Is hepatitis B virus smarter than the immune system?

✍ Scribed by Marion Peters

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 272 KB
• Volume: 21
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840210340

✦ Synopsis

It has been suggested that mutations within immunodominant cytotoxic T-lymphocyte (CTL) epitopes may be exploited by viruses to evade protective immune responses critical for ~1earance.l'~ Viral escape could originate from passive mechanisms, such as mutations within crucial CTL epitopes, either affecting major histocompatibility complex binding or T-cell antigen receptor (TCR) recognition. Additionally, it has recently been shown that substitutions of TCR contact sites can yield analogue peptides that can still interact with the T-cell receptor but be unable to deliver a full stimulatory signal, thus inducing anergy" or acting as an antagonist for the TCR?-* We report here that hepatitis B virus isolates derived from two chronically infected patients display variant epitopes that act as natural TCR antagonists with the capacity to inhibit the CTL response to the wildtype epitope. During natural infection, TCR antagonist mutations of CTL epitopes could contribute to the development of viral persistence, especially if the antiviral CTL response is monospecific or the epitope is strongly immunodominant.