Immune Activation In HIV-infected Patients Research Articles

Characterization of the Intestinal Fungal Microbiome in HIV and HCV Mono-Infected or Co-Infected Patients.

Intestinal mycobiome dysbiosis plays an important role in the advancement of HIV- and HCV-infected patients. Co-infection with HCV is an important risk factor for exacerbating immune activation in HIV-infected patients, and gut fungal microbial dysbiosis plays an important role. However, no systematic study has been conducted on the intestinal fungal microbiome of HIV/HCV co-infected patients to date. Patients infected with HIV and HCV, either alone or in combination, and healthy volunteers were included. Stool samples were collected for fungal ITS sequencing and for further mycobiome statistical analysis. We found that the abundance of fungal species significantly decreased in the HIV/HCV co-infection group compared to in the healthy control group, while no significant differences were found in the mono-infection groups. Low-CD4 + T-cell patients in the HIV group and high-ALT-level patients in the HCV group were discovered to have a more chaotic fungal community. Furthermore, the opportunistic pathogenic fungal profiles and fungal inter-correlations in the co-infection group became less characteristic but more complicated than those in the mono-infection groups. Intestinal fungal dysregulation occurs in HIV- and HCV-infected patients, and this dysregulation is further complicated in HIV/HCV co-infected patients.

Plasma Extracellular Vesicle Subtypes as Potential Biomarkers of Immune Activation in HIV-Infected Patients

Chronic immune activation and systemic inflammation during HIV infection despite effective antiretroviral therapy (ART) is associate with non-AIDS co-morbidities in people living with HIV (PLWH). Previous studies have shown that plasma levels of extracellular vesicles (EVs) may be used as immune activation or inflammatory biomarkers of HIV disease progression. Several studies have focused on microRNA and mitochondrial DNA (mtDNA) levels reached concomitantly in immune cells and EVs. We hypothesized that large and small EVs could contain different amounts of microRNA and mtDNA and that could reflect immune activation associated with elevated CD8 T cell count or low CD4/CD8 ratio in PLWH receiving ART. Plasma EVs obtained from PLWH and uninfected control were sized using dynamic light scattering and quantified using flow cytometry. Expression of mature miR-92, miR-155, miR-223 and mtDNA was measured by qRT-PCR. Positive correlation have been observed between CD8+ T cell count and large EV abundance, AChE activity in small EVs and negative correlation with miR-155 levels in small EVs. CD4/CD8 ratio was positively correlated with large EVs abundance and negatively with AChE activity in small EVs and PMN-associated copies of miR-92. MicroRNA-155 level in small EVs were positively correlated with monocyte counts. MiR-155 and mtDNA contents of large EVs were increased more than miR-92 and miR-223 contents in small EVs. A positive correlation was observed between large EVs mtDNA content and CD4 T cell count. These findings suggest that profiling the microRNA and mtDNA contents of EV might provide new functional biomarkers of immune activation and inflammation. Funding Statement: This study was funded through Canadian Institutes of Health Research (CIHR) grants MOP 188726; MOP-267056 (HIV/AIDS initiative) to C.G., MOP-03230 to J.P.R. and to C.T. for the cohort establishment and CIHR Foundation Grant FDN-143218 to M.A. for the studentship awarded to W.W.B., as well as by the Fonds de recherche du Quebec – Sante (FRQ-S) AIDS and infectious diseases network. C.T. is an FRQ-S scholar and holder of the Pfizer/Universite de Montreal chair on HIV translational Research. J-P.R. holds the Louis Lowenstein chair in Hematology & Oncology at McGill University. M-A.J. holds a CIHR Canada Research Chair tier 2 in Immuno-Virology. The infrastructure of the Centre de recherche du CHU de Quebec – Universite Laval is supportes by the FRQ-S. Declaration of Interests: The authors declare that no competing interests exist. Ethics Approval Statement: This study received approval from the ethics review boards of Centre de recherche du CHU de Quebec, Quebec, Canada and the McGill University Health Centre, Montreal, Quebec, Canada. All subjects were anonymous volunteers and provided written informed consent to participate in the study.

Immune activation and HIV-specific T cell responses are modulated by a cyclooxygenase-2 inhibitor in untreated HIV-infected individuals: An exploratory clinical trial.

