Sex Differences in Spontaneous Degranulation Activity of Intrahepatic Natural Killer Cells during Chronic Hepatitis B: Association with Estradiol Levels

Differences in the intrahepatic expression of immune checkpoint molecules on T cells and natural killer cells in chronic HBV patients

Background

Patients with chronic hepatitis B virus (HBV) infection are characterized by impaired immune response that fails to eliminate HBV. Immune checkpoint molecules (ICMs) control the amplitude of the activation and function of immune cells, which makes them the key regulators of immune response.

Methods

We performed a multiparametric flow cytometry analysis of ICMs and determined their expression on intrahepatic lymphocyte subsets in untreated and treated patients with HBV in comparison with non-pathological liver tissue.

Results

The liver of untreated HBV patients exhibited a high accumulation of PD-1+CD8+ T cells, while the frequencies of 4-1BB+ T cells, 4-1BB+ natural killer (NK) cells, and TIM-3+CD8+ T cells were the highest in the chronic hepatitis phase. Our findings showed that the HBeAg status is linked to a distinct immune phenotype of intrahepatic CD8+ T cells and NK cells characterized by high expression of ICMs, particularly 4-1BB. Importantly, antiviral treatment partially restored the normal expression of ICMs. Finally, we described important differences in ICM expression between intrahepatic and circulating NK cells in HBV patients.

Conclusions

Our study shows clear differences in the intrahepatic expression of ICMs on NK cells and T cells in chronic HBV patients depending on their clinical stage.

Sex differences in chronic liver disease and benign liver lesions

The epidemiology, natural history, and therapeutic responses of chronic liver diseases and liver lesions often vary by sex. In this review, we summarize available clinical and translational data on these aspects of the most common liver conditions encountered in clinical practice, including the potential contributions of sex hormones to the underlying pathophysiology of observed differences. We also highlight areas of notable knowledge gaps and discuss sex disparities in access to liver transplant and potential strategies to address these barriers. Given established sex differences in immune response, drug metabolism, and response to liver-related therapies, emerging clinical trials and epidemiological studies should prioritize dedicated analyses by sex to inform sex-specific approaches to liver-related care.

Immune checkpoints on T and NK cells in the context of HBV infection: Landscape, pathophysiology and therapeutic exploitation

In hepatitis B virus (HBV) infection, the interplay between the virus and the host immune system is crucial in determining the pathogenesis of the disease. Patients who fail to mount a sufficient and sustained anti-viral immune response develop chronic hepatitis B (CHB). T cells and natural killer (NK) cells play decisive role in viral clearance, but they are defective in chronic HBV infection. The activation of immune cells is tightly controlled by a combination of activating and inhibitory receptors, called immune checkpoints (ICs), allowing the maintenance of immune homeostasis. Chronic exposure to viral antigens and the subsequent dysregulation of ICs actively contribute to the exhaustion of effector cells and viral persistence. The present review aims to summarize the function of various ICs and their expression in T lymphocytes and NK cells in the course of HBV infection as well as the use of immunotherapeutic strategies targeting ICs in chronic HBV infection.

Late Effects of Heavy-Ion Space Radiation on Splenocyte Subpopulations and NK Cytotoxic Function

With current goals of increased space exploration and travel to Mars, there has been great interest in understanding the long-term effects of high atomic number, high energy (HZE) ion exposure on various organ systems and the immune system. Little is known about late effects on the immune system after high-LET exposure. Therefore, our objective was to determine how natural killer (NK) cell populations were affected in geriatric mice that were exposed to HZE particles during middle-age, thereby representing elderly retired astronauts that undertook deep space missions.

Methods

10 month old male CBA/CaJ mice were whole-body irradiated: sham (control); 150-cGy gamma-rays (delivered in 1 fraction); 40-cGy 1-GeV/nu 28Si14+ ions (delivered in 3 fractions); 40-cGy 1-GeV/nu 16O8+ ions (1 fraction); and 40-cGy 1-GeV/nu 16O8+ ions (3 fractions). The mice were sacrificed 1-1.5 yr post-exposure, and the spleens harvested. Splenocyte effector (E) cells were harvested and added to 51Cr-labeled Yac-1 target (T) cells in E:T ratios of 12:1, 25:1, 50:1, and 100:1. NK cytotoxicity was measured with 51Cr release. In addition, 2 million splenocytes were aliquoted and stained with a seven-antibody cocktail, and flow cytometry was used to determine the percentage of NK, B lymphocytes, and T lymphocytes in the splenocyte population.

