I f suffering through a cold or the flu weren't bad enough by itself, a new study hints at the existence of a mechanism by which microbial infections may inflame or even initiate autoimmune disorders such as multiple sclerosis.
Autoimmune disorders are one of the continuing mysteries of immunology.
These diseases initially confounded researchers, who thought the immune system deleted all cells capable of acting against the body's own tissues. In recent years, however, investigators have found that people and animals harbor immune cells that, though normally inactive, can selectively target the body's own molecules. Infections have long been a prime suspect, since they frequently predate the onset of an autoimmune disorder or a worsening of an existing autoimmune illness. One infection-based theory of autoimmunity, known as molecular mimicry, begins with the observation that some molecules of microorganisms resemble those of the host they infect. Consequently, as the host mounts a defense against infecting microbes, it may inadvertently activate some immune cells that recognize its own molecules.