1994 年 14 巻 5 号 p. 363-368
We have identified a novel ligand for CD44, a cell surface glycoprotein implicat ed in tumor metastasis and lymphocyte homing. When a mouse T cell line CTLL-2 was transfected with cDNA encoding a hemopoietic form of mouse CD44, CTLL-2 cells exhibited a new self-abhesive phenotype, forming large aggregates. The aggregation was blocked by neutralizing antiCD44 monoclonal antibody but unaffected by hyaluronidase, indicating the involvement of CD44 and its nonhyaluronate ligand in the cell aggregation. The ability to induce CD44-dependent aggregation was found in culture supernatants of CTLL-2 and its CD44 transfectants. The use of soluble CD44 chimeric protein revealed that CTLL-2 and its transfectants synthesized a large-molecular weight protein (gp600) which bound specifically to CD44.
Biochemical analyses revealed that the gp600 is a non-hyaluronate proteoglycan termed serglycin which is stored in and shed from secretary granules of NK and myeloid cells.