Abstract
Thymocytes and splenic T cells from C57BL/6 mice were analyzed for their content of glycosphingolipids (GSL) by high performance liquid chromatography. Glucosylceramide and lactosylceramide were shown to be the major GSL of thymocytes from mice 1 to 30 weeks of age, whereas a third GSL, asialo GM1, was found only in trace amounts. In splenic T lymphocytes, however, asialo GM1 was shown to increase in concentration with age. It reached a peak at 5 to 10 weeks of age, at a concentration 10 to 20 times that of thymocytes or neonatal splenic T cells. These studies confirm the previous finding with antibodies to asialo GM1, that this glycosphingolipid is a true differentiation antigen in the mouse. Subsequent analysis of C57BL/6 bg/bg (beige) mice, which lack natural killer function, demonstrates that levels of asialo GM1 in the splenic T cell population do not increase with age but remain at the level of 2- to 3-week-old normal mice, indicating that asialo Gm1 may be an important cell surface component in the generation of natural cell-mediated cytotoxicity.