NEUTRAL GLYCOSPHINGOLIPIDS AND GANGLIOSIDES FROM SPLEEN T-LYMPHOBLASTS OF GENETICALLY DIFFERENT INBRED MOUSE STRAINS

The gangliosides G(M1b), GalNAc-G(M1b), and G(D1 alpha), are typical c ompounds of concanavalin A stimulated splenic T lymphoblasts of CBA/J inbred mice. Their structural characterization has been described in p revious studies. The intention of this work was the comparative TLC im munostaining analysis of the glycosphingolipid composition of lectin s timulated splenic T lymphoblasts obtained from six genetically differe nt inbred mouse strains. The strains examined were AKR, BALB/c, C57BL/ 6, CBA/J, DBA/2 and WHT/Ht, which are commonly used for biochemical an d immunological studies. The neutral glycosphingolipid GgOse(4)Cer, th e precursor for G(M1b)-type gangliosides, was expressed by all six str ains investigated. AKR, C57BL/6 and DBA/2 showed high and BALB/c, CBA/ J and WHT/Ht diminished expression in T lymphoblasts, based on single cell calculation. The gangliosides G(M1b) and GalNAc-G(M1b), elongatio n products of GgOse(4)Cer, displayed strain-specific differences in th eir intensities, which were found to correlate with the intensities of GgOse(4)Cer expression of the same strains. Concerning sialic acid su bstitution of gangliosides, G(M1b) and GalNAc-G(M1b), predominantly ca rry N-acetylneuraminic acid, whereas choleragenoid receptors G(M1a), a nd Gal-GalNAc-G(M1b), which are also expressed by all six strains, are characterized by dominance of N-glycolylneuraminic acid. Two highly p olar gangliosides, designated with X and Y, which have not been previo usly recognized in murine lymphoid tissue, were detected by positive a nti-GalNAc-G(M1b) antibody and choleragenoid binding, respectively. Bo th gangliosides were restricted to AKR, DBA12 and C57BL/6 mice. The ot her three strains BALB/c, CBA/J and WHT/Ht are lacking these structure s. In summary, the G(M1b)-type pathway is quite active in all six stra ins analysed in this study. Strain-specific genetic variations in T ly mphoblast gangliosides were observed with the occurrence of gangliosid es X and Y. This study and data from other groups strongly indicate fo r G(M1b)-type gangliosides a functional association with T cell activa tion and leukocyte mediated reactions.