Pathologically elevated immune activation and inflammation contribute to HIV disease progression and immunodeficiency, potentially mediated by elevated levels of prostaglandin E2, which suppress HIV-specific T cell responses. We have previously shown that a high dose of the cyclooxygenase-2 inhibitor celecoxib can reduce HIV-associated immune activation and improve IgG responses to T cell-dependent vaccines. In this follow-up study, we included 56 HIV-infected adults, 28 antiretroviral therapy (ART)-naïve and 28 on ART with undetectable plasma viremia but CD4 counts below 500 cells/μL. Patients in each of the two study groups were randomized to receive 90 mg qd of the cyclooxygenase-2 inhibitor etoricoxib for six months, two weeks or to a control arm, respectively. T cell activation status, HIV Gag-specific T cell responses and plasma inflammatory markers, tryptophan metabolism and thrombin generation were analyzed at baseline and after four months. In addition, patients received tetanus toxoid, conjugated pneumococcal and seasonal influenza vaccines, to which IgG responses were determined after four weeks. In ART-naïve patients, etoricoxib reduced the density of the activation marker CD38 in multiple CD8+ T cell subsets, improved Gag-specific T cell responses, and reduced in vitro plasma thrombin generation, while no effects were seen on plasma markers of inflammation or tryptophan metabolism. No significant immunological effects of etoricoxib were observed in ART-treated patients. Patients receiving long-term etoricoxib treatment had poorer tetanus toxoid and conjugated pneumococcal vaccine responses than those receiving short-course etoricoxib. Cyclooxygenase-2 inhibitors may attenuate harmful immune activation in HIV-infected patients without access to ART.

Short Communication: Immune Activation Is Present in HIV-1-Exposed Seronegative Individuals and Is Independent of Microbial Translocation.

Analyses of immune activation in HIV-exposed seronegative individuals (HESN) yielded discrepant results. To clarify this issue we performed an extensive investigation of immune parameters in HESN and, in particular, we analyzed in these individuals the possible presence of microbial translocation, the most widely accepted reason driving immune activation in HIV-infected patients. Results showed that immune activation, a skewing of T lymphocyte maturation, and increased responsiveness to lipopolysaccharide (LPS) characterize the HESN phenotype; this is not driven by alterations of the gastrointestinal barrier and microbial translocation. The activation state seen in HESN may influence the induction of stronger adaptive antiviral immune responses and may represent a virus exposure-induced innate immune protective phenotype against HIV.

Differential effects of viremia and microbial translocation on immune activation in HIV-infected patients throughout ritonavir-boosted darunavir monotherapy.

The purpose of this article is to evaluate the evolution of microbial translocation (MT) and its role in CD4+ and CD8+ T cells immune activation (IA) in HIV-1-infected patients on ritonavir-boosted darunavir monotherapy (mtDRV/rtv).Prospective study of consecutive HIV-1-infected patients switched to mtDRV/rtv as a simplification regimen. Subjects were classified according to the virological behavior during a 24-month follow-up as continuous undetectable viral load, blips, intermittent viremia, and virological failure (VF). MT was evaluated by plasma LPS and 16S genomic rDNA (16S rDNA) levels, whereas IA was assessed by the coexpression of HLA-DR and CD38 in CD4+ and CD8+ T cells, and plasma sCD14 levels.Seventy-one patients were included in this substudy of the MonDar cohort (ClinicalTrials.gov: NCT01505722). At baseline, CD4+ (ρ = −0.352, P = 0.01) and CD8+ T-cell activation (ρ = −0.468, P < 0.001) were correlated with time with viral suppression, but not with MT markers. A significant decrease in plasma LPS levels was found only in patients without VF (baseline, 77.8 vs month 24, 60.4 pg/mL; P < 0.001]. Both plasma 16S rDNA and sCD14 levels were unchanged irrespective of the viral behavior. The only variable independently associated with a decrease in CD4+ and CD8+ T cells activation was an undetectable HIV-1 viremia (β = 4.78, P < 0.001 and β = 2.93, P = 0.005, respectively).MT does not have a pivotal role in T-cell activation, at least in patients with long-term viral suppression. The viremic episodes and VF are the main factors related to CD4+ and CD8+ T-cells IA, even during mtDRV/rtv.

