Smith, Richard M.

The thymus provides a unique microenvironment that facilitates T lymphocytes differentiation and maturation. However, the thymus atrophies after puberty which leads to an overall expression of metabolism gene pathways and low gene expression of certain peroxide scavenger enzymes such as catalase in thymic stromal compartments. From this data, we postulate that thymic stromal cells are highly susceptible to oxidative damage. We utilized a transgenic mice model overexpressing human catalase targeted to the mitochondria (mCat) to test our hypothesis that gerater oxidative protection should lower the degree of thymus atrophy. Our experiment focused on a direct comparison of organ weights (thymus, kidney, lymph nodes, spleen and heart), cellularity and histology between transgenic and wildtype mice. We found that mCat had selective increases in thymus size.