Eta-1 (Osteopontin): An Early Component of Type-1 (Cell-Mediated) Immunity

✍ Scribed by Ashkar, S.

• Book ID: 121162135
• Publisher: American Association for the Advancement of Science
• Year: 2000
• Tongue: English
• Weight: 843 KB
• Volume: 287
• Category: Article
• ISSN: 0036-8075
• DOI: 10.1126/science.287.5454.860

✦ Synopsis

Cell-mediated (type-1) immunity is necessary for immune protection against most intracellular pathogens and, when excessive, can mediate organ-specific autoimmune destruction. Mice deficient in Eta-1 (also called osteopontin) gene expression have severely impaired type-1 immunity to viral infection [herpes simplex virus–type 1 (KOS strain)] and bacterial infection (Listeria monocytogenes) and do not develop sarcoid-type granulomas. Interleukin-12 (IL-12) and interferon-γ production is diminished, and IL-10 production is increased. A phosphorylation-dependent interaction between the amino-terminal portion of Eta-1 and its integrin receptor stimulated IL-12 expression, whereas a phosphorylation-independent interaction with CD44 inhibited IL-10 expression. These findings identify Eta-1 as a key cytokine that sets the stage for efficient type-1 immune responses through differential regulation of macrophage IL-12 and IL-10 cytokine expression.