Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
158 result(s) for "Collier, Ann C."
Sort by:
Levels of HIV-1 persistence on antiretroviral therapy are not associated with markers of inflammation or activation
Antiretroviral therapy (ART) reduces levels of HIV-1 and immune activation but both can persist despite clinically effective ART. The relationships among pre-ART and on-ART levels of HIV-1 and activation are incompletely understood, in part because prior studies have been small or cross-sectional. To address these limitations, we evaluated measures of HIV-1 persistence, inflammation, T cell activation and T cell cycling in a longitudinal cohort of 101 participants who initiated ART and had well-documented sustained suppression of plasma viremia for a median of 7 years. During the first 4 years following ART initiation, HIV-1 DNA declined by 15-fold (93%) whereas cell-associated HIV-1 RNA (CA-RNA) fell 525-fold (>99%). Thereafter, HIV-1 DNA levels continued to decline slowly (5% per year) with a half-life of 13 years. Participants who had higher HIV-1 DNA and CA-RNA before starting treatment had higher levels while on ART, despite suppression of plasma viremia for many years. Markers of inflammation and T cell activation were associated with plasma HIV-1 RNA levels before ART was initiated but there were no consistent associations between these markers and HIV-1 DNA or CA-RNA during long-term ART, suggesting that HIV-1 persistence is not driving or driven by inflammation or activation. Higher levels of inflammation, T cell activation and cycling before ART were associated with higher levels during ART, indicating that immunologic events that occurred well before ART initiation had long-lasting effects despite sustained virologic suppression. These findings should stimulate studies of viral and host factors that affect virologic, inflammatory and immunologic set points prior to ART initiation and should inform the design of strategies to reduce HIV-1 reservoirs and dampen immune activation that persists despite ART.
Cells producing residual viremia during antiretroviral treatment appear to contribute to rebound viremia following interruption of treatment
During antiretroviral therapy (ART) that suppresses HIV replication to below the limit-of-quantification, virions produced during ART can be detected at low frequencies in the plasma, termed residual viremia (RV). We hypothesized that a reservoir of HIV-infected cells actively produce and release virions during ART that are potentially infectious, and that following ART-interruption, these virions can complete full-cycles of replication and contribute to rebound viremia. Therefore, we studied the dynamics of RV sequence variants in 3 participants who initiated ART after ~3 years of infection and were ART-suppressed for >6 years prior to self-initiated ART-interruptions. Longitudinal RV C2V5env sequences were compared to sequences from pre-ART plasma, supernatants of quantitative viral outgrowth assays (QVOA) of cells collected during ART, post-ART-interruption plasma, and ART-re-suppression plasma. Identical, \"putatively clonal,\" RV sequences comprised 8-84% of sequences from each timepoint. The majority of RV sequences were genetically similar to those from plasma collected just prior to ART-initiation, but as the duration of ART-suppression increased, an increasing proportion of RV variants were similar to sequences from earlier in infection. Identical sequences were detected in RV over a median of 3 years (range: 0.3-8.2) of ART-suppression. RV sequences were identical to pre-ART plasma viruses (5%), infectious viruses induced in QVOA (4%) and rebound viruses (5%) (total n = 21/154 (14%) across the 3 participants). RV sequences identical to ART-interruption \"rebound\" sequences were detected 0.1-7.4 years prior to ART-interruption. RV variant prevalence and persistence were not associated with detection of the variant among rebound sequences. Shortly after ART-re-suppression, variants that had been replicating during ART-interruptions were detected as RV (n = 5). These studies show a dynamic, virion-producing HIV reservoir that contributes to rekindling infection upon ART-interruption. The persistence of identical RV variants over years suggests that a subpopulation of HIV-infected clones frequently or continuously produce virions that may resist immune clearance; this suggests that cure strategies should target this active as well as latent reservoirs.
