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Displaying publications 41 - 44 of 44 in total

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Positive Hepatitis B Core Antibody Is Associated With Cirrhosis and Hepatocellular Carcinoma in Nonalcoholic Fatty Liver Disease

Chan TT, Chan WK, Wong GL, Chan AW, Nik Mustapha NR, Chan SL, et al.

Am J Gastroenterol, 2020 06;115(6):867-875.
PMID: 32149781 DOI: 10.14309/ajg.0000000000000588

OBJECTIVES: Previous exposure to hepatitis B virus (HBV) may increase the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C. We aim to study the impact of previous HBV infection on the severity and outcomes of patients with nonalcoholic fatty liver disease (NAFLD).
METHODS: This was a multicenter study of 489 patients with biopsy-proven NAFLD and 69 patients with NAFLD-related or cryptogenic HCC. Antihepatitis B core antibody (anti-HBc) was used to detect the previous HBV infection.
RESULTS: In the biopsy cohort, positive anti-HBc was associated with lower steatosis grade but higher fibrosis stage. 18.8% and 7.5% of patients with positive and negative anti-HBc had cirrhosis, respectively (P < 0.001). The association between anti-HBc and cirrhosis remained significant after adjusting for age and metabolic factors (adjusted odds ratio 2.232; 95% confidence interval, 1.202-4.147). At a mean follow-up of 6.2 years, patients with positive anti-HBc had a higher incidence of HCC or cirrhotic complications (6.5% vs 2.2%; P = 0.039). Among patients with NAFLD-related or cryptogenic HCC, 73.9% had positive anti-HBc. None of the patients had positive serum HBV DNA. By contrast, antihepatitis B surface antibody did not correlate with histological severity.
DISCUSSION: Positive anti-HBc is associated with cirrhosis and possibly HCC and cirrhotic complications in patients with NAFLD. Because a significant proportion of NAFLD-related HCC may develop in noncirrhotic patients, future studies should define the role of anti-HBc in selecting noncirrhotic patients with NAFLD for HCC surveillance.

Matched MeSH terms: Hepatitis B Antibodies/immunology*
Exposure to Electrophiles Impairs Reactive Persulfide-Dependent Redox Signaling in Neuronal Cells

Ihara H, Kasamatsu S, Kitamura A, Nishimura A, Tsutsuki H, Ida T, et al.

Chem Res Toxicol, 2017 09 18;30(9):1673-1684.
PMID: 28837763 DOI: 10.1021/acs.chemrestox.7b00120

Electrophiles such as methylmercury (MeHg) affect cellular functions by covalent modification with endogenous thiols. Reactive persulfide species were recently reported to mediate antioxidant responses and redox signaling because of their strong nucleophilicity. In this study, we used MeHg as an environmental electrophile and found that exposure of cells to the exogenous electrophile elevated intracellular concentrations of the endogenous electrophilic molecule 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), accompanied by depletion of reactive persulfide species and 8-SH-cGMP which is a metabolite of 8-nitro-cGMP. Exposure to MeHg also induced S-guanylation and activation of H-Ras followed by injury to cerebellar granule neurons. The electrophile-induced activation of redox signaling and the consequent cell damage were attenuated by pretreatment with a reactive persulfide species donor. In conclusion, exogenous electrophiles such as MeHg with strong electrophilicity impair the redox signaling regulatory mechanism, particularly of intracellular reactive persulfide species and therefore lead to cellular pathogenesis. Our results suggest that reactive persulfide species may be potential therapeutic targets for attenuating cell injury by electrophiles.

Matched MeSH terms: Antibodies/immunology
Fulltext Human CD3+ T-Cells with the Anti-ERBB2 Chimeric Antigen Receptor Exhibit Efficient Targeting and Induce Apoptosis in ERBB2 Overexpressing Breast Cancer Cells

Munisvaradass R, Kumar S, Govindasamy C, Alnumair KS, Mok PL

Int J Mol Sci, 2017 Sep 08;18(9).
PMID: 28885562 DOI: 10.3390/ijms18091797

Breast cancer is a common malignancy among women. The innate and adaptive immune responses failed to be activated owing to immune modulation in the tumour microenvironment. Decades of scientific study links the overexpression of human epidermal growth factor receptor 2 (ERBB2) antigen with aggressive tumours. The Chimeric Antigen Receptor (CAR) coding for specific tumour-associated antigens could initiate intrinsic T-cell signalling, inducing T-cell activation, and cytotoxic activity without the need for major histocompatibility complex recognition. This renders CAR as a potentially universal immunotherapeutic option. Herein, we aimed to establish CAR in CD3+ T-cells, isolated from human peripheral blood mononucleated cells that could subsequently target and induce apoptosis in the ERBB2 overexpressing human breast cancer cell line, SKBR3. Constructed CAR was inserted into a lentiviral plasmid containing a green fluorescent protein tag and produced as lentiviral particles that were used to transduce activated T-cells. Transduced CAR-T cells were then primed with SKBR3 cells to evaluate their functionality. Results showed increased apoptosis in SKBR3 cells co-cultured with CAR-T cells compared to the control (non-transduced T-cells). This study demonstrates that CAR introduction helps overcome the innate limitations of native T-cells leading to cancer cell apoptosis. We recommend future studies should focus on in vivo cytotoxicity of CAR-T cells against ERBB2 expressing tumours.

Matched MeSH terms: Single-Chain Antibodies/immunology
Fulltext Virus-like Particles Identify an HIV V1V2 Apex-Binding Neutralizing Antibody that Lacks a Protruding Loop

Cale EM, Gorman J, Radakovich NA, Crooks ET, Osawa K, Tong T, et al.

Immunity, 2017 05 16;46(5):777-791.e10.
PMID: 28514685 DOI: 10.1016/j.immuni.2017.04.011

Most HIV-1-specific neutralizing antibodies isolated to date exhibit unusual characteristics that complicate their elicitation. Neutralizing antibodies that target the V1V2 apex of the HIV-1 envelope (Env) trimer feature unusually long protruding loops, which enable them to penetrate the HIV-1 glycan shield. As antibodies with loops of requisite length are created through uncommon recombination events, an alternative mode of apex binding has been sought. Here, we isolated a lineage of Env apex-directed neutralizing antibodies, N90-VRC38.01-11, by using virus-like particles and conformationally stabilized Env trimers as B cell probes. A crystal structure of N90-VRC38.01 with a scaffolded V1V2 revealed a binding mode involving side-chain-to-side-chain interactions that reduced the distance the antibody loop must traverse the glycan shield, thereby facilitating V1V2 binding via a non-protruding loop. The N90-VRC38 lineage thus identifies a solution for V1V2-apex binding that provides a more conventional B cell pathway for vaccine design.

Matched MeSH terms: HIV Antibodies/immunology*