» Articles » PMID: 9649436

Stat1 Combines Signals Derived from IFN-gamma and LPS Receptors During Macrophage Activation

Overview
Journal EMBO J
Date 1998 Jul 3
PMID 9649436
Citations 78
Authors
Affiliations
Soon will be listed here.
Abstract

Complete activation of macrophages during immune responses results from stimulation with the activating cytokine interferon-gamma (IFN-gamma) and a second stimulus, usually a microbial product. Bacterial infection of macrophages, or treatment with bacterial lipopolysaccharide (LPS), resulted in rapid Stat1 phosphorylation on Ser727 (S727) independently of concomitant tyrosine phosphorylation. IFN-gamma also caused rapid phosphorylation of S727. In both situations, S727 phosphorylation was reduced by pre-treatment of cells with the serine kinase inhibitor H7. When macrophages were treated sequentially or simultaneously with LPS and IFN-gamma, the pool of molecules phosphorylated on both Tyr701 (Y701) and S727 was strongly increased. Consistently, Stat1-dependent transcription in response to IFN-gamma was significantly enhanced if the cells were pre-treated with bacterial LPS. The relative amount of S727-phosphorylated Stat1 in the non-tyrosine phosphorylated fraction was considerably smaller than that in the tyrosine-phosphorylated fraction. No evidence was found for an effect of S727 phosphorylation on the phosphorylation of Y701 by IFN-gamma. Thus, serine and tyrosine phosphorylation of Stat1 are caused independently of each other, but the serine kinase may recognize tyrosine-phosphorylated Stat1 preferentially in the course of an IFN-gamma response. The data suggest Stat1 to be a convergence point for immunological stimuli in a macrophage proinflammatory response.

Citing Articles

Identification of signaling networks associated with lactate modulation of macrophages and dendritic cells.

Sangsuwan R, Thuamsang B, Pacifici N, Tachachartvanich P, Murphy D, Ram A Heliyon. 2025; 11(3):e42098.

PMID: 39975831 PMC: 11835580. DOI: 10.1016/j.heliyon.2025.e42098.


Clinical-grade extracellular vesicles derived from umbilical cord mesenchymal stromal cells: preclinical development and first-in-human intra-articular validation as therapeutics for knee osteoarthritis.

Figueroa-Valdes A, Luz-Crawford P, Herrera-Luna Y, Georges-Calderon N, Garcia C, Tobar H J Nanobiotechnology. 2025; 23(1):13.

PMID: 39806427 PMC: 11730155. DOI: 10.1186/s12951-024-03088-x.


Retinoblastoma-binding Protein 9 Suppresses Intestinal Inflammation and Inflammation-induced Tumorigenesis in Mice.

Hamada K, Nakanishi Y, Muta Y, Omatsu M, Iwane K, Ikeda M Cell Mol Gastroenterol Hepatol. 2024; 19(3):101435.

PMID: 39631567 PMC: 11786897. DOI: 10.1016/j.jcmgh.2024.101435.


C5aR1 inhibition reprograms tumor associated macrophages and reverses PARP inhibitor resistance in breast cancer.

Li X, Poire A, Jeong K, Zhang D, Ozmen T, Chen G Nat Commun. 2024; 15(1):4485.

PMID: 38802355 PMC: 11130309. DOI: 10.1038/s41467-024-48637-y.


Inhibition of pro-inflammatory signaling in human primary macrophages by enhancing arginase-2 via target site blockers.

Fitzsimons S, Munoz-San Martin M, Nally F, Dillon E, Fashina I, Strowitzki M Mol Ther Nucleic Acids. 2023; 33:941-959.

PMID: 37701067 PMC: 10494319. DOI: 10.1016/j.omtn.2023.08.023.


References
1.
Durbin J, Hackenmiller R, Simon M, Levy D . Targeted disruption of the mouse Stat1 gene results in compromised innate immunity to viral disease. Cell. 1996; 84(3):443-50. DOI: 10.1016/s0092-8674(00)81289-1. View

2.
Strehlow I, Seegert D, Frick C, Bange F, Schindler C, Bottger E . The gene encoding IFP 53/tryptophanyl-tRNA synthetase is regulated by the gamma-interferon activation factor. J Biol Chem. 1993; 268(22):16590-5. View

3.
Beadling C, Ng J, Babbage J, Cantrell D . Interleukin-2 activation of STAT5 requires the convergent action of tyrosine kinases and a serine/threonine kinase pathway distinct from the Raf1/ERK2 MAP kinase pathway. EMBO J. 1996; 15(8):1902-13. PMC: 450109. View

4.
Look D, Pelletier M, Holtzman M . Selective interaction of a subset of interferon-gamma response element-binding proteins with the intercellular adhesion molecule-1 (ICAM-1) gene promoter controls the pattern of expression on epithelial cells. J Biol Chem. 1994; 269(12):8952-8. View

5.
Darnell Jr J, Kerr I, Stark G . Jak-STAT pathways and transcriptional activation in response to IFNs and other extracellular signaling proteins. Science. 1994; 264(5164):1415-21. DOI: 10.1126/science.8197455. View