Phenotypic and functional alterations of monocyte subsets with aging.

BACKGROUND: It has been widely accepted that monocytes are one of the central mediators contributing to inflammaging. However, it remains unclear whether aged monocytes, similar to aged T cells, have characteristics of hyperactivation and increased expression of co-inhibitory molecules. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from young (21-40 years old), middle-aged (41-60 years old), and older human subjects (> 60 years old). Flow cytometry was used to monitor changes in the expression of surface molecules of monocyte subsets and cytokine-producing capacity. RESULTS: We observed increased tumor necrosis factor-α: TNF-α and decreased interleukin-6 (IL-6) production in monocytes from older adults compared with young and middle-aged adults. Older adults had a greater percentage of intermediate and non-classical monocyte subsets, along with increased levels of the immune activation markers human leukocyte antigen-DR (HLA-DR), and adhesion molecules cluster of differentiation molecule 11b (CD11b) and L-selectin (CD62L). Furthermore, we observed increased C-C motif chemokine receptor 2 (CCR2) expression on classical monocytes and decreased C-X3-C motif chemokine receptor 1 (CX3CR1) expression on non-classical monocytes in older adult subjects. The expression of co-inhibitory receptors was reduced on monocyte subsets in older adults. CONCLUSIONS: Circulating monocytes in older adults exhibit increased expression of activation, adhesion, and migration markers, but decreased expression of co-inhibitory molecules.

PDK1/mTOR Signaling in Myeloid Cells Differentially Regulates the Early and Late Stages of Sepsis.

The cecal ligation and perforation (CLP) model is the gold standard for the polymicrobial sepsis. In the CLP mice, the myeloid cells play an important role in septic shock. The phenotypes and the activation state of the macrophage and neutrophil correlate with their metabolism. In the present study, we generated the specific myeloid deletion of PDK1 and mTOR mice, which was the important regulator of metabolic signaling. We found that the deletion of PDK1 in the myeloid cells could aggravate the early septic shock in the CLP mice, as well as the deletion of mTORC1 and mTORC2. Moreover, PDK1 deletion attenuated the inflammation induced by LPS in the late stage on CLP mice, which was exacerbated in mTORC1 and mTORC2 knockout mice. Both PDK1 and mTORC1/2 could not only regulate the cellular metabolism but also play important roles on the myeloid cells in the secondary stimulation of sepsis. The present study will provide a theoretical prospect for the therapy of the septic shock in different stages.

PD-1+ TIGIT+ CD8+ T cells are associated with pathogenesis and progression of patients with hepatitis B virus-related hepatocellular carcinoma.

Hepatitis B virus-associated hepatocellular carcinoma (HBV-HCC) is usually considered an inflammation-related cancer associated with chronic inflammation triggered by exposure to HBV and tumor antigens. T-cell exhaustion is implicated in immunosuppression of chronic infections and tumors. Although immunotherapies that enhance immune responses by targeting programmed cell death-1(PD-1)/PD-L1 are being applied to malignancies, these treatments have shown limited response rates, suggesting that additional inhibitory receptors are also involved in T-cell exhaustion and tumor outcome. Here, we analyzed peripheral blood samples and found that coexpression of PD-1 and T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) was significantly upregulated on CD4+ and CD8+ T cells from patients with HBV-HCC compared with those from patients with chronic HBV or HBV-liver cirrhosis. Additionally, PD-1+ TIGIT+ CD8+ T-cell populations were elevated in patients with advanced stage and progressed HBV-HCC. Importantly, PD-1+ TIGIT+ CD8+ T-cell populations were negatively correlated with overall survival rate and progression-free survival rates. Moreover, we showed that PD-1+ TIGIT+ CD8+ T cells exhibit features of exhausted T cells, as manifested by excessive activation, high expression of other inhibitory receptors, high susceptibility to apoptosis, decreased capacity for cytokine secretion, and patterns of transcription factor expression consistent with exhaustion. In conclusion, PD-1+ TIGIT+ CD8+ T-cell populations are associated with accelerated disease progression and poor outcomes in HBV-HCC, which might not only have important clinical implications for prognosis but also provide a rationale for new targets in immunotherapy.

