Transcriptional Reprogramming during Effector-to-Memory Transition Renders CD4+ T Cells Permissive for Latent HIV-1 Infection.

The latent reservoir for HIV-1 in resting memory CD4+ T cells is the major barrier to curing HIV-1 infection. Studies of HIV-1 latency have focused on regulation of viral gene expression in cells in which latent infection is established. However, it remains unclear how infection initially becomes latent. Here we described a unique set of properties of CD4+ T cells undergoing effector-to-memory transition including temporary upregulation of CCR5 expression and rapid downregulation of cellular gene transcription. These cells allowed completion of steps in the HIV-1 life cycle through integration but suppressed HIV-1 gene transcription, thus allowing the establishment of latency. CD4+ T cells in this stage were substantially more permissive for HIV-1 latent infection than other CD4+ T cells. Establishment of latent HIV-1 infection in CD4+ T could be inhibited by viral-specific CD8+ T cells, a result with implications for elimination of latent HIV-1 infection by T cell-based vaccines.

An Ultra-broadband Metallic Plasmonic Antenna for Ultrasensitive Molecular Fingerprint Identification.

Near-field enhanced mid-infrared light-matter interactions via metallic plasmonic antennae (PA) have attracted much attention but are inevitably limited by the detuning between their narrow band and the broad applied spectral range. Here, we develop a new low-temperature incubation synthetic method to acquire uniform Ag microparticles (MPs) with numerous hotspots. Their plasmonic band is remarkably extended by the plasmonic coupling of numerous hotspots and covers the entire mid-infrared range (400-4000 cm-1). Hence, the almost complete molecular fingerprint of 4-mercaptobenzonitrile was successfully probed for the first time via resonant surface-enhanced infrared absorption (rSEIRA), and the rSEIRA spectra of different essential amino acids were further detected and exhibit a high spectral identification degree assisted by machine learning. This work changes the inertia perception of "narrow band and large size but small hotspot area" of mid-infrared metallic PA and paves the way for the ultrasensitive mid-infrared optical sensing.

CBX4 contributes to HIV-1 latency by forming phase-separated nuclear bodies and SUMOylating EZH2.

The retrovirus HIV-1 integrates into the host genome and establishes a latent viral reservoir that escapes immune surveillance. Molecular mechanisms of HIV-1 latency have been studied extensively to achieve a cure for the acquired immunodeficiency syndrome (AIDS). Latency-reversing agents (LRAs) have been developed to reactivate and eliminate the latent reservoir by the immune system. To develop more promising LRAs, it is essential to evaluate new therapeutic targets. Here, we find that CBX4, a component of the Polycomb Repressive Complex 1 (PRC1), contributes to HIV-1 latency in seven latency models and primary CD4+ T cells. CBX4 forms nuclear bodies with liquid-liquid phase separation (LLPS) properties on the HIV-1 long terminal repeat (LTR) and recruits EZH2, the catalytic subunit of PRC2. CBX4 SUMOylates EZH2 utilizing its SUMO E3 ligase activity, thereby enhancing the H3K27 methyltransferase activity of EZH2. Our results indicate that CBX4 acts as a bridge between the repressor complexes PRC1 and PRC2 that act synergistically to maintain HIV-1 latency. Dissolution of phase-separated CBX4 bodies could be a potential intervention to reactivate latent HIV-1.

Exploring the relationship between illness perception, self-management and quality of life among HIV-positive men who have sex with men.

