Hughes R C, Sanford B, Jeanloz R W
Proc Natl Acad Sci U S A. 1972 Apr;69(4):942-5. doi: 10.1073/pnas.69.4.942.
Strain A mouse ascites tumor cells that were treated with neuraminidase (EC 3.2.1.18) (these cells show decreased tumor-forming ability in allogeneic C3H mice) rapidly regenerate sialoglycoproteins at the cell surface during culture. The incorporation of labeled D-glucosamine into membrane glycoproteins of cells that were treated or untreated with neuraminidase proceeds at similar rates. Surface glycoproteins that contain sialic acid are synthesized de novo during culture of neuraminidase-treated cells, and in nondividing cells, synthesis is accompanied by turnover of the membrane glycoproteins. The rate of turnover of membrane glycoproteins that lack sialic acid residues is the same as that occurring in non-dividing cells that are not treated with neuraminidase and that are cultured under identical conditions. Turnover of the surface membrane of nondividing cells leads to the accumulation of glycoproteins in the supernatant medium of cell cultures. The rapid regeneration of cell surfaces that contain sialic acid by TA3 cells that were treated with neuraminidase, makes it unlikely that the rejection of these cells in vivo, in C3H mice, is due solely to the induction of a primary immune response to new or to previously concealed antigenic specificities that would be expressed on the surface of the sialic acid-depleted cell.
用神经氨酸酶（EC 3.2.1.18）处理过的A系小鼠腹水瘤细胞（这些细胞在同种异体C3H小鼠中显示出降低的肿瘤形成能力）在培养过程中能迅速在细胞表面再生唾液酸糖蛋白。标记的D-葡萄糖胺掺入经或未经神经氨酸酶处理的细胞的膜糖蛋白中的速率相似。在经神经氨酸酶处理的细胞培养过程中，含唾液酸的表面糖蛋白是重新合成的，并且在非分裂细胞中，合成伴随着膜糖蛋白的周转。缺乏唾液酸残基的膜糖蛋白的周转速率与在相同培养条件下未经神经氨酸酶处理的非分裂细胞中的周转速率相同。非分裂细胞表面膜的周转导致糖蛋白在细胞培养上清液中积累。经神经氨酸酶处理的TA3细胞能迅速再生含唾液酸的细胞表面，这使得这些细胞在C3H小鼠体内被排斥不太可能仅仅是由于对唾液酸缺失细胞表面新的或先前隐藏的抗原特异性引发了初次免疫反应。