Sepsis-Induced Thymic Atrophy Is Associated with Defects in Early Lymphopoiesis.

Impaired T lymphopoiesis is associated with immunosuppression of the adaptive immune response and plays a role in the morbidity and mortality of patients and animal models of sepsis. Although previous studies examined several intrathymic mechanisms that negatively affect T lymphopoiesis, the extrathymic mechanisms remain poorly understood. Here, we report a dramatic decrease in the percentage of early T lineage progenitors (ETPs) in three models of sepsis in mice (cecal ligation and puncture, lipopolysaccharide continuous injection, and poly I:C continuous injection). However, septic mice did not show a decrease in the number of bone marrow (BM) precursor cells. Instead, the BM progenitors for ETPs expressed reduced mRNA levels of CC chemokine receptor (CCR) 7, CCR9 and P-selectin glycoprotein ligand 1, and exhibited impaired homing capacity in vitro and in vivo. Furthermore, RNA-Seq analysis and real-time PCR showed a marked downregulation of several lymphoid-related genes in hematopoietic stem and progenitor cells. Hematopoietic stem and progenitor cells differentiated into myeloid cells but failed to generate T lymphocytes in vitro and in vivo. Our results indicate that the depletion of ETPs in septic mice might be a consequence of an impaired migration of BM progenitors to the thymus, as well as a defect in lymphoid lineage commitment. Stem Cells 2016;34:2902-2915.

A Novel CD48-Based Analysis of Sepsis-Induced Mouse Myeloid-Derived Suppressor Cell Compartments.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous subset of cells that expands dramatically in many disease states and can suppress T-cell responses. MDSCs mainly include monocytic and granulocytic subpopulations that can be distinguished in mice by the expression of Ly6G and Ly6C cell surface markers. This identification system has been validated in experimental tumor models, but not in models of inflammation-associated conditions such as sepsis. We challenged growth factor independent 1 transcription repressor green fluorescent protein (Gfi1:GFP) knock-in reporter mice with cecal ligation and puncture surgery and found that CD11b+Ly6GlowLy6Chigh MDSCs in this sepsis model comprised both monocytic and granulocytic MDSCs. The evidence that conventional Ly6G/Ly6C marker analysis may not be suited to study of inflammation-induced MDSCs led to the development of a novel strategy of distinguishing granulocytic MDSCs from monocytic MDSCs in septic mice by expression of CD48. Application of this novel model should help achieve a more accurate understanding of the inflammation-induced MDSC activity.

[Effect of Huanglian Jiedu Decoction on Monocyte Development in apoE Gene Knockout Mice].

