INHIBITION OF HUMAN HL-60 CELL RESPONSES TO CHEMOTACTIC FACTORS BY ANTISENSE MESSENGER-RNA DEPLETION OF G-PROTEINS

Chemotactic factors bound to receptors of the seven-transmembrane doma in family signal leukocytes through associated guanine nucleotide-bind ing (G) proteins. Human leukocytes of the HL-60 line, which express G protein-coupled receptors for leukotriene B4 (LTB4) and N-formyl-methi onyl-leucyl-phenylalanine (fMLP) after differentiation with vitamin D3 and transforming growth factor-beta, were transfected with expression plasmids containing antisense-oriented cDNAs encoding the alpha-chain s of G(o), G(i1), G(i2), and G(i3). Antisense mRNA for G(o) and G(i2) alpha-chains suppressed by over 80% the level of the respective G prot ein. G(o)-deficient HL-60 cells had depressed functional and intracell ular calcium responses to LTB4 and fMLP, but no alterations in the res ponses of cyclic adenosine 3',5'-monophosphate (cAMP). In contrast, HL -60 cells deficient in G(i2) lost only responses of the intracellular concentration of cAMP. Antisense mRNA suppression of distinct G protei ns thus may delineate some transductional requirements for cellular re sponses.