AIMS: This study aimed to explore the mediating effect of self-management (SM) on the relationship between illness perception and quality of life (QOL) among Human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). DESIGN: A cross-sectional study. METHODS: We explored the effect of illness perception and self-management on QOL using the multiple regression model. Moreover, we conducted a simple mediation analysis to examine the role of SM in the relationship between illness perception and QOL. In addition, a parallel mediation analysis was performed to investigate the differences in domains of SM on the relationship between illness perception and QOL. RESULTS: Among 300 Chinese HIV-positive MSM, the mean score of SM was 39.9 ± 6.97, with a range of 14.0-54.0. The higher score in SM indicated a higher level of HIV SM. SM was negatively related to illness perception (r = -0.47) while positively related to QOL (r = 0.56). SM partially mediated the relationship between illness perception and QOL, accounting for 25.3% of the total effect. Specifically, both daily self-management health practices and the chronic nature of the self-management domain played a parallel role in mediating the relationship between illness perception and QOL. CONCLUSION: Our study demonstrated that SM was a significant factor influencing QOL among HIV-positive MSM. Focusing on daily self-management health practices and the chronic nature of self-management could be the potential key targets for enhancing HIV self-management strategies. IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE: This study emphasized the role of SM in the well-being of HIV-positive MSM and underscored the importance of developing interventions that integrate SM strategies to improve QOL in this population. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.

Characteristics and clinical significance of plasma IL-18, sCD14, and sCD163 levels in patients with HIV-1 infection.

Biomarkers of monocyte-macrophages activation and inflammation in plasma such as interleukin-18 (IL-18), soluble leukocyte differentiation antigen 14 (sCD14), and sCD163 are associated with disease severity and prognosis in HIV-1 infected patients, however, their relationships with efficacy of antiretroviral therapy (ART) need further investigation. We aimed to characterize and explore the clinical significance of plasma IL-18, sCD14, and sCD163 in this population. This was a retrospective cohort study consisting of HIV-1 infected patients enrolled in a randomized, controlled, open-label, noninferiority trial (ALTERLL study), with follow-up time points including initiation of ART (baseline), 12-, 24- and 48-weeks of treatment. Plasma levels of IL-18, sCD14, and sCD163 were measured using the enzyme-linked immunosorbent assay method. Viral suppression was defined as HIV-1 RNA < 20 copies/ml. Among the 193 studied patients (median age of 29.0 years, 180 males), IL-18 and sCD163 had U-shaped regression curves and sCD14 had an inverted U-shaped regression curve while the virus was decreased and immune function recovered. Patients with higher levels of IL-18 or lower levels of sCD163 at baseline were less likely to achieve viral suppression at Week 12 or Week 24 of treatment, respectively. In multivariate analysis, baseline sCD163 ≤ 500 pg/ml (adjusted odds ratio 0.33, 95% confidence interval 0.16-0.68) was independently associated with a lower rate of viral suppression at Week 24 of treatment. In conclusion, we demonstrated different dynamic changes among IL-18, sCD14, and sCD163 after ART. Baseline sCD163 level could be a potential predictor of early virological response to ART. Further validation and mechanistic research are needed.

Adherence to Antiretroviral Therapy and Its Predictive Factors Among People Living with HIV in China: A Behavioral Theory-Based Prospective Cohort Study.

BACKGROUND: Free antiretroviral therapy (ART) has been expanded to all people living with HIV (PLWH) in China since 2016, and adherence to ART has been shown to be the primary determinant of viral suppression. This study aimed to investigate the ART adherence and its associated factors among PLWH in China in the context of a scaling-up of treatment policy. METHOD: A prospective cohort study was conducted from June 2016 to May 2018 in Guangzhou, China. A total of 400 eligible participants were recruited from the Guangzhou Eighth People's hospital in Guangzhou, China. The Theory of Planned Behavior and the Behavioral Maintenance Theory were applied to guide the questionnaire design. Participants were invited to completed self-administered questionnaire at baseline and months 3 and 6 post-baseline. Logistic regression models were fitted to explore factors associated with ART adherence. RESULTS: Of the 400 participants, the prevalence of optimal ART adherence was 83.6% at month 3 and 83.3% at month 6. The baseline attitude (ORa = 1.11, P < 0.05), behavioral intention (ORa = 1.90, P < 0.05), and outcome expectations (ORa = 1.09, P < 0.001) predicted ART adherence at month 3 in adjusted analyses, but only outcome expectations (ORa = 1.09, P < 0.01) remained significant in the final multivariate model. At month 3, negative experiences (ORa = 0.62, P < 0.05) were the only predictor of adherence at month 6. CONCLUSION: Approximately 15% of participants reported suboptimal ART adherence. The developments of tailored interventions that target factors such as outcome expectations at baseline and negative experiences during treatment are warranted.