OBJECTIVE: To observe monocyte (Mo) development in wild type C57BL/6 mice and apoE gene knockout (apoE(-/-)) mice, and to evaluate the immuno-regulatory effect of Huanglian Jiedu Decoction (HJD) on peripheral Mo development in apoE(-/-) mice. METHODS: Four, 8, 12, and 16 weeks old female C57BL/6 mice were set up as control groups of different ages, while 4, 8, 12, and 16 weeks old female apoE(-/-) mice were set up as hyperlipidemia groups of different ages. Four-week old female C57BL/6 mice were recruited as a blank group. Four-week old female apoE(-/-) mice were randomly divided into the control group, the Western medicine group, and the Chinese medicine group by paired comparison, 5 in each group. Equivalent clinical dose was administered to mice according to body weight. Mice in the Western medicine group were administered with Atrovastatin at the daily dose of 10 mg/kg by gastrogavage, while those in the Chinese medicine group were administered with HJD at the daily dose of 5 g/kg by gastrogavage. Body weight was detected each week. After 4 weeks blood lipids levels (such as TG, TC, LDL-C, and HDL-C), and the proportions of Mo and Ly6c(hi) were detected. RESULTS: Compared with 4-week-old homogenic mice, the proportion of Mo decreased in 16-week-old C57BL/6 mice (P < 0.05). Levels of TC and TG, and the proportion of Ly6c(hi) subtype increased, but the proportion of Mo de- creased in 8-week-old apoE(-/-) mice (P <0. 05). Levels of TC, TG, and LDL-C increased in 12-week-old apoE(-/-) mice (P < 0.05). Levels of TC, TG, LDL-C, and HDL-C increased in 16-week-old apoE(-/-) mice (P < 0.05, P < 0.01). Compared with 8-week-old homogenic mice, the proportion of Mo decreased in 16-week-old C57BL/6 mice (P < 0.05); levels of TC and LDL-C increased in 12-week-old apoE(-/-) mice (P < 0.05); levels of TC and HDL-C increased in 16-week-old apoE(-/-) mice (P < 0.05, P < 0.01). Compared with C57BL/6 mice of the same age, TC and TG increased, HDL-C decreased (P < 0.01) in 4-and 8-week-old apoE(-/-) mice (P < 0.01); levels of TC, TG, LDL-C increased, and HDL-C level decreased in 12- and 16-week-old apoE(-/-) mice (P < 0.05, P < 0.01); the proportion of Mo increased in 4-week-old apoE(-/-) mice (P < 0.05); proportions of Mo and Ly6c(hi) increased in 8-week-old apoE(-/-) mice (P < 0.05). Compared with the blank control group, levels of TC, TG, and LDL-C, proportions of Mo and Ly6c(hi) increased (P < 0.01, P < 0.05), but HDL-C level decreased (P <0. 01) in the control group after intervention. Compared with the control group, body weight gained less in the Western medicine group and the Chinese medicine group (P < 0.05); the proportion of Ly6c(hi) subtype decreased in the Chinese medicine group (P < 0.05). CONCLUSIONS: In development process blood lipids levels in apoE(-/-) mice are not only associated with age. Blood lipids levels induced growth changes in natural immune system are also correlated with age. In early stage of lipids development HJD intervention could correct this special immune disorder in apoE(-/-) mice.

Expansion of activated regulatory T cells by myeloid-specific chemokines via an alternative pathway in CSF of bacterial meningitis patients.

Previous studies have demonstrated that activation/expansion by certain cytokines as well as recruitment by specific chemokines is involved in enrichment of regulatory T (Treg) cells in local tissues or organs under pathological conditions. Recent evidence indicates that human Treg cells are a heterogeneous population that comprises three distinct subpopulations: CD25⁺CD45RA⁺ resting Treg (rTreg) cells, CD25(hi)CD45RA⁻ activated Treg (aTreg) cells, which are both suppressive, and CD25⁺CD45RA⁻ cytokine-secreting T cells with proinflammatory capacity. Moreover, rTreg cells can proliferate and convert to aTreg cells. Here, we found an increase in aTreg-cell frequency in the cerebrospinal fluid (CSF) of patients with postneurosurgery bacterial meningitis. We revealed that such an increased aTreg-cell frequency in the CSF was not due to enhanced chemotaxis. Instead of a classic conversion pathway from rTreg to aTreg cells, we identified an alternative route of Treg-cell conversion from cytokine-secreting cells to aTreg cells induced by myeloid-specific chemokine CXC chemokine receptor (CXCR) ligand 5 via CXCR1 and CXCR2 receptors, or by CSF myeloid cells in a cell-cell contact manner. Our results reveal a different view of how the immune system controls overwhelming local immune responses during infection, and provide evidence of how innate immunity negatively regulates adaptive immunity.

Sphingosine-1-phosphate/S1P receptors signaling modulates cell migration in human bone marrow-derived mesenchymal stem cells.

The recruitment of bone marrow-derived mesenchymal stem cells (BMSCs) to damaged tissues and sites of inflammation is an essential step for clinical therapy. However, the signals regulating the motility of these cells are still not fully understood. Sphingosine-1-phosphate (S1P), a bioactive sphingolipid metabolite, is known to have a variety of biological effects on various cells. Here, we investigated the roles of S1P and S1P receptors (S1PRs) in migration of human BMSCs. We found that S1P exerted a powerful migratory action on human BMSCs. Moreover, by employing RNA interference technology and pharmacological tools, we demonstrated that S1PR1 and S1PR3 are responsible for S1P-induced migration of human BMSCs. In contrast, S1PR2 mediates the inhibition of migration. Additionally, we explored the downstream signaling pathway of the S1P/S1PRs axis and found that activation of S1PR1 or S1PR3 increased migration of human BMSCs through a G i /extracellular regulated protein kinases 1/2- (ERK1/2-) dependent pathway, whereas activation of S1PR2 decreased migration through the Rho/Rho-associated protein kinase (ROCK) pathway. In conclusion, we reveal that the S1P/S1PRs signaling axis regulates the migration of human BMSCs via a dual-directional mechanism. Thus, selective modulation of S1PR's activity on human BMSCs may provide an effective approach to immunotherapy or tissue regeneration.

