Presence in mouse bone marrow of mediator-dependent cytotoxic effector cells against tumors.

The role of bone marrow cells as cytotoxic effector cells against tumor cells was examined in vitro. Bone marrow cells from normal C3H/He mice could lyse murine MM46 tumor cells in the presence of wheat germ agglutinin or syngeneic antitumor antibody. Bone marrow cells alone did not cause lysis. Eleven other lectins (concanavalin A, phytohemagglutinin, pokeweek mitogen, Lens culinaris hemagglutinin, Ulex europaeus agglutinin, peanut agglutinin, Bandeiraea simplicifolia agglutinin, Bauhinia purpurea agglutinin, soybean agglutinin, Limulus polyphemus agglutinin and Helix aspersa agglutinin) did not induce cytolysis. Enrichment of polymorphonuclear leukocytes (PMNs) by the method of free flow electrophoresis enhanced the activity of WGA-dependent cytolysis. These results suggest that PMNs series in the bone marrow of normal mice can lyse tumor cells with appropriate mediators.