Effect of SARS-CoV-2 Breakthrough Infection on HIV Reservoirs and T-Cell Immune Recovery in 3-Dose Vaccinated People Living with HIV.

People living with human immunodeficiency virus (PLWH) are a vulnerable population with a higher risk of severe coronavirus disease 2019 (COVID-19); therefore, vaccination is recommended as a priority. Data on viral reservoirs and immunologic outcomes for PLWH breakthrough infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are currently limited. In this study, we investigated the effects of SARS-CoV-2 breakthrough infection on hematological parameters, human immunodeficiency virus (HIV) reservoir size, and T-cell recovery in PLWH receiving antiretroviral therapy (ART) after SARS-CoV-2 booster vaccination. The results indicated that during breakthrough infection, booster vaccination with homologous and heterologous vaccines was safe in PLWH after receiving two doses of inactivated vaccination. The absolute CD4 counts decreased in the heterologous group, whereas the CD8 counts decreased in the homologous booster group after breakthrough infection in PLWH. Breakthrough infection increased HIV reservoirs and was associated with increased T-cell activation in PLWH who received virally suppressed ART and a 3-dose vaccination. According to our data, the breakthrough infection of SARS-CoV-2 may put PLWH at a greater risk for increased HIV reservoirs, even if these individuals were virally suppressed with ART after 3-dose SARS-CoV-2 vaccination.

Elevated glutamate impedes anti-HIV-1 CD8 + T cell responses in HIV-1-infected individuals on antiretroviral therapy.

CD8 + T cells are essential for long-lasting HIV-1 control and have been harnessed to develop therapeutic and preventive approaches for people living with HIV-1 (PLWH). HIV-1 infection induces marked metabolic alterations. However, it is unclear whether these changes affect the anti-HIV function of CD8 + T cells. Here, we show that PLWH exhibit higher levels of plasma glutamate than healthy controls. In PLWH, glutamate levels positively correlate with HIV-1 reservoir and negatively correlate with the anti-HIV function of CD8 + T cells. Single-cell metabolic modeling reveals glutamate metabolism is surprisingly robust in virtual memory CD8 + T cells (TVM). We further confirmed that glutamate inhibits TVM cells function via the mTORC1 pathway in vitro. Our findings reveal an association between metabolic plasticity and CD8 + T cell-mediated HIV control, suggesting that glutamate metabolism can be exploited as a therapeutic target for the reversion of anti-HIV CD8 + T cell function in PLWH.

Pyroptotic MAITs link microbial translocation with severity of alcohol-associated liver disease.

BACKGROUND: Mucosal-associated invariant T cells (MAITs) are markedly reduced in patients with alcohol-associated liver disease (ALD); however, the potential mechanism underlying MAITs' loss remains elusive. Hence, we aimed to explore what induced MAITs' loss and its clinical significance. METHODS: The characteristics of pyroptotic MAITs were evaluated in a cohort of patients with ALD, including 41 patients with alcohol-associated liver cirrhosis (ALC) and 21 patients with ALC complicated with severe alcoholic hepatitis (ALC + SAH). RESULTS: In patients with ALD, blood MAITs were significantly decreased, hyperactivated, and displayed enhanced cell death through pyroptosis. The frequencies of pyroptotic MAITs increased with disease severity in patients with ALC and patients with ALC + SAH. These frequencies were negatively associated with the frequencies of MAITs and positively correlated with the levels of MAITs' activation, plasma levels of intestinal fatty acid-binding protein (a marker of intestinal enterocyte damage), soluble CD14, lipopolysaccharide-binding protein, and peptidoglycan recognition proteins (surrogate markers of microbial translocation). Pyroptotic MAITs were also found in the liver of patients with ALD. Interestingly, MAITs underwent further activation and pyroptosis in vitro under stimulation by Escherichia coli or direct bilirubin. Notably, blocking IL-18 signaling reduced the activation and frequencies of pyroptotic MAITs. CONCLUSIONS: The loss of MAITs in patients with ALD is, at least in part, due to cell death from pyroptosis and is associated with the severity of ALD. Such increased pyroptosis may be affected by dysregulated inflammatory responses to intestinal microbial translocation or direct bilirubin.

Metabolic interventions improve HBV envelope-specific T-cell responses in patients with chronic hepatitis B.

