A recent study published in Frontiers in Immunology investigates the immune response to bone infections, such as Staphylococcus aureus, that cause osteomyelitis. Their research stands to give medical professionals a better understanding of the condition, which would help them develop a treatment. There is currently no immunotherapy to treat osteomyelitis, and this study aims to address this issue.

About Osteomyelitis

Osteomyelitis occurs when bacteria infects the bone, typically in the legs, spine, or arms. When an infection travels through the bloodstream to a bone, or if an injury exposes the bone to germs, people can get osteomyelitis. Symptoms consist of fatigue, fever, excessive sweating, bone pain, chills, bone fragmentation, swelling, malaise, and open wounds. After noticing these characteristic symptoms, doctors will use bone scans, MRIs, X-rays, blood tests, and bone biopsies to obtain a diagnosis. Treatment consists of antibiotics, bone grafts, surgery to remove any dead tissue, and amputation if the case is severe.

About the Study

A number of bacteria can cause osteomyelitis, but Staphylococcus aureus is the major pathogen. Despite this knowledge, there has been no success in creating an immunotherapy to combat the bacterial infections. This failure is partly attributed to the amount of research that was conducted using rodent models, as these models stray too far from the human immune system. The fact that S. aureus stops the immune system from targeting it by secreting immunotoxins in rodent models makes the process even more difficult.

In order to create a better study of S. aureus and its role in osteomyelitis, the team of researchers utilized mice implanted with human hematopoietic stem cells. They evaluated how the mice’s immune cells were able to respond to a bacterial infection of the bone, which would then give them a better understanding of how the disease works in humans. They discovered that:

• Infected mice experienced increased weight loss, higher numbers of Staphylococcal abscess communities (SACs), bacterial dissemination, and osteolysis
• Higher number of human T cells in infected mice than uninfected mice
  • There needs to be further research into this, but researchers believe that the bacteria activates and proliferates T cells in infected bones

The largest takeaway from this study is that these mice models are a preferable method to study osteomyelitis. You can find more about this study here.