Grant: CIHR Fellowship

The overall goal of this proposal is to determine how long chain polyunsaturated fatty acids (PUFA) affect immunity during early infancy. T cells are essential components of the immune system and they develop their function in the early postnatal period. An important function of these cells is establishing 'oral tolerance', which is the body's ability to distinguish between beneficial and harmful dietary proteins. The inability to develop oral tolerance results in food allergies and other childhood diseases such as asthma. Dr. Field research group has demonstrated that the type of fat fed to infants or young animals can influence T cell development. The explanation how this happens and the effect of diet fat on the development of oral tolerance are not known. The first objective of my research is to determine the best balance of PUFA in the diet to ensure optimal T cell function and the development of oral tolerance. This will be determined by conducting a series of experiments using rodent models where the diet is changed in the lactating mother or the young animal. It is thought that PUFA likely affect T cell function by changing in the composition and/or content of fats in the cell membrane. Exactly how a change in plasma membrane fats alters T cell function has not been established and is the second objective of this proposal. We will be studying specialized parts of the cell membrane called 'lipid rafts'. Lipid rafts are involved in generating signaling messages that direct the function of T cells. We propose to study how a change in the fat composition of the lipid raft affects the messages generated in the cell and how that ultimately directs how a cell functions. Our studies will provide a fundamental understanding of the role of fats in the diet on the essential functions of T cells early in life and will assist in defining fatty acid requirements to optimize the immune health of women and their infants.