Ligation of IFN-gamma-induced HLA-DR molecules on fibroblasts induces RANTES expression via c-Jun N-terminal kinase (JNK) pathway.
The role of human leukocyte antigen (HLA) class II molecules on non-antigen presenting cells has been a matter of controversy. We recently reported that ligation of HLA-DR molecule with anti-HLA-DR antibodies (L243) and/or antigenic peptide/T cell receptor complex resulted in a secretion of several chemokines such as RANTES. In the present study, we aimed to detect putative signal transduction pathway leading to RANTES production from fibroblasts when the DR molecules were ligated with L243. Protein tyrosine kinase inhibitor (GF109203X) suppressed RANTES expression in a dose dependent manner for up to 50% from gingival fibroblasts (GF), while protein kinase C inhibitor (genistein) had no inhibitory effect. Ligation of DR molecules with L243 resulted in tyrosine phosphorylation of 54 kDa cellular protein. Thus, we suspected that either Jun N-terminal kinase-2 (JNK-2) or Src family proteins were involved in HLA-DR-mediated signaling. JNK inhibitor (SP600125), but not Src inhibitor (PP2), suppressed both L243 stimulated RANTES mRNA expression and protein secretion. The maximum inhibition for RANTES production by SP600125 was more than 80%. Additionally, JNK inhibitor nearly completely blocked tumor necrosis factor-alpha (TNF-alpha)-induced RANTES production in GF. Furthermore, ligation of GF HLA-DR with L243 induced selective phosphorylation of JNK-2. We concluded that JNK-2 was one of the HLA-DR-mediated signal transduction pathways.
Meguro
Michio
M
Department of Patho-physiology/Periodontal Science, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8525, Japan.
Nishimura
Fusanori
F
Ohyama
Hideki
H
Takashiba
Shogo
S
Murayama
Yoji
Y
Matsushita
Sho
S
D015153:Blotting, Western; D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D005347:Fibroblasts / Q000378:metabolism*; D006684:HLA-DR Antigens / Q000378:metabolism*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation; D015398:Signal Transduction
D018946:Chemokine CCL5; D006684:HLA-DR Antigens; D007371:Interferon-gamma; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases