Single-cell landscape of immunological responses in patients with COVID-19.

In coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the relationship between disease severity and the host immune response is not fully understood. Here we performed single-cell RNA sequencing in peripheral blood samples of 5 healthy donors and 13 patients with COVID-19, including moderate, severe and convalescent cases. Through determining the transcriptional profiles of immune cells, coupled with assembled T cell receptor and B cell receptor sequences, we analyzed the functional properties of immune cells. Most cell types in patients with COVID-19 showed a strong interferon-α response and an overall acute inflammatory response. Moreover, intensive expansion of highly cytotoxic effector T cell subsets, such as CD4+ effector-GNLY (granulysin), CD8+ effector-GNLY and NKT CD160, was associated with convalescence in moderate patients. In severe patients, the immune landscape featured a deranged interferon response, profound immune exhaustion with skewed T cell receptor repertoire and broad T cell expansion. These findings illustrate the dynamic nature of immune responses during disease progression.

Single-cell RNA sequencing reveals intrahepatic and peripheral immune characteristics related to disease phases in HBV-infected patients.

OBJECTIVE: A comprehensive immune landscape for HBV infection is pivotal to achieve HBV cure. DESIGN: We performed single-cell RNA sequencing of 2 43 000 cells from 46 paired liver and blood samples of 23 individuals, including six immune tolerant, 5 immune active (IA), 3 acute recovery (AR), 3 chronic resolved and 6 HBV-free healthy controls (HCs). Flow cytometry and histological assays were applied in a second HBV cohort for validation. RESULTS: Both IA and AR were characterised by high levels of intrahepatic exhausted CD8+ T (Tex) cells. In IA, Tex cells were mainly derived from liver-resident GZMK+ effector memory T cells and self-expansion. By contrast, peripheral CX3CR1+ effector T cells and GZMK+ effector memory T cells were the main source of Tex cells in AR. In IA but not AR, significant cell-cell interactions were observed between Tex cells and regulatory CD4+ T cells, as well as between Tex and FCGR3A+ macrophages. Such interactions were potentially mediated through human leukocyte antigen class I molecules together with their receptors CANX and LILRBs, respectively, contributing to the dysfunction of antiviral immune responses. By contrast, CX3CR1+GNLY+ central memory CD8+ T cells were concurrently expanded in both liver and blood of AR, providing a potential surrogate marker for viral resolution. In clinic, intrahepatic Tex cells were positively correlated with serum alanine aminotransferase levels and histological grading scores. CONCLUSION: Our study dissects the coordinated immune responses for different HBV infection phases and provides a rich resource for fully understanding immunopathogenesis and developing effective therapeutic strategies.

Compromised long-lived memory CD8+ T cells are associated with reduced IL-7 responsiveness in HIV-infected immunological nonresponders.

Immune deficiency is one of the hallmarks of HIV infection and a major cause of adverse outcomes in people living with HIV (PLWH). Long-lived memory CD8+ T cells (LLMCs) are essential executors of long-term protective immunity; however, the generation and maintenance of LLMCs during chronic HIV infection are not well understood. In the present study, we analyzed circulating LLMCs in healthy controls (HCs) and PLWH with different disease statuses, including treatment naïve patients (TNs), complete responders (CRs), and immunological nonresponders (INRs). We found that both TNs and INRs showed severely compromised LLMCs compared with HCs and CRs, respectively. The decrease of LLMCs in TNs correlated positively with the reduction of their precursors, namely memory precursor effector T cells (MPECs), which might be associated with elevated pro-inflammatory cytokines. Strikingly, INRs showed an accumulation of MPECs, which exhibited diminished responsiveness to interleukin 7 (IL-7), thereby indicating abrogated differentiation into LLMCs. Moreover, in vitro studies showed that treatment with dexamethasone could improve the IL7-phosphorylated (p)-signal transducer and activator of transcription (STAT5) response by upregulating the expression of the interleukin 7 receptor (IL-7Rα) on MPECs in INRs. These findings provide insights that will encourage the development of novel therapeutics to improve immune function in PLWH.

