TNF and bacterial infectious disease: TNF is produced by macrophages, but is expressed by a variety of cells and is a major regulator of inflammation and leucocyte trafficking.14,15; Although a key role of TNF in controlling intracellular bacterial infections is uncontested, the function of membrane TNF, which is subsequently cleaved by the metalloproteinase-disintegrin TACE (TNF-α converting enzyme16) into the secreted trimeric TNF is, in mycobacterial host resistance, less clear.