Hypothermia predicts the prognosis in colon ascendens stent peritonitis mice.

BACKGROUND: The mortality rate of severe sepsis remains unacceptably high. It is difficult to make advances in the treatment of this problematic and increasingly frequent medical condition. In severe sepsis, hypothermia can be recognized as an important feature. The present study investigated the role of hypothermia in the prognosis of the colon ascendens stent peritonitis (CASP) model. METHODS: We employed the CASP model for wild-type C57BL/6 mice. We compared physiologic indices in survivor and non-survivor groups after CASP to test whether low temperature might be a helpful predictor in sepsis. To certify this hypothesis, we examined the survival rate, peritoneal leukocytes, and organ damage. We also measured the bacterial burden and inflammatory cytokine levels at different times. RESULTS: The temperature varied dramatically in the survivors' group compared with the non-survivors' group at 18 h. We divided the CASP models into a mild group and a severe group, based on temperatures above or below 32°C at 18 h. Mice in the severe group had a lower survival rate (0% versus 87.5%), more peritoneal leukocytes, more bacterial culture results, higher expressions of cytokines, and more classical features in pathology compared with the mild group. CONCLUSIONS: Hypothermia (below 32°C at 18 h) might be a predictor of prognosis in CASP-induced sepsis.

HTE- and AI-assisted development of DHP-catalyzed decarboxylative selenation.

1,4-Dihydropyridine (DHP) derivatives play key roles in biology, but are rarely used as catalysts in synthesis. Here, we developed a DHP derivative-catalyzed decarboxylative selenation reaction that showed a broad substrate scope, with the assistance of high-throughput experimentation (HTE) and artificial intelligence (AI). The AI-based model could identify the key structural features and give accurate prediction of unseen reactions (R2 = 0.89, RMSE = 9.0%, and MAE = 6.3%). Our work not only developed the catalytic applications of DHP derivatives, but also demonstrated the power of the combination of HTE and AI to advance chemical synthesis.

A Nomogram Prognostic Model for Advanced Hepatocellular Carcinoma Based on the Interaction Between CD8+T Cell Counts and Age.

Objective: CD8+T cells are essential components of the adaptive immune system and are crucial in the body's immune system. This study aimed to investigate how the prognosis of patients with advanced hepatocellular carcinoma (HCC) was affected by their CD8+ T cell counts and age and established an effective nomogram model to predict the overall survival (OS). Methods: A total of 427 patients with advanced HCC from Beijing Ditan Hospital, Capital Medical University, were enrolled in this study and randomly divided into training and validation groups, with 300 and 127 individuals in each group, respectively. Cox regression analysis was used to screen for independent risk factors for advanced HCC, and the interactive relationship between CD8+T cells and patient age was examined to establish a nomogram prediction model. Results: Cox multivariate regression and interaction analyses indicated that tumor number, tumor size, aspartate aminotransferase (AST), C-reactive protein (CRP), relationship of CD8+T cell counts and age were independent predictors of 6-month OS in patients with advanced HCC, and the nomogram model was established based on these factors. The area under the receiver operating characteristic curve (AUC) of the nomogram model for predicting the 3-month, 6-month, and 12-month OS rates were 0.821, 0.802, and 0.756, respectively. Moreover, in clinical practice, patients with true-positive survival benefit more than true-positive death, therefore, we selected 25% as the clinical decision threshold probability based on probability density functions (PDFs) and clinical utility curves (CUCs), which can distinguish approximately 92% of patients who died and 37% of patients who survived. Conclusion: The nomogram model based on CD8+T cell counts and age accurately assessed the prognosis of patients with advanced HCC and suggested that high CD8+T cell levels are beneficial to the survival of patients with advanced HCC.