Dynamics of HIV reservoir decay and naïve CD4 T-cell recovery between immune non-responders and complete responders on long-term antiretroviral treatment.

BACKGROUND: The dynamics of viral reservoir decay and naïve CD4 T-cell recovery between immunological non-responders (INR) and complete responders (CR) during long-term antiretroviral treatment (ART) are not fully known. METHODS: Twenty-eight chronic HIV-infected individuals on 5-year ART were divided into two groups: INR (CD4 counts ≤350 cells/µL, n = 13) and CR (CD4 counts ≥500 cells/µL, n = 15). The levels of HIV DNA and cell-associated HIV RNA (CA-RNA), CD4 counts, naïve CD4 counts and their correlations were analyzed at baseline, years 1, 3 and 5 of ART between the two groups. Expression of PD-1 on CD4 T-cells was quantified by flow cytometry. Linear mixed effect models were used to estimate the change procession in repeated measurements over 5 years. Slopes of the above-mentioned indicators were estimated using participant-specific linear regressions, respectively. RESULTS: INR maintained higher levels of HIV DNA and CA-RNA with higher percentages of PD-1+CD4 T-cells compared with CR during 5-year ART, concurrent with lower naïve CD4 T-cells. However, the rates of HIV DNA and CA-RNA decay in INR were not different from that in CR over time, and INR had higher rates of naïve CD4 T-cell percentage recovery. The baseline levels of HIV DNA were positively associated with the 5-year levels of HIV DNA, but negatively associated with the 5-year naïve CD4 counts. CONCLUSIONS: INR maintained significantly higher viral reservoir and lower naïve CD4 T-cells compared with CR during 5-year ART, however, the rates of reservoir decay and naïve CD4 T-cell percentage growth within INR were not lower than that in CR over time.

Transforming growth factor-ß promotes the function of HIV-specific CXCR5+ CD8 T cells.

HIV replication can be inhibited by CXCR5+ CD8 T cells (follicular cytotoxic T cell [TFC]) which transfer into B-cell follicles where latent HIV infection persists. However, how cytokines affect TFC remain unclear. Understanding which cytokines show the ability to affect TFC could be a key strategy toward curing HIV. Similar mechanisms could be used for the growth and transfer of TFCs and follicular helper T (TFH) cells; as a result, we hypothesized that cytokines IL-6, IL-21, and transforming growth factor-ß (TGF-ß), which are necessary for the differentiation of TFH cells, could also dictate the development of TFCs. In this work, lymph node mononuclear cells and peripheral blood mononuclear cells from HIV-infected individuals were cocultured with IL-6, IL-21, and TGF-ß. We then carried out T-cell receptor (TCR) repertoire analysis to compare the differences between CXCR5- and CXCR5+ CD8 T cells. Our results showed that the percentage and function of TFC can be enhanced by stimulation with TGF-ß. Besides, TGF-ß stimulation enhanced the diversity of TCR and complementarity-determining region 3 sequences. HIV DNA showed a negative correlation with TFC. The use of TGF-ß to promote the expression of CXCR5+ CD8 T cells could become a new treatment approach for curing HIV.

Serum Copper Concentrations, Effect Modifiers and Blood Pressure: Insights from NHANES 2011-2014.

