The role of microbial translocation and gut microbiota in HIV-1 infection

HIV-1 infection is characterized by persistent systemic inflammation and immune activation, even in patients receiving effective antiretroviral therapy (ART). Translocation of microbial compounds from a leaky gut to systemic circulation, so called microbial translocation (MT), is a major driver of the immune activation. Additionally, gut microbiota dysbiosis in HIV-1 infected patients further facilitate and fuel MT. The objectives of this thesis were to study: * how different ART regimens and usage of antibiotics affect markers of MT (I, II) * the alternations of gut microbiota during HIV-1 infection and the effect of ART (III,IV) In a clinical randomized trial, HIV-1 infected subjects started ART based on efavirenz (n=37) or ritonavir-boosted lopinavir (n=34). Levels of MT markers and of enterocyte death were elevated at baseline (BL), and MT markers declined until follow up after 72 weeks, but the reduction of anti-flagellin IgG antibodies was significant only in lopinavir treated patients. Levels of Intestinal Fatty Acid Binding Protein (I-FABP) remained unchanged at 72 weeks, but were temporarily increased after one month in efavirenz treated patients. 29 subjects with concomitant use of antibiotics had superior reduction of soluble CD14 (sCD14) levels. These data show that choice of ART and antibiotics usage could affect the kinetics of some MT markers. To further explore the impact of antibiotics usage on MT, we performed a longitudinal study on HIV-1 patients initiating ART without (n=13) or with (n=13) co-trimoxazole (TMP-SMX) as prophylaxis against Pneumocystis jirovecii. Following ART, levels of LPS-binding protein (LBP) were reduced only in the TMP-SMX group, whilst levels of sCD14 declined in both groups after one year. The LBP decrease remained significant in a multivariate analysis model adjusting for co-variates including BL CD4+ T-cell count. This study confirmed that concomitant use of antibiotics and ART in severely immune deteriorated individuals may beneficially influence the kinetics of MT markers. In the third study, the composition of gut microbiota was determined by 16S rRNA sequencing in 28 HIV-1 progressors, 3 Elite controllers (EC) and 9 uninfected controls at BL, and additionally after ten months of ART in 16 subjects. Gut microbiome α-diversity was reduced in HIV-1 infected individuals as compared to controls, and further declined after introduction of ART. At BL, α-diversity was positively correlated with CD4+ T-cell counts, but in contrary several markers of MT/immune activation were inversely correlated. Microbiome of EC had the lowest interindividual variation (ß-diversity), clustering together in PCoA analysis. The bacterial composition at genus level was altered in HIV-1 progressors with higher abundance of Lactobacillus, and depletion of Lachnobacterium, Faecalibacterium and Hemophilus. Thus, this study showed that the alternations of gut microbiota during HIV-1 infection are associated with the level of immune dysfunction, and that almost one year of ART does not restore the shifts in the gut microbiome. In the last work, we studied the gut microbiome of 16 EC in relation to 32 matched ART naive HIV-1 positive individuals and 16 uninfected controls. The number of observed genera and richness indices Chao-1 and ACE were significantly higher in EC as compared to naive patients. The gut microbiota in EC was enriched in genera Succinivibrio, Sutterella, Rhizobium, Delftia, Anaerofilum and Oscillospira, whilst Blautia and Anaerostipes were reduced. Determination of inferred bacterial functionality by PICRUSt analysis revealed that carbohydrate metabolism related genes were depleted in EC. In contrary, pathways related to fatty acid metabolism, PPAR-signaling and lipid biosynthesis proteins were more abundant in EC vs naive. The kynurenine pathway of tryptophan metabolism was altered only during progressive HIV-1 infection, and kynurenine tryptophan (K/T) ratio was inversely associated with gut microbiota richness. This study shows that EC have richer gut microbiota than untreated HIV-1 patients with progressive infection, with a unique bacterial composition and a distinct metabolic profile which may be involved in the control of HIV-1. In summary, data from the studies in my thesis reveal that MT in HIV-1 infection is reduced by ART but also that the choice of ART influences this decline. Additionally, the antibiotics usage may affect the levels of MT. The complexity, composition and functionality of gut microbiota are disturbed in HIV-1 infected individuals with progressive disease, whilst EC have a unique gut microbiota profile that eventually contributes to their control of HIV-1