Results

Mice exposed to either a single fraction of 150-cGy gamma rays or 40-cGy 16O8+ ions in 3 fractions were found to have significant decreases in NK cytotoxicity of approximately 30% and 25%, respectively. No significant differences were observed in NK cytotoxicity for 40-cGy 16O8+ ions delivered in 1 fraction, or 40-cGy 28Si14+ ions delivered in 3 fractions. No significant differences were observed in the percentage of spleen cells that were NK (%NK) amongst the groups.

Conclusion

Fractionated HZE ion exposure has the potential to affect the innate arm of the immune system long after exposure, leading to decreases in NK cell function. Therefore, protective countermeasures may need to be considered to decrease the risk of reduced long-term immune function in elderly retired astronauts that undertook deep space missions.

Gender as a factor affecting NK cell activity in patients successfully treated for chronic hepatitis C with direct-acting antivirals

Chronic hepatitis C (CHC) affects the activity of natural killer (NK) cells, but successful interferon- free treatment partially restores it. The goal of this study was to assess whether gender influences NK functionality. We examined 21 post-menopausal women and 24 men with CHC who were treated with direct-acting antivirals (DAA) and 33 healthy volunteers. Using flow cytometry, we analysed KIR2DS4, NKG2D, NKp30, KIR2DL2/DL3, NKG2A and TRAIL on the surface of NK cells. Intracellular granzyme B was also assessed and serum CXCL10 was quantified via ELISA. Overall, patients with CHC had higher expression of KIR2DS4, NKG2A, and NKp30 relative to the control group. Further, CHC patients had a lower percentage of NK cells among lymphocytes relative to the control group. After treatment, KIR2DS4, KIR2DL2/DL, NKG2A, TRAIL and NKp30 on NK cells were decreased whilst the percentage of NK cells and the expression of granzyme B and NKG2D increased. Prior to treatment, serum CXCL10 was elevated, but it was inhibited post-treatment. We observed gender-specific differences in the expression of KIR2DL2/DL3 (higher in women) and NKp30 (elevated in men) compared to CHC/control groups. After treatment, KIR2DL2/DL3, NKp30 and CXCL10 dropped only in the female group while granzyme B increased in the male group. In conclusion, the response of NK cells among men and women of post-menopausal ages with CHC differs. Our research may lead to more studies on the different nature of female and male immune systems in the context of HCV infection and treatment.

Increased Intrahepatic Expression of Immune Checkpoint Molecules in Autoimmune Liver Disease

Immune checkpoint molecules (ICM) are critical in maintaining immunologic homeostasis and participate in preventing or promoting autoimmune disease development. Exploring a large panel of intrahepatic inhibitory and stimulatory ICM is necessary for drawing a general picture of the immune alterations in autoimmune hepatitis (AIH). Here, we performed a multiparametric analysis of ICM, including PD-1, TIM3, LAG3, CTLA-4, OX40 and 4-1BB, and we determined their expression on intrahepatic lymphocyte subsets in untreated and in treated patients with AIH in comparison to normal liver tissue. AIH patient-derived liver tissue revealed the overexpression of ICM, mainly PD-1 and 4-1BB, as well as the strong correlation between PD-1⁺ CD8⁺ T-cell abundance and severity of AIH (alanine transaminase and aspartate transaminase levels). Our results show that the ICM play an important role in the loss of immune homeostasis in the liver, providing an attractive approach to investigate their role as targets for effective therapeutic interventions.

Influence of Gender and Reproductive Factors on Liver Fibrosis in Patients With Chronic Hepatitis B Infection

INTRODUCTION:

The role of reproductive factors in the development of chronic hepatitis B (CHB) remains unknown. We assessed the potential contributions of gender, menopausal status, and menarche age to liver fibrosis in CHB.

METHODS:

A cross-sectional prospective study included 716 women and 716 age-matched men with CHB who were not currently receiving antiviral therapy. Liver stiffness measurement using transient elastography was used to stage liver fibrosis as F0–F1 (<7.2 kPa), F ≥ 2 (7.2 kPa), F ≥ 3 (9.4 kPa), and F = 4 (12.2 kPa). Female patients were asked regarding their age at menarche and menopausal status using a questionnaire.