Au Polyhedron Array with Tunable Crystal Facets by PVP-Assisted Thermodynamic Control and Its Sharp Shape As Well As High-Energy Exposed Planes Co-Boosted SERS Activity.

A route is developed for directly growing 2D Au polyhedron arrays with controllable exposed facets of polyhedron by utilizing the substrate-supported 2D Au quasi-spherical nanoparticle arrays as the Au seed arrays, which cannot be realized by traditional lithography. In the reaction system, polyvinyl pyrrolidone (PVP) plays a vital role in guiding the reduced Au atoms and stabilizing the substrate-supported Au seeds. More importantly, by thermodynamic control, PVP as a capping agent can further direct the formation of {111} facets. The key to guarantee the integrity and periodicity of array is a proper reduction of Au ions and low growth rate of crystal. Benefiting from the higher electric field intensity near the sharp vertexes and edges of Au polyhedra and the exposed {110} facets with high energy, the Au polyhedron array with {110} facets encasing polyhedron exhibits good, stable surface enhanced Raman scattering activity toward 4-aminothiophenol among the involved arrays. The proposed fabrication approach tremendously enriches the structural diversity of Au nanoarrays on substrates and greatly overcomes the shortcoming of traditional lithography.

Atom Absorption Energy Directed Symmetry-Breaking Synthesis of Au-Ag Hierarchical Nanostructures and Their Efficient Photothermal Conversion.

Asymmetric plasmonic hierarchical nanostructures (HNs) are of great significance in optics, catalysis, and sensors, but the complex growth kinetics and lack of fine structure design limit their practical applications. Herein, a new atom absorption energy strategy is developed to achieve a series of Au-Ag HNs with the continuously tuned contact area in Janus and Ag island number/size on Au seeds. Different from the traditional passive growth mode, this strategy endows seed with a hand to capture the hetero atoms in a proactive manner, which is beyond the size, shape, and assembles of Au seed. Density functional theory reveals ththe adsorption of PDDA on Au surface leads to lower formation energy of Au-Ag bonds (-3.96 eV) than FSDNA modified Au surface (-2.44 eV). The competitive adsorption of two ligands on Au seed is the decisive factor for the formation of diverse Au-Ag HNs. In particular, the Au-Ag2 HNs exhibit outstanding photothermal conversion capability in the near-infrared window, and in vivo experiments verify them as superior photothermal therapy agents. This work highlights the importance of the atom absorption energy strategy in unlocking the diversity of HNs and may push the synthesis and application of superstructures to a higher level.

Prevalence of doravirine cross-resistance in HIV-infected adults who failed first-line ART in China, 2014-18.

OBJECTIVES: To evaluate the prevalence and characteristics of doravirine resistance and cross-resistance in patients who failed first-line ART in China. METHODS: From 2014 to 2108, 4132 patients from five provinces were tested for drug resistance by genotypic resistance testing. Drug resistance mutations were assessed using the Stanford HIVdb algorithm Version 9.0. Sequences classified as having low-level, intermediate and high-level resistance were defined as having drug resistance. RESULTS: Overall, the prevalence of doravirine and other NNRTIs cross-resistance was 69.5%, with intermediate and high-level resistance accounting for 56.4%. Doravirine resistance highly correlated with efavirenz (r = 0.720) and nevirapine (r = 0.721) resistance and moderately correlated with etravirine (r = 0.637) and rilpivirine (r = 0.692) resistance. The most frequent doravirine-associated resistance mutations were V106M (8.7%), K101E (6.8%) and P225H (5.1%). High-level resistance was mainly due to Y188L (3.2%) and M230L (2.7%). There were significant differences between genotypes and provinces. Compared with CRF01_AE, CRF07_BC (OR = 0.595, 95% CI = 0.546-0.648) and CRF08_BC (OR = 0.467, 95% CI = 0.407-0.536) were associated with lower risks of doravirine resistance. Conversely, genotype A (OR = 3.003, 95% CI = 1.806-4.991) and genotype B (OR = 1.250, 95% CI = 1.021-1.531) were associated with higher risks of doravirine resistance. The risk of doravirine resistance was significantly lower in Xinjiang compared with other provinces. CONCLUSIONS: In China, the prevalence of doravirine cross-resistance among patients who have failed first-line ART is high. Therefore, doravirine should not be used blindly without genotypic resistance testing and is not recommended for people who have failed first-line NNRTI-based ART.