(1) Background: Epidemiological studies on the relationship between serum copper and hypertension are contradictory. We assessed the relationship between serum copper and blood pressure among adults in the United States. (2) Methods: We divided hypertension into two categories: treated hypertension and untreated hypertension. Linear or logistic regression analysis was applied to investigate the association between serum copper concentrations and blood pressure levels. (3) Results: As compared to quartile 1, the odds ratios (ORs) for untreated hypertension in quartiles 2, 3, and 4 were 1.02 (0.74-1.42), 1.23 (0.88-1.72), and 1.08 (0.74-1.58), respectively, in multivariable analysis (all p > 0.05). In non-hypertension, as compared with quartile 1, the ß (95% CI) of systolic blood pressure for quartiles 2, 3, and 4 was -0.92 (-2.07-0.23), -0.05 (-1.30-1.20), and -0.48 (-1.83-0.88), respectively, in multivariable analysis (all p > 0.05). As compared to quartile 1, the ORs for treated hypertension in quartiles 2, 3, and 4 were 1.36 (0.88-2.10), 1.35 (0.87-2.09), and 1.56 (0.98-2.47), respectively, upon multivariable analysis including antihypertensive medication use as a covariate (all p > 0.05). Furthermore, 1SD increase in serum copper was non-significantly associated with 1.16 (0.97-1.37)-fold increased risk of hypertension in multivariable analysis (p = 0.096). (4) Conclusion: In the present study, we discovered that the serum copper concentration was not related with hypertension or blood pressure levels. Antihypertensive drug use may distort the correlation between copper and blood pressure levels. Information on antihypertensive drug use may be taken into account when identifying new risk factors for hypertension.

Severe intestinal barrier damage in HIV-infected immunological non-responders.

The intestinal epithelial barrier plays an important role during human immunodeficiency virus (HIV) disease progression. However, the extent to which the intestinal epithelial barrier is damaged in immunological non-responders (INRs) and immunological responders (IRs) is largely unknown. In this study, we investigated and compared the levels of intestinal gland damage and related molecules, including the tight junction protein claudin-1, apoptosis marker caspase-3, HIV DNA, CD4+ T cell count, and inflammation marker tumor necrosis factor-α (TNF-α) among the IRs (n = 10), INRs (n = 8), and healthy controls (HCs, n = 7). Intestinal damage was not completely restored in both INRs and IRs and was more serious in INRs than that in IRs. Moreover, intestinal damage was positively correlated with HIV DNA levels and negatively correlated with CD4+ T cell counts. These results provide insight into understanding the characteristics of intestinal epithelial barrier damage between IRs and INRs.

[Prospective controlled trial of safety of human umbilical cord derived-mesenchymal stem cell transplantation in patients with decompensated liver cirrhosis].

OBJECTIVE: To evaluate the safety of human umbilical cord derived-mesenchymal stem cell (UC-MSC) transplantation therapy in patients with decompensated liver cirrhosis. METHODS: UC-MSCs were transplanted intravenously into patients with decompensated liver cirrhosis. Serum levels of glucose (GLU), total cholesterol (TC), blood urea nitrogen (BUN), alpha fetoprotein (AFP), white blood cells (WBC), and prothrombin activity (PA) were detected at different time points after UC-MSCs transplantation. RESULTS: Most UC-MSC transplanted patients experienced an improvement in quality of life, to varying degrees. With the exception of low-grade fever in a few patients, side effects and oncogenic events were rare (treatment group: 1/38 vs. control group: 1/16; P more than 0.05). The UC-MSCs transplantation showed no effect on GLU, TC, BUN, AFP, WBC, or PA. CONCLUSION: UC-MSCs transplantation in patients with decompensated liver cirrhosis is safe and may improve the patient's quality of life.

J-shaped association between serum albumin levels and long-term mortality of cardiovascular disease: Experience in National Health and Nutrition Examination Survey (2011-2014).

