Methicilin-Resistant
Strephlococcus aureus (AKA MRSA) is becoming a huge problem in some parts of the country. You have probably heard of staph infections before, which occur when wounds are not properly sterilized. That's because
S. aureus is all over our skin, it's a commensalist organism that usually doesn't cause us problems. And like most bacteria, a good sulfactant such as soap kills them without issue. And up until recently, antibiotics worked in most cases when they ended up inside people.
However, and like many pathogenic organisms these days, they are becoming resistant. In MRSA infections, there isn't much treatment that works because, as I said, it's resistant to antibiotics and /all over your skin/. If you get one MRSA infection, chances are that a second staph infection will also be MRSA.
So the current work is towards a vaccine.The heretical approach was inspired, in part, by a patient. As part of an ongoing project to root out the causes of recurring infections, in 2009 two of Daum's team members went to the home of a toddler who had recently been in the emergency department. But the girl wasn't there; she was in the hospital's intensive-care unit with a new infection. When Daum tracked her down, he noticed something odd in her records. She had had unusually frequent abscesses and repeated bouts of pneumonia.
Acting on a hunch, Daum teamed up with Steven Holland, chief of the clinical infectious diseases laboratory at the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, to carry out a detailed genetic analysis. Daum's hunch was right: the girl had a mutation that Holland had recently linked to a rare immunodeficiency called Job's syndrome7. People with the syndrome have persistent, smouldering S. aureus infections, owing to an inability to make a type of lymphocyte, or immune cell, called a TH17 cell.
These cells, which make a proinflammatory protein called interleukin-17, have become a hot topic in vaccine research. They are produced by a different branch of the immune system from the one that makes antibodies, yet they still seem to be involved in the body's memory of exposures to pathogens.
Daum believes that TH17 cells are the key to an S. aureus vaccine. It looks like T cells are very important in staphylococcal immunity, he says. Spellberg demonstrated in 2009 that a vaccine that stimulated production of interleukin 17 could protect mice against infections of S. aureus and Candida albicans8. (That vaccine is now being developed by NovaDigm Therapeutics as NDV3.)
