Inhibition of human HL-60 cell responses to chemotactic factors by antisense messenger RNA depletion of G proteins.
- E J Goetzl,
- R S Shames,
- J Yang,
- F W Birke,
- Y F Liu,
- P R Albert and
- S An
Abstract
Chemotactic factors bound to receptors of the seven-transmembrane domain family signal leukocytes through associated guanine nucleotide-binding (G) proteins. Human leukocytes of the HL-60 line, which express G protein-coupled receptors for leukotriene B4 (LTB4) and N-formyl-methionyl-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-chains of Go, Gi1, Gi2, and Gi3. Antisense mRNA for Go and Gi2 alpha-chains suppressed by over 80% the level of the respective G protein. Go-deficient HL-60 cells had depressed functional and intracellular calcium responses to LTB4 and fMLP, but no alterations in the responses of cyclic adenosine 3',5'-monophosphate (cAMP). In contrast, HL-60 cells deficient in Gi2 lost only responses of the intracellular concentration of cAMP. Antisense mRNA suppression of distinct G proteins thus may delineate some transductional requirements for cellular responses.