Background: Cardiovascular disease (CVD) is a constellation of heart, brain, and peripheral vascular diseases with common soil hypothesis of etiology, and its subtypes have been well-established in terms of the albumin-mortality association. However, the association between albumin and the mortality of CVD as a whole remains poorly understood, especially the non-linear association. We aimed to investigate the association of albumin levels with long-term mortality of CVD as a whole. Materials and methods: This study included all CVD patients who participated in the National Health and Nutrition Examination Survey (NHANES 2011-2014). CVD was defined as coronary heart disease, stroke, heart failure, or any combination of these two or three diseases. Serum albumin was tertile partitioned: tertile 1, <4.1; tertile 2, 4.1-4.3; and tertile 3, >4.3 g/dl. COX proportional hazards model was used to assess the association between the serum albumin levels and CVD mortality. Restricted cubic spline (RCS) curves were used to explore the non-linear relationship. Results: A total of 1,070 patients with CVD were included in the analysis, of which 156 deaths occurred during a median 34 months of follow-up. On a continuous scale, per 1 g/dl albumin decrease was associated with an adjusted HR (95% CI) of 3.85 (2.38-6.25). On a categorical scale, as compared with tertile 3, the multivariable adjusted hazard ratio (95% CI) was 1.42 (0.74-2.71) for the tertile 2, and 2.24 (1.20-4.16) for the tertile 1, respectively, with respect to mortality. RCS curve analysis revealed a J-shaped association between albumin and CVD mortality. Conclusion: A J-shaped association between low serum albumin levels and increased long-term mortality of CVD has been revealed. This J-shaped association's implications for CVD prevention and treatment are deserving of being further studied.

Global transcriptomic characterization of T cells in individuals with chronic HIV-1 infection.

To obtain a comprehensive scenario of T cell profiles and synergistic immune responses, we performed single-cell RNA sequencing (scRNA-seq) on the peripheral T cells of 14 individuals with chronic human immunodeficiency virus 1 (HIV-1) infection, including nine treatment-naive (TP) and eight antiretroviral therapy (ART) participants (of whom three were paired with TP cases), and compared the results with four healthy donors (HD). Through analyzing the transcriptional profiles of CD4+ and CD8+ T cells, coupled with assembled T cell receptor sequences, we observed the significant loss of naive T cells, prolonged inflammation, and increased response to interferon-α in TP individuals, which could be partially restored by ART. Interestingly, we revealed that CD4+ and CD8+ Effector-GNLY clusters were expanded in TP cases, and persistently increased in ART individuals where they were typically correlated with poor immune restoration. This transcriptional dataset enables a deeper understanding of the pathogenesis of HIV-1 infection and is also a rich resource for developing novel immune targeted therapeutic strategies.

Implications of the accumulation of CXCR5+ NK cells in lymph nodes of HIV-1 infected patients.

BACKGROUND: B cell follicles are immune-privileged sites where intensive HIV-1 replication and latency occur, preventing a permanent cure. Recent study showed that CXCR5+ NK cells in B cell follicles can inhibit SIV replication in African green monkeys, but this has not been reported in HIV-1 infected patients. METHODS: Lymphocytes and tissue sections of lymph node were collected from 11 HIV-1 positive antiretroviral therapy (ART)-naive and 19 HIV-1 negative donors. We performed immunofluorescence and RNA-scope to detect the location of CXCR5+ NK cells and its relationship with HIV-1 RNA, and performed flow cytometry and RNA-seq to analyze the frequency, phenotypic and functional characteristics of CXCR5+ NK cells. The CXCL13 expression were detected by immunohistochemistry. FINDINGS: CXCR5+ NK cells, which accumulated in LNs from HIV-1 infected individuals, expressed high levels of activating receptors such as NKG2D and NKp44. CXCR5+ NK cells had upregulated expression of CD107a and ß-chemokines, which were partially impaired in HIV-1 infection. Importantly, the frequency of CXCR5+NK cells was inversely related to the HIV-1 viral burden in LNs. In addition, CXCL13-the ligand of CXCR5-was upregulated in HIV-1 infected individuals and positively correlated with the frequency of CXCR5+ NK cells. INTERPRETATION: During chronic HIV-1 infection, CXCR5+ NK cells accumulated in lymph node, exhibit altered immune characteristics and underlying anti-HIV-1 effect, which may be an effective target for a functional cure of HIV-1.

