CXCR5+ CD4+ T cell subsets and their relationship to immune dysfunction in chronic hepatitis B-associated liver cirrhosis

The independent prognostic value of perioperative hepatic venous pressure gradient measurements in patients with portal hypertension who underwent laparoscopic splenectomy plus esophagogastric devascularization

BACKGROUND

Hepatic venous pressure gradient (HVPG) is considered the gold standard for diagnosing portal hypertension (PHT). Laparoscopic splenectomy plus esophagogastric devascularization (LSED) is an important surgery for treating PHT. However, the variation trend of HVPG after surgery is not clear. Moreover, whether HVPG can provide precise prognostic information for patients undergoing surgery remains to be further studied. This study aimed to investigate the independent prognostic value of HVPG in LSED.

METHODS

From January 2016 to March 2023, 135 patients with PHT underwent LSED at our hospital were retrospectively evaluated. We analyzed the correlations between clinical indicators and history of upper gastrointestinal bleeding (UGIB). Among them, 57 patients remeasured postoperative HVPG. We further investigated the postoperative alterations of HVPG and correlative factors, as well as the relationship between the HVPG and postoperative UGIB.

RESULTS

In this study, we found that 94 patients with preoperative UGIB (16.27 ± 5.73 mmHg) had a higher baseline HVPG than the other 41 patients without (14.02 ± 5.90 mmHg) (p = 0.04). The mean postoperative HVPG significantly decreased (-3.57 ± 8.09 mmHg, p = 0.001) compared to the baseline, and 66% of patients (38/57) experienced a decreased HVPG-response after surgery. The baseline HVPG and preoperative CTP class B were associated with the decreased HVPG-response (p<0.05). Additionally, patients with postoperative HVPG decreased>20% from baseline exhibited better recurrent hemorrhage-free survival rates than those without (log-rank, p = 0.013).

CONCLUSION

We found that LSED led to a significantly decreased HVPG, and patients with postoperative HVPG decreased >20% obtained better UGIB-free survival benefits than those without.

Triptolide attenuates CCL4-induced liver fibrosis by regulating the differentiation of CD4+ T cells in mice

Liver fibrosis is a major global health issue, and immune dysregulation is a main contributor. Triptolide is a natural immunosuppressive agent with demonstrated effectiveness in ameliorating liver fibrosis, but whether it exerts anti-liver fibrotic effects via immunoregulation remains obscure. In this study, first, by employing a CCL4-induced liver fibrosis mouse model, we demonstrated that triptolide could alleviate pathological damage to liver tissue and attenuate liver function damaged by CCL4. In addition, triptolide inhibited the expression of liver fibrotic markers such as hydroxyproline, collagen type IV, hyaluronidase, laminin, and procollagen type III, and the protein expression of α-SMA in CCL4-induced liver fibrosis. Second, with the help of network pharmacology, we predicted that triptolide's anti-liver fibrotic effects might occur through the regulation of Th17, Th1, and Th2 cell differentiation, which indicated that triptolide might mitigate liver fibrosis via immunoregulation. Finally, multiplex immunoassays and flow cytometry were adopted to verify this prediction. The results suggested that triptolide could reverse the aberrant expression of inflammatory cytokines caused by CCL4 and regulate the differentiation of Th1, Th2, Th17, and Treg cells. In conclusion, triptolide could attenuate CCL4-induced liver fibrosis by regulating the differentiation of CD4+ T cells. The results obtained in this study extended the application of triptolide and introduced a new mechanism of triptolide's anti-liver fibrotic effects.

Characterization of intrahepatic B cells in acute-on-chronic liver failure

Background and objectives

Acute on chronic liver failure (ACLF) is characterized by the immunologic dissonance during the prolonged pathogenic development. Both abnormal innate immune response and adaptive T-cell response have been reported in patients with ACLF; however, less is known regarding B cells in ACLF pathogenesis. Previous reports were only based on immunophenotyping of peripheral blood samples. Here, we aim to dissect liver-infiltrating B-cell subpopulation in ACLF.

Methods

Paired liver perfusate and peripheral blood were freshly collected from healthy living donors and recipients during liver transplantation. Liver tissues were obtained from patients with ACLF, cirrhosis, and healthy controls. Flow cytometry was used to characterize the phenotypic and functional alterations in intrahepatic and circulating B-cell populations from ACLF, cirrhosis, and healthy controls. The expression of CD19⁺ and CD138⁺ on liver tissues was examined by immunohistochemistry staining.

