chondroitin-sulfates and Lymphoma

Normal murine splenic T lymphocytes and T-lymphoma cells were incubated with [35S]sulphate in low-sulphate medium for 4 hr. Gel filtration and SDS-PAGE revealed that the radiolabelled macromolecules secreted by these cells were almost exclusively chondroitin sulphate and heparan sulphate proteoglycans of relatively low molecular weight (MW), 100,000-200,000. Triton X-100 extracts of the cells contained similar proteoglycans. Under the conditions employed the incorporation of radiolabel by cells grown in vivo was equally distributed between cell-retained and secreted fractions, whereas cells grown in vitro retained some 75% of incorporated label. In general heparan sulphate predominated over chondroitin sulphate in both secreted and cell-retained fractions. Cell extracts also contained a minor proportion of free glycosaminoglycan, which is almost exclusively heparan sulphate. These chains, like those incorporated into the proteoglycan, were around 12,000 MW. The T-lymphoma cells RDM-4, whether grown in vitro or in vivo, also incorporated a substantial proportion of [35S]sulphate into a single, cell-retained protein, 100,000 MW. No such radiolabelled protein was detectable in T cells.

Topics: Animals; Cell Line; Cells, Cultured; Chondroitin Sulfate Proteoglycans; Chondroitin Sulfates; Chromatography, Agarose; Electrophoresis, Polyacrylamide Gel; Glycosaminoglycans; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Lymphoma; Mice; Mice, Inbred AKR; Mice, Inbred C3H; Spleen; T-Lymphocytes

Splenic B and T lymphocytes metabolically labelled in vitro with [35S]-H2SO4 show differential sulphation of chondroitin sulphate, the major sulphated glycosaminoglycan in both cell-retained and secreted fractions. In B cells, 6-O-sulphation is more abundant than 4-O-sulphation, whereas in T cells sulphation occurs predominantly in the 4-O-position. The murine lymphoma lines AKTB-1b and EL-4, of B and T origin respectively, show even more marked differences. AKTB-1b follows the pattern of normal B cells, whilst in EL-4 only chondroitin 4-sulphate is synthesized.

Topics: Animals; B-Lymphocytes; Chondroitin; Chondroitin Sulfates; Chromatography, High Pressure Liquid; Lymphoma; Mice; Mice, Inbred AKR; Mice, Inbred C3H; Spleen; T-Lymphocytes