Transmission networks of hepatitis C virus among HIV/HCV-coinfected patients in Guangdong, China.

BACKGROUND: Coinfection with hepatitis C virus (HCV) is common in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients due to shared routes of transmission. We aimed to investigate the characteristics of HCV subgenotypes among HIV/HCV-coinfected patients in Guangdong and explore the molecular transmission networks and related risk factors for HCV strains. METHODS: Plasma samples were obtained from 356 HIV/HCV-coinfected patients for HCV NS5B region sequencing. A neighbor-joining phylogenetic tree was constructed to affirm HCV subgenotypes. The transmission networks based on maximum likelihood phylogenetic tree were determined by Cluster Picker, and visualized using Cytoscape 3.2.1. RESULTS: A total of 302 HCV NS5B sequences were successfully amplified and sequenced from the 356 plasma samples. A neighbor-joining phylogenetic tree based on the 302 NS5B sequences revealed the profile of HCV subgenotypes circulating among HIV/HCV coinfection patients in Guangdong. Two predominant strains were found to be 6a (58.28%, 176/302) and 1b (18.54%, 56/302), followed by 3a (10.93%, 33/302), 3b (6.95%, 21/302), 1a (3.64%, 11/302), 2a (0.99%, 3/302) and 6n (0.66%, 2/302). A molecular transmission network of five major HCV genotypes was constructed, with a clustering rate of 44.04%. The clustering rates of subgenotypes 1a, 3a, 3b, 1b, and 6a were 18.18% (2/11), 42.42%, 52.38%, 48.21%, and 44.89%, respectively. Multivariate logistic regression analysis showed no significant effects from sex, age, transmission route, geographical region, baseline CD4 + T cell count or subgenotype (P > 0.05), except marital status. Married or cohabiting people (compared with unmarried people) had more difficulty forming transmission networks. CONCLUSIONS: In summary, this study, based on HCV NS5B subgenotypes, revealed the HCV subtype diversity and distribution among HIV/HCV-coinfected patients in Guangdong. Marital status inclined to be the factor influencing HCV transmission networks formation.

Baseline and Process Factors of Anti-Retroviral Therapy That Predict Loss to Follow-up Among People Living with HIV/AIDS in China: A Retrospective Cohort Study.

We explored the predictors and predictive models of loss to follow-up (LTFU) during the first year of anti-retroviral therapy (ART). LTFU was defined as the failure to visit the clinic for antiretroviral drugs for ≥ 90 days after the last missed scheduled visit. Based on the electronic medical records of 5953 patients who were HIV positive and began ART between 2016 and 2019 in China, the LTFU rate was 7.24 (95% confidence interval 6.49-7.97) per 100 person-years during the first year of ART. ART baseline factors were associated with LTFU, but were non-optimal predictors. A model including ART process-related factors such as follow-up behaviors and physical health status had an area under the receiver operating characteristic curve of 73.4% for predicting LTFU. Therefore, the medical records of follow-up visits can be used to identify patients with a high risk of LTFU and allow interventions to be implemented proactively.

Extraction and Quantification of Nanoparticulate Mercury in Natural Soils.