Impact of Autologous Dendritic Cell–Based Immunotherapy (AGS-004) on B- and T-Cell Subset Changes and Immune Activation in HIV-Infected Patients Receiving Antiretroviral Therapy

We previously reported that a combination of antiretroviral therapy with 4 monthly injections of each patient's own autologous dendritic cells (AGS-004) electroporated with CD40 ligand and with HIV RNA antigens obtained from each patient's own pre-antiretroviral therapy plasma induced HIV-specific CD8 T-cell responses in 10 patients. To assess other AGS-004-induced immune changes, we evaluated the modifications in B- and T-cell subsets and the level of immune activation in these patients. The proportion of Bm1 naive cells was increased along with an augmentation of the proliferation marker Ki67. Memory B-cell frequency, CD4 and CD8 T-cell subsets, regulatory T-cell frequency, and CD38/HLA-DR/PD-1 T-cell activation levels remained unchanged after AGS-004 dendritic cell immunotherapy.

The HIV-1 Tat Protein Induces the Activation of CD8+ T Cells and Affects In Vivo the Magnitude and Kinetics of Antiviral Responses

T cells are functionally compromised during HIV infection despite their increased activation and proliferation. Although T cell hyperactivation is one of the best predictive markers for disease progression, its causes are poorly understood. Anti-tat natural immunity as well as anti-tat antibodies induced by Tat immunization protect from progression to AIDS and reverse signs of immune activation in HIV-infected patients suggesting a role of Tat in T cell dysfunctionality. The Tat protein of HIV-1 is known to induce, in vitro, the activation of CD4+ T lymphocytes, but its role on CD8+ T cells and how these effects modulate, in vivo, the immune response to pathogens are not known. To characterize the role of Tat in T cell hyperactivation and dysfunction, we examined the effect of Tat on CD8+ T cell responses and antiviral immunity in different ex vivo and in vivo models of antigenic stimulation, including HSV infection. We demonstrate for the first time that the presence of Tat during priming of CD8+ T cells favors the activation of antigen-specific CTLs. Effector CD8+ T cells generated in the presence of Tat undergo an enhanced and prolonged expansion that turns to a partial dysfunctionality at the peak of the response, and worsens HSV acute infection. Moreover, Tat favors the development of effector memory CD8+ T cells and a transient loss of B cells, two hallmarks of the chronic immune activation observed in HIV-infected patients. Our data provide evidence that Tat affects CD8+ T cell responses to co-pathogens and suggest that Tat may contribute to the CD8+ T cell hyperactivation observed in HIV-infected individuals.

Lack of correlation between the size of HIV proviral DNA reservoir and the level of immune activation in HIV-infected patients with a sustained undetectable HIV viral load for 10 years

BackgroundThe persistence of HIV residual replication in patients with an undetectable plasma viral load (pVL) may limit immune recovery and facilitate inflammation-induced comorbidities. ObjectiveThe objective was to evaluate any correlation between immune restoration and intracellular [IC] HIV-DNA in cART-treated patients with a sustained undetectable pVL. Study designThis retrospective cross sectional study included 62 patients with a median duration of undetectable pVL of 10.3 years. IC HIV DNA in peripheral mononuclear blood cells (PBMCs) and T cell subsets were measured at the last visit. pVL, CD4+ and CD8+ T cell counts were retrospectively collected from the onset of long-term inhibition by antiretroviral treatment. The patients were separated into two groups: 27 non-blippers (sustained pVL<threshold value during all the visits) and 35 blippers (≥1 episodes of pVL>threshold but <1000 copies/ml). The median pVL in blippers was 115 copies/ml. ResultsThe median IC HIV DNA rate was 34 copies/106 PBMCs (71% ≥20 copies/106 PBMCs) with no significant difference between the groups. The proportion of CD8+CD38+ and CD8+DR+ T cells was higher in blipper patients, but the difference was only significant for the CD8+DR+ marker (p=0.036). No correlation was found between markers of immune activation on CD4+ and CD8+ T cells and the IC HIV-DNA level. ConclusionNo relation was found between the size of HIV reservoirs and immune activation in patients with sustained undetectable pVL. Mechanisms of immune activation have to be better understood in order to define specific therapeutic interventions.