CCL5-Secreting Virtual Memory CD8+ T Cells Inversely Associate With Viral Reservoir Size in HIV-1-Infected Individuals on Antiretroviral Therapy.

Recent studies highlighted that CD8+ T cells are necessary for restraining reservoir in HIV-1-infected individuals who undergo antiretroviral therapy (ART), whereas the underlying cellular and molecular mechanisms remain largely unknown. Here, we enrolled 60 virologically suppressed HIV-1-infected individuals, to assess the correlations of the effector molecules and phenotypic subsets of CD8+ T cells with HIV-1 DNA and cell-associated unspliced RNA (CA usRNA). We found that the levels of HIV-1 DNA and usRNA correlated positively with the percentage of CCL4+CCL5- CD8+ central memory cells (TCM) while negatively with CCL4-CCL5+ CD8+ terminally differentiated effector memory cells (TEMRA). Moreover, a virtual memory CD8+ T cell (TVM) subset was enriched in CCL4-CCL5+ TEMRA cells and phenotypically distinctive from CCL4+ TCM subset, supported by single-cell RNA-Seq data. Specifically, TVM cells showed superior cytotoxicity potentially driven by T-bet and RUNX3, while CCL4+ TCM subset displayed a suppressive phenotype dominated by JUNB and CREM. In viral inhibition assays, TVM cells inhibited HIV-1 reactivation more effectively than non-TVM CD8+ T cells, which was dependent on CCL5 secretion. Our study highlights CCL5-secreting TVM cells subset as a potential determinant of HIV-1 reservoir size. This might be helpful to design CD8+ T cell-based therapeutic strategies for cure of the disease.

Interleukin-17-producing CD4(+) T cells increase with severity of liver damage in patients with chronic hepatitis B.

UNLABELLED: Interleukin-17 (IL-17)-producing CD4(+) T cells (Th17)-mediated immune response has been demonstrated to play a critical role in inflammation-associated disease; however, its role in chronic hepatitis B virus (HBV) infection remains unknown. Here we characterized peripheral and intrahepatic Th17 cells and analyzed their association with liver injury in a cohort of HBV-infected patients including 66 with chronic hepatitis B (CHB), 23 with HBV-associated acute-on-chronic liver failure (ACLF), and 30 healthy subjects as controls. The frequency of circulating Th17 cells increased with disease progression from CHB (mean, 4.34%) to ACLF (mean, 5.62%) patients versus healthy controls (mean, 2.42%). Th17 cells were also found to be largely accumulated in the livers of CHB patients. The increases in circulating and intrahepatic Th17 cells positively correlated with plasma viral load, serum alanine aminotransferase levels, and histological activity index. In vitro, IL-17 can promote the activation of myeloid dendritic cells and monocytes and enhance the capacity to produce proinflammatory cytokines IL-1beta, IL-6, tumor necrosis factor (TNF)-alpha, and IL-23 in both CHB patients and healthy subjects. In addition, the concentration of serum Th17-associated cytokines was also increased in CHB and ACLF patients. CONCLUSION: Th17 cells are highly enriched in both peripheral blood and liver of CHB patients, and exhibit a potential to exacerbate liver damage during chronic HBV infection.

HIV-1-Specific CD11c+ CD8+ T Cells Display Low PD-1 Expression and Strong Anti-HIV-1 Activity.