Effect of Early versus Deferred Antiretroviral Therapy for HIV on Survival
The timing of the initiation of antiretroviral therapy in asymptomatic patients with HIV infection is unclear. In this retrospective study involving patients in North America from 1996 through 2005, the deferral of therapy until the patient's CD4+ count had fallen below one of the two thresholds of interest (a range of 351 to 500 cells or >500 cells per cubic millimeter) was associated with a relative hazard of death of 1.69 and 1.94, respectively. In this retrospective study involving patients in North America, deferral of therapy until the patient's CD4+ count had fallen below one of the two thresholds of interest (a range of 351 to 500 cells or >500 cells per cubic millimeter) was associated with an increase in the risk of death of 69% and 94%, respectively. The use of antiretroviral therapy has dramatically reduced disease progression and death among patients with human immunodeficiency virus (HIV) infection, 1 , 2 but the optimal time to begin therapy is uncertain. 3 , 4 Current guidelines recommend treatment for asymptomatic patients who have a CD4+ count of less than 350 cells per cubic millimeter on the basis of accumulating observational data. 5 , 6 However, these guidelines note the lack of data from randomized clinical trials regarding the timing of the initiation of antiretroviral therapy. 3 , 4 Data from randomized trials are limited to an analysis of a subgroup of 477 patients 7 from the Strategies for . . .
Antigen specificities and proviral integration sites differ in HIV-infected cells by timing of antiretroviral treatment initiation
Despite effective antiretroviral therapy (ART), persons living with HIV harbor reservoirs of persistently infected CD4+ cells, which constitute a barrier to cure. Initiation of ART during acute infection reduces the size of the HIV reservoir, and we hypothesized that in addition, it would favor integration of proviruses in HIV-specific CD4+ T cells, while initiation of ART during chronic HIV infection would favor relatively more proviruses in herpesvirus-specific cells. We further hypothesized that proviruses in acute ART initiators would be integrated into antiviral genes, whereas integration sites (ISs) in chronic ART initiators would favor genes associated with cell proliferation and exhaustion. We found that the HIV DNA distribution across HIV-specific versus herpesvirus-specific CD4+ T cells was as hypothesized. HIV ISs in acute ART initiators were significantly enriched in gene sets controlling lipid metabolism and HIF-1α-mediated hypoxia, both metabolic pathways active in early HIV infection. Persistence of these infected cells during prolonged ART suggests a survival advantage. ISs in chronic ART initiators were enriched in a gene set controlling EZH2 histone methylation, and methylation has been associated with diminished long terminal repeat transcription. These differences that we found in antigen specificities and IS distributions within HIV-infected cells might be leveraged in designing cure strategies tailored to the timing of ART initiation.
Abacavir/Lamivudine Versus Tenofovir DF/Emtricitabine as Part of Combination Regimens for Initial Treatment of HIV: Final Results
Background. AIDS Clinical Trials Group A5202 compared blinded abacavir/lamivudine (ABC/3TC) to tenofovir DF/emtricitabine (TDF/FTC) with efavirenz (EFV) or atazanavir/ritonavir (ATV/r) in human immunodeficiency virus (HIV)-infected treatment-naive patients, stratified by screening HIV RNA (< or ≥10⁵ copies/mL). Due to higher virologie failure with ABC/3TC in the high HIV RNA stratum, blinded treatment was stopped in this group, but study follow-up continued for all patients. Methods. Primary endpoints were times to virologie failure, regimen modification, and safety event. Results. In the low HIV RNA stratum, time to virologie failure was similar for ABC/3TC vs TDF/FTC with ATV/r (hazard ratio [HR] 1.25, 95% confidence interval [CI] 0.76, 2.05) or EFV (HR 1.23, 95% CI 0.77, 1.96), with significantly shorter times to regimen modification for ABC/3TC with EFV or ATV/r and to safety events with EFV. Prior to stopping blinded treatment in the high stratum, higher virologie failure rates were seen with ABC/3TC with EFV (HR 2.46, 95% CI 1.20, 5.05) or ATV/r (HR 2.22, 95% CI 1.19, 4.14). Conclusions. In the low HIV RNA stratum, times to virologie failure for ABC/3TC or TDF/FTC were not different with EFV or ATV/r. In the high stratum, virologie failure rate was significantly higher for ABC/3TC than for TDF/FTC when given with either EFV or ATV/r.
