Experimental studies on bacterial product CANTASTIM derived from Pseudomonas aeruginosa. II. Protective effect in Salmonella typhimurium infection
Salageanu, A.; Ceacareanu, B.; Popescu, D.; Istrate, N.; Szegli, G.
Roumanian Archives of Microbiology and Immunology 56(1-2): 17-26
1998
ISSN/ISBN: 1222-3891 PMID: 9558981 Document Number: 496255
Integrin-mediated activation of monocytes is an important aspect involved in the increase of proinflammatory cytokine messages. Tyrosine phosphorylation of proteins is one of the earliest events involved in these processes: Therefore, we selected two inhibitors, one for tyrosine kinases (quercitin) and another for tyrosine phosphatases (sodium orthovanadate) and we studied their capacity to modulate monocyte adhesion to fibronectin. Our results showed that quercitin strongly inhibits both tyrosine phosphorylation and cell adhesion. Sodium orthovanadate induces a modest increase of tyrosine phosphorylation and a weak enhancement of cell adhesion. When a combination of the two inhibitors was used, the tyrosine phosphorylation level displayed a strong enhancement. In contrast, cell adhesion was inhibited, but to the same degree. These observations indicate that tyrosine kinases may be more important than tyrosine phosphatases in the modulation of cell adhesion by flavonoid compounds.