Purification and Characterization of a Mitogenic Lectin fromCephalosporium, a Pathogenic Fungus Causing Mycotic Keratitis

Abstract

Ophthalmic mycoses caused by infectious fungi are being recognized as a serious concern since they lead to total blindness.Cephalosporiumis one amongst several opportunistic fungal species implicated in ophthalmic infections leading to mycotic keratitis. A mitogenic lectin has been purified from the mycelia of fungusCephalosporium, isolated from the corneal smears of a keratitis patient.Cephalosporiumlectin (CSL) is a tetramer with subunit mass of 14 kDa, agglutinates human A, B, and O erythrocytes, and exhibits high affinity for mucin compared to fetuin and asialofetuin but does not bind to simple sugars indicating its complex sugar specificity. CSL showed strong binding to normal human peripheral blood mononuclear cells (PBMCs) to elicit mitogenic activity. The sugar specificity of the lectin and its interaction with PBMCs to exhibit mitogenic effect indicate its possible role in adhesion and infection process ofCephalosporium.