Exhaustion of HIV-1-specific CD8+ T cells prevents optimal control of HIV-1 infection. Identifying unconventional CD8+ T cell subsets to effectively control HIV-1 replication is vital. In this study, the role of CD11c+ CD8+ T cells during HIV-1 infection was evaluated. The frequencies of CD11c+ CD8+ T cells significantly increased and were negatively correlated with viral load in HIV-1-infected treatment-naïve patients. HIV-1-specific cells were enriched more in CD11c+ CD8+ T cells than in CD11c- CD8+ T cells, which could be induced by HIV-1-derived overlapping peptides, marking an HIV-1-specific CD8+ T cell population. This subset expressed higher levels of activating markers (CD38 and HLA-DR), cytotoxic markers (granzyme B, perforin, and CD107a), and cytokines (IL-2 and TNF-α), with lower levels of PD-1 compared to the CD11c- CD8+ T cell subset. In vitro analysis verified that CD11c+ CD8+ T cells displayed a stronger HIV-1-specific killing capacity than the CD11c- counterparts. These findings indicate that CD11c+ CD8+ T cells have potent immunotherapeutic efficacy in controlling HIV-1 infection.

Mesenchymal stem cell therapy in decompensated liver cirrhosis: a long-term follow-up analysis of the randomized controlled clinical trial.

BACKGROUND: Mesenchymal stem cell (MSC) infusion was reported to improve liver function in patients with decompensated liver cirrhosis (DLC); however, whether the medication can improve outcome of these patients is poorly understood. METHODS: This prospective, open-labeled, randomized controlled study enrolled 219 patients with HBV-related DLC who were divided into control group (n = 111) and umbilical cord-derived MSC (UC-MSC)-treated group (n = 108), then all of them received a follow-up check from October 2010 to October 2017. The treated patients received three times of UC-MSC infusions at 4-week intervals plus conventional treatment that was only used for control group. The overall survival rate and HCC-free survival rate were calculated as primary endpoints and the liver function and adverse events associated with the medication were also evaluated. RESULTS: During the follow-up check period from 13 to 75th months, there was a significantly higher overall survival rate in the treated group than the control group, while the difference of the hepatocellular carcinoma event-free survival rate between the treated and control groups was not observed during the 75-month follow-up. UC-MSC treatment markedly improved liver function, as indicated by the levels of serum albumin, prothrombin activity, cholinesterase, and total bilirubin during 48 weeks of follow-up. No significant side effects or treatment-related complications were observed in the UC-MSC group. CONCLUSIONS: Therapy of UC-MSC is not only well tolerated, but also significantly improves long-term survival rate, as well as the liver function in patients with HBV-related DLC. UC-MSC medication, therefore, might present a novel therapeutic approach for the disease.

Reversal of the CD8+ T-Cell Exhaustion Induced by Chronic HIV-1 Infection Through Combined Blockade of the Adenosine and PD-1 Pathways.

Background: Targeting immune checkpoints for HIV treatment potentially provides a double benefit resulting from the ability to restore viral-specific CD8+ T-cell functions and enhance HIV production from reservoir cells. Despite promising pre-clinical data, PD-1 blockade alone in HIV-1-infected patients with advanced cancer has shown limited benefits in controlling HIV, suggesting the need for additional targets beyond PD-1. CD39 and PD-1 are highly co-expressed on CD8+ T cells in HIV-1 infection. However, the characteristics of CD39 and PD-1 dual-positive CD8+ T-cell subsets in chronic HIV-1 infection remain poorly understood. Methods: This study enrolled 72 HIV-1-infected patients, including 40 treatment naïve and 32 ART patients. A total of 11 healthy individuals were included as controls. Different subsets of CD8+ T cells defined by CD39 and/or PD-1 expression were studied by flow cytometry. The relationships between the frequencies of the different subsets and parameters indicating HIV-1 disease progression were analyzed. Functional (i.e., cytokine secretion, viral inhibition) assays were performed to evaluate the impact of the blockade of adenosine and/or PD-1 signaling on CD8+ T cells. Results: The proportions of PD-1+, CD39+, and PD-1+CD39+ CD8+ T cells were significantly increased in treatment naïve patients but were partially lowered in patients on antiretroviral therapy. In treatment naïve patients, the proportions of PD-1+CD39+ CD8+ T cells were negatively correlated with CD4+ T-cell counts and the CD4/CD8 ratio, and were positively correlated with viral load. CD39+CD8+ T cells expressed high levels of the A2A adenosine receptor and were more sensitive to 2-chloroadenosine-mediated functional inhibition than their CD39- counterparts. In vitro, a combination of blocking CD39/adenosine and PD-1 signaling showed a synergic effect in restoring CD8+ T-cell function, as evidenced by enhanced abilities to secrete functional cytokines and to kill autologous reservoir cells. Conclusion: In patients with chronic HIV-1 infection there are increased frequencies of PD-1+, CD39+, and PD-1+CD39+ CD8+ T cells. In treatment naïve patients, the frequencies of PD-1+CD39+ CD8+ T cells are negatively correlated with CD4+ T-cell counts and the CD4/CD8 ratio and positively correlated with viral load. Combined blockade of CD39/adenosine and PD-1 signaling in vitro may exert a synergistic effect in restoring CD8+ T-cell function in HIV-1-infected patients.