The role of lipopolysaccharide as a marker of immune activation in HIV-1 infected patients: a systematic literature review

BackgroundRecent observational studies suggest a role for lipopolysaccharide (LPS) as a marker of immune activation in HIV-infected patients, with potential repercussions on the effectiveness of antiretroviral regimens.ObjectA systematic review of LPS as a marker of immune activation in HIV-1 infected patients.Data sourcesMEDLINE register of articles and international conference proceedings.Review methodsCase–control studies comparing the role of plasma LPS as a marker of immune activation in HIV-infected patients versus HIV negative subjects.Data synthesisTwo hundred and six articles were selected using MEDLINE, plus 51 studies presented at international conferences. Plasma LPS is a marker of immune activation in HIV-infected patients, determining the entry of central memory CD4+ T cells into the replication cycle and finally generating cell death. Plasma LPS probably results from immune-mediated alterations of the intestinal barrier, which can occur soon after HIV seroconversion. LPS is a likely marker of disease progression, as it drives chronic monocyte activation, and some studies suggest that hyperexpression of CCR5 receptors, related to LPS plasma levels, could be responsible for monocyte trafficking in the brain compartment and for the appearance of HIV-associated neurocognitive disorders. Long-term combination antiretroviral therapy (cART) generally reduces LPS concentrations, but rarely to the same levels as in the control group. This phenomenon probably depends on ongoing but incomplete repair of the mucosal barrier. Only in patients achieving maximal viral suppression (i.e. viral load < 2.5 cp/ml) are LPS levels comparable to healthy donors. In successfully treated patients who did not restore CD4+ T cells, one hypothesis is that the degree of residual microbial translocation, measured by LPS, alters the turnover of CD4+ T cells.ConclusionsLPS is a marker of microbial translocation, responsible for chronic immune activation in HIV-infected patients. Even in successfully treated patients, LPS values are rarely normal. Several studies suggest a role for LPS as a negative predictive marker of immune restoration in patients with blunted CD4 T cell gain.

HIV-related immune activation and non-AIDS-related complications: story unfolds.

For several years, an interesting story has been emerging that links persistent immune activation in HIV-infected patients with non–AIDS-related complications and, potentially, accelerated aging. In 2011, several new chapters were added to this fascinating narrative. A large epidemiologic study found that, compared with HIV-uninfected individuals, HIV-infected patients had higher rates of chronic diseases typical of aging, including kidney disease, diabetes, bone fracture, and cardiovascular disease. The risk for multiple concurrent comorbidities was about the same for a 40-year-old HIV-infected …

Immune Activation in HIV-Infected Patients Treated with Different ARV Regimens

Objectives: To evaluate the effects of starting therapy with either Truvada (TVD) or Combivir (CBV) in combination with Efavirenz (EFV) or a boosted Protease Inhibitor (LPV/r, ATV/r, fAPV/r and SQV/r) on clinical, immunological, and virological parameters in HIV-infected antiretroviral (ARV) naive patients. Methods: Twenty-seven patients were prospectively enrolled and received TVD-EFV, 32 TVD-PI/r, 24 CBV-EFV, and 23 CBV-PI/r. Immunovirological analyses were performed at baseline and after 3, 6, 9 and 12 months after initiation of therapy; a full set of data is available for 51 patients. Results: Median CD4+ cell counts and HIV-RNA plasma viremia were comparable in the four groups of patients (TVD-EFV, TVD-PI/r, CBV-EFV, CBV-PI/r) at baseline. At month 12 HIV RNA plasma viremia was <50 cps/ml in all patients. Median CD4 cell counts increases were higher, although not significantly, in CBV-EFV and TVD-EFV patients. Finally, CD8+/CD38+/CDRO+T lymphocytes were significantly decreased after 12 months of therapy in all patients with, possibly, a faster effect seen in the EFV groups. Conclusions: Immunologic parameters are similarly affected by different ARV combinations, even if EFV-associated immunomodulation might be marginally better.

