Functional tuftsin binding sites on macrophage-like tumor line P388D1 and on bone marrow cells differentiated in vitro into mononuclear phagocytes.

Mouse bone marrow cells, differentiated in vitro into mononuclear phagocytes (BMDMP), posess functional tuftsin binding sites, i.e. both tuftsin binding capacity and augmented phagocytic response related to tuftsin binding. The binding capacity of BMDMP was shown to be higher by a factor of about three than that exhibited by mouse monocytes and by normal, thioglycollate and Corynebacterium parvum induced peritoneal macrophages. The relatively high binding capacity did not depend on experimental variations in the in vitro culture of these populations (i.e. length of in vitro cultivation, source of serum or presence of conditioned medium leading to cell proliferation). The macrophage-like line, P388D1, was also shown to possess functional tuftsin binding sites and its binding capacity was comparable to that of the peritoneal macrophage populations.