HBV S antigen evolution in the backdrop of HDV infection affects epitope processing and presentation

Sajjad, Mehwish; Ali, Syed; Baig, Samina; Sharafat, Shaheen; Khan, Bilal Ahmed; Khan, Saeed; Mughal, Muhammad Nouman; Abidi, Syed Hani

doi:10.1002/jmv.26711

Cited by 5 publications

(2 citation statements)

References 59 publications

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“…Interestingly, a study by Sajjad et al revealed unique mutations in the HBsAg gene, which were only observed in HDV/HBV-coinfected patients. For instance, the tryptophan at position 196 of HBsAg was mutated to leucine in almost all HDV/HBV-coinfected patients, although none of the HBV-monoinfected patients carried this mutation [ 241 ]. The tryptophan at position 196 was previously shown to be essential for HBsAg and L-HDAg interaction.…”

Section: Increased Quasispecies Formation Of Hbv By Coinfection With Hdvmentioning

confidence: 99%

Cellular Factors Involved in the Hepatitis D Virus Life Cycle

Thiyagarajah

Basic

Hildt

2023

Viruses

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Hepatitis D virus (HDV) is a defective RNA virus with a negative-strand RNA genome encompassing less than 1700 nucleotides. The HDV genome encodes only for one protein, the hepatitis delta antigen (HDAg), which exists in two forms acting as nucleoproteins. HDV depends on the envelope proteins of the hepatitis B virus as a helper virus for packaging its ribonucleoprotein complex (RNP). HDV is considered the causative agent for the most severe form of viral hepatitis leading to liver fibrosis/cirrhosis and hepatocellular carcinoma. Many steps of the life cycle of HDV are still enigmatic. This review gives an overview of the complete life cycle of HDV and identifies gaps in knowledge. The focus is on the description of cellular factors being involved in the life cycle of HDV and the deregulation of cellular pathways by HDV with respect to their relevance for viral replication, morphogenesis and HDV-associated pathogenesis. Moreover, recent progress in antiviral strategies targeting cellular structures is summarized in this article.

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Section: Increased Quasispecies Formation Of Hbv By Coinfection With Hdvmentioning

confidence: 99%

Cellular Factors Involved in the Hepatitis D Virus Life Cycle

Thiyagarajah

Basic

Hildt

2023

Viruses

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“…Some of these mutations affected the generation of proteasomal sites, binding of HBsAg epitopes to MHC-I and -II ligands, and subsequent generation of T- cell epitopes. Selective amplification of these mutations at certain strategic locations might not only enable HBV to counteract the inhibitory effects of HDV on HBV replication, but also facilitate its survival by escaping the immune response ( 132 ). The percentage of conserved HBsAg-positions was significantly higher in HBV/HDV coinfection than HBV monoinfection.…”

Section: Immune Mechanisms and Hbsag Serum Level Changes In Hbv Coinf...mentioning

confidence: 99%

Immune Mechanisms Underlying Hepatitis B Surface Antigen Seroclearance in Chronic Hepatitis B Patients With Viral Coinfection

Gao

et al. 2022

Front. Immunol.

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It is considered that chronic hepatitis B patients have obtained functional cure if they get hepatitis B surface antigen (HBsAg) seroclearance after treatment. Serum HBsAg is produced by cccDNA that is extremely difficult to clear and dslDNA that is integrated with host chromosome. High HBsAg serum level leads to failure of host immune system, which makes it unable to produce effective antiviral response required for HBsAg seroclerance. Therefore, it is very difficult to achieve functional cure, and fewer than 1% of chronic hepatitis B patients are cured with antiviral treatment annually. Some chronic hepatitis B patients are coinfected with other chronic viral infections, such as HIV, HCV and HDV, which makes more difficult to cure. However, it is found that the probability of obtaining HBsAg seroclearance in patients with coinfection is higher than that in patients with HBV monoinfection, especially in patients with HBV/HIV coinfection who have an up to 36% of HBsAg 5-year-seroclerance rate. The mechanism of this interesting phenomenon is related to the functional reconstruction of immune system after antiretroviral therapy (ART). The quantity increase and function recovery of HBV specific T cells and B cells, and the higher level of cytokines and chemokines such as IP-10, GM-CSF, promote HBsAg seroclearance. This review summarizes recent studies on the immune factors that have influence on HBsAg seroconversion in the chronic hepatitis B patients with viral coinfection, which might provide new insights for the development of therapeutic approaches to partially restore the specific immune response to HBV and other viruses.

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Incidence of long COVID-19 in people with previous SARS-Cov2 infection: a systematic review and meta-analysis of 120,970 patients

et al. 2022

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The long-term consequences of the coronavirus disease 19 (COVID-19) are likely to be frequent but results hitherto are inconclusive. Therefore, we aimed to define the incidence of long-term COVID signs and symptoms as defined by the World Health Organization, using a systematic review and meta-analysis of observational studies. A systematic search in several databases was carried out up to 12 January 2022 for observational studies reporting the cumulative incidence of long COVID signs and symptoms divided according to body systems affected. Data are reported as incidence and 95% confidence intervals (CIs). Several sensitivity and meta-regression analyses were performed. Among 11,162 papers initially screened, 196 were included, consisting of 120,970 participants (mean age: 52.3 years; 48.8% females) who were followed-up for a median of six months. The incidence of any long COVID symptomatology was 56.9% (95% CI 52.2–61.6). General long COVID signs and symptoms were the most frequent (incidence of 31%) and digestive issues the least frequent (7.7%). The presence of any neurological, general and cardiovascular long COVID symptomatology was most frequent in females. Higher mean age was associated with higher incidence of psychiatric, respiratory, general, digestive and skin conditions. The incidence of long COVID symptomatology was different according to continent and follow-up length. Long COVID is a common condition in patients who have been infected with SARS-CoV-2, regardless of the severity of the acute illness, indicating the need for more cohort studies on this topic.

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HBV S antigen evolution in the backdrop of HDV infection affects epitope processing and presentation

Cited by 5 publications

References 59 publications

Cellular Factors Involved in the Hepatitis D Virus Life Cycle

Cellular Factors Involved in the Hepatitis D Virus Life Cycle

Immune Mechanisms Underlying Hepatitis B Surface Antigen Seroclearance in Chronic Hepatitis B Patients With Viral Coinfection

Incidence of long COVID-19 in people with previous SARS-Cov2 infection: a systematic review and meta-analysis of 120,970 patients

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