Immunohistochemical localization of human tear lysozyme.

Possible local sources of human tear lysozyme were investigated using an indirect immunofluorescence technique. Lysozyme was identified in 20% to 50% of acinar and ductular epithelial cells of both main and accessory lacrimal glands. The staining was granular in character and confined to the apices of the cells. Cells that stained positive tended to be grouped. Interstitial tissues of main and accessory lacrimal tissues did not stain. Conjunctiva and all other ocular tissues examined were unstained by antilysozyme antisera. Our findings are compatible with lysozyme either being produced in lacrimal tissue or being concentrated from plasma. The absence of any other lysozyme-specific fluorescence in the interstitial elements of the lacrimal tissues supports the notion of local synthesis by acinar lacrimal tissue.