RESULTS:

Of the 716 women, 121 (16.9%) were postmenopausal, and 80 (11.2%) had advanced liver fibrosis. Multivariate logistic regression analysis showed that the postmenopausal status compared with the premenopausal status (odds ratio [OR] = 3.65–8.83; P < 0.05) and age at menarche of >14 years compared with <13 years (OR = 2.85–3.95; P < 0.05) were significantly associated with advanced fibrosis. Compared with premenopausal women, age-matched men had a higher OR for advanced fibrosis (P < 0.05). Compared with postmenopausal women, age-matched men did not show a significant difference in the degree of liver fibrosis (P > 0.05). Longitudinal data analysis showed that postmenopausal women (n = 31) were significantly less likely to undergo regression of liver fibrosis after antiviral treatment vs premenopausal women (n = 19) (26.3% vs 74.2%, respectively; P < 0.001).

DISCUSSION:

Menopause and late menarche aggravated liver fibrosis in untreated CHB, besides menopause delayed fibrosis regression under antiviral therapy. The protective effect of female gender against fibrosis was lost for postmenopausal women.

TRANSLATIONAL IMPACT:

It is important to consider menopausal status and age at menarche in establishing surveillance strategies among CHB females. Postmenopausal estrogen therapy may be considered for the prevention or treatment of liver fibrosis.

Immunologic Features of Patients With Advanced Hepatocellular Carcinoma Before and During Sorafenib or Anti-programmed Death-1/Programmed Death-L1 Treatment

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Today, a promising treatment strategy is focused on the enhancement of antitumor immune responses by immune checkpoint modification. However, as only 20% of patients with HCC are responders, identification of predictive factors is urgently required. Therefore, for the first time, the features of the intrahepatic and circulating immune system in patients with advanced-stage HCC, before and during the treatment, were analyzed.

METHODS

We collected fresh HCC biopsies, along with adjacent tumor-free liver tissues and peripheral blood samples, from 21 patients with advanced HCC. Furthermore, we performed an extensive immunomonitoring of patients with HCC treated with sorafenib or programmed death (PD)-1/PD-L1 pathway blockade using multiparametric flow cytometry.

RESULTS

We observed that regardless of the treatment, low baseline intratumoral CD4/CD8 T-cell ratio was associated with better overall survival (P = 0.0002). The baseline frequency of intratumoral PD-1 CD8 T cells was significantly lower in patients responding to sorafenib treatment than in the nonresponders (P = 0.0117), and the frequency of circulating PD-1 T cells increased with tumor progression (P = 0.0329). By contrast, responders to PD-1/PD-L1 pathway blockade showed a trend of high baseline frequency of intratumoral PD-1 CD8 T cells. Moreover, we observed a trend of LAG3 and TIM3 upregulation on circulating T cells in nonresponding patients to PD-1/PD-L1 pathway blockade.

DISCUSSION

Immunosuppressive state, characterized by an enhanced intratumoral CD4/CD8 T-cell ratio, was associated with poor prognosis. Additionally, our results suggest that the frequency of intratumoral PD-1 CD8 T cells may serve as a biomarker to identify which individuals will benefit from which treatment and support the use of combination strategies.

Abnormal Expression of ERα in Cholangiocytes of Patients With Primary Biliary Cholangitis Mediated Intrahepatic Bile Duct Inflammation

ERα, one of the classical receptors of estrogen, has been found to be abnormally up-regulated in patients with primary biliary cholangitis (PBC), which is an important factor leading to ductopenia. ERα-mediated signaling pathways are involved in proliferation of human intrahepatic biliary epithelial cells (HiBECs) and portal inflammation. Our previous studies have shown that the expression levels of ERα in the liver tissues of PBC patients are positively correlated with the levels of serum pro-inflammatory cytokines. The present study was designed to assess the relationship between abnormal ERα expression in small bile ducts and the progression of PBC. We examined the levels of multiple cytokines and analyzed their relationship with clinical parameters of livers functions in a cohort of 43 PBC patients and 45 healthy controls (HC). The levels of ERα expression and the relation with the levels of cytokines were further assessed. The localization of cytokines and ERα-mediated signaling pathways in liver were examined using immunohistochemistry. The possible underlying mechanisms of these alterations in PBC were explored in vitro. Our results demonstrated that the levels of IL-6, IL-8, and TNF-α were increased in PBC patients, and positively correlated with the serum AKP levels and ERα expression levels. Moreover, the expression of these cytokines were up-regulated in HiBECs that were stimulated with 17β-estradiol and PPT (an ERα agonist) and they also were positive in intrahepatic bile duct of PBC patients. The ERα-mediated expression of pro-inflammatory cytokines was induced by JNK, P38, and STAT3 phosphorylation in HiBECs. In addition, the CD54 expression was increased in HiBECs after ERα activation, which induced peripheral blood monouclear cells (PBMCs) recruitment. In conclusion, the present study highlighted a key role of abnormal ERα expression in inducing an inflammatory phenotype of HiBECs, which was critical in the development of inflammation and damage in small bile duct.