Results

In this study, we first deciphered the intrahepatic B cells subsets of patients with ACLF. We found that the ACLF liver harbored reduced fraction of naïve B cells and elevated percentage of CD27⁺CD21^- activated memory B cells (AM), CD27^-CD21^- atypical memory B cells (atMBC), CD27⁺IgD^-IgM⁺(IgM⁺ memory B cells), and CD27⁺CD38⁺⁺ plasma cells than cirrhosis and healthy controls. Moreover, these B subpopulations demonstrated enhanced activation and altered effector functions. Specifically, the ACLF liver was abundant in atMBC expressing higher CD11c and lower CD80 molecule, which was significantly correlated to alanine aminotransferase and aspartate aminotransferase. In addition, we found that intrahepatic CD27⁺CD38⁺⁺plasma cells were preferentially accumulated in ACLF, which expressed more CD273 (PD-L2) and secreted higher granzyme B and IL-10. Finally, the enriched hepatic plasma B cells were in positive association with disease severity indices including alkaline phosphatase and gamma-glutamyl transferase.

Conclusions

In this pilot study, we showed an intrahepatic B-cell landscape shaped by the ACLF liver environment, which was distinct from paired circulating B-cell subsets. The phenotypic and functional perturbation in atMBC and plasma cells highlighted the unique properties of infiltrating B cells during ACLF progression, thereby denoting the potential of B-cell intervention in ACLF therapy.

T cells and liver fibrosis

Liver fibrosis develops from the excessive deposition of extracellular matrix in the liver caused by chronic liver inflammation or various chronic injuries, and it eventually develops into liver cirrhosis. The process of liver fibrosis is closely related to the immune response, and increasing evidence reveals the role of T lymphocytes, including Th1, Th2, Th17, regulatory T cells, and mucosa‐associated invariant T cells, in liver fibrosis. These immune cells play antifibrotic or profibrotic roles during fibrosis, and the reversal of fibrosis by targeting immune cells has attracted widespread attention. Activation of hepatic stellate cells, which form the core of fibrosis, is regulated by various immune mediators, including various immune cells and their associated cytokines. Therefore, the mechanism of action elicited by each cell type must be further elucidated to provide a basis for the design of new therapeutic targets. The purpose of this review is to summarize the roles and mechanisms of T lymphocytes and their subsets in liver fibrosis and highlight the biomarkers and potential therapeutic targets associated with these cells.

IL-2 contributes to cirrhosis-associated immune dysfunction by impairing follicular T helper cells in advanced cirrhosis

BACKGROUND & AIMS

Patients with decompensated cirrhosis suffer from recurrent infections and inadequate responses to prophylactic vaccinations. However, many patients present with hypergammaglobulinemia (HGG), indicating a sustained ability to generate antibody responses. As follicular T helper (Tfh) cells are central facilitators of humoral immunity, we hypothesized that Tfh cell responses may be altered in advanced liver disease and we aimed to identify the mechanisms underlying any such alterations.

METHODS

Tfh, regulatory T (Treg) cells, B cells, circulating cytokines and immunoglobulins were analyzed in cohorts of patients with compensated (n = 37) and decompensated cirrhosis (n = 82) and in non-cirrhotic controls (n = 45). Intrahepatic T cells were analyzed in 8 decompensated patients. The influence of IL-2 on Tfh cell function was evaluated in vitro, including Tfh cell cloning and T cell-B cell co-cultures with clones and primary tonsil-derived Tfh cells.

RESULTS

Tfh cell frequencies were reduced in patients with decompensated cirrhosis, with phenotypic signatures indicative of increased IL-2 signaling. Soluble IL-2 receptor (sCD25) was elevated in these patients and CD4 T cells were more responsive to IL-2 signaling, as characterized by STAT5 phosphorylation. IL-2 exposure in vitro diminished the Tfh phenotype and resulted in impaired Tfh helper function in co-culture experiments with naïve B cells. Tfh cells were barely detectable in cirrhotic livers. IL-2 signatures on Tfh cells in decompensated patients correlated with immunoglobulin levels, which were found to be associated with improved survival.

CONCLUSIONS

Tfh cell impairment represents a previously underestimated feature of cirrhosis-associated immune dysfunction that is driven by IL-2. The presence of HGG in decompensated patients predicts an intact Tfh cell compartment and is associated with a favorable outcome.

LAY SUMMARY

Patients with advanced cirrhosis often fail to generate protective immunity after prophylactic vaccinations and suffer from recurring infections that are associated with high mortality. Follicular T helper (Tfh) cells are specialized CD4 T cells that enable the emergence of antibody responses against microbial pathogens. This report demonstrates that Tfh cells are impaired in patients with advanced cirrhosis due to interleukin-2 signaling, a cytokine that is known to impair the generation of Tfh cells.