, therefore, essential to enhance the rate of therapeutic effectiveness. As such, this study aims to investigate the role of circulating extracellular vesicles (EVs) as early biomarkers for clinical parameters associated with treatment response in patients with MS. We conducted an observational study involving patients with MS initiating a new DMT. Levels, size, and microRNA content of EVs derived from neurons (L1CAM⁺), oligodendrocytes (MOG⁺), and B (CD20⁺) and T (CD3⁺) cells were assessed both before and at 3 months after treatment initiation. Their correlation with therapeutic response over 12 months in patients with MS was also analyzed. The response to treatment was evaluated using the No Evidence of Disease Activity composite (NEDA), which includes clinical relapses, new lesions on MRI, progression of motor and cognitive disability, and brain atrophy. The levels and size of CD3⁺ and L1CAM⁺ EVs correlated with relapses, new lesions on MRI, and progression of motor disability while the CD20⁺ EV subpopulation reflected cognitive impairment. MicroRNA sequencing demonstrated differential expression of miR-28-3p, miR-326, miR-98-5p, miR-144-5p, miR-98-3p, miR-23a-3p, and miR-146a-5p in responders and non responders. miR-186-5p expression correlated negatively with brain atrophy. Combining EV levels and microRNA expression provided an early and robust model for therapeutic response, with significant correlations enhancing the model's accuracy. This study underscores the potential of specific EV characteristics and microRNA content as early biomarkers for treatment response in patients with MS. The downregulation of specific microRNAs emerges as a promising indicator of favorable clinical outcomes, thereby suggesting their utility in early therapeutic decision making. Notably, our findings regarding miR-186-5p as a biomarker for brain atrophy represent a novel contribution to the field. Overall, early EV levels and microRNA content analysis at 3 months after treatment initiation seem to be promising as regards anticipating irreversible neurologic damage, thereby offering a valuable tool for optimizing MS treatment management.

Dengue virus (DENV) is a global health threat, with approximately 390 million infections annually, ranging from mild dengue fever to severe dengue hemorrhagic fever and shock syndrome. MicroRNA (miRNA) are crucial post-transcriptional regulators which may regulate host resistance to DENV infection. This study aimed to identify miRNAs involved in natural resistance to DENV infection. Individuals from a dengue-endemic area were classified as susceptible (SD) or resistant (RD) according to their anti-DENV antibody status. RD individuals were seronegative despite high local DENV infection prevalence. Monocytes susceptibility to DENV infection was assessed in vitro. The miRNome profiles of the monocytes from 7 individuals per group were assessed upon mock or DENV-2 infection. The antiviral effect of differentially expressed miRNAs was analyzed using miRNA mimics in HeLa cells followed by infection with DENV-1, DENV-2, DENV-3, and DENV-4 serotypes. We performed RNA-seq on miRNA mimic-transfected cells to identify miRNA-targeted genes interacting with DENV proteins. Monocytes from RD individuals exhibit lower DENV-2 production in vitro. The miRNAs miR-155, miR-132-3p, miR-576-5p were overexpressed in monocytes from RD group upon DENV-2 infection. The transfection of miR-155-5p mimic reduced DENV infection and viral production in HeLa cells, regulating 18 genes interacting with DENV proteins and downregulating target genes involved in interferon response, TP53 regulation, apoptosis, and vesicle trafficking (e.g. HSD17B12, ANXA2 ). Therefore, we show that monocytes from RD individuals show a distinct miRNA expression profile and reduced viral production. In vitro miR-155-5p upregulation induces an antiviral state, revealing potential therapeutic targets to treat dengue.

People with HIV (PWH) experience chronic inflammation and more age-related comorbidities despite antiretroviral therapy (ART). Classical senescence biomarkers (e.g., SA-βGal, p16^INK4a, γH2AX and Bcl-2) and senescence-associated secretory phenotype (SASP) factors such as IL-6 reflect cellular senescence. This study assesses those markers in a male cohort of PWH across infection stages, pre/post-ART. We analyzed blood samples from 39 PWH at primary, chronic and advanced HIV infection, before and after one year on ART, and 13 age- and sex-matched HIV-negative controls. Classical cellular senescence biomarkers in T-cells and monocytes, along with plasma SASP factors and immune checkpoints, were assessed via flow cytometry and Luminex. PWH exhibited elevated cellular senescence, SASP and immune checkpoint markers (such as SA-βGal, p16^INK4a, γH2AX, Bcl-2, CD87, IL-6, IL-10, TNF-RI/RII, CD30, IL-8, RANTES, CXCL1, PD-1, PD-L1, PD-L2, LAG-3, CTLA-4 and TIM-3) particularly in chronic and advanced stages, which generally persisted after ART, but not in PWH treated in primary HIV infection. Senescence biomarkers in T-cells and SASP components in plasma positively correlated with immunosenescence, T-cell activation, HIV p24 expression and negatively correlated with CD4 count and CD4/CD8 ratio. HIV infection promotes persistent cellular senescence despite ART in advanced and chronic infection. Thus, future senolytic or senomorphic strategies against cellular senescence may reduce chronic inflammation and aging-related complications in PWH.

Introduction: HIV controllers maintain low viral loads without therapy, offering a natural model for a functional cure. The regulatory role of the small non-coding RNA (sncRNA) transcriptome in CD4+ T cells has been scarcely explored. Our study aimed to characterize the sncRNA and coding RNA landscape in CD4+ T cells from HIV controllers and to assess the potential antiviral activity of key non-coding RNAs. Methods: We performed sncRNA-Seq and RNA-Seq on CD4+ T cells from elite controllers (ECs, n=10), viremic controllers (n=6), and untreated (n=8) and treated (n=9) non-controllers. Differential expression analysis, miRNA-mRNA correlation, interaction mapping, and functional annotation were conducted. To assess antiviral activity, inhibitors for candidate miRNAs were transfected into CEM-NKR.CCR5 cells, which were then infected with a replication-competent HIV-1 clone. Results: The sncRNA compartment of elite controllers was distinct, including overexpression of specific transfer RNA (tRNA)-Lys isoacceptors and a cluster of five PIWI-interacting RNAs (piRNA) associated with tRNA-Lys genomic repeats. Noteworthy, miR-99b-5p and miR-125a-5p were significantly downregulated in elite controllers compared to both non-controller groups. Concurrently, the coding transcriptome of elite controllers displayed an enrichment in p53 signaling, inflammatory response, cell activation, and oxidative stress. Several genes upregulated in these processes (e.g., THBS1 , DPM2 ) were identified as validated targets of miR-99b-5p and miR-125a-5p. Finally, in vitro experiments showed that miR-99b-5p and miR-125a-5p inhibition, individually or in combination, reduced viral replication by 17.6%, 16.3%, and 21.4%, respectively. Discussion: Elite controllers exhibit a distinctive sncRNA signature in CD4+ T cells. The coordinated downregulation of miR-99b-5p and miR-125a-5p may contribute to a restrictive cellular environment and reducing viral replication, revealing a novel layer of post-transcriptional regulation in natural HIV control. These findings underscore these miRNAs and their potentially regulated counterparts as potential targets for future therapeutic strategies.