CD70-induced differentiation of proinflammatory Th1/17/22/GM lymphocytes associated with disease progression and immune reconstitution during HIV infection.

Immune overactivation is a hallmark of chronic HIV infection, which is critical to HIV pathogenesis and disease progression. The imbalance of helper T cell (Th) differentiation and subsequent cytokine dysregulation are generally considered to be the major drivers of excessive activation and inflammatory disorders in HIV infection. However, the accurate factors driving HIV-associated Th changes remained to be established. CD70, which was a costimulatory molecule, was found to increase on CD4+ T cells during HIV infection. Overexpression of CD70 on CD4+ T cells was recently reported to associate with highly pathogenic proinflammatory Th1/Th17 polarization in multiple sclerosis. Thus, the role of CD70 in the imbalance of Th polarization and immune overactivation during HIV infection needs to be investigated. Here, we found that the elevated frequency of CD70 + CD4+ T cells was negatively correlated with CD4 count and positively associated with immune activation in treatment-naïve people living with HIV (PLWH). More importantly, CD70 expression defined a population of proinflammatory Th1/17/22/GM subsets in PLWH. Blocking CD70 decreased the mRNA expression of subset-specific markers during Th1/17/22/GM polarization. Furthermore, we demonstrated that CD70 influenced the differentiation of these Th cells through STAT pathway. Finally, it was revealed that patients with a high baseline level of CD70 on CD4+ T cells exhibited a greater risk of poor immune reconstitution after antiretroviral therapy (ART) than those with low CD70. In general, our data highlighted the role of CD70 in Th1/17/22/GM differentiation during HIV infection and provided evidence for CD70 as a potential biomarker for predicting immune recovery.

Sepsis induces non-classic innate immune memory in granulocytes.

Secondary infection in patients with sepsis triggers a new wave of inflammatory response, which aggravates organ injury and increases mortality. Trained immunity boosts a potent and nonspecific response to the secondary challenge and has been considered beneficial for the host. Here, using a murine model of polymicrobial infection, we find that the primary infection reprograms granulocytes to boost enhanced inflammatory responses to the secondary infection, including the excessive production of inflammatory cytokines, respiratory burst, and augmented phagocytosis capacity. However, these reprogramed granulocytes exhibit "non-classic" characteristics of innate immune memory. Two mechanisms are independently involved in the innate immune memory of granulocytes: a metabolic shift in favor of glycolysis and fatty acid synthesis and chromatin remodeling leading to the transcriptional inactivity of genes encoding inhibitors of TLR4-initiated signaling pathways. Counteracting the deleterious effects of stressed granulocytes on anti-infection immunity might provide a strategy to fight secondary infections during sepsis.

Decreased CD73+ Double-Negative T Cells and Elevated Level of Soluble CD73 Correlated With and Predicted Poor Immune Reconstitution in HIV-Infected Patients After Antiretroviral Therapy.

Although extensive use of antiretroviral therapy (ART) has made great progress in controlling HIV replication and improving CD4+ T cell recovery, the immune reconstitution remained insufficient in some patients, who were defined as poor immunological responders (PIRs). These PIRs were at a high risk of AIDS-related and non-AIDS complications, resulting in higher morbidity and mortality rate. Thus, it is a major challenge and urgently needed to distinguish PIRs early and improve their immune function in time. Immune activation is a key factor that leads to impaired immune reconstitution in people living with HIV (PLWH) who are receiving effective ART. Double negative T cells (DNT) were reported to associate with the control of immune activation during HIV infection. However, the precise mechanisms by which DNT cells exerted their suppressive capacity during HIV infection remained puzzled. CD73, both a soluble and a membrane-bound form, display immunosuppressive effects through producing adenosine (ADO). Thus, whether DNT cells expressed CD73 and mediated immune suppression through CD73-ADO pathway needs to be investigated. Here, we found a significant downregulation of CD73 expression on DNT cells in treatment-naïve PLWH (TNs) compared to healthy controls, accompanied with increased concentration of sCD73 in plasma. Both the frequency of CD73+ DNT cells and the level of plasma sCD73 recovered after ART treatment. However, PIRs showed decreased percentage of CD73+ DNT cells compared to immunological responders (IRs). The frequency of CD73+ DNT cells was positively correlated with CD4+ T cell count and CD4/CD8 ratio, and negatively correlated with immune activation in PLWH. The level of sCD73 also showed a negative correlation to CD4+ T cell count and CD4/CD8 ratio. More importantly, in the present cohort, a higher level of sCD73 at the time of initiating ART could predict poor immune reconstitution in PLWH after long-term ART. Our findings highlighted the importance of CD73+ DNT cells and sCD73 in the disease progression and immune reconstitution of PLWH, and provided evidences for sCD73 as a potential biomarker of predicting immune recovery.

