Loss of naive T lymphocytes is associated with advanced liver fibrosis in alcohol use disorder

Differential peripheral memory T cell subsets sensitively indicate the severity of nonalcoholic fatty liver disease

AIM

Differential patterns of peripheral memory T cell subsets in nonalcoholic fatty liver disease (NAFLD) were assessed using flow cytometry (FCM) to elucidate their association with NAFLD severity and provide a new noninvasive method to sensitively detect the disease severity in addition to existing biomarkers.

METHODS

We assessed the differential frequencies of peripheral memory T cell subsets in 103 patients with NAFLD according to the degree of liver fibrosis (FIB) using FCM analysis. We focused on the following populations: CCR7+ CD45RA+ naïve T, CCR7+ CD45RA- central memory T cells (TCM), CCR7- CD45RA- effector memory T, and CCR7- CD45RA+ terminally differentiated effector memory T (TEMRA) cells in CD4+ and CD8+ T, Th1, Th2, and Th17 cells, respectively. To evaluate the pathological progression of the disease, these frequencies were also examined according to the degree of the NAFLD activity score (NAS).

RESULTS

Several significant correlations were observed between laboratory parameters and peripheral memory T lymphocyte frequencies according to the degree of liver FIB and NAS in NAFLD. In univariate and multivariate analyses, the frequency of CD8+ TEMRA cells predicted severe FIB, and the predictive power was validated in an independent cohort. Furthermore, the frequencies of several memory T cell subsets sensitively indicated the pathological progression of NAFLD (Th17 TCM: steatosis, CD4+ TCM: lobular inflammation, and CD8+ TEMRA and effector memory T cells: hepatocellular ballooning).

CONCLUSIONS

Our results suggest that the analysis of peripheral memory T lymphocyte frequencies can noninvasively predict severe FIB and sensitively indicate the pathological progression of NAFLD.

Pre-administration of human umbilical cord mesenchymal stem cells has better therapeutic efficacy in rats with D-galactosamine-induced acute liver failure

BACKGROUND

Acute liver failure (ALF) is characterized by an intense systemic inflammatory response, single or multiple organ system failure and high mortality. However, specific and effective treatments for ALF patients are still lacking. According to the current investigation, human umbilical cord mesenchymal stem cells (hUCMSCs) have shown remarkable potential to enhance the functional recovery of injured livers. We aimed to investigate the therapeutic effects of time-differentiated hUCMSCs administration regimens on ALF.

METHODS

The rat model of ALF was induced by D-galactosamine (D-gal), and hUCMSCs were administered via the tail vein 12 h before or 2 h after induction. The potential mechanisms of hUCMSCs in treatment of ALF, regulation cell subset and secretion of inflammatory factors, were verified by co-culturing with PBMCs in vitro. Liver function indicators were detected by an automatic biochemistry analyzer and inflammatory factors were obtained by ELISA detection. The distribution of hUCMSCs in rats after administration was followed by quantitative real-time fluorescence PCR.

RESULTS

The findings of the study discovered that administration of hUCMSCs 12 h prior to surgery could significantly improve the survival rate of rats, stabilize various liver function indicators in serum levels of ALT, AST, T-BIL, or ALB diminish inflammatory infiltration in liver tissue, and inhibit the secretion of inflammatory factors.

CONCLUSION

Our data showed that pre-transplantation of hUCMSCs had a better therapeutic effect on ALF rats, providing empirical evidence for preclinical studies. Thus, the timing of hUCMSCs transplantation is necessary for the optimal clinical treatment effect.

Single nuclear RNA sequencing of terminal ileum in patients with cirrhosis demonstrates multi-faceted alterations in the intestinal barrier