Increased mucosal neutrophil survival is associated with altered microbiota in HIV infection
Gastrointestinal (GI) mucosal dysfunction predicts and likely contributes to non-infectious comorbidities and mortality in HIV infection and persists despite antiretroviral therapy. However, the mechanisms underlying this dysfunction remain incompletely understood. Neutrophils are important for containment of pathogens but can also contribute to tissue damage due to their release of reactive oxygen species and other potentially harmful effector molecules. Here we used a flow cytometry approach to investigate increased neutrophil lifespan as a mechanism for GI neutrophil accumulation in chronic, treated HIV infection and a potential role for gastrointestinal dysbiosis. We report that increased neutrophil survival contributes to neutrophil accumulation in colorectal biopsy tissue, thus implicating neutrophil lifespan as a new therapeutic target for mucosal inflammation in HIV infection. Additionally, we characterized the intestinal microbiome of colorectal biopsies using 16S rRNA sequencing. We found that a reduced Lactobacillus: Prevotella ratio associated with neutrophil survival, suggesting that intestinal bacteria may contribute to GI neutrophil accumulation in treated HIV infection. Finally, we provide evidence that Lactobacillus species uniquely decrease neutrophil survival and neutrophil frequency in vitro, which could have important therapeutic implications for reducing neutrophil-driven inflammation in HIV and other chronic inflammatory conditions.
U.S. patient preferences for long‐acting HIV treatment: a discrete choice experiment
Introduction Recent advances in long‐acting antiretroviral therapy (LA‐ART) could provide new options for HIV treatment and reduce adherence barriers, if regimens are acceptable to patients. We elicited preferences for key attributes of potential LA‐ART regimens among people with HIV (PWH) in the United States, focusing on four treatment modes (oral tablets, subcutaneous injections, intramuscular injections, and implants), product characteristics and location of administration. Methods A discrete choice experiment was conducted among PWH aged ≥18 years recruited from HIV clinics in Washington State and Atlanta, Georgia from March 2021 to June 2022. Participants responded to 17 choice scenarios, each with three options: two systematically generated hypothetical LA‐ART regimens and a constant opt‐out (their current daily oral treatment). LA‐ART regimen descriptions included treatment mode, pain, dosing frequency, location, pre‐treatment time with undetectable viral load, pre‐treatment negative reaction testing and “late‐dose leeway” (i.e. flexibility or forgiveness in timing the next dose). We used conditional logistic regression, with an interaction between treatment mode and pain, to estimate preference weights for all attribute levels. Results Seven hundred participants (350 at each site) enrolled, with median age 51 years (range 18–73); 70% identified as cisgender male, 24% as cisgender female and 6% as non‐binary or transgender. LA oral tablets were the only mode preferred over current daily oral treatment, with annual implants and injections the next most preferred LA‐ART option. Longer time between doses was preferred, and administration at home was preferred to clinics, which were preferred to pharmacies. Attributes with less impact on preferences included oral lead‐in treatment to achieve viral suppression or test for negative reactions and late‐dose leeway around the prescribed dosing interval. Participants in Atlanta were more likely to prefer their current daily oral ART than participants from Seattle. Conclusions PWH in the United States may soon have several options for LA‐ART. Our results suggest that LA oral tablets will be preferred by many patients over their current daily oral treatment, while implants and injections with longer duration may be acceptable to some. Future research should investigate sources of preference heterogeneity and actual uptake of and adherence to LA‐ART products, when available.
Decay of the HIV Reservoir in Patients Receiving Antiretroviral Therapy for Extended Periods: Implications for Eradication of Virus
The persistence of latently infected resting CD4+ T cells has been clearly demonstrated in human immunodeficiency virus (HIV)—infected individuals receiving effective antiviral therapy. However, estimates of the half-life of this viral reservoir have been quite divergent. We demonstrate clear evidence for decay of this HIV reservoir in patients who initiated antiviral therapy early in infection. The half-life of this latent viral reservoir was estimated to be 4.6 months. It is projected that it will take up to 7.7 years of continuous therapy to completely eliminate latently infected resting CD4+ T cells in infected individuals who initiate antiviral therapy early in HIV infection.