Nanoparticulate mercury (Hg-NPs) are ubiquitous in nature. However, the lack of data on their concentration in soils impedes reliable risk assessments. This is due to the analytical difficulties resulting from low ambient Hg concentrations and background interferences of heterogeneous soil components. Here, coupled to single particle inductively coupled plasma-mass spectrometry (spICP-MS), a standardized protocol was developed for extraction and quantification of Hg-NPs in natural soils with a wide range of properties. High particle number-, particle mass-, and total mass-based recoveries were obtained for spiked HgS-NPs (74-120%). Indigenous Hg-NPs across soils were within 107-1011 NPs g-1, corresponding to 3-40% of total Hg on a mass basis. Metacinnabar was the primary Hg species in extracted samples from the Wanshan mercury mining site, as characterized by X-ray absorption spectroscopy and transmission electron microscopy. In agreement with the spICP-MS analysis, electron microscopy revealed comparable size distribution for nanoparticles larger than 27 nm. These indigenous Hg-NPs contributed to 5-65% of the measured methylmercury in soils. This work paves the way for experimental determinations of indigenous Hg-NPs in natural soils, which is critical to understand the biogeochemical cycling of mercury and thereby the methylation processes governing the public exposure to methylmercury.

High stone-free rate immediately after suctioning flexible ureteroscopy with Intelligent pressure-control in treating upper urinary tract calculi.

BACKGROUND: The retrospective observational study aimed to evaluate the safety and efficacy of suctioning flexible ureteroscopy with Intelligent pressure-control (SFUI) on treating upper urinary tract calculi in a large cohort. METHODS: Between July 2020 and August 2021, 278 patients with upper urinary tract calculi who underwent SFUI in our hospital were enrolled. Outcomes were stone-free rate (SFR) in one session and one-month after SFUI treatment, and complications scored by the Clavien-Dindo classification. RESULTS: A total of 310 kidneys underwent SFUI were included. The median surgery time was 75 min (ranged 60-110 min). One session and one-month SFRs were 80.65% and 82.26%, respectively. The one-session SFR was ≧ 87% in patients with Guy's stone score of Grade I among stone size < 40 mm. Risk factors for unsuccessful stone-free in one session were stone history (adjusted odds ratio (aOR): 2.39, 95% confidence interval (CI): 1.21-4.73), stone size of 40-49 mm (aOR: 4.37, 95% CI: 1.16-16.45), Guy's stone score ≧ Grade II (Grade II, aOR: 3.54, 95% CI: 1.18-10.59; Grade III, aOR: 10.95, 95% CI: 2.65-45.25). The incidence of Clavien-Dindo grade II-III complication was 3.26%. Complication is associated with Guy's stone score III (aOR: 22.36, 95% CI: 1.81-276.36). CONCLUSION: SFUI shows good safety and efficiency on treating upper urinary tract calculi. Patients with stone size < 40 mm or Guy's stone score of Grade I have a high chance to reach stone-free after SFUI treatment.

Long-term Effects of a Social Media-Based Intervention (Run4Love) on Depressive Symptoms of People Living With HIV: 3-Year Follow-up of a Randomized Controlled Trial.

BACKGROUND: Emerging studies have shown the effectiveness of mobile health (mHealth) interventions in reducing depressive symptoms among people living with HIV. Most of these studies included only short-term follow-up, with limited data on long-term effects. OBJECTIVE: The purpose of this study is to assess the long-term effects of a randomized controlled trial called Run4Love on depressive symptoms among people living with HIV at 1-year and 3-year follow-ups. METHODS: A total of 300 people living with HIV with depressive symptoms were recruited and randomized to an intervention or a control group in Guangzhou, China, from September 2017 to January 2018. The intervention group received a 3-month Run4Love program, including adapted evidence-based cognitive behavioral stress management courses and exercise promotion via WeChat (Tencent), a popular social media app. The control group received usual care and a brochure on nutrition. The primary outcome was reduction in depressive symptoms, measured using the Center for Epidemiological Studies-Depression (CES-D) scale. Data used in this study were collected at baseline and at the 1-year and 3-year follow-ups. Generalized estimating equations were used to examine the group differences at 1-year and 3-year follow-ups. RESULTS: Approximately half of the participants completed the assessment at 1-year (149/300, 49.7%) and 3-year (177/300, 59%) follow-ups. At 1-year follow-up, participants in the intervention group reported significant reduction in depressive symptoms compared with the control group (CES-D: from 23.9 to 18.1 in the intervention group vs from 24.3 to 23.3 in the control group; mean -4.79, SD 13.56; 95% CI -7.78 to -1.81; P=.002). At 3-year follow-up, between-group difference in CES-D remained statistically significant (from 23.9 to 20.5 in the intervention group vs from 24.3 to 24.4 in the control group; mean -3.63, SD 13.35; 95% CI -6.71 to -0.54; P=.02). No adverse events were reported during the 3-year follow-up period. CONCLUSIONS: The mHealth intervention, Run4Love, significantly reduced depressive symptoms among people living with HIV, and the intervention effects were sustained at 1-year and 3-year follow-ups. Further research is needed to explore the mechanisms of the long-term effects of mHealth interventions such as Run4Love and to implement these effective interventions among people living with HIV. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-IPR-17012606; https://trialsearch.who.int/Trial2.aspx?TrialID=ChiCTR-IPR-17012606. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/10274.

