Chondroitin sulphate proteoglycan production by NK cells and T cells: effects of xylosides on proliferation and cytotoxic function.
Cultured human NK cells and T cells grown in the presence of IL-2 and phytohaemagglutinin incorporated 35S sulphate into two distinct macromolecular species. The larger molecule was identified as a chondroitin-4-sulphate proteoglycan and was present in both cell-associated and secreted material. The smaller component was identified as free glycosaminoglycan and was present only in the cell-associated material. The sulphated macromolecules synthesized by NK cells were smaller than those produced by T cells. Growth in the presence of beta-D-xyloside led to a decrease in proteoglycan production, together with an increase in the synthesis of free glycosaminoglycan. The latter molecule was found in the secreted as well as the cell-associated fraction. In all instances, growth of T cells was inhibited by xyloside in a dose-dependent fashion. However, growth of NK cells from 3/7 donors was stimulated at low concentrations of xyloside (0.25 and 0.5 mM). Growth of NK cells in xyloside had no effect on their lytic activity, and the 'NK-like' cytolytic capacity of cultured T cells was similarly unaffected. Both NK cells and T cells grown in xyloside at a concentration resulting in a 50% inhibition of intact proteoglycan synthesis did not show increased susceptibility to autolysis in the presence of NK-cell targets. These findings suggest that optimal production of the intact proteoglycan molecule may not be essential for NK-cell lytic function or protection of effector cells in vitro.
Christmas
S E
SE
Department of Immunology, Paterson Institute for Cancer Research, Christie Hospital and Holt Radium Institute, Manchester, U.K.
Steward
W P
WP
Lyon
M
M
Gallagher
J T
JT
Moore
M
M
D002478:Cells, Cultured; D011508:Chondroitin Sulfate Proteoglycans / Q000096:biosynthesis*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D006025:Glycosaminoglycans / Q000032:analysis; D006027:Glycosides / Q000494:pharmacology; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects / Q000378:metabolism*; D011509:Proteoglycans / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*
D011508:Chondroitin Sulfate Proteoglycans; D006025:Glycosaminoglycans; D006027:Glycosides; D011509:Proteoglycans; C008646:4-nitrophenyl beta-D-xyloside