Possible role of human herpesvirus 6 as a trigger of autoimmune disease
http://www.ncbi.nlm.nih.gov/pubmed/24282390
Abstract
Human herpesvirus 6
(HHV-6) infection is common and has a worldwide distribution. Recently,
HHV-6A and HHV-6B have been reclassified into two distinct species
based on different biological features (genetic, antigenic, and cell
tropism) and disease associations. A role for HHV-6A/B has been proposed
in several autoimmune disorders (AD), including multiple sclerosis
(MS), autoimmune connective tissue diseases, and Hashimoto's
thyroiditis. The focus of this review is to discuss the above-mentioned
AD associated with HHV-6 and the mechanisms proposed for
HHV-6A/B-induced autoimmunity. HHV-6A/B could trigger autoimmunity by
exposing high amounts of normally sequestered cell antigens, through
lysis of infected cells. Another potential trigger is represented by
molecular mimicry, with the synthesis of viral proteins that resemble
cellular molecules, as a mechanism of immune escape. The virus could
also induce aberrant expression of histocompatibility molecules thereby
promoting the presentation of autoantigens. CD46-HHV-6A/B interaction is
a new attractive mechanism proposed: HHV-6A/B (especially HHV-6A) could
participate in neuroinflammation in the context of MS by promoting
inflammatory processes through CD46 binding. Although HHV-6A/B has the
ability to trigger all the above-mentioned mechanisms, more studies are
required to fully elucidate the possible role of HHV-6A/B as a trigger
of AD.