Mutations in Hepatitis D Virus Allow It to Escape Detection by CD8 T Cells and Evolve at the Population Level.

Background & Aims: Hepatitis D virus (HDV) superinfection in patients with hepatitis B virus (HBV) is associated with rapid progression to liver cirrhosis and hepatocellular carcinoma. Treatment options are limited, and no vaccine is available. Although HDV-specific CD8 T cells are thought to control the virus, little is known about which HDV epitopes are targeted by virus-specific CD8 T cells or why these cells ultimately fail to control the infection.

Amino Acid Substitutions within HLA-B*27-Restricted T Cell Epitopes Prevent Recognition by Hepatitis Delta Virus-Specific CD8 T Cells.

Virus-specific CD8 T cell response seems to play a significant role in the outcome of hepatitis delta virus (HDV) infection. However, the HDV-specific T cell epitope repertoire and mechanisms of CD8 T cell failure in HDV infection have been poorly characterized. We therefore aimed to characterize HDV-specific CD8 T cell epitopes and the impacts of viral mutations on immune escape.

CD8+ T-Cell Responses in Hepatitis B and C: The (HLA-) A, B, and C of Hepatitis B and C.

Approximately 500 million people are chronically infected with the hepatitis B virus (HBV) or hepatitis C virus (HCV) worldwide and are thus at high risk of progressive liver disease, leading to liver fibrosis, cirrhosis and ultimately hepatocellular cancer. Virus-specific CD8+ T-cells play a major role in viral clearance in >90% of adult patients who clear HBV and in approximately 30% of patients who clear HCV in acute infection. However, several mechanisms contribute to the failure of the adaptive CD8+ T-cell response in those patients who progress to chronic infection.

Short-term effects of high-dose khat on sperm parameters and reproductive hormonal levels in olive baboons (Papio anubis).

The biological effects of khat (Catha edulis) on reproduction and fertility are inadequately investigated and controversial, hence we determined the effects of oral administration of high-dose khat on sperm parameters and male hormonal levels in olive baboons. In this study, 6 male baboons received a high dose of khat (500 g/week) during 1 month. Electroejaculation for sperm studies (concentration, motility and chromatin integrity) and plasma collection for hormonal analysis (testosterone, prolactin and cortisol) were done weekly during 1 month before and 1 month during khat administration as well as 2 weeks after the last dose of khat administration.