Expression of IL-2 receptor β and γ chains by human gingival fibroblasts and up-regulation of adhesion to neutrophils in response to IL-2

To investigate the role of human gin- gival fibroblasts (HGF), the major constituents of gingival tissue in periodontal inflammatory disease, the expression of interleukin-2 receptor (IL-2R) , , and chains was examined. Immunohistochem- istry showed a pronounced accumulation of CD8 T cells in the inflamed lamina propria of gingival tissue from patients with adult periodontitis. HGF express IL-2R and IL-2R at mRNA and protein levels, but the expression of IL-2R could not be detected, as assessed by reverse transcriptase-poly- merase chain reaction and flow cytometry. IL- 2R ,- , and - expressed on HGF were function- ally active, as addition of neutralizing anti-IL-2R and - antibodies caused inhibition of the IL-2- induced production of monocyte chemoattractant protein-1 (MCP-1), and addition of IL-2 induced phosphorylation of Janus tyrosine kinase 3, which is critical in signaling through IL-2R in HGF. The IL-2-induced MCP-1 production was significantly inhibited by pretreatment with neutralizing anti- body to IL-15. Addition of IL-2 also induced a marked up-regulation of the expression of intercel- lular adhesion molecule-1 (ICAM-1) on the surface of HGF, which in turn, significantly augmented the adhesion of human neutrophils, which were inhib- ited by an anti-ICAM-1 antibody. These results sug- gest that HGF express functional IL-2R, re- spond to IL-2 from infiltrated T cells, and actively participate in the inflammatory process in the peri- odontal region and that IL-15 produced by HGF sustains IL-2-mediated signaling in HGF. J. Leu- koc. Biol. 74: 000-000; 2003.