Positive Coping as a Mediator of Mobile Health Intervention Effects on Quality of Life Among People Living With HIV: Secondary Analysis of the Randomized Controlled Trial Run4Love.

BACKGROUND: The effectiveness of psychosocial interventions on quality of life (QOL) among people living with HIV has been validated, including mobile health (mHealth) interventions. However, it is unclear which components of such interventions account for these effects. OBJECTIVE: This study aims to examine positive coping as a potential mediator of the effects of an mHealth intervention on QOL among people living with HIV. METHODS: For this secondary analysis, we used data from an mHealth-based randomized controlled trial, Run4Love, which was conducted to improve QOL and mental health outcomes of people living with HIV. A total of 300 participants were randomly assigned to the intervention group to receive the adapted cognitive-behavioral stress management courses and regular physical activity promotion or the waitlist control group in a 1:1 ratio. Our analysis focused on positive coping and QOL, which were repeatedly measured at baseline and at 3-, 6-, and 9-month follow-ups. Latent growth curve models were constructed to explore the mediating role of positive coping in the effects of the mHealth intervention on QOL. RESULTS: Positive coping served as a mediator in the effect of the mHealth intervention on QOL for up to 9 months. The mHealth intervention had a significant and positive indirect effect on the slope of QOL via the slope of positive coping (b=2.592×1.620=4.198, 95% CI 1.189-7.207, P=.006). The direct effect of the intervention was not significant (b=0.552, 95% CI -2.154 to 3.258, P=.69) when controlling for the mediator. CONCLUSIONS: The longitudinal findings suggest that positive coping could be a crucial mediator of the mHealth intervention in enhancing QOL among people living with HIV. These findings underscore the importance of improving positive coping skills in mHealth interventions to improve QOL among people living with HIV.

Talaromyces marneffei Mp1p Antigen Detection may Play an Important Role in the Early Diagnosis of Talaromycosis in Patients with Acquired Immunodeficiency Syndrome.

Talaromycosis is a life-threatening fungal disease commonly seen in patients with acquired immunodeficiency syndrome (AIDS), which is endemic in Southern China and Southeast countries. The diagnostic methods available for talaromycosis are relatively time-consuming and yield a high mortality. Therefore, early diagnosis of talaromycosis is extremely important. We aimed to determine a potential method for assisting in its early diagnosis. A total of 283 patients with AIDS admitted to our hospital were prospectively included in this cross-sectional study and divided into those with Talaromyces marneffei (TSM group, n = 93) and those without Talaromyces marneffei (non-TSM group, n = 190). The diagnostic accuracy of the Mp1p enzyme immunoassay (EIA), galactomannan (GM) assay, and blood culture performed within 3 days of hospitalisation were evaluated, using talaromycosis confirmed by culture and/or pathology as the gold standard. The positivity rates in the Mp1p EIA, GM assay, and blood culture were 72%, 64.5%, and 81.7%, respectively, in the TSM group. The sensitivity, specificity, and positive and negative predictive values of the Mp1p EIA were 72.0% (67/93), 96.8% (184/190), 91.8% (67/73), and 87.6% (184/210), respectively. The Mp1p EIA showed a substantial agreement with the gold standard (kappa: 0.729) and superiority to the GM assay (kappa: 0.603); it also showed a superior diagnostic accuracy in the patients with CD4+ counts of < 50 cells/µL compared to those with CD4+ counts ranged from 50-100 cells/µL. The Mp1p EIA has the advantage of assisting in the early diagnosis of talaromycosis in patients with AIDS, especially those with low CD4+ counts.

