Mice lacking all of the Skint family genes

gamma delta T cells develop in the thymus and play important roles in protection against infection and tumor development, but the mechanisms by which the thymic microenvironment supports gamma delta T cell differentiation remain largely unclear. Skintl, a B7-related protein expressed in thymic epithelial cells, was shown to be essential for the development of mouse V gamma 5V delta 1 gamma delta T cells. The Skint family in mouse consists of 11 members, Skintl-11. Here we generated mutant mice lacking the entire genomic region that contains all of the Skint genes. These mice exhibited a marked reduction of V gamma 5V delta 1 gamma delta T cells in the thymus and skin, but surprisingly, had normal development of other gamma delta T cell subsets and leukocytes including alpha beta T, B and myeloid cells. This phenotype is essentially identical to that of Skintl -deficient mice. These results indicate that the Skint family exerts an exclusive function in regulating the development of V gamma 5V delta 1 gamma delta T cells and is dispensable for development of other leukocytes.