Gangliosides of murine T lymphocyte subpopulations.

Gangliosides from murine T lymphoblasts were analyzed by high-performance thin-layer chromatography followed by in situ neuraminidase treatment and immunostaining of the resulting asialogangliosides and compared with those from thymocytes and cloned T lymphocytes with defined functions. The ganglioside IVNeuGc/Ac-GgOse5Cer (GalNAc-GM1b), a marker for T lymphoblasts [Müthing, J., Egge, H., Kniep, B., & Mühlradt, P. F. (1987) Eur. J. Biochem. 163, 407-416], was found only in small amounts as the N-acetylated species in gangliosides from thymocytes and a cytolytic T cell clone. Two helper clones expressed this ganglioside like T blasts. The structures of the two major disialogangliosides from T blasts, IVNeuAc,IIINeuAc-GgOse4Cer (GD1 alpha type) with C24:0/24:1 and C16:0 fatty acids, were elucidated by neuraminidase treatment and immunostaining and by fast atom bombardment mass spectrometry. Gangliosides of this type were detected in thymocytes only in minor amounts, whereas GM1b-type gangliosides prevailed in cells from this organ. Analysis of the T lymphoblast gangliosides from six genetically unrelated mouse strains showed that terminally sialylated GgOse4Cer (GM1b), IVNeuAc-GgOse5Cer (GalNAc-GM1b), and IVNeuAc,IIINeuAc-GgOse4Cer (GD1 alpha) were conserved structures in all strains examined. We conclude that maturation or stimulation of T cells may be correlated with elongation of a common GM1b-type precursor structure resulting in GalNAc-GM1b or GD1 alpha-type gangliosides.