Understanding the risks of mercury sulfide nanoparticles in the environment: Formation, presence, and environmental behaviors.

Mercury (Hg) could be microbially methylated to the bioaccumulative neurotoxin methylmercury (MeHg), raising health concerns. Understanding the methylation of various Hg species is thus critical in predicting the MeHg risk. Among the known Hg species, mercury sulfide (HgS) is the largest Hg reservoir in the lithosphere and has long been considered to be highly inert. However, with advances in the analytical methods of nanoparticles, HgS nanoparticles (HgS NPs) have recently been detected in various environmental matrices or organisms. Furthermore, pioneering laboratory studies have reported the high bioavailability of HgS NPs. The formation, presence, and transformation (e.g., methylation) of HgS NPs are intricately related to several environmental factors, especially dissolved organic matter (DOM). The complexity of the behavior of HgS NPs and the heterogeneity of DOM prevent us from comprehensively understanding and predicting the risk of HgS NPs. To reveal the role of HgS NPs in Hg biogeochemical cycling, research needs should focus on the following aspects: the formation pathways, the presence, and the environmental behaviors of HgS NPs impacted by the dominant influential factor of DOM. We thus summarized the latest progress in these aspects and proposed future research priorities, e.g., developing the detection techniques of HgS NPs and probing HgS NPs in various matrices, further exploring the interactions between DOM and HgS NPs. Besides, as most of the previous studies were conducted in laboratories, our current knowledge should be further refreshed through field observations, which would help to gain better insights into predicting the Hg risks in natural environment.

X4-Tropic Latent HIV-1 Is Enriched in Peripheral Follicular Helper T Cells and Is Correlated with Disease Progression.

Follicular helper T (TFH) cells have been shown to support productive human immunodeficiency virus type 1 (HIV-1) replication and to serve as a key component of the latent viral reservoir. However, the viral characteristics of this latent reservoir and the clinical relevance of this reservoir remain unclear. In this study, we assessed the tropic composition of latent viruses from peripheral TFH (pTFH), non-TFH memory, and naive CD4+ T cells from individuals with HIV-1 infections on suppressive combined antiretroviral therapy (cART). X4-tropic latent HIV-1 was preferentially enriched in pTFH cells compared to levels in the other two subsets. Interestingly, the ratio of X4-tropic latent HIV-1 in pTFH cells not only was robustly and inversely correlated with blood CD4+ T cell counts across patients but also was prognostic of CD4+ T cell recovery in individuals on long-term cART. Moreover, patients with higher X4-tropic latent HIV-1 ratios in pTFH cells showed greater risks of opportunistic coinfections. These findings reveal the characteristics of latent HIV-1 in TFH cells and suggest that the ratio of X4-tropic latent HIV-1 in pTFH cells is a valuable indicator for disease progression and cART efficacy.IMPORTANCE TFH cells have been shown to harbor a significant amount of latent HIV-1; however, the viral characteristics of this reservoir and its clinical relevance remain largely unknown. In this study, we demonstrate that X4-tropic latent HIV-1 is preferentially enriched in pTFH cells, which also accurately reflects the viral tropism shift. The ratio of X4-tropic proviruses in pTFH cells but not in other memory CD4+ T cell subsets is inversely and closely correlated with blood CD4+ T cell counts and CD4+ T cell recovery rates with cART. Our data suggest that the ratio of X4-tropic provirus in peripheral TFH cells can be easily measured and reflects disease progression and treatment outcomes during cART.