Patients with cirrhosis have intestinal barrier dysfunction but the role of the individual cell types in human small intestine is unclear. We performed single-nuclear RNA sequencing (snRNAseq) in the pinch biopsies of terminal ileum of four age-matched men [56 years, healthy control, compensated, early (ascites and lactulose use) and advanced decompensated cirrhosis (ascites and rifaximin use)]. Cell type proportions, differential gene expressions, cell-type specific pathway analysis using IPA, and cellular crosstalk dynamics were compared. Stem cells, enterocytes and Paneth cells were lowest in advanced decompensation. Immune cells like naive CD4 + T cells were lowest while ITGAE + cells were highest in advanced decompensation patients. MECOM had lowest expression in stem cells in advanced decompensation. Defensin and mucin sulfation gene (PAPSS2) which can stabilize the mucus barrier expression were lowest while IL1, IL6 and TNF-related genes were significantly upregulated in the enterocytes, goblet, and Paneth cells in decompensated subjects. IPA analysis showed higher inflammatory pathways in enterocytes, stem, goblet, and Paneth cells in decompensated patients. Cellular crosstalk analysis showed that desmosome, protease-activated receptors, and cadherin-catenin complex interactions were most perturbed in decompensated patients. In summary, the snRNAseq of the human terminal ileum in 4 subjects (1 control and three cirrhosis) identified multidimensional alteration in the intestinal barrier with lower stem cells and altered gene expression focused on inflammation, mucin sulfation and cell-cell interactions with cirrhosis decompensation.

Single-cell transcriptomics of peripheral blood mononuclear cells indicates impaired immune and inflammatory responses in alcohol-associated hepatitis

Alcohol-associated hepatitis (AH) is often diagnosed at advanced stages, and severe AH usually carries poor prognosis and high short-term mortality. In addition, it is challenging to understand the molecular mechanisms of immune dysregulation and inflammation in AH due to the cellular complexity and heterogeneity. Using single-cell RNA sequencing, previous studies found that AH causes dysfunctional innate immune response in monocytes, involving activation of pattern recognition receptors (PRRs) and cytokine signaling pathways. To better understand the coordinated systemic immune response in AH patients, we performed combined single-cell transcriptome, cell-surface protein, and lymphocyte antigen receptor analysis of peripheral blood mononuclear cell (PBMC) samples. Our results showed inflammatory cytokines and chemokines were highly expressed in AH, including IL-2, IL-32, CXC3R1 and CXCL16 in monocytes and NK cells, whereas HLA-DR genes were reduced in monocytes. In addition, we also found altered differentiation of T-helper cells (TH1 and TH17), which could further lead to neutrophil recruitment and macrophage activation. Lastly, our results also suggest impaired NK-cell activation and differentiation in AH with reduced gene expression of KLRC2 and increased gene expression of KLRG1. Our findings indicate different mechanisms may be involved in impaired immune and inflammatory responses for the cellular subtypes of the PBMCs in AH.

Pilot study on the influence of acute alcohol exposure on biophysical parameters of leukocytes

Objective: This pilot study explores the influence of acute alcohol exposure on cell mechanical properties of steady-state and activated leukocytes conducted with real-time deformability cytometry. Methods: Nineteen healthy male volunteers were enrolled to investigate the effect of binge drinking on biophysical properties and cell counts of peripheral blood leukocytes. Each participant consumed an individualized amount of alcohol to achieve a blood alcohol concentration of 1.2 ‰ as a mean peak. In addition, we also incubated whole blood samples from healthy donors with various ethanol concentrations and performed stimulation experiments using lipopolysaccharide and CytoStim™ in the presence of ethanol. Results: Our findings indicate that the biophysical properties of steady-state leukocytes are not significantly affected by a single episode of binge drinking within the first two hours. However, we observed significant alterations in relative cell counts and a shift toward a memory T cell phenotype. Moreover, exposure to ethanol during stimulation appears to inhibit the cytoskeleton reorganization of monocytes, as evidenced by a hindered increase in cell deformability. Conclusion: Our observations indicate the promising potential of cell mechanical analysis in understanding the influence of ethanol on immune cell functions. Nevertheless, additional investigations in this field are warranted to validate biophysical properties as biomarkers or prognostic indicators for alcohol-related changes in the immune system.

