abstract mutations have been described in all of the four open reading frames of the hepatitis b virus (hbv), however, from a clinical perspective the surface escape mutant is the most troublesome. hepatitis b surface antigen (hbsag) variants may impair diagnosis, or allow the virus to escape vaccine-induced immunity or passive immunoglobulin therapy. hbv mutants with amino acid substitutions, ...

Topical blockade of the gp41 fusogenic protein of HIV-1 is one possible strategy by which microbicides could prevent HIV transmission, working early against infection, by inhibiting viral entry into host cells. In this study, we examined the potential of gp41 fusion inhibitors (FIs) as candidate anti-HIV microbicides. Preclinical evaluation of four FIs, C34, T20, T1249, and L'644, was performed...

Escape from cytotoxic T-lymphocyte (CTL) pressure is common in HIV-1 infection of humans and simian immunodeficiency virus (SIV) infections of macaques. CTL escape typically incurs a fitness cost as reversion back to wild-type can occur upon transmission. We utilized sequence-specific primers and DNA probes with real-time polymerase chain reaction (PCR) to sensitively and specifically track wil...

Many current-generation human immunodeficiency virus (HIV) vaccines induce specific T cells to control acute viremia, but their utility following infection with escape mutant virus is unclear. We studied reversion to wild type of an escape mutant simian-HIV in major histocompatibility complex-matched vaccinated pigtail macaques. High levels of vaccine-induced CD8+ T cells strongly correlated wi...

HIV-1 mutates extensively in vivo to escape immune control by CD8+ T cells (CTLs). The CTL escape mutant virus might also revert back to wild-type upon transmission to new hosts if significant fitness costs are incurred by the mutation. Immune escape and reversion can be extremely fast if they occur very early after infection, whereas they are much slower when they begin later during infection....

The haemagglutinin (HA) of influenza A/H2N2 virus possesses six antigenic sites (I-A to I-D, II-A and II-B), and sites I-A, I-B and I-C are located in the regions corresponding to sites A, B and D on the H3 HA. We demonstrated previously that most escape mutants selected by mAbs to site I-A, I-B or I-C had acquired a new oligosaccharide at position 160, 187 or 131, respectively, but this has ne...

While an essential role of HIV-1 integrase (IN) for integration of viral cDNA into human chromosome is established, studies with IN mutants and allosteric IN inhibitors (ALLINIs) have suggested that IN can also influence viral particle maturation. However, it has remained enigmatic as to how IN contributes to virion morphogenesis. Here, we demonstrate that IN directly binds the viral RNA genome...

Escape mutant (EM) virus that evades CD8+ T cell recognition is frequently observed following infection with HIV-1 or SIV. This EM virus is often less replicatively "fit" compared to wild-type (WT) virus, as demonstrated by reversion to WT upon transmission of HIV to a naïve host and the association of EM virus with lower viral load in vivo in HIV-1 infection. The rate and timing of reversion i...