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A growing body of evidence has shown that hepatitis B surface antigen (HBsAg) mutations can influence the occurrence of occult hepatitis B infection (OBI), particularly amino acid substitutions in small hepatitis B surface proteins (SHBs). The mechanistic basis for these results, however, remains unclear. This study was designed to explore the potential impact and mechanisms of OBI-related SHBs mutations on serum HBsAg. Huh7 and HepG2 cells were transfected with plasmids encoding wild-type (WT) or OBI-related SHB mutation-containing sequences, after which a chemiluminescence approach was used to detect HBsAg levels in cell culture supernatants. Western blotting was further used to assess HBsAg and endoplasmic reticulum stress (ERS)-related protein levels in lysates prepared from these cells, while the localization of HBsAg within cells was assessed via immunofluorescent staining. Cells transfected with OBI-related SHB mutation-encoding plasmids exhibited lower supernatant HBsAg levels than cells transfected with WT plasmids. Intracellular and extracellular HBsAg levels in these mutant plasmid-transfected cells were lower relative to those for WT plasmid-transfected cells, and HBsAg accumulation within the ER was detected via immunofluorescent staining in cells transfected with OBI-related SHB mutation-encoding plasmids, ERS-related protein content was also significantly increased in mutant plasmid-transfected cells as compared to those in the WT group. These results suggest that proteins harboring OBI-related mutations may tend to accumulate in the ER, thereby triggering an ERS response and impairing the transcription and translation of HBsAg via the activation of the unfolded protein response and ER-associated protein degradation pathway. These effects ultimately reduce the overall assembly of HBV virions in the ER and their associated secretion.

Objective: In breast diagnostic imaging, the morphological variability of breast tumors and the inherent ambiguity of ultrasound images pose significant challenges. Moreover, multi-task computer-aided diagnosis systems in breast imaging may overlook inherent relationships between pixel-wise segmentation and categorical classification tasks. 
Approach. In this paper, we propose a multi-task learning network with deep inter-task interactions that exploits the inherently relations between two tasks. First, we fuse self-task attention and cross-task attention mechanisms to explore the two types of interaction information, location and semantic, between tasks. In addition, a feature aggregation block is developed based on the channel attention mechanism, which reduces the semantic differences between the decoder and the encoder. To exploit inter-task further, our network uses an circle training strategy to refine heterogeneous feature with the help of segmentation maps obtained from previous training. 
Main results. The experimental results show that our method achieved excellent performance on the BUSI and BUS-B datasets, with DSCs of 81.95% and 86.41% for segmentation tasks, and F1 scores of 82.13% and 69.01% for classification tasks, respectively. 
Significance. The proposed multi-task interaction learning not only enhances the performance of all tasks related to breast tumor segmentation and classification but also promotes research in multi-task learning, providing further insights for clinical applications.}., (© 2025 Institute of Physics and Engineering in Medicine. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Backgrounds and Aims: CD8+T cells are crucially associated with the fight against hepatitis B virus (HBV) infection. CD161 has been shown to express remarkably on HCV-specific CD8+T cells. However, the accurate function of CD161+CD8+T cells in HBV immunity or pathogenesis remains undetermined., Methods: Blood samples were collected from 25 chronic hepatitis B (CHB) patients. Peripheral blood levels of CD161+CD8+T cells and their correlation with serum ALT levels were analyzed in CHB patients. To analyze the in vivo CD161+CD8+T cell's number, function, and intrahepatic recruitment characteristics, HBV replication mouse models were established. The expression of CD161 on HBV-specific CD8+T cells was also detected by analyzing CD161+CD8+T cell functions during infection., Results: Patients with CHB infection had a markedly lower peripheral blood frequency of CD161+CD8+T cells than did healthy controls and negatively correlated with serum ALT level. Furthermore, compared to the control mice, the frequency of CD161+CD8+T cells was significantly decreased in the blood of acute and chronic HBV-replicating mice. Moreover, CHB-replicating mice had significantly increased hepatic levels of CD161+CD8+T cells, which was not observed in the acute group of mice. Additionally, the CD161+CD8+T cells were categorized into CD161 hi and CD161 int CD8+T cells and it was revealed that in the liver of CHB-replicating mice the primary recruited cells were CD161 hi CD8+T. Intrahepatic CD161 hi CD8+T cells demonstrated increased CXCR6 expression, enhanced production of cytokine IL-17 and TNF-ɑ, and reduced IFN-γ secretion. Accordingly, the CXCL16 mRNA expression in the liver tissue of CHB-replication mice was markedly higher than in acute HBV-replicating and control mice. The study also revealed that HBV-specific CD8+T cells were mainly CD161-CD8+T cells., Conclusion: During HBV infection, the intrahepatic recruitment of CD161+CD8+T cells was mainly CD161 hi CD8+T cell subpopulation, which has a weak antiviral response, but increased pro-inflammatory effect, suggesting that CD161 may serve as a potential marker of liver-damaging T cells., (© 2025 The Author(s). Immunity, Inflammation and Disease published by John Wiley & Sons Ltd.)