Immune Dysfunctions of CD56neg NK Cells Are Associated With HIV-1 Disease Progression.

Background: Populations of natural killer cells lacking CD56 expression [CD56neg natural killer (NK) cells] have been demonstrated to expand during human immunodeficiency virus (HIV)-1 infection. However, their phenotypic and functional characteristics have not been systematically analyzed, and their roles during disease progression remain poorly understood. Methods: In this study, 84 donors, namely 34 treatment-naïve HIV-1-infected patients (TNs), 29 HIV-1-infected patients with successful antiretroviral therapy (ARTs), and 21 healthy controls (HCs), were enrolled. The phenotypic and functional characteristics of CD56neg NK cells were analyzed using single-cell RNA-sequencing (scRNA-seq) and flow cytometry. A potential link between the characteristics of CD56neg NK cells and the clinical parameters associated with HIV-1 disease progression was examined. Results: The frequency of the CD56neg NK cell population was significantly increased in TNs, which could be partially rescued by ART. Flow cytometry analyses revealed that CD56neg NK cells were characterized by high expression of CD39, TIGIT, CD95, and Ki67 compared to CD56dim NK cells. In vitro assays revealed reduced IFN-γ and TNF-α secretion, as well as decreased expression of granzyme B and perforin in CD56neg NK cells. In line with the data obtained by flow cytometry, scRNA-seq analysis further demonstrated impaired cytotoxic activities of CD56neg NK cells. Notably, a negative correlation was observed between CD39, CD95, and Ki67 expression levels in CD56neg NK cells and CD4+ T cell counts. Conclusions: The results presented in this study indicate that the CD56neg NK cell population expanded in HIV-1-infected individuals is dysfunctional and closely correlates with HIV-1 disease progression.

NLRP3 inflammasome induces CD4+ T cell loss in chronically HIV-1-infected patients.

Chronic HIV-1 infection is generally characterized by progressive CD4+ T cell depletion due to direct and bystander death that is closely associated with persistent HIV-1 replication and an inflammatory environment in vivo. The mechanisms underlying the loss of CD4+ T cells in patients with chronic HIV-1 infection are incompletely understood. In this study, we simultaneously monitored caspase-1 and caspase-3 activation in circulating CD4+ T cells, which revealed that pyroptotic and apoptotic CD4+ T cells are distinct cell populations with different phenotypic characteristics. Levels of pyroptosis and apoptosis in CD4+ T cells were significantly elevated during chronic HIV-1 infection, and decreased following effective antiretroviral therapy. Notably, the occurrence of pyroptosis was further confirmed by elevated gasdermin D activation in lymph nodes of HIV-1-infected individuals. Mechanistically, caspase-1 activation closely correlated with the inflammatory marker expression and was shown to occur through NLRP3 inflammasome activation driven by virus-dependent and/or -independent ROS production, while caspase-3 activation in CD4+ T cells was more closely related to T cell activation status. Hence, our findings show that NLRP3-dependent pyroptosis plays an essential role in CD4+ T cell loss in HIV-1-infected patients and implicate pyroptosis signaling as a target for anti-HIV-1 treatment.