BACKGROUND: Restoration of HBV-specific T cell immunity is a promising approach for the functional cure of chronic Hepatitis B (CHB), necessitating the development of valid assays to boost and monitor HBV-specific T cell responses in patients with CHB. METHODS: We analyzed hepatitis B virus (HBV) core- and envelope (env)-specific T cell responses using in vitro expanded peripheral blood mononuclear cells (PBMCs) from patients with CHB exhibiting different immunological phases, including immune tolerance (IT), immune activation (IA), inactive carrier (IC), and HBeAg-negative hepatitis (ENEG). Additionally, we evaluated the effects of metabolic interventions, including mitochondria-targeted antioxidants (MTA), polyphenolic compounds, and ACAT inhibitors (iACAT), on HBV-specific T-cell functionality. RESULTS: We found that HBV core- and env-specific T cell responses were finely coordinated and more profound in IC and ENEG than in the IT and IA stages. HBV env-specific T cells were more dysfunctional but prone to respond to metabolic interventions using MTA, iACAT, and polyphenolic compounds than HBV core-specific T-cells. The responsiveness of HBV env-specific T cells to metabolic interventions can be predicted by the eosinophil (EO) count and the coefficient of variation of red blood cell distribution width (RDW-CV). CONCLUSION: These findings may provide valuable information for metabolically invigorating HBV-specific T-cells to treat CHB.

Serum cytokine change profile associated with HBsAg loss during combination therapy with PEG-IFN-α in NAs-suppressed chronic hepatitis B patients.

Objective: The aim of this study was to explore the profile of cytokine changes during the combination therapy with pegylated interferon alpha (PEG-IFN-α) and its relationship with HBsAg loss in nucleos(t)ide analogs (NAs)-suppressed chronic hepatitis B patients. Methods: Seventy-six patients with chronic hepatitis B with HBsAg less than 1,500 IU/ml and HBV DNA negative after receiving ≥ 1-year NAs therapy were enrolled. Eighteen patients continued to take NAs monotherapy (the NAs group), and 58 patients received combination therapy with NAs and PEG-IFN-α (the Add-on group). The levels of IFNG, IL1B, IL1RN, IL2, IL4, IL6, IL10, IL12A, IL17A, CCL2, CCL3, CCL5, CXCL8, CXCL10, TNF, and CSF2 in peripheral blood during treatment were detected. Results: At week 48, 0.00% (0/18) in the NAs group and 25.86% (15/58) in the Add-on group achieved HBsAg loss. During 48 weeks of combined treatment, there was a transitory increase in the levels of ALT, IL1RN, IL2, and CCL2. Compared to the NAs group, CXCL8 and CXCL10 in the Add-on group remain higher after rising, yet CCL3 showed a continuously increasing trend. Mild and early increases in IL1B, CCL3, IL17A, IL2, IL4, IL6, and CXCL8 were associated with HBsAg loss or decrease >1 log, while sustained high levels of CCL5 and CXCL10 were associated with poor responses to Add-on therapy at week 48. Conclusions: The serum cytokine change profile is closely related to the response to the combination therapy with PEG-IFN-α and NAs, and may help to reveal the mechanism of functional cure and discover new immunological predictors and new therapeutic targets.

Reduction of natural killer cells is associated with poor outcomes in patients with hepatitis B virus-related acute-on-chronic liver failure.

BACKGROUND AND AIMS: Natural killer (NK) cells are critical innate effectors that respond to viral infections and contribute to immunopathology. Here, we aimed to investigate the role of NK cells in hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) and elucidate the underlying mechanism by examining their phenotypic and functional profiles. METHODS: We included patients with HBV-ACLF (n = 37) and chronic hepatitis B (n = 19), and healthy controls (n = 13) in our study. We examined the phenotype and function of different subsets of peripheral NK cells using flow cytometry and RNA-sequencing analysis, and screened liver NK cells using immunohistochemistry. We detected inflammatory cytokines using a Luminex assay. In addition, we analyzed the relationships between these parameters and disease severity. RESULTS: Peripheral NK cells were decreased and characterized by high expression of caspase-3, Ki67, CXCR3, NKG2D, NKp46, CD107a, and GM-CSF, and typified by higher cell migration and immune response by RNA-sequencing analysis in patients with HBV-ACLF than in those with chronic hepatitis B. Accumulations of CXCL-10 and NK cells were found in the liver, and excessive production of CXCL-10 in the peripheral blood contributed to the apoptosis of NK cells in vitro. The decrease in NK cells was associated with the level of HBV DNA and disease severity and had good prognostic performance in predicting the outcome of patients with HBV-ACLF through AUROC analysis. CONCLUSION: NK cells were significantly decreased and showed dysfunction of phenotypic and functional profiles across distinct subsets in the peripheral blood of patients with ACLF. Crosstalk between CXCL-10 and NK cells may mediate the unbalanced distribution of NK cells. Understanding the dysfunction and decrease in NK cells may provide new insights into ACLF pathogenesis.

