sepharose and Leukemia--Myeloid--Acute

Colonies of the HL-60 human leukaemic promyelocytic cell line developing in semisolid agar gel capillaries were established. The endogenous inhibitory fraction GI-3, specific for myeloid cells, hydrocortisone and adriamycin decreased colony number in a dose dependent manner. ED50 values amounted to 220, 10(-1) and 4.5 X 10(-3), micrograms/ml respectively. If administered in combination, the endogenous inhibitor, steroid hormone and cytostatic agent exhibited a marked synergism. They affected HL-60 cells additively, and in some cases, a slight potentiation occurred. The experiments demonstrate the possibility of augmenting the inhibitory activity of cytostatics and hormones on leukaemic cells by endogenous inhibitors without an increase in drug toxicity.

Topics: Animals; Bone Marrow; Cattle; Cell Division; Cell Line; Dose-Response Relationship, Drug; Doxorubicin; Drug Synergism; Humans; Hydrocortisone; Leukemia, Myeloid, Acute; Mice; Sepharose; Spleen; Tissue Extracts

A modified single cell cytotoxicity assay using poly-L-lysine coated cover slips (PLL-SCCA) was employed to study the frequency and surface marker profile of human peripheral blood lymphocytes (PBL) with NK reactivity against K 562 target cells. When compared with the previously described agarose single cell cytotoxicity assay (A-SCCA) identical results were obtained. For 13 donors tested 18.1 +/- 4.4% of the PBL formed conjugates with K 562 and 2.7 +/- 1.6% displayed NK reactivity. In contrast to the A-SCCA, the PLL-modified assay permits direct identification of both conjugate forming (TBC) and cytolytic PBL (NK) by means of surface markers. Indirect immunofluorescence studies with monoclonal anti-PBL antibodies revealed that neither the plating procedures nor the incubation conditions employed affected the expression of the antigens recognized by these reagents. This method of directly identifying NK cells showed that OKM1+ cells were enriched among the NK cells as compared to PBL and TBC (55% vs. 23% and 43%, respectively). In contrast, the OKT3+ or Leu1+ fraction of the NK cells was reduced as compared to PBL and TBC. However, using this method of identification at the effector cell level, a substantial proportion of the NK cells were OKT3+ or Leu1+ (57% or 58% respectively, 7 donors). Approximately 25% of the NK cells were Leu2a+ and 30% were Leu3a+, respectively. However, the size of the Leu3a+ fraction varied considerably with individual donors and the size of this fraction appeared to be inversely related to that of the donors NK pool.

Topics: Antibodies, Monoclonal; Antigens, Surface; Cytotoxicity, Immunologic; Humans; Immunologic Techniques; Killer Cells, Natural; Kinetics; Leukemia, Myeloid, Acute; Lymphocytes; Polylysine; Sepharose