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Background The role of extracellular vesicles (EVs) in human immunodeficiency virus (HIV) pathogenesis is unknown. We examine the cellular origin of plasma microvesicles (MVs), a type of ectocytosis-derived EV, the presence of mitochondria in MVs, and their relationship to circulating cell-free mitochondrial deoxyribonucleic acid (ccf-mtDNA) in HIV-infected patients and controls. Methods Five participant groups were defined: 30 antiretroviral therapy (ART)-naive; 30 ART-treated with nondetectable viremia; 30 elite controllers; 30 viremic controllers; and 30 HIV-uninfected controls. Microvesicles were quantified and characterized from plasma samples by flow cytometry. MitoTrackerDeepRed identified MVs containing mitochondria and ccf-mtDNA was quantified by real-time polymerase chain reaction. Results Microvesicle numbers were expanded at least 10-fold in all HIV-infected groups compared with controls. More than 79% were platelet-derived MVs. Proportions of MVs containing mitochondria (22.3% vs 41.6%) and MV mitochondrial density (706 vs 1346) were significantly lower among HIV-infected subjects than controls, lowest levels for those on ART. Microvesicle numbers correlated with ccf-mtDNA levels that were higher among HIV-infected patients. Conclusions A massive release of platelet-derived MVs occurs during HIV infection. Some MVs contain mitochondria, but their proportion and mitochondrial densities were lower in HIV infection than in controls. Platelet-derived MVs may be biomarkers of platelet activation, possibly reflecting pathogenesis even in absence of HIV replication.

[Objectives] To analyse whether integrase inhibitor (InSTI)-based regimens achieve better immunological recovery than NNRTI- or boosted PI (bPI)-based regimens as initial ART., [Methods] In a retrospective analysis, we selected patients who initiated ART with two NRTIs plus an InSTI, an NNRTI or a bPI and maintained both the same ‘third drug’ and an HIV-RNA, [Results] Of the 836 patients included, 208, 481 and 147 initiated with InSTI, NNRTI and bPI, respectively. For CD4+, %CD4+ and CD4+/CD8+ two main slopes were identified: from month 0 to month 6, with the highest increments; and from month 6 to month 24, with smaller increases every semester. Although the patients on InSTI achieved undetectable viral load faster, for CD4+ and %CD4+ there were no differences in the slopes of change according to the third drug either for the first phase (P=0.137 and P=0.393, respectively) or from month 6 onwards (P=0.834 and P=0.159, respectively). The increase in CD4+/CD8+ was slightly higher for bPI compared with InSTI (difference of 0.0119, 95% CI 0.0020–0.0205; P=0.018), but clinically negligible. From month 6 onwards, no differences were found between treatment groups (P=0.176)., [Conclusions] Immune restoration measured as CD4+ count, %CD4+ and CD4+/CD8+ increases was independent of the third antiretroviral drug class used when given with two NRTIs., This work was supported by Red de Investigación en SIDA (RD16/0025/0020-ISCIII-FEDER) and Instituto de Salud Carlos III and Proyectos de investigación en salud (AES 2018) (exp. PI18/01298).

Persistent cytomegalovirus (CMV) infection has been suggested to be a major driving force in the immune deterioration and an underlying source of age-related diseases in the elderly. CMV antibody titers are associated with lower responses to vaccination, cardiovascular diseases, frailty, and mortality. CMV infection is also associated with shorter T-cell telomeres and replicative senescence. Although an age-related deregulation of CMV-specific T-cell responses could be an underlying cause of the relationship between CMV and immune defects, strong and polyfunctional responses are observed in elderly individuals, casting uncertainty on their direct role in age-related immune frailty. In this study, we longitudinally followed a cohort of healthy donors aged over 50 years, assessing their mortality rates and time to death during a 2-year period. Specific T-cell responses to the immunodominant antigen pp65 (IFNγ, TNFα, IL2, MIP1α, CD107a, and perforin production) were analyzed at the beginning of the 2-year observation period. A cytotoxic CD8 pp65-specific T-cell response, without cytokine or chemokine coexpression, was independently associated with all-cause mortality in these elderly individuals. This pp65-specific CD8 T-cell response could be a useful tool to identify individuals with depressed immune function and a higher risk of death.

Objectives: This study examined the homeostatic parameters possibly related to HIV-infected patients who, despite being under suppressive highly active antiretroviral therapy (HAART), show low-level CD4 T cell repopulation (LLR). Methods: Twenty-one LLR individuals, 20 HIV-infected controls with satisfactory CD4 T cell repopulation (R) and 14 healthy subjects were studied. Markers related to activation, senescence and proliferation were analysed for both the CD4 and CD8 T cell subsets. Additionally, soluble CD14 (sCD14) and high-sensitivity C-reactive protein (hsCRP) were measured, and the CD34+ cells and the levels of interleukin-7 (IL-7) receptor were quantified. Results: The frequency of naive CD4 T cells from LLR patients was significantly reduced, and these cells showed increased expression of markers for activation, senescence and proliferation as compared with naive CD4 T cells from R patients. Naive CD8 T cells were also reduced when compared with those from R patients, but did not exhibit an altered phenotype. Moreover, frequencies of effector memory T cells were higher in LLR than R patients. No differences between LLR and R patients were observed for sCD14 levels, CD34+ cells and the IL-7 receptor, although LLR patients showed a tendency toward increased levels of hsCRP >2 μg/mL. Conclusions: Patients with low CD4 T cell restoration under suppressive HAART show significant alterations in T cell homeostasis that do not appear to be related to a reduction in haematopoietic progenitors. sCD14 levels were not specifically altered in these patients. Our results agree with our previously proposed model of premature immunosenescence in LLR patients and further describe homeostatic features associated with poor CD4 recovery. © The Author 2012. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy., This work was supported by the Spanish AIDS Research Network of Excellence (RIS; Red de Investigación en SIDA) [RD06/0006/0021 to MMPB and RD06/0006/0035]; the Consejería de Salud of Junta de Andalucía [PI-0366/07]; the Fundación para la Investigación y la prevención del SIDA en España (FIPSE) [366884/07 to GML]; and the Fondos de Investigación Sanitaria (FIS) [P11/02014 and Miguel Servet Grants CP07/00240 to YMP and CP08/00172 to ERM].