CXCR5+ CD4+ T follicular helper cells participate in the pathogenesis of primary biliary cirrhosis.

UNLABELLED: There is increasing interest in the role of T follicular helper (Tfh) cells in autoimmunity from the perspective of both their role in breach of tolerance and their effects on the natural history of disease progression. Indeed, the critical role of Tfh cells in autoimmunity is further highlighted based on their location in the germinal center (GC), a pathogenic hot spot for development of autoreactivity. To address the role of Tfh cells in primary biliary cirrhosis (PBC), we comprehensively evaluated the immunobiology of CXCR5(+) CD4(+) Tfh cells in 69 patients with PBC, including a nested subgroup of 16 autoimmune hepatitis (AIH) and 20 healthy controls (HC), followed for 1 year. We report herein several key observations. First, there was an increased frequency of circulating Tfh cells in patients with PBC compared to AIH (P < 0.05) and HC (P < 0.01). Second, the function of circulating Tfh cells from PBC patients, including interleukin (IL)-21 production (P < 0.05), the ability to promote B-cell maturation, and autoantibody production, were greater than HC. Third, the frequency of these cells was significantly decreased in ursodeoxycholic acid (UDCA) responders compared to UDCA-treated nonresponders, in both cross-sectional (P = 0.023) and longitudinal studies (P = 0.036), respectively. Indeed, similar increases of Tfh cells were noted in liver and spleen. CONCLUSION: These results significantly extend our understanding of lymphoid subpopulations in PBC and their relative role in disease expression. Our data also provide a novel biomarker for evaluation of the effectiveness of new therapeutic approaches.

N-Linked Glycosylation at an Appropriate Position in the Pre-S2 Domain Is Critical for Cellular and Humoral Immunity against Middle HBV Surface Antigen.

Infection with hepatitis B virus (HBV) remains a worldwide health problem, and DNA-based vaccines against HBV have been tested for therapeutic applications. HBV possesses three envelope lipoproteins that are translated from a single reading-frame: large, middle, and small HBV surface antigens. Among these envelope proteins, the middle HBV surface antigen (MHBs) contains a constitutive N-linked glycosylation site at position 4 (Asn4) in the amino-terminal portion (MQWNSTTFHQ) of pre-S2 domain. Asn4 (shown in bold) is essential for secretion of viral particles and conserved among all serotypes of HBV, but its influence on the immunogenicity of MHBs remains unknown. Here, we constructed four MHBs genes carrying mutations, underlined, in the amino-terminal portion of pre-S2 domain. One mutant protein contains Q at position 4 (MQWQSTTFHQ). In addition, each of three mutant MHBs proteins contains a N-linked glycosylation site (N-X-S/T), relocated to position 5 (MQWQNTTFHQ), 6 (MQWQSNTSHQ) or 7 (MQWQSTNFTQ) in pre-S2 domain. The expression and immunogenic properties of mutant DNA vaccines were examined in 293T human renal epithelial cells and in BALB/c mice, respectively. We showed that Asn4 was critical for secretion and immunogenicity of MHBs. Moreover, the MHBs protein that carries a N-linked glycosylation site at position 5 or 7 retained the properties similar to wild-type MHBs. In contrast, the secretion-defective mutant protein carrying Asn at position 6 induced only marginal humoral and cellular immune responses in mice, despite the N-linked glycosylation. In conclusion, N-linked glycosylation at an appropriate position in pre-S2 domain is an essential requirement for DNA vaccine expressing MHBs.

An efficient electrochemical sensor based on the Ce-MOF/g-C3N5 composite for the detection of nitrofurazone.

The Ce-MOF/g-C3N5 composite was first constructed using a simple reflux method in an oil bath. Herein, we report that the electrochemical sensor fabricated based on this composite exhibits high performance in the detection of nitrofurazone. Interestingly, this sensor exhibits an extra-wide linear range of detection composed of two line segments (7-100 µM and 100-2913 µM), as well as a low detection limit (LOD) of 6.15 µM (S/N = 3) under optimal experimental conditions. Additionally, the sensor demonstrates exceptional selectivity, reproducibility and stability. More importantly, the proposed electrochemical sensor can effectively monitor nitrofurazone in real samples such as urea and tap water, and obtain ideal recoveries. The sensor has such excellent performance because of the synergistic effect of the two components in the Ce-MOF/g-C3N5 composite. Compared with Ce-MOF, the introduction of g-C3N5 effectively not only enhances the conductivity of Ce-MOF/g-C3N5 but also exposes more active sites, which is conducive to increasing the electrocatalytic activity to reduce nitrofurazone. This research contributes new scientific research ideas for fabricating ideal electrochemical sensors based on g-C3N5 and MOFs.

Impaired function of CD4+ T follicular helper (Tfh) cells associated with hepatocellular carcinoma progression.

BACKGROUND AND AIMS: CD4+ T follicular helper (Tfh) cells, a new subset of immune cells, have been demonstrated to be involved in the development and prognosis of tumors. However, their functional role in human hepatocellular carcinoma (HCC) is relatively unknown, and the detailed mechanisms in HCC development remain to be described. METHODS: A total of 85 HCC patients with hepatitis B virus (HBV) infection, 25 HBV-relative liver cirrhosis (LC) patients, and 20 healthy controls (HC) were randomly enrolled. Flow cytometric analysis, immunohistochemical staining, and relative function (i.e., cytokine secretion, B cell maturation) assays were used to analyze the properties of CXCR5+CD4+ T cells. In addition, the relationship between the frequency of CXCR5+CD4+ T cells and overall survival rates or disease-free survival rates was also analyzed by the Kaplan-Meier method. RESULTS: The frequency of circulating CXCR5+CD4+ T cells was significantly decreased in HCC patients compared with HBV-relative liver cirrhosis (LC) patients and healthy controls, and the decrease in circulating CXCR5+CD4+ T cells correlated with disease progression. The proportion of infiltrated CXCR5+CD4+ T cells was significantly decreased in tumor regions compared with nontumor regions. Furthermore, compared with healthy controls, the function of circulating CXCR5+CD4+ T cells in HCC was impaired, with reduced IL-21 secretion and dysfunction in promoting B cell maturation. Importantly, follow-up data indicated that a decreased frequency of circulating CXCR5+CD4+ T cells was also associated with reduced disease-free survival time in HCC patients. CONCLUSIONS: Impairment of CD4+ T follicular helper cells may influence the development of HBV-associated HCC. Decreased CD4+ T follicular helper cells may represent a potential prognostic marker and serve as a novel therapeutic target for HCC patients.