Tingting Li

While occult hepatitis B virus infection is a known risk factor for progressive liver diseases, the mechanistic basis for this association is poorly understood. To investigate this, we conducted a comparative study involving 40 OBI blood donors and 100 healthy blood donors to assess clinical parameters of liver fibrosis, including serum biomarkers, the FIB-4 index, and liver stiffness measurement. Transcriptome sequencing of peripheral blood mononuclear cells from these donors identified IL-17F as significantly upregulated in the OBI group. Mechanistically, we found that IL-17F was chiefly secreted by CD4 ⁺ T cells upon HBcAg stimulation and functionally promoted the expression of key fibrosis-related cytokines and markers. Collectively, our study unveils a novel pathway wherein HBcAg induces CD4 ⁺ T cells to secrete IL-17F, which in turn accelerates liver fibrogenesis, providing a mechanistic basis for OBI-associated liver disease. IMPORTANCE: This study reveals, for the first time, a novel mechanism by which OBI drives liver fibrosis, demonstrating that HBcAg stimulates CD4 ⁺ T cells to secrete IL-17F, which in turn activates macrophages and hepatic stellate cells, thereby promoting liver inflammation and fibrosis. This discovery not only elucidates a key molecular pathway underlying OBI-related liver disease progression, but also provides an important theoretical foundation for developing IL-17F-targeted diagnostic approaches and anti-fibrotic therapies.

Brucellosis is a zoonotic disease that poses a significant threat to public health and the development of animal husbandry, making early and rapid diagnosis essential for effective control. In this study, a double-antigen sandwich time-resolved fluorescent immunochromatographic assay (EuCM-TRFICA) utilizing europium chelate microsphere (EuCM) was developed for the highly sensitive quantification of Brucella antibodies in human serum. This is the first report of a double-antigen sandwich TRFICA utilizing Brucella LPS, which enables the detection of total antibodies with superior sensitivity compared to the previously reported colloidal gold immunochromatographic assay (AuNP-ICA) and time-resolved fluorescence LFIA (TF-LFIA). Under the optimal parameters, EuCM-TRFICA exhibited a satisfactory linear range from 0.156 to 5.00 IU/mL, and its limit of detection (0.145 IU/mL) was lower than that (0.3125 IU/mL) of AuNP-ICA. Furthermore, it effectively identified positive samples missed by the serum agglutination test (SAT) or the rose bengal test (RBT). EuCM-TRFICA exhibited high specificity, with only weak cross-reactivity observed against Yersinia enterocolitica O9, which has been reported to share similar antigenic epitopes. Precision evaluation showed that both intra- and inter-assay coefficients of variation (CV) were below 10.55%. The recoveries of spiked samples ranged from 91.94% to 108.85%, confirming reliable accuracy. In the testing of 49 confirmed positive samples and 60 negative samples, EuCM-TRFICA achieved 100% accuracy, outperforming SAT (92.7%), RBT (86.2%), and ELISA (97.2%). In conclusion, the EuCM-TRFICA exhibits excellent performance in terms of sensitivity, quantitative capability, and detection speed. It features simple operation, a short detection time of 15 min, quantitative readout, and controllable costs. This assay shows promise as a potentially efficient technical tool for early on-site screening and epidemic surveillance in this preliminary cohort, which may be valuable for managing human brucellosis.

Ovarian cancer remains the deadliest gynecological malignancy, largely because early screening is inadequate. This work reports a smartphone-based fluorescent homogeneous immunoassay sensor (SFHIS) that combines aggregation-induced emission luminogen-doped metal-organic framework microspheres (AMOFs) as donors and spiky carbon nanospheres (CNPs) as acceptors. Target antigen–antibody sandwich formation brings donor and acceptor into proximity, inducing efficient Förster resonance energy transfer (FRET) and fluorescence quenching, which is linearly related to the natural logarithm of antigen concentration. A dual-correction algorithm removes internal filter effects, enabling accurate quantification. The SFHIS shows linear ranges of 0.8−51.2 U/mL for CA125 and 8–256 pmol/L for HE4, with limits of detection of 0.67 U/mL and 1.03 pmol/L, respectively. The assay is completed within 25 min without washing, exhibits intra- and inter-batch CVs < 10%, no cross-reactivity with CEA, AFP, or PSA, and correlates strongly with chemiluminescence assays (CA125: R² = 0.970; HE4: R² = 0.982; P < 0.05). This portable, low-cost platform offers rapid, reliable biomarker detection suitable for clinical laboratories, primary care, community health, and resource-limited settings.

