The vaccine platform developed by Children’s Hospital of Pittsburgh researchers, working in collaboration with researchers from the University of Pittsburgh and Louisiana State University, suggests that the immune system can be primed to ward off other infections as well, such as those caused by the flu, smallpox or exposure to anthrax, even in patients who have the highest risk for infection.
The vaccine consisting of a specific antigen to pneumocystis and a molecule normally expressed on activated T-cells of the immune system offers protection from infection even in the absence of essential immune cells.
Pneumocystis is a common and very serious infection in people with deficient function of CD4+ T-cells, such as patients with transplanted organs, HIV and children with leukemia. Without normal reservoirs of these particular T-cells that are key to immune responses, these patients are unable to stave off an infection that in most people causes, at most, a bad cold.
“While we’ll need to replicate these findings in larger animal models, our studies indicate it may be feasible to develop vaccines for bioterrorism agents and transplant patients, as well as high-risk individuals who have defective CD4+ T-cell function,” said Dr Jay Kolls, division chief at the Children’s Hospital of Pittsburgh. “We are excited about the results because they indicate that we can engineer a vaccine to create a new protection for those who are immunosuppressed.”
The number of people with compromised immune systems continues to rise, a population that cannot be protected against polio, flu and other infectious agents with existing vaccines that depend on a normal T-cell response. As such, the researchers were motivated to develop CD4+ T-cell-independent therapeutic strategies to meet this growing need.