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.

Activation-induced pyroptosis contributes to the loss of MAIT cells in chronic HIV-1 infected patients.

BACKGROUND: Mucosal-associated invariant T (MAIT) cells are systemically depleted in human immunodeficiency virus type 1 (HIV-1) infected patients and are not replenished even after successful combined antiretroviral therapy (cART). This study aimed to identify the mechanism underlying MAIT cell depletion. METHODS: In the present study, we applied flow cytometry, single-cell RNA sequencing and immunohistochemical staining to evaluate the characteristics of pyroptotic MAIT cells in a total of 127 HIV-1 infected individuals, including 69 treatment-naive patients, 28 complete responders, 15 immunological non-responders, and 15 elite controllers, at the Fifth Medical Center of Chinese PLA General Hospital, Beijing, China. RESULTS: Single-cell transcriptomic profiles revealed that circulating MAIT cells from HIV-1 infected subjects were highly activated, with upregulation of pyroptosis-related genes. Further analysis revealed that increased frequencies of pyroptotic MAIT cells correlated with markers of systemic T-cell activation, microbial translocation, and intestinal damage in cART-naive patients and poor CD4+ T-cell recovery in long-term cART patients. Immunohistochemical staining revealed that MAIT cells in the gut mucosa of HIV-1 infected patients exhibited a strong active gasdermin-D (GSDMD, marker of pyroptosis) signal near the cavity side, suggesting that these MAIT cells underwent active pyroptosis in the colorectal mucosa. Increased levels of the proinflammatory cytokines interleukin-12 (IL-12) and IL-18 were observed in HIV-1 infected patients. In addition, activated MAIT cells exhibited an increased pyroptotic phenotype after being triggered by HIV-1 virions, T-cell receptor signals, IL-12 plus IL-18, and combinations of these factors, in vitro. CONCLUSIONS: Activation-induced MAIT cell pyroptosis contributes to the loss of MAIT cells in HIV-1 infected patients, which could potentiate disease progression and poor immune reconstitution.

Immunological alterations after immunotherapy with short lived HBV-TCR T cells associates with long-term treatment response in HBV-HCC.

The application of hepatitis B virus (HBV)-T-cell receptor (TCR) T-cell immunotherapy in patients with HBV-related hepatocellular carcinoma (HBV-HCC) has been apathetic, as the expression of HBV antigens by both normal HBV-infected hepatocytes and HCC cells with HBV-DNA integration increases the risk of on-target off-tumor severe liver inflammatory events. To increase the safety of this immunotherapeutic approach, we developed messenger RNA (mRNA) HBV-TCR-redirected T cells that-due to the transient nature of mRNA-are functionally short lived and can be infused in escalating doses. The safety of this approach and its clinical potential against primary HBV-HCC have never been analyzed in human trials; thus, we studied the clinical and immunological parameters of 8 patients with chronic HBV infection and diffuse nonoperable HBV-HCC treated at weekly intervals with escalating doses (1 × 104 , 1 × 105 , 1 × 106 , and 5 × 106 TCR+ T cells/kg body weight) of T cells modified with HBV-TCR encoding mRNA. The treatment was well tolerated with no severe systemic inflammatory events, cytokine storm, or neurotoxicity observed in any of these patients throughout treatment. Instead, we observed a destruction of the tumor lesion or a prolonged stable disease in 3 of 8 patients. Importantly, the patients without clinically relevant reductions of HCC did not display any detectable peripheral blood immunological alterations. In contrast, signs of transient localized liver inflammation, activation of the T-cell compartment, and/or elevations of serum chemokine (C-X-C motif) ligand (CXCL) 9 and CXCL10 levels were detected in patients with long-term clinical benefit. Conclusion: We show that despite the reduced in vivo half-life (3-4 days), adoptive transfer of mRNA HBV-TCR T cells into patients with HBV-HCC show long-term clinical benefit that was associated with transient immunological alterations.