PIWIL4 Maintains HIV-1 Latency by Enforcing Epigenetically Suppressive Modifications on the 5' Long Terminal Repeat.

Although substantial progress has been made in depicting the molecular pathogenesis of human immunodeficiency virus type 1 (HIV-1) infection, the comprehensive mechanism of HIV-1 latency and the most promising therapeutic strategies to effectively reactivate the HIV-1 latent reservoir to achieve a functional cure for AIDS remain to be systematically illuminated. Here, we demonstrated that piwi (P element-induced Wimpy)-like RNA-mediated gene silencing 4 (PIWIL4) played an important role in suppressing HIV-1 transcription and contributed to the latency state in HIV-1-infected cells through its recruitment of various suppressive factors, including heterochromatin protein 1α/ß/γ, SETDB1, and HDAC4. The knockdown of PIWIL4 enhanced HIV-1 transcription and reversed HIV-1 latency in both HIV-1 latently infected Jurkat T cells and primary CD4+ T lymphocytes and resting CD4+ T lymphocytes from HIV-1-infected individuals on suppressive combined antiretroviral therapy (cART). Furthermore, in the absence of PIWIL4, HIV-1 latently infected Jurkat T cells were more sensitive to reactivation with vorinostat (suberoylanilide hydroxamic acid, or SAHA), JQ1, or prostratin. These findings indicated that PIWIL4 promotes HIV-1 latency by imposing repressive marks at the HIV-1 5' long terminal repeat. Thus, the manipulation of PIWIL4 could be a novel strategy for developing promising latency-reversing agents (LRAs).IMPORTANCE HIV-1 latency is systematically modulated by host factors and viral proteins. During this process, the suppression of HIV-1 transcription plays an essential role in promoting HIV-1 latency. In this study, we found that PIWIL4 repressed HIV-1 promoter activity and maintained HIV-1 latency. In particular, we report that PIWIL4 can regulate gene expression through its association with the suppressive activity of HDAC4. Therefore, we have identified a new function for PIWIL4: it is not only a suppressor of endogenous retrotransposons but also plays an important role in inhibiting transcription and leading to latent infection of HIV-1, a well-known exogenous retrovirus. Our results also indicate a novel therapeutic target to reactivate the HIV-1 latent reservoir.

Persistent chronic immune activation in HIV/HBV-coinfected patients after antiretroviral therapy.

We studied the characteristics of immune activation and investigated the underlying mechanisms in patients with human immunodeficiency virus-1/hepatitis B virus (HIV/HBV) coinfection after receiving HBV-active antiretroviral therapy. Forty patients with HIV/HBV coinfection, 38 patients with HIV monoinfection and 20 healthy controls were enrolled. CD4+ count, HIV load, HBV load, markers of immune activation and regulatory T-cell (Treg cell) frequency were assessed and compared between HIV-monoinfected and HIV/HBV-coinfected patients at week 0 (baseline), 12, 24, 36 and 48 after the onset of HBV-active antiretroviral therapy. Before antiretroviral therapy, frequencies of CD4+ HLADR+ CD38+ , CD8+ HLADR+ CD38+ , and Treg cells, and sCD163 and sCD14 levels were significantly higher in both HIV/HBV-coinfected patients and HIV-monoinfected patients, compared with healthy controls. Frequencies of CD4+ HLADR+ CD38+ and CD8+ HLADR+ CD38+ cells decreased following antiretroviral therapy in both groups. sCD163 levels did not change significantly in both groups and no significant difference was observed between the two groups at each time point during the 48-week antiretroviral therapy. In week 24, levels of sCD14 and frequencies of Treg cells appeared significantly higher in HIV/HBV-coinfected patients than in HIV-monoinfected patients, in which sCD14 levels and Treg cell frequencies declined to those in healthy controls. The Treg cell frequency was consistent with that of sCD14 levels in HIV/HBV-coinfected patients. Coinfection with HBV significantly increases sCD14 levels in HIV-infected patients during HBV-active antiretroviral therapy, which may potentially contribute to liver inflammation.