A novel prediction model to evaluate the probability of CD4+/CD8+ cell ratio restoration in HIV-infected individuals.

BACKGROUND: Our study aimed to develop a clinical prediction model to evaluate the possibility of CD4+/CD8+ ratio restoration in HIV-positive individuals. METHODS: About 1980, HIV/AIDS patients initiated with antiretroviral treatment from 1 January 2013, to 30 December 2016, at Beijing Ditan Hospital and achieved persistent virological suppression during the 4 years follow-up were included in this study. Multivariate Cox proportional regression analysis was used to identify the independent risk factors and establish a predictive model. The model's performance was assessed using the area under the receiver operating characteristic and calibration plots. RESULTS: Overall, after 4 years of treatment, a total of 455 individuals (22.98%) restored their CD4+/CD8+ ratio (≥1). The area under the receiver operating characteristic was 0.782 and 0.743 in the deriving and validation cohort, respectively. The ultimate model included five indexes: age at AIDS diagnosis, albumin, and syphilis status, and baseline CD4+ and CD8+ values. A nomogram further visualized the model, and the calibration plots indicated high agreement of predicted and observed outcomes. CONCLUSION: Our prediction model might be practical and easily applied to recognize HIV/AIDS individuals most likely to benefit from modern antiretroviral therapy.

High Levels of CD244 Rather Than CD160 Associate With CD8+ T-Cell Aging.

Aging leads to functional dysregulation of the immune system, especially T cell defects. Previous studies have shown that the accumulation of co-inhibitory molecules plays an essential role in both T cell exhaustion and aging. In the present study, we showed that CD244 and CD160 were both up-regulated on CD8+ T cells of elderly individuals. CD244+CD160- CD8+ T cells displayed the increased activity of ß-GAL, higher production of cytokines, and severe metabolic disorders, which were characteristics of immune aging. Notably, the functional dysregulation associated with aging was reversed by blocking CD244 instead of CD160. Meanwhile, CD244+CD160+ CD8+ T cells exhibited features of exhaustion, including lower levels of cytokine, impaired proliferation, and intrinsic transcriptional regulation, compared to CD244+CD160- population. Collectively, our findings demonstrated that CD244 rather than CD160 acts as a prominent regulator involved in T cell aging, providing a solid therapeutic target to improve disorders and comorbidities correlated to immune system aging.

Elevated Foxp3+ double-negative T cells are associated with disease progression during HIV infection.

Persistent immune activation, which occurs during the whole course of HIV infection, plays a pivotal role in CD4+ T cells depletion and AIDS progression. Furthermore, immune activation is a key factor that leads to impaired immune reconstitution after long-term effective antiretroviral therapy (ART), and is even responsible for the increased risk of developing non-AIDS co-morbidities. Therefore, it's imperative to identify an effective intervention targeting HIV-associated immune activation to improve disease management. Double negative T cells (DNT) were reported to provide immunosuppression during HIV infection, but the related mechanisms remained puzzled. Foxp3 endows Tregs with potent suppressive function to maintain immune homeostasis. However, whether DNT cells expressed Foxp3 and the accurate function of these cells urgently needed to be investigated. Here, we found that Foxp3+ DNT cells accumulated in untreated people living with HIV (PLWH) with CD4+ T cell count less than 200 cells/µl. Moreover, the frequency of Foxp3+ DNT cells was negatively correlated with CD4+ T cell count and CD4/CD8 ratio, and positively correlated with immune activation and systemic inflammation in PLWH. Of note, Foxp3+ DNT cells might exert suppressive regulation by increased expression of CD39, CD25, or vigorous proliferation (high levels of GITR and ki67) in ART-naive PLWH. Our study underlined the importance of Foxp3+ DNT cells in the HIV disease progression, and suggest that Foxp3+ DNT may be a potential target for clinical intervention for the control of immune activation during HIV infection.