Background: Natural killer (NK) cells are key effectors of innate immunity with broad-spectrum anti-tumor activity. However, peripheral blood-derived NK (PBNK) cells are typically quiescent, which limits their therapeutic utility. This study aimed to develop an efficient strategy for the in vitro activation and expansion of PBNK cells and then evaluate their potential anti-tumor efficacy in vitro and vivo. Methods: NK cells were isolated from healthy blood donors’ peripheral blood and stimulated with anti-CD16 and anti-CD137 antibodies in the presence of interleukin-2 (IL-2) and interleukin-15 (IL-15) under serum-free conditions, generating super NK (SNK) cells. The expression levels of activating and inhibitory receptors on the expanded SNK cells were assessed by flow cytometry. Cytotoxicity against tumor cells was assessed at various effector-to-target (E:T) ratios in vitro. In vivo, anti-tumor efficacy was evaluated in K562-engrafted NSG mice. RNA sequencing was performed to identify differentially expressed genes (DEGs) between SNK and PBNK cells. Results: Stimulation with anti-CD16 and anti-CD137 antibodies resulted in significant expansion of donor-derived NK cells, with over 861.9 ± 48.84-fold expansion (n = 5) within 15 days of culture. SNK cells exhibited significantly elevated expression of activating receptors, including NKG2D. Functionally, SNK cells demonstrated superior cytotoxicity compared with PBNK cells across all tested E:T ratios in vitro and higher expressions of the effector molecules interferon-gamma (IFN-γ) and granzyme B (Gzm B). In vivo, adoptive SNK cell transfer resulted in significant tumor suppression and prolonged survival in a dose-dependent manner. Transcriptomic analysis revealed significant enrichment of DEGs associated with cytokine and chemokine signaling, immune activation, and cytotoxic effector function compared with the PBNK cells. Conclusions: Anti-CD16/CD137 antibody stimulation, in combination with IL-2 and IL-15, facilitates robust activation and rapid expansion of functionally enhanced NK cells from peripheral blood. The resulting SNK cells demonstrated enhanced anti-tumor efficacy both in vitro and in vivo and may be used as allogeneic NK cell-based immunotherapy in future cancer treatment strategies.

Background and Aims: Hepatitis C virus (HCV) vaccines are urgently needed to achieve WHO's goal for the elimination of viral hepatitis by 2030. The lack of suitable animal models for evaluating vaccine efficacy has greatly hindered the development of HCV vaccines. By using the rat model chronically infected with rodent hepacivirus from Rattus norvegicus (RHV‐rn1), a hepacivirus homologously close to HCV as a surrogate model of HCV infection, we assessed the protective effectiveness of the RHV‐rn1 vaccine Sad23L‐RHVns. Methods: Sad23L‐RHVns vaccine was constructed with the nonstructural proteins (NS) 3–5B genes of RHV‐rn1. SD rats were immunised with Sad23L‐RHVns by prime or prime‐boost regimen via intramuscular injection, then challenged 4 weeks post vaccination by RHV‐rn1. A part of the rats were rechallenged with a variant 15 weeks post the first challenge of RHV‐rn1. Results: The specific T‐cell responses to NS3‐5B antigens were induced by prime immunisation, which were significantly enhanced by boost vaccination. The inoculated rats and controls were challenged by wild‐type RHV‐rn1, of all the primed and control rats having persistently high levels of viremia, whereas 7 of 9 (77.8%) boosted rats cleared RHV‐rn1 infection. Interestingly, the resolver acquired immune protection against re‐challenging with variant and showed significantly higher T‐cell responses than the nonresolver in 25 weeks post rechallenge. Conclusions: Sad23L‐RHVns with prime‐boost regimen protected 77.8% of rats against wild‐type RHV‐rn1 infection, and resolvers showed high levels and maintenance of T cell immunity against the variant. Our findings that maintenance of effective T cell immunity is required for RHV‐rn1 resolution may provide insight to develop the HCV vaccine in humans.