Predictive Factors for Response to PD-1/PD-L1 Checkpoint Inhibition in the Field of Hepatocellular Carcinoma: Current Status and Challenges

Immunotherapies targeting immune checkpoints are fast-developing therapeutic approaches adopted for several tumor types that trigger unprecedented rates of durable clinical responses. Immune checkpoint programmed cell death protein 1 (PD-1), expressed primarily by T cells, and programmed cell death ligand 1 (PD-L1), expressed mainly by tumor cells, macrophages, and dendritic cells, are molecules that impede immune function, thereby allowing tumor cells to proliferate, grow and spread. PD-1/PD-L1 checkpoint inhibitors have emerged as a promising treatment strategy of hepatocellular carcinoma (HCC). However, only a minority of HCC patients benefit from this therapy. To find a niche for immune checkpoint inhibition in HCC patients, future strategies might require predictive factor-based patient selection, to identify patients who are likely to respond to the said therapy and combination strategies in order to enhance anti-tumor efficacy and clinical success. This review provides an overview of the most recent data pertaining to predictive factors for response to PD-1/PD-L1 checkpoint inhibition in the field of HCC.

Identification of novel susceptibility loci associated with hepatitis B surface antigen seroclearance in chronic hepatitis B

BACKGROUND/AIMS

The seroclearance of hepatitis B virus (HBV) surface antigen (HBsAg) is regarded as a functional cure of chronic hepatitis B (CHB) although it occurs rarely. Recently, several genome-wide association studies (GWASs) revealed various genetic alterations related to the clinical course of HBV infection. However, all of these studies focused on the progression of HBV infection to chronicity and had limited application because of the heterogeneity of HBV genotypes. In the present study, we aimed to determine susceptibility genetic markers for seroclearance of HBsAg in CHB patients with a homogenous viral genotype.

METHODS

One hundred patients with CHB who had experienced HBsAg seroclearance before 60 years of age and another 100 with CHB showing high serum levels of HBsAg even after 60 years of age were enrolled. Extreme-phenotype GWAS was conducted using blood samples of participants.

RESULTS

We identified three single nucleotide polymorphisms, rs7944135 (P = 4.17 × 10-6, odds ratio [OR] = 4.16, 95% confidence interval [CI] = 2.27-7.63) at 11q12.1, rs171941 (P = 3.52×10-6, OR = 3.69, 95% CI = 2.13-6.42) at 5q14.1, and rs6462008 (P = 3.40×10-6, OR = 0.34, 95% CI = 0.22-0.54) at 7p15.2 as novel susceptibility loci associated with HBsAg seroclearance in patients with CHB. The flanking genes at these loci including MPEG1, DTX4, MTX3, and HOXA13 were suggested to have functional significance. In addition, through functional analysis, CXCL13 was also presumed to be related.

CONCLUSIONS

To the best of our knowledge, this study is the first GWAS regarding the seroclearance of HBsAg in CHB patients. We identify new susceptibility loci for cure of CHB, providing new insights into its pathophysiology.

Combination of AKT inhibitor ARQ 092 and sorafenib potentiates inhibition of tumor progression in cirrhotic rat model of hepatocellular carcinoma

The prognosis of patients with advanced hepatocellular carcinoma (HCC) is very poor. The AKT pathway is activated in almost half of HCC cases and in addition, long term exposure to conventional drug treatment of HCC, sorafenib, often results in over-activation of AKT, leading to HCC resistance. Therefore, it is important to assess the safety and the efficacy of selective allosteric AKT inhibitor ARQ 092 (Miransertib) in combination with sorafenib.

Here, we demonstrated in vitro that the combination of ARQ 092 with sorafenib synergistically suppressed proliferation, promoted apoptosis, and reduced migration. To test the effect of the combination in vivo, rats with diethylnitrosamine-induced cirrhosis and fully developed HCC were randomized and treated with vehicle, sorafenib, ARQ 092 or the combination of ARQ 092 with sorafenib; (n=7/group) for 6 weeks. Tumor progression, size of tumors and the mean tumor number were significantly reduced by the combination treatment compared to the control or single treatments. This effect was associated with a significant increase in apoptotic response and reduction in proliferation and angiogenesis. Sirius red staining showed a decrease in liver fibrosis. Moreover, treatments improved immune response in blood and in tumor microenvironment.

Thus, the combination of ARQ 092 with sorafenib potentiates inhibition of tumor progression and gives the possibility of therapeutic improvement for patients with advanced HCC.