An invertebrate defense molecule activates membrane conductance in mammalian cells by means of its lectin-like domain

The invertebrate defense molecule Coelomic Cytolytic Factor-1 (CCF-1) and t he mammalian cytokine Tumor Necrosis Factor (TNF) share a similar lectin-li ke domain that, upon interaction with specific sugars, causes lysis of Afri can trypanosomes. In contrast to TNF, CCF- I does not require an acidificat ion of a lysosomal compartment for this activity. Moreover, we could demons trate using the whole cell patch clamp technique that both TNF and CCF-1 ac tivate amiloride-sensitive channels in mammalian cells, in a TNF receptor-i ndependent way, but, unlike TNF, CCF-1 does not require acidic conditions f or this activity. These data confirm the functional analogies of an inverte brate defense molecule and a mammalian cytokine, based on a similar lectin- like interaction. (C) 2001 Elsevier Science Ltd. All rights reserved.