Immunotherapy of HBV-related advanced hepatocellular carcinoma with short-term HBV-specific TCR expressed T cells: results of dose escalation, phase I trial.

BACKGROUND & AIMS: Immunotherapy with hepatitis B virus (HBV)-specific TCR redirected T (HBV-TCR-T) cells in HBV-related hepatocellular carcinoma (HBV-HCC) patients after liver transplantation was reported to be safe and had potential therapeutic efficacy. We aim to investigate the safety of HBV-TCR-T-cell immunotherapy in advanced HBV-HCC patients who had not met the criteria for liver transplantation. METHODS: We enrolled eight patients with advanced HBV-HCC and adoptively transferred short-lived autologous T cells expressing HBV-specific TCR to perform an open-label, phase 1 dose-escalation study (NCT03899415). The primary endpoint was to evaluate the safety of HBV-TCR-T-cell therapy according to National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.03) during the dose-escalation process. The secondary endpoint was to assess the efficacy of HBV-TCR-T-cell therapy by evaluating the anti-tumor responses using RECIST criteria (version 1.1) and the overall survival. RESULTS: Adverse events were observed in two participants among the 8 patients enrolled. Only one patient experienced a Grade 3 liver-related adverse event after receiving a dose of 1 × 105 HBV-TCR-T cells/kg, then normalized without interventions with immunosuppressive agents. Among the patients, one achieved a partial response lasting for 27.7 months. Importantly, most of the patients exhibited a reduction or stabilization of circulating HBsAg and HBV DNA levels after HBV-TCR-T-cell infusion, indicating the on-target effects. CONCLUSIONS: The adoptive transfer of HBV-TCR-T cells into advanced HBV-HCC patients were generally safe and well-tolerated. Observations of clinical efficacy support the continued development and eventual application of this treatment strategy in patients with advanced HBV-related HCC. CLINICAL TRIALS REGISTRATION: This study was registered at ClinicalTrials.gov (NCT03899415).

Increased Neutrophil Aging Contributes to T Cell Immune Suppression by PD-L1 and Arginase-1 in HIV-1 Treatment Naïve Patients.

Neutrophils are characterized by their heterogeneity. They fight against pathogens and are involved in tissue injury repair and immune system regulation. Neutrophils have an extremely short life span in the peripheral blood and undergo aging after being released from the bone marrow. The over-aggregation of aged neutrophils is associated with phenotypical and functional changes. Here, we aimed to investigate the dynamics of neutrophil aging and its relationship with T cell exhaustion in HIV-1 infection, as they are not well understood. In this study, we enrolled 23 treatment naïve (TN) patients, 23 individuals that had received antiretroviral therapy (ART), and 21 healthy controls (HC). In these cohorts, we measured the degree of neutrophil aging, and its possible correlation with T cell dysfunction. In TN patients, peripheral neutrophils showed a more distinct aging phenotype and were over-activated compared to those in ART-treated patients. The degree of neutrophil aging was positively correlated with HIV-1 RNA viral load and negatively correlated with CD4+ T cell count. Moreover, aged neutrophils had impaired reactive oxygen species (ROS) production after lipopolysaccharide (LPS) stimulation, and were characterized by increased PD-L1 and arginase-1 expression in a time-dependent manner. Aged neutrophils demonstrated an increased inhibition of IFN-γ and TNF-α secretion by CD8+ T cell compared to non-aged neutrophils. The inhibition effect could be partially reversed by blocking PD-L1 and arginase-1 in vitro, and LPS was identified as an important activator of neutrophil aging. These results provide evidence that dampening neutrophil aging may provide a novel approach to recover T cell dysfunction in patients with HIV-1 infection.

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.

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.

HLA-mismatched allogeneic adoptive immune therapy in severely immunosuppressed AIDS patients.

Severely immunosuppressed AIDS patients with recurrent opportunistic infections (OIs) represent an unmet medical need even in the era of antiretroviral therapy (ART). Here we report the development of a human leukocyte antigen (HLA)-mismatched allogeneic adaptive immune therapy (AAIT) for severely immunosuppressed AIDS patients. Twelve severely immunosuppressed AIDS patients with severe OIs were enrolled in this single-arm study. Qualified donors received subcutaneous recombinant granulocyte-colony-stimulating factor twice daily for 4-5 days to stimulate hematopoiesis. Peripheral blood mononuclear cells were collected from these donors via leukapheresis and transfused into the coupled patients. Clinical, immunological, and virological parameters were monitored during a 12-month follow-up period. We found AAIT combined with ART was safe and well-tolerated at the examined doses and transfusion regimen in all 12 patients. Improvements in clinical symptoms were evident throughout the study period. All patients exhibited a steady increase of peripheral CD4+ T cells from a median 10.5 to 207.5 cells/µl. Rapid increase in peripheral CD8+ T-cell count from a median 416.5 to 1206.5 cells/µl was found in the first 90 days since initiation of AAIT. In addition, their inflammatory cytokine levels and HIV RNA viral load decreased. A short-term microchimerism with donor cells was found. There were no adverse events associated with graft-versus-host disease throughout the study period. Overall, AAIT treatment was safe, and might help severely immunosuppressed AIDS patients to achieve a better immune restoration. A further clinical trial with control is necessary to confirm the efficacy of AAIT medication.

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.

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.

Changes of Damage Associated Molecular Patterns in COVID-19 Patients.

Background: The development of severe coronavirus disease 2019 (COVID-19) is associated with systemic hyperinflammation, which drives multi-organ failure and death. Disease deterioration tends to occur when the virus is receding; however, whether other factors besides viral products are involved in the inflammatory cascade remains unclear. Methods: Twenty-eight COVID-19 patients with laboratory-confirmed SARS-CoV-2 infection hospitalized at the Fifth Medical Center of Chinese PLA General Hospital from January 23 to February 20, 2020 and nine healthy donors during the same period were recruited in the study. COVID-19 patients were grouped as mild, moderate, severe based on disease severity. Plasma damage-associated molecular patterns (DAMPs), including high mobility group box 1 (HMGB1), calprotectin (S100A8/A9), surfactant protein A (SP-A), cold-inducible RNA-binding protein (CIRBP), and Histone H4 were detected by ELISA assay, and analyzed in combination with clinical data. Plasma cytokines, chemokines and lymphocytes were determined by flow cytometry. Results: Plasma levels of HMGB1 (38292.3 ±â€Š4564.4 vs. 32686.3 ±â€Š3678.1, P = 0.002), S100A8/A9 (1490.8 ±â€Š819.3 vs. 742.2 ±â€Š300.8, P = 0.015), and SP-A (6713.6 ±â€Š1708.7 vs. 5296.3 ±â€Š1240.4, P = 0.048) were increased in COVID-19 patients compared to healthy donors, while CIRBP (57.4 ±â€Š30.7 vs. 111.9 ±â€Š55.2, P = 0.004) levels decreased. Five DAMPs did not vary among mild, moderate, and severe patients. Moreover, SP-A levels correlated positively with inflammatory cytokines and negatively with time elapsed after symptom onset, whereas CIRBP showed an opposite pattern. Conclusions: These findings suggest SP-A may involve in the inflammation of COVID-19, while CIRBP likely plays a protective role. Therefore, DAMPs represent a potential target in the prevention or treatment of COVID-19.

HIV Reservoir Decay and CD4 Recovery Associated With High CD8 Counts in Immune Restored Patients on Long-Term ART.