Relationship between Regulatory T Cells and Immune Activation in Human Immunodeficiency Virus-Infected Patients Interrupting Antiretroviral Therapy

Persistent immune activation plays a central role in driving Human Immunodeficiency Virus (HIV) disease progression. Whether CD4+CD25+ regulatory T cells (Tregs) are harmful by suppressing HIV-specific immune responses and/or beneficial through a decrease in immune activation remains debatable. We analysed the relationship between proportion and number of regulatory T cells (Tregs) and immune activation in HIV-infected patients interrupting an effective antiretroviral therapy (ART). Twenty-five patients were included in a substudy of a prospective multicenter trial of treatment interruption (TI) (ANRS 116). Proportions and numbers of Tregs and the proportion of activated CD4 and CD8 T cells were assessed at baseline and month 12 (M12) of TI. Specific anti-HIV CD4 and CD8 responses were investigated at baseline and M12. Non parametric univariate analyses and multivariate linear regression models were conducted. At baseline, the proportion of Tregs negatively correlated with the proportion of HLA-DR+CD8+T cells (r = −0.519). Following TI, the proportion of Tregs increased from 6.3% to 7.2% (p = 0.029); absolute numbers of Tregs decreased. The increase in the proportion of HLA-DR+CD38+CD8+T cells was significantly related to the increase in proportion of Tregs (p = 0.031). At M12, the proportion of Tregs did not negatively correlate with CD8 T-cell activation. Nevertheless, Tregs retain a suppressive function since depletion of Treg-containing CD4+CD25+ cells led to an increase in lymphoproliferative responses in most patients studied. Our data suggest that Tregs are efficient in controlling residual immune activation in patients with ART-mediated viral suppression. However, the insufficient increase in the proportion and/or the decrease in the absolute number of Tregs result in a failure to control immune activation following TI.Trial RegistrationClinicalTrials.gov NCT00118677

Proteinuria, Creatinine Clearance, and Immune Activation in Antiretroviral‐Naive HIV‐Infected Subjects

Because both renal disease and immune activation predict progression to acquired immunodeficiency syndrome (AIDS), we evaluated the associations between proteinuria>or=1+, as determined by dipstick analysis (7 [7%] of 1012 subjects); creatinine clearance of <90 mL/min (195 [18%] of 1071 subjects); and percentages of peripheral activated CD8 cells (CD8+CD38+HLA-DR+ cells) in antiretroviral-naive, human immunodeficiency virus (HIV)-infected subjects who were enrolled in AIDS Clinical Trials Group studies 384 and A5095. Proteinuria, but not creatinine clearance, was associated with higher percentages of CD8+CD38+HLA-DR+ cells (55% vs. 50%; P=.01), with even more pronounced differences noted among men and among blacks and Hispanics. Proteinuria may be a surrogate measurement of greater immune activation in HIV-infected patients initiating antiretroviral therapy.

Inflammatory cytokines and inhibitors in HIV infection: correlation between interleukin-1 receptor antagonist and weight loss.

To determine serum levels of the interleukin-1 receptor antagonist (IL-1Ra), together with cytokines, other cytokine inhibitors and markers of immune activation in HIV-infected patients. Sixty-one HIV-patients were classified into Center for Disease Control and Prevention (CDC) groups A (n = 14), B (n = 14) and C (n = 33). Serum levels of IL-1Ra, IL-1 beta, IL-6, tumour necrosis factor (TNF-alpha, TNF soluble receptors (TNF-sR) and IL-2sR were measured by enzyme-linked immunosorbent assay. CD4+ cell counts, p24 antigen, immunoglobulin (Ig) A, beta 2-microglobulin, triglycerides and neopterin were measured according to standard procedures. Weight variation was measured as the percentage of baseline weight lost or gained during the 3 months before sampling. Serum levels of IL-1Ra were significantly elevated in HIV-infected patients, compared with control subjects (S47 +/- 104 and 133 +/- 7 pg/ml), but did not vary significantly with the HIV disease stage, CD4+ cell count or p24 antigenaemia. IL-1Ra levels correlated with IL-1 beta (P < 0.005), IL-6 (P < 0.0001) and TNF-sR55 (P < 0.0001) levels, but not with those of TNF-alpha, TNF-sR75, IL-2sR, neopterin or IgA. IL-1 Ra and IL-1 Ra/IL-1 beta ratio were the only parameters significantly elevated (R = -0.67, P < 0.0001) in the HIV-infected patients with marked weight loss (n = 12; mean of weight variation, -13.9 +/- 2.1% relative to the other patients, regardless of HIV disease stage and opportunistic infections. IL-1Ra levels are significantly elevated in HIV infected patients, independently of immune deficiency. We propose that IL-1Ra accumulates in intense systemic inflammation, a state which does not seem to be reflected by the elevation of a single cytokine or the activation at a single cell system and which is correlated with marked weight loss.