Increased SAMHD1 transcript expression correlates with interferon-related genes in HIV-1-infected patients.

PURPOSE: To investigate the contribution of SAMHD1 to HIV-1 infection in vivo and its relationship with IFN response, the expression of SAMHD1 and IFN-related pathways was evaluated in HIV-1-infected patients. METHODS: Peripheral blood mononuclear cells (PBMC) from 388 HIV-1-infected patients, both therapy naïve (n = 92) and long-term HAART treated (n = 296), and from 100 gender and age-matched healthy individuals were examined. CD4+ T cells, CD14+ monocytes and gut biopsies were also analyzed in HIV-1-infected subjects on suppressive antiretroviral therapy. Gene expression levels of SAMDH1, ISGs (MxA, MxB, HERC5, IRF7) and IRF3 were evaluated by real-time RT-PCR assays. RESULTS: SAMHD1 levels in HIV-1-positive patients were significantly increased compared to those in healthy donors. SAMHD1 expression was enhanced in treated patients compared to naïve patients (p < 0.0001) and healthy donors (p = 0.0038). Virologically suppressed treated patients exhibited higher SAMHD1 levels than healthy donors (p = 0.0008), viraemic patients (p = 0.0001) and naïve patients (p < 0.0001). SAMHD1 levels were also increased in CD4+ T cells compared to those in CD14+ monocytes and in PBMC compared to those of GALT. Moreover, SAMHD1 was expressed more strongly than ISGs in HIV-1-infected patients and positive correlations were found between SAMHD1, ISGs and IRF3 levels. CONCLUSIONS: SAMHD1 is more strongly expressed than the classical IFN-related genes, increased during antiretroviral therapy and correlated with ISGs and IRF3 in HIV-1-infected patients.

Direct-acting antiviral therapy enhances total CD4+ and CD8+ T-cells responses, but does not alter T-cells activation among HCV mono-infected, and HCV/HIV-1 co-infected patients.

AIM: Chronic immune activation and poor T-cell immune response are strongly associated with disease progression and pathogenesis of both hepatitis C virus (HCV) and human immunodeficiency virus (HIV)-1 infections. Little is known about the impact of anti-HCV Interferon (IFN)-free direct-acting antiviral (DAA) therapy on the systemic T-cells activation and patterns of peripheral T-cells producing pro-inflammatory cytokines. PATIENTS AND METHODS: Forty-five subjects including 18 HCV mono-infected, 17 HCV/HIV-1 co-infected patients under antiretroviral therapy (ART), and 10 healthy controls (HCs) were recruited. Blood samples were collected at baseline (T0) and 12 weeks after the end of DAA therapy (T1). Cell phenotypes (CD3, CD4, CD8), activation markers (CD38 and HLA-DR), and frequency of IFN-γ, interleukin (IL)-17, and IL-22 producing CD4+ and CD8+ T-cells were measured by flow cytometry. Plasma levels of related cytokines were also measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Both HCV, and HCV/HIV-1 patients before and after therapy, showed significant higher percentages of any T-cell subset expressing CD38 and/or HLA-DR compared to HCs. No differences were observed in T-cells activation at T1 compared to T0 in patient groups, and when HCV patients were compared to HCV/HIV-1 group (P>0.05). After therapy, the potential of total circulating T helper (Th) and T cytotoxic (Tc) cells producing IFN-γ, IL-17, and IL-22 were increased. Plasma level of IFN-γ at baseline was showed difference compared to HCs, and significantly reduced after therapy (P<0.05). CONCLUSION: Total T-cells immune response enhances after therapy, however, the state of immune activation may remain elevated for a longtime after the end of treatment and contribute to post-Sustained Virologic Response (SVR) consequences.

A pilot study on the effects of probiotic supplementation on neuropsychological performance and microRNA-29a-c levels in antiretroviral-treated HIV-1-infected patients.

INTRODUCTION: The gut microbiota is involved in the regulation of cognition, mood, anxiety, and pain, and can impact cognitive functions by producing neuroactive substances or releasing bacterial by-products and metabolites. No information is available on the effects of a probiotic supplementation on brain function of HIV+ subjects. In light of the above considerations, we performed a pilot study in cART-treated HIV-1-positive patients with long-term virologic suppression. The aims were to analyze the effect of high-concentration multistrain probiotic supplementation (Vivomixx®; Visbiome®) on several neurocognitive abilities and to evaluate the safety of this supplementation. METHODS: To address those issues, neurocognitive performances were explored by administering neuropsychological tests; moreover, miRNA-29a-c levels were measured in cerebrospinal fluid (CSF) to confirm the persistent undetectable levels of HIV-RNA in the central nervous system after probiotic supplementation. RESULTS: Our results show that the Rey auditory verbal learning test (RAVLT) (immediate and delayed recall), Rey-Osterrieth complex figure test (ROCF) (copy immediate and delayed recall), phonological verbal fluency (PVF) test, Toronto alexithymia scale-20 (Tas-20), State-trait anxiety inventory Y-2 (STAY Y-2), and time and weight estimation test (STEP) scores improved significantly during the study. Moreover, we found unchanged levels, associated to high degree of individual variability, in miRNA-29 levels in CSF collected before and after probiotic supplementation. CONCLUSIONS: In conclusion, we observed that HIV patients treated with 6 months of this probiotic supplementation appear to have an improvement in some neurocognitive functions; moreover, this approach is safe and did not modify significantly the levels of miRNA in CSF. Further studies are needed to better understand the contribution of the probiotics in modulating gut-brain-axis in HIV patients.

Probiotics Differently Affect Gut-Associated Lymphoid Tissue Indolamine-2,3-Dioxygenase mRNA and Cerebrospinal Fluid Neopterin Levels in Antiretroviral-Treated HIV-1 Infected Patients: A Pilot Study.

Recently the tryptophan pathway has been considered an important determinant of HIV-1 infected patients' quality of life, due to the toxic effects of its metabolites on the central nervous system (CNS). Since the dysbiosis described in HIV-1 patients might be responsible for the microbial translocation, the chronic immune activation, and the altered utilization of tryptophan observed in these individuals, we speculated a correlation between high levels of immune activation markers in the cerebrospinal fluid (CSF) of HIV-1 infected patients and the over-expression of indolamine-2,3-dioxygenase (IDO) at the gut mucosal surface. In order to evaluate this issue, we measured the levels of neopterin in CSF, and the expression of IDO mRNA in gut-associated lymphoid tissue (GALT), in HIV-1-infected patients on effective combined antiretroviral therapy (cART), at baseline and after six months of probiotic dietary management. We found a significant reduction of neopterin and IDO mRNA levels after the supplementation with probiotic. Since the results for the use of adjunctive therapies to reduce the levels of immune activation markers in CSF have been disappointing so far, our pilot study showing the efficacy of this specific probiotic product should be followed by a larger confirmatory trial.