Transmission of HIV-1 drug resistance mutations within partner-pairs: A cross-sectional study of a primary HIV infection cohort
Transmission of human immunodeficiency virus type 1 (HIV-1) drug resistance mutations, particularly that of minority drug-resistant variants, remains poorly understood. Population-based studies suggest that drug-resistant HIV-1 is less transmissible than drug-susceptible viruses. We compared HIV-1 drug-resistant genotypes among partner-pairs in order to assess the likelihood of transmission of drug resistance mutations and investigate the role of minority variants in HIV transmission. From 1992-2010, 340 persons with primary HIV-1 infection and their partners were enrolled into observational research studies at the University of Washington Primary Infection Clinic (UWPIC). Out of 50 partner-pairs enrolled, 36 (72%) transmission relationships were confirmed by phylogenetic distance analysis of HIV-1 envelope (env) sequences, and 31 partner-pairs enrolled after 1995 met criteria for this study. Drug resistance mutations in the region of the HIV-1 polymerase gene (pol) that encodes protease and reverse transcriptase were assessed by 454-pyrosequencing. In 25 partner-pairs where the transmission direction could be determined, 12 (48%) transmitters had 1-4 drug resistance mutations (23 total) detected in their HIV-1 populations at a median frequency of 6.0% (IQR 1.5%-98.7%, range 1.0%-99.6%). Of 10 major mutations detected in five transmitters at a frequency >95%, 100% (95% CI 69.2%-100%) were detected in recipients. All of these transmitters were antiretroviral (ARV)-naïve at the time of specimen collection. Fourteen mutations (eight major mutations and six accessory mutations) were detected in nine transmitters at low frequencies (1.0%-11.8%); four of these transmitters had previously received ARV therapy. Two (14% [95% CI 1.8%-42.8%]) G73S accessory mutations were detected in both transmitter and recipient. This number is not significantly different from the number expected based on the observed frequencies of drug-resistant viruses in transmitting partners. Limitations of this study include the small sample size and uncertainties in determining the timing of virus transmission and mutation history. Drug-resistant majority variants appeared to be commonly transmitted by ARV-naïve participants in our analysis and may contribute significantly to transmitted drug resistance on a population level. When present at low frequency, no major mutation was observed to be shared between partner-pairs; identification of accessory mutations shared within a pair could be due to transmission, laboratory artifact, or apolipoprotein B mRNA-editing enzyme, catalytic polypeptides (APOBECs), and warrants further study.
Superior Control of HIV-1 Replication by CD8+ T Cells Targeting Conserved Epitopes: Implications for HIV Vaccine Design
A successful HIV vaccine will likely induce both humoral and cell-mediated immunity, however, the enormous diversity of HIV has hampered the development of a vaccine that effectively elicits both arms of the adaptive immune response. To tackle the problem of viral diversity, T cell-based vaccine approaches have focused on two main strategies (i) increasing the breadth of vaccine-induced responses or (ii) increasing vaccine-induced responses targeting only conserved regions of the virus. The relative extent to which set-point viremia is impacted by epitope-conservation of CD8(+) T cell responses elicited during early HIV-infection is unknown but has important implications for vaccine design. To address this question, we comprehensively mapped HIV-1 CD8(+) T cell epitope-specificities in 23 ART-naïve individuals during early infection and computed their conservation score (CS) by three different methods (prevalence, entropy and conseq) on clade-B and group-M sequence alignments. The majority of CD8(+) T cell responses were directed against variable epitopes (p<0.01). Interestingly, increasing breadth of CD8(+) T cell responses specifically recognizing conserved epitopes was associated with lower set-point viremia (r = - 0.65, p = 0.009). Moreover, subjects possessing CD8(+) T cells recognizing at least one conserved epitope had 1.4 log10 lower set-point viremia compared to those recognizing only variable epitopes (p = 0.021). The association between viral control and the breadth of conserved CD8(+) T cell responses may be influenced by the method of CS definition and sequences used to determine conservation levels. Strikingly, targeting variable versus conserved epitopes was independent of HLA type (p = 0.215). The associations with viral control were independent of functional avidity of CD8(+) T cell responses elicited during early infection. Taken together, these data suggest that the next-generation of T-cell based HIV-1 vaccines should focus on strategies that can elicit CD8(+) T cell responses to multiple conserved epitopes of HIV-1.