A University of California, Los Angeles study published online this week in Science offers clues about how various bacteria masquerade as viruses and, as a result, trick the immune system into using the wrong defense strategy. As explained in a university release, the bacteria manipulates the body into using a protein called interferon-beta to fend off its attack, but such an approach dose more harm than good:
Not only is interferon-beta ineffective against bacteria, but it can also block the action of interferon-gamma, to the advantage of bacteria. Further, if a real virus were to infect the body, triggering interferon-beta, it would divert the attention of the immune response, preventing an attack on the bacterial invader. The researchers say this may explain why the flu can lead to a more serious bacteria-based infection like pneumonia.
In the study, researchers used leprosy as a model to understand how bacteria can fool the immune system. Senor author Robert Modlin, MD, said the team opted to study leprosy because it "is an outstanding model for studying immune mechanisms in host defense since it presents as a clinical spectrum that correlates with the level and type of immune response of the pathogen."
The above image shows leprosy bacteria marked in red and with the interferon-beta highlighted in green.
Photo by UCLA