Comprehensive bioinformatics and machine learning analysis identify VCAN as a novel biomarker of hepatitis B virus-related liver fibrosis

Hepatitis B virus (HBV) infection remains the leading cause of liver fibrosis (LF) worldwide, especially in China. Identification of decisive diagnostic biomarkers for HBV-associated liver fibrosis (HBV-LF) is required to prevent chronic hepatitis B (CHB) from progressing to liver cancer and to more effectively select the best treatment strategy. We obtained 43 samples from CHB patients without LF and 81 samples from CHB patients with LF (GSE84044 dataset). Among these, 173 differentially expressed genes (DEGs) were identified. Functional analysis revealed that these DEGs predominantly participated in immune-, extracellular matrix-, and metabolism-related processes. Subsequently, we integrated four algorithms (LASSO regression, SVM-RFE, RF, and WGCNA) to determine diagnostic biomarkers for HBV-LF. These analyses and receive operating characteristic curves identified the genes for phosphatidic acid phosphatase type 2C (PPAP2C) and versican (VCAN) as potentially valuable diagnostic biomarkers for HBV-LF. Single-sample gene set enrichment analysis (ssGSEA) further confirmed the immune landscape of HBV-LF. The two diagnostic biomarkers also significantly correlated with infiltrating immune cells. The potential regulatory mechanisms of VCAN underlying the occurrence and development of HBV-LF were also analyzed. These collective findings implicate VCAN as a novel diagnostic biomarker for HBV-LF, and infiltration of immune cells may critically contribute to the occurrence and development of HBV-LF.

Identification of Immune Microenvironment Changes and the Expression of Immune-Related Genes in Liver Cirrhosis

Liver inflammation and the immune response have been recognized as critical contributors to cirrhosis pathogenesis. Immunity-related genes (IRGs) play an essential role in immune cell infiltration and immune reactions; however, the changes in the immune microenvironment and the expression of IRGs involved in cirrhosis remain unclear. CD45+ liver cell single-cell RNA (scRNA) sequencing data (GSE136103) from patients with cirrhosis were analyzed. The clusters were identified as known cell types through marker genes according to previous studies. GO and KEGG analyses among differentially expressed genes (DEGs) were performed. DEGs were screened to identify IRGs based on the ImmPort database. The protein-protein interaction (PPI) network of IRGs was generated using the STRING database. IRGs activity was calculated using the AUCell package. RNA microarray expression data (GSE45050) of cirrhosis were analyzed to confirm common IRGs and IRGs activity. Relevant regulatory transcription factors (TFs) were identified from the Human TFDB database. A total of ten clusters were obtained. CD8+ T cells and NK cells were significantly decreased in patients with cirrhosis, while CD4+ T memory cells were increased. Enrichment analyses showed that the DEGs focused on the regulation of immune cell activation and differentiation, NK-cell mediated cytotoxicity, and antigen processing and presentation. Four common TFs, IRF8, NR4A2, IKZF3, and REL were expressed in both the NK cluster and the DEGs of liver tissues. In conclusion, we proposed that the reduction of the CD8+ T cell cluster and NK cells, as well as the infiltration of CD4+ memory T cells, contributed to immune microenvironment changes in cirrhosis. IRF8, NR4A2, IKZF3, and REL may be involved in the transcriptional regulation of NK cells in liver fibrosis. The identified DEGs, IRGs, and pathways may serve critical roles in the development and progression of liver fibrosis.

Social stressors associated with age-related T lymphocyte percentages in older US adults: Evidence from the US Health and Retirement Study

Exposure to stress is a risk factor for poor health and accelerated aging. Immune aging, including declines in naïve and increases in terminally differentiated T cells, plays a role in immune health and tissue specific aging, and may contribute to elevated risk for poor health among those who experience high psychosocial stress. Past data have been limited in estimating the contribution of life stress to the development of accelerated immune aging and investigating mediators such as lifestyle and cytomegalovirus (CMV) infection. This study utilizes a national sample of 5,744 US adults over age 50 to assess the relationship of social stress (viz., everyday discrimination, stressful life events, lifetime discrimination, life trauma, and chronic stress) with flow cytometric estimates of immune aging, including naïve and terminally differentiated T cell percentages and the ratio of CD4+ to CD8+ cells. Experiencing life trauma and chronic stress was related to a lower percentage of CD4+ naïve cells. Discrimination and chronic stress were each associated with a greater percentage of terminally differentiated CD4+ cells. Stressful life events, high lifetime discrimination, and life trauma were related to a lower percentage of CD8+ naïve cells. Stressful life events, high lifetime discrimination, and chronic stress were associated with a higher percentage of terminally differentiated CD8+ cells. High lifetime discrimination and chronic stress were related to a lower CD4+:CD8+ ratio. Lifestyle factors and CMV seropositivity partially reduced these effects. Results identify psychosocial stress as a contributor to accelerating immune aging by decreasing naïve and increasing terminally differentiated T cells.

