Development of receptors for leukotriene B4 on HL-60 cells induced to differentiate by 1 alpha,25-dihydroxyvitamin D3.
The incubation of HL-60 human promyelocytic leukemia cells for 7 days with 100 nM 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] induced differentiation into monocyte-like cells, as assessed by morphologic and biochemical characteristics. Stereospecific receptors for leukotriene B4 (LTB4) developed on the surface of the HL-60 cell-derived monocytes that had the capacity to transduce LTB4 stimulation of a transient increase in the cytosolic concentration of calcium ([Ca+2]in). HL-60 cell-derived monocytes, but not undifferentiated HL-60 cells, expressed a high affinity subset of 6400 +/- 3700 receptors per cell with a dissociation constant (Kd) of 2.3 +/- 1 nM (mean +/- SD, n = 3) and a low affinity subset of approximately 2.2 X 10(6) receptors per cell with an apparent Kd of 680 +/- 410 nM. Derivatives of LTB4 inhibited the binding of [3H]LTB4 to HL-60 cell-derived monocytes with a rank order of potency of LTB4 greater than 20-OH-LTB4 greater than 3-aminopropyl amide-LTB4, which is similar to the order for LTB4 receptors of human blood PMNL. In contrast, leukotrienes C4 and D4 and formyl-methionyl chemotactic peptides did not inhibit the binding of [3H] LTB4, which demonstrates the specificity of these receptors for isomers of 5,12-dihydroxy-eicosatetraenoic acid. LTB4 stimulated an increase in [Ca+2]in in HL-60 cell-derived monocytes which reached 50% of the maximal level at an LTB4 concentration of 0.5 nM (EC50). Preincubation of HL-60 cell-derived monocytes with 10 nM LTB4 resulted in a selective loss of high affinity receptors, as assessed by binding of [3H]LTB4, and a 200-fold increase in the EC50 for stimulation by LTB4 of increases in [Ca+2]in, without alterations in either the low affinity receptors for LTB4 or the responsiveness of [Ca+2]in to formyl-methionyl chemotactic peptides. HL-60 cells that are induced to differentiate into monocytes thus develop stereospecific receptors for LTB4 with binding and transductional characteristics similar to those of human blood PMNL.
D002117:Calcitriol / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D007975:Leukotriene B4 / Q000378:metabolism* / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D018077:Receptors, Leukotriene; D011982:Receptors, Prostaglandin / Q000096:biosynthesis* / Q000187:drug effects
D011956:Receptors, Cell Surface; D018077:Receptors, Leukotriene; D011982:Receptors, Prostaglandin; D007975:Leukotriene B4; D002117:Calcitriol; D002118:Calcium