Background: Whether varying CD8 counts influence the human immunodeficiency virus (HIV) reservoir and CD4 restoration in patients with CD4 counts ≥ 500 cells/µL after long-term antiretroviral therapy (ART) remains unknown. In this study, we analyzed relationships between CD8 levels and viral reservoir decay or CD4 recovery in immune restored patients on long-term ART. Methods: Chronic HIV-infected patients who received 5 years of ART with CD4 counts ≥ 500 cells/µL were grouped according to CD8 counts: CD8 <500 (Group 1), 500-1,000 (Group 2), and ≥1,000 cells/µL (Group 3). CD4 recovery, viral decay, CD8 T-cell function, and their correlations were analyzed during ART among the three groups. Results: Dynamics of viral decay and CD4 recovery were different among the three groups. Both viral decay and CD4 recovery were higher in Group 3 than the other two groups after 5 years of ART, mainly during years 3-5 of ART. Higher expression levels of Ki67 while PD-1 levels were lower on CD8 T-cells in Group 3 compared with the other groups, and Group 3 showed stronger CD8 T-cells functional capacity after 3 years of ART. Reduced HIV DNA levels and increased CD4 counts between years 3 and 5 of ART were positively correlated with CD8 counts and function. Conclusions: High CD8 counts are beneficial for persistent viral decay and CD4 recovery in immune restored patients during long-term ART.

Improved survival ratios correlate with myeloid dendritic cell restoration in acute-on-chronic liver failure patients receiving methylprednisolone therapy.

Acute-on-chronic liver failure (ACLF) is a severe life-threatening complication. Liver transplantation is the only available therapeutic option; however, several limitations have restricted its use in patients. The use of corticosteroids as an optional therapy for ACLF has received a great deal of interest. The rationale behind its use is the possible role of the immune system in initiating and perpetuating hepatic damage. In order to assess the relationship between myeloid dendritic cells (mDCs) and the efficacy of methylprednisolone (MP) treatment for hepatitis B virus (HBV)-associated ACLF patients, we recruited 30 HBV-associated ACLF patients who had received MP treatment at 10-day intervals; 26 patients received conservative medical (CM) management as a control. The functionality of DC subsets was lower in these ACLF patients compared with healthy subjects. In addition, compared with survivors, dead/transplanted patients had lower functional mDC in both groups. Furthermore, a decreased numbers of mDC at baseline was associated with high mortality of ACLF patients. Importantly, MP treatment resulted in a significant decrease in 28-day mortality, and all MP patients exhibited an initial rapid decrease in circulating mDC numbers within 10 days of MP treatment. Subsequently, MP survivors displayed a continuous increase in mDC numbers accompanied by a decrease in total bilirubin levels by more than 30%. However, MP dead/transplanted patients lacked these sequential responses compared with survivors. This evidence suggests strongly that the higher mDC numbers at baseline and the recovery of mDC number at the end of treatment may represent a prognostic marker for favorable response to corticosteroid treatment in ACLF patients.

Regulatory T cells are associated with post-cryoablation prognosis in patients with hepatitis B virus-related hepatocellular carcinoma.

BACKGROUND: We carried out this study to evaluate the association between regulatory T cells (Treg) and prognosis and progression after cryoablation in patients with hepatitis-B virus-related hepatocellular carcinoma. METHODS: Peripheral Treg frequency in 111 patients with hepatocellular carcinoma (HCC) was detected by flow cytometry. Treg frequency and function were re-examined during patient follow up. A possible association between Treg and α-fetoprotein (AFP) was also analyzed, and the distribution of resident CD4(+) and CD8(+) T cells and FoxP3(+) T cells in the liver tissue of patients with HCC was examined by immunohistochemistry. RESULTS: Treg frequency significantly increased with disease progression. Our longitudinal study showed that Treg frequency had significantly decreased in 17 patients with HCC regression following cryoablation, but the frequency had dramatically increased in 14 patients with HCC recurrence or progression. Furthermore, AFP levels varied in a way comparable with Treg frequency in patients with elevated AFP recorded before therapy. Significantly increased suppressive effects of Treg on proliferation and cytokine secretion of CD8(+) and CD4(+) T cells were observed during follow up in patients with tumor progression, but not in patients with tumor response. Moreover, the numbers of CD8(+), CD4(+), and FoxP3(+) cells infiltrating the tumors around the cryotherapeutic zones were significantly decreased after argon-helium cryoablation, and this was associated with a reduction in the FoxP3/CD8 ratio. Importantly,increased quantities of circulating CD4(+)CD25(+)FoxP3(+) Treg and tumor infiltrating FoxP3(+) cells before cryoablation were associated with high recurrence or risk of progression in HCC patients after cryoablation. CONCLUSIONS: Treg variation is associated with tumor regression or progression in HCC following cryoablation and may be used as a marker to estimate HCC progression.