Increased Natural Killer Cells Are Associated with Alcohol Liver Fibrosis and with T Cell and Cytotoxic Subpopulations Change

Natural killer (NK) cells play a therapeutic role in liver fibrosis (LF). We aimed to analyze NK cells in heavy drinkers without cirrhosis or decompensated liver disease and establish correlations with other related subpopulations. Data on sociodemographic characteristics, alcohol consumption, laboratory parameters, and immunophenotyping of NK (CD16⁺/CD56⁺), T (CD3⁺), B (CD19⁺), NKT (CD16⁺/CD56⁺/CD3⁺), and cytotoxic (CD3^-CD8⁺) cells were collected. Fibrosis-4 (FIB-4) scores were used to compare patients without (FIB-4 < 1.45) and with (FIB-4 > 3.25) advanced LF (ALF). We included 136 patients (76% male) with a mean age of 49 years who had a 15-year alcohol use disorder (AUD) and alcohol consumption of 164 g/day. Patients with ALF (n = 25) presented significantly lower absolute total lymphocyte, T cell, B cell, and NKT cell numbers than patients without LF (n = 50; p < 0.01). However, the NK cells count was similar (208 ± 109 cells/µL vs. 170 ± 105 cells/µL) in both groups. The T cells percentage was lower (80.3 ± 5.6% vs. 77 ± 7%; p = 0.03) and the NK cells percentage was higher (9.7 ± 5% vs. 13 ± 6%; p = 0.02) in patients with ALF than in those without LF. The percentages of NK cells and T cells were inversely correlated in patients without (r = –0.65, p < 0.01) and with ALF (r = −0.64; p < 0.01). Additionally, the NK cells and CD3^-CD8⁺ cell percentages were positively correlated in patients without (r = 0.87, p < 0.01) and with (r = 0.92; p < 0.01) ALF. Conclusions: Heavy drinkers without decompensated liver disease showed an increase in NK cells related to T cells lymphopenia and an increase in cytotoxic populations. The interaction of NK cells with other subpopulations may modify alcohol-related liver disease progression.

Alcohol Use Is Associated With Intestinal Dysbiosis and Dysfunctional CD8+ T-Cell Phenotypes in Persons With Human Immunodeficiency Virus

BACKGROUND

Inflammation persists among persons with human immunodeficiency virus (PWH) despite effective antiretroviral therapy and may contribute to T-cell dysfunction. Alcohol use is prevalent among PWH and promotes intestinal leak, dysbiosis, and a proinflammatory milieu. Whether alcohol use is associated with T-cell late differentiation remains to be investigated.

METHODS

Data and samples from PWH (N = 359 of 365) enrolled in the New Orleans Alcohol Use in HIV Study were used. Alcohol use was assessed by self-report (Alcohol Use Disorders Identification Test; lifetime alcohol exposure; 30-day Alcohol Timeline Followback) and phosphatidylethanol (PEth) quantitation. In a subset of participants, fecal bacterial content was assessed by ribosomal 16S marker gene deep sequencing and quantitative polymerase chain reaction. Intestinal leak was assessed by fecal-to-plasma α-1-antitrypsin (A1AT) enzyme-linked immunosorbent assay ratio. Peripheral T-cell populations were quantified by flow cytometry.

RESULTS

Alcohol Use Disorder Identification Test scores were positively associated with activated-senescent, exhausted, and terminal effector memory CD45RA+CD8+ but not CD4+ T cells (cells/μL) after confounder adjustment (P < .050). Phosphatidylethanol was positively associated with A1AT (P < .050). The PEth and activated-senescent CD8+ were associated with bacterial β-diversity (P < .050) and positively associated with the relative abundance of coabundant Prevotellaceae members (q < .100).

CONCLUSIONS

Alcohol use among PWH is associated with CD8+ T-cell late differentiation, intestinal leak, and dysbiosis. Alcohol-associated dysbiosis is implicated in CD8+ T-cell senescence.