Richer gut microbiota with distinct metabolic profile in HIV infected Elite Controllers

Gut microbiota dysbiosis features progressive HIV infection and is a potential target for intervention. Herein, we explored the microbiome of 16 elite controllers (EC), 32 antiretroviral therapy naive progressors and 16 HIV negative controls. We found that the number of observed genera and richness indices in fecal microbiota were significantly higher in EC versus naive. Genera Succinivibrio, Sutterella, Rhizobium, Delftia, Anaerofilum and Oscillospira were more abundant in EC, whereas Blautia and Anaerostipes were depleted. Additionally, carbohydrate metabolism and secondary bile acid synthesis pathway related genes were less represented in EC. Conversely, fatty acid metabolism, PPAR-signalling and lipid biosynthesis proteins pathways were enriched in EC vs naive. The kynurenine pathway of tryptophan metabolism was altered during progressive HIV infection, and inversely associated with microbiota richness. In conclusion, EC have richer gut microbiota than untreated HIV patients, with unique bacterial signatures and a distinct metabolic profile which may contribute to control of HIV

Incidence of hypertension in people with HIV who are treated with integrase inhibitors versus other antiretroviral regimens in the RESPOND cohort consortium.

OBJECTIVE To compare the incidence of hypertension in people living with HIV receiving integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy (ART) versus non-nucleoside reverse transcriptase inhibitors (NNRTIs) or boosted protease inhibitors (PIs) in the RESPOND consortium of HIV cohorts. METHODS Eligible people with HIV were aged ≥18 years who initiated a new three-drug ART regimen for the first time (baseline), did not have hypertension, and had at least two follow-up blood pressure (BP) measurements. Hypertension was defined as two consecutive systolic BP measurements ≥140 mmHg and/or diastolic BP ≥90 mmHg or initiation of antihypertensives. Multivariable Poisson regression was used to determine adjusted incidence rate ratios (aIRRs) of hypertension, overall and in those who were ART naïve or experienced at baseline. RESULTS Overall, 4606 people living with HIV were eligible (INSTIs 3164, NNRTIs 807, PIs 635). The median baseline systolic BP, diastolic BP, and age were 120 (interquartile range [IQR] 113-130) mmHg, 78 (70-82) mmHg, and 43 (34-50) years, respectively. Over 8380.4 person-years (median follow-up 1.5 [IQR 1.0-2.7] years), 1058 (23.0%) participants developed hypertension (incidence rate 126.2/1000 person-years, 95% confidence interval [CI] 118.9-134.1). Participants receiving INSTIs had a higher incidence of hypertension than those receiving NNRTIs (aIRR 1.76; 95% CI 1.47-2.11), whereas the incidence was no different in those receiving PIs (aIRR 1.07; 95% CI 0.89-1.29). The results were similar when the analysis was stratified by ART status at baseline. CONCLUSION Although unmeasured confounding and channelling bias cannot be excluded, INSTIs were associated with a higher incidence of hypertension than were NNRTIs, but rates were similar to those of PIs overall, in ART-naïve and ART-experienced participants within RESPOND

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

Calibration of the CMS hadron calorimeters using proton-proton collision data at root s=13 TeV

Methods are presented for calibrating the hadron calorimeter system of theCMSetector at the LHC. The hadron calorimeters of the CMS experiment are sampling calorimeters of brass and scintillator, and are in the form of one central detector and two endcaps. These calorimeters cover pseudorapidities vertical bar eta vertical bar ee data. The energy scale of the outer calorimeters has been determined with test beam data and is confirmed through data with high transverse momentum jets. In this paper, we present the details of the calibration methods and accuracy.Peer reviewe

Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The second-order Fourier coefficients (v(2)) characterizing the azimuthal distributions of Y(1S) and Y(2S) mesons produced in PbPb collisions at root s(NN) = 5.02 TeV are studied. The Y mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb(-1). The scalar product method is used to extract the v2 coefficients of the azimuthal distributions. Results are reported for the rapidity range vertical bar y vertical bar < 2.4, in the transverse momentum interval 0 < pT < 50 GeV/c, and in three centrality ranges of 10-30%, 30-50% and 50-90%. In contrast to the J/psi mesons, the measured v(2) values for the Y mesons are found to be consistent with zero. (C) 2021 The Author(s). Published by Elsevier B.V.Peer reviewe