Expression and function of galectin-3, a β-galactoside-binding protein in activated T lymphocytes

Abstract

Abstract A soluble beta-galactoside-binding lectin, galectin-3 has been shown tobe involved in cell adhesion and activation of immune cells. Althoughgalectin-3 is known to be expressed in various types of cells, it hasnot been shown whether galectin-3 is expressed in T lymphocytes. Wepresent evidence here that galectin-3 is expressed in activated murineT lymphocytes including CD4+ and CD8+ T cellsbut not in resting T cells. Galectin-3 expression was induced byanti-CD3 mAb or mitogen and enhanced by common γ-chain signalingcytokines, IL-2, IL-4, and IL-7, in activated T lymphocytes, whereasthe inflammatory cytokines including TNF-α and IFN-γ did not.Galectin-3 expression and proliferation were down-regulated bywithdrawal of IL-2 and gamma irradiation. Anti-sense but not sensephosphorothioated oligonucleotides for galectin-3 inhibited galectin-3expression and blocked proliferation of T cells significantly. Thisstudy suggests that up-regulation of galectin-3 plays an important rolein proliferation of activated T lymphocytes.