Systematic Discovery and Pathway Analyses of Metabolic Disturbance in COVID-19.

Background: The ongoing global coronavirus disease 2019 (COVID-19) pandemic is posing a serious public health threat to nations worldwide. Understanding the pathogenesis of the disease and host immune responses will facilitate the discovery of therapeutic targets and better management of infected patients. Metabolomics technology can provide an unbiased tool to explore metabolic perturbation. Methods: Twenty-six healthy controls and 50 COVID-19 patients with mild, moderate, and severe symptoms in the Fifth Medical Center of PLA General Hospital from January 22 to February 16, 2020 were recruited into the study. Fasting blood samples were collected and subject to metabolomics analysis by liquid chromatography-mass spectrometry. Metabolite abundance was measured by peak area and was log-transformed before statistical analysis. The principal component analysis, different expression analysis, and metabolic pathway analysis were performed using R package. Co-regulated metabolites and their associations with clinical indices were identified by the weighted correlation network analysis and Spearman correlation coefficients. The potential metabolite biomarkers were analyzed using a random forest model. Results: We uncovered over 100 metabolites that were associated with COVID-19 disease and many of them correlated with disease severity. Sets of highly correlated metabolites were identified and their correlations with clinical indices were presented. Further analyses linked the differential metabolites with biochemical reactions, metabolic pathways, and biomedical MeSH terms, offering contextual insights into disease pathogenesis and host responses. Finally, a panel of metabolites was discovered to be able to discriminate COVID-19 patients from healthy controls, and also another list for mild against more severe cases. Our findings showed that in COVID-19 patients, citrate cycle, sphingosine 1-phosphate in sphingolipid metabolism, and steroid hormone biosynthesis were downregulated, while purine metabolism and tryptophan metabolism were disturbed. Conclusion: This study discovered key metabolites as well as their related biological and medical concepts pertaining to COVID-19 pathogenesis and host immune response, which will facilitate the selection of potential biomarkers for prognosis and discovery of therapeutic targets.

[Evaluation of the consistency between the measurement results of residual bone height and root surface area in periodontal supporting tissue].

PURPOSE: To explore the percentage of residual support height (Ph) and the percentage of residual root surface area (Ps) in evaluating periodontal support ability by simulating different stages of periodontitis based on the curved surface modeling. METHODS: Fifteen cone-beam CT (CBCT) images including 420 teeth in total were collected. The data were reconstructed into 3-dimensional teeth models by Mimics software.The 3D surface model of the tooth was then optimized by Geomagic software and then imported into Solidworks software to simulate different periodontal support height. Ph and Ps were measured and calculated to evaluate the consistency of Ph and Ps results in all tooth types. The data were analyzed with SPSS 22.0 software package. RESULTS: RSA in incisors, canines and premolars: coronal 1/3>middle 1/3>apical 1/3. RSA in molars: middle 1/3>coronal 1/3>apical 1/3. Maxillary first molar had the largest RSA, accounting for 11.60% of the dentition, which was about 3.18 times than mandibular central incisor. The difference between Ph and Ps in all types of teeth was statistically significant (P<0.01). The 95% confidence interval(CI) of the difference between Ph and Ps in the maxillary incisor, mandibular incisor, mandibular canine was between the clinical consistency limit (-15%, 15%). In the remaining tooth types, 95%CI of the difference between Ph and Ps was beyond the clinical consistency limit (-15%, 15%). CONCLUSIONS: For single-root tooth, except maxillary canine, the remaining periodontal support height could replace periodontal support area. For multi-rooted tooth, judging the ability of periodontal support ability only by alveolar bone absorption ratio in 2D index has significant limitations. Full consideration is needed to focus on root morphological discrepancy when determining the extent of periodontal disease.