Blocking viruses. Viruses, such as HIV, SARS, and avian flu, pose some of the most serious global health threats, and finding ways to prevent viral infections is a major biomedical challenge. Some viruses cause infection when they successfully attach to and fuse with the outer membrane of a healthy cell, enabling viruses to inject their own genetic material into the cell.

Recently, NICHD researchers collaborated with other scientists to discover the mechanism by which viruses gain entry into healthy cells. The investigators learned that molecules called defensins appear to prevent viruses from entering cells by thwarting the fusion of the viral and cell membranes. Preventing viruses from entering cells enables the immune system to identify them for later destruction. Defensins are produced by cells that line the surfaces of many organs and tissues and are among the first cells to come into contact with viruses. This basic but elegant scientific discovery helps to explain how defensins work, allowing scientists to unravel the mystery of why some individuals are more resistant than others to certain types of viral infections. The finding also opens the door to new strategies for preventing viral illnesses. This is critical in an era of concern about pandemic viral infections and biological threats using viral agents.

Preventing type 1 diabetes in family members. Type 1 diabetes runs in families: siblings and offspring of someone with diabetes are 10 times more likely to develop the disease than the general public. Testing high-risk relatives of people with type 1 diabetes for genetic and autoimmune markers can identify with remarkable precision those most likely to develop diabetes within five years. No preventive therapy, however, is currently available to offer these high-risk relatives. NICHD-supported investigators found that some relatives identified by high levels of certain type 1 diabetes biomarkers could benefit from a daily dose of 7.5 mg of oral insulin. In fact, treated high-risk relatives were able to reduce their chance of developing diabetes by 43 percent, which is equal to delaying the onset of diabetes by 4.5 years. These findings imply that some relatives of patients with type 1 diabetes could prevent or delay the onset of the disease by simply swallowing a capsule every day. Considering that a diagnosis of type 1 diabetes means a lifetime of monitoring blood sugar levels, a carefully controlled diet, and increased risk of adverse health effects, this small preventative step may actually help to improve the health and quality of life of individuals at highest risk of developing type 1 diabetes.