Dr. Jay Kolls, Professor and Chairman of Genetics at the LSU Health Sciences Center New Orleans School of Medicine, has been awarded a $2.1 million grant over five years by the National Heart, Lung, and Blood Institute of the National Institutes of Health to determine the role and identify which T-helper cells fight the opportunistic infection, Pneumocystis carinii pneumonia (PCP), which can be a complication of HIV/AIDS. It can also be a complication of cancer, organ or bone marrow transplantation, as well as the chronic use of corticosteroids or other medications that affect the immune system.
Pneumocystis carinii pneumonia remains an important clinical problem and although there is a well-known relationship between CD4 cell count and the risk of Pneumocystis carinii infection, defense mechanisms against it are not fully understood. Dr. Kolls and his research team will study the role of a subset of CD4 cells which he believes are missing in Pneumocystis carinii infection and which when restored, produce an effective immune response to the infection. These are the T-helper cells, Th1, Th2, and Th17. The research funded under this grant will determine the role of interleukin-23 and interleukin-12 in regulating Th1 immunity to Pneumocystis carinii, and the team hopes to show that by vaccinating genetically engineered mice with CD4+ T-cells belonging to any of these T-cell subsets, immunity will be sufficient to protect against PCP.
"This research will define the types of T-cells that are needed to prevent this life-threatening infection," notes Dr. Kolls. "It is our hope that vaccines can activate these cells to prevent or treat PCP."
According to the Centers for Disease Control and Prevention, Pneumocystis pneumonia (PCP), which is caused by Pneumocystis jirovecii (formerly P. carinii), is frequently the first serious illness encountered by HIV-infected persons. During the early years of the AIDS epidemic, PCP was the AIDS-defining illness for as many as two thirds of patients in the United States. Although a decline in incidence of PCP occurred during the era of highly active antiretroviral therapy (HAART), PCP remains the most common serious opportunistic illness in HIV-infected persons. Patients in the developing world without access to PCP prophylaxis or antiretroviral drugs remain at high risk, and PCP continues to develop in certain groups in industrialized countries. There is also a potential for drug resistance to develop.