| This thesis is an investigation of the ability of acutely protein-energy malnourished weanling C57BU6J mice to respond to exogenous fms-Iike tyrosine kinase 3 ligand (Flt3L), a hematopoietic cytokine. Murine Flt3L was produced in HEK-293 cells transfected with the pUMVC3-mFlex plasmid and its biological activity was tested in healthy mice by ten daily subcutaneous injections of 1 J.1g Flt3L followed by enumeration of splenic CD11c+F4/80 -/1ow dendritic cells, F4/80+ macrophages, CD4 + and CD8+ T cells and CD19+ B cells. Dendritic cells were the only cell type to increase in the Flt3L-treated mice. When FLt3L was administered to acutely malnourished weanlings according to the same dosing schedule, an identical response emerged in terms of splenic cell numbers. In addition, exogenous FlT3L prevented depression in the inflammatory cell-mediated (delayed hypersensitivity) response to sheep red blood cells. These findings put focus on the dendritic cell and challenge the current T cell-centric, multifactorial model of malnutrition-associated immunedepression. |
