Cutting edge: Role of osteopontin and integrin ?v in T cell-mediated anti-inflammatory responses in endotoxemia.

ABSTRACT: The immune system is equipped with mechanisms that downregulate hyperinflammation to avoid collateral damage. We demonstrated recently that unprimed T cells downregulate macrophage TNF production through direct interaction with macrophages in the spleen during LPS endotoxemia. How T cell migration toward macrophages occurs upon LPS injection is still not clear. In this study, we demonstrate that secreted osteopontin (sOPN) plays a role in the T cell migration to initiate the suppression of hyperinflammation during endotoxemia. Osteopontin levels in splenic macrophages were upregulated 2 h after LPS treatment, whereas T cell migration toward macrophages was observed 3 h after treatment. Neutralization of sOPN and blockade of its receptor, integrin ?v, significantly inhibited CD4(+) T cell migration and increased susceptibility to endotoxemia. Our study demonstrates that the sOPN/integrin ?v axis, which induces T cell chemotaxis toward macrophages, is critical for suppressing hyperinflammation during the first 3 h of endotoxemia.

SUBMITTER: Inoue M 

PROVIDER: S-EPMC4458449 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature