Abstract: A cell mediated immune response system glycoprotein having a molecular weight of about 90,000 and having at least one sialic acid moiety as a biologically active site is disclosed. The glycoprotein is specifically bound by wheat germ agglutinin and also by the hydrophobically binding ligand Blue A (Cibacron Blue F3G-A) but does not bind to lysine. The glycoprotein is a necessary cofactor with Interleukin-1 in the biosynthesis of T-cell growth factor (I1-2). A process for producing a serum-free and mitogen-free I1-2 in vitro by adding the glycoprotein to a serum-free- and mitogen-free Interleukin-1 preparation is described. The method for producing the serum-free and mitogen-free Interleukin-1 is also described. A chemically defined T-cell growth culture medium containing the new glycoprotein as the only protein substance is used in the above process and also provides a means for studying regulation of T-cell lymphocyte growth.

Abstract: A cell mediated immune response system glycoprotein having a molecular weight of about 90,000 and having at least one sialic acid moiety as a biologically active site is disclosed. The glycoprotein is specifically bound by wheat germ agglutinin and also by the hydrophobically binding ligand Blue A (Cibacron Blue F3G-A) but does not bind to lysine. The glycoprotein is a necessary cofactor with Interleukin-1 in the biosynthesis of T-cell growth factor (I1-2). A process for producing a serum-free and mitogen-free I1-2 in vitro by adding the glycoprotein to a serum-free- and mitogen-free Interleukin-1 preparation is described. The method for producing the serum-free and mitogen-free Interleukin-1 is also described. A chemically defined T-cell growth culture medium containing the new glycoprotein as the only protein substance is used in the above process and also provides a means for studying regulation of T-cell lymphocyte growth.

Abstract: A cell mediated immune response system glycoprotein having a molecular weight of about 90,000 and having at least one sialic acid moiety as a biologically active site is disclosed. The glycoprotein is specifically bound by wheat germ agglutinin and also by the hydrophobically binding ligant Blue A (Cibacron Blue F3G-A) but does not bind to lysine. The glycoprotein is a necessary cofactor with Interleukin-1 in the biosynthesis of T-cell growth factor (I1-2). A process for producing a serum-free and mitogen-free I1-2 in vitro by adding the glycoprotein to a serum-free- and mitogen-free Interleukin-1 preparation is described. The method for producing the serum-free and mitogen-free Interleukin-1 is also described. A chemically defined T-cell growth culture medium containing the new glycoprotein as the only protein substance is used in the above process and also provides a means for studying regulation of T-cell lymphocyte growth.

Abstract: Suppression of the immunological rejection mechanism of a host which has received an organ transplant in achieved by the daily administration to the host of a ganglioside agent which effectively blocks the soluble immunological cell mediator interleukin 2 and /or a blastogenic factor. By binding to the mediator for T cell blast formation the mediator is prevented from binding to the asialo GM1 receptor on the surface of the T effector cell. Blastogenesis does not occur and the cell mediated rejection of the graft is prevented.