Altered T-Cell Subsets are Associated with Dysregulated Cytokine Secretion of CD4+ T Cells During HIV Infection.

BACKGROUND: CD4+ T cells play a critical role in the regulation of immunopathogenesis in HIV infection. Previous studies have shown contradictory results of the CD4+ T-cell responses in people living with HIV (PLHIV). METHODS: A cross-sectional study was performed on 40 healthy controls, 134 ART-naïve PLHIV, and 34 individuals who experienced 3-year ART with low baseline CD4 count from 4 August 2016 to 23 January 2019. We determined the frequencies of CD4+ T-cell subsets and described the cytokine secretion pattern of total and subsets of CD4+ T cells in these individuals. RESULTS: We found that CD4+ T cells in PLHIV displayed enhanced secretion of pro-inflammation cytokines and polyfunctionality due to HIV disease progression (r = -0.282, P = 0.0035 for IFN-γ; r = -0.412, P = 0.0002 for TNF-α; r = -0.243, P < 0.0001 for GM-CSF; r = -0.252, P = 0.0093 for IFN-γ+ TNF-α+ cells). However, the altered T-cell subsets, as presented by the loss of naïve cells and expansion of memory/effector population in PLHIV, were associated with discordant results in total and subsets of CD4+ T cells. As major cytokine-producing T subsets, effector/memory CD4 subsets showed impaired cytokine production (P < 0.05). We further demonstrated that 3-year ART treatment could improve CD4 counts by increasing the pool of naïve T cells but could not restore cytokine secretion in CD4+ T-cell subsets (P < 0.05). CONCLUSION: These data identified the impaired capacity of cytokine secretion in CD4+ T-cell subsets due to HIV disease progression, and the altered T-cell subsets were associated with pseudo-elevation of cytokine production in total CD4+ T cells. This study collectively suggested the importance of therapies that can preserve and/or enhance the function of CD4+ T cells in strategies of HIV remission.

CD200R Combined Neutrophil-Lymphocyte Ratio Predict 90-Day Mortality in HBV-Related Acute-On-Chronic Liver Failure.

Background: Survival of acute-on-chronic liver failure (ACLF) cannot be properly predicted based on clinical characteristics. Aims: This study aimed to develop a predictive model to evaluating the prognosis for hepatitis B virus-related ACLF (HBV-ACLF) based on specific laboratory and immune indicators. Methods: Baseline laboratory results were obtained and immune indicators were detected by flow cytometry. A predictive model, which estimates the prognosis at 90-day follow-up, was developed using data from a prospective study on 45 patients hospitalized of HBV-ACLF from June 2016 to April 2018 at the Beijing Ditan Hospital, Capital Medical University. The prognostic values of the predictive factors were determined by the area under the receiver operating characteristic (AUROC) curves. Results: Six factors exhibited statistical differences between the survival and non-survival groups: proportions of CD4+TN, CD4+TEM, CD8+TN, CD8+TEM, CD200R+CD4+T cells and neutrophil-lymphocyte ratio (NLR). CD200R combined with the NLR had an AUROC of 0.916, which was significantly higher than the AUROC values of CD200R+CD4+T cells (0.868), NLR (0.761), model for end-stage liver disease (MELD) (0.840), MELD-Na (0.870), Child-Turcotte-Pugh (CTP) (0.580), or chronic liver failure-consortium ACLF (CLIF-C ACLF) score(0.840). At the cut-off point of-3.87, matching the maximum Youden index determined by ROC analysis, the positive predictive and negative predictive values for the mortality were 0.86 and 0.97, respectively. Conclusions: The 90-day prediction model based on baseline levels of CD200R+CD4+T cells and NLR offers potential predictive value for the mortality of HBV-ACLF.