Cell-Mediated Immunity in Vitro: A Highly Sensitive Assay for Human Lymphotoxin

Abstract

A new in vitro technique for the assay of human lymphotoxin (LT) is described. The method uses monolayer tube cultures of an exquisitely sensitive cell type pretreated with mitomycin-C (MC). The use of MC permits the differentiation of growth inhibition and actual cytotoxicity. In addition, the use of MC-treated target cells considerably increases the sensitivity of the LT assay. The method is very simple, rapid, reproducible, and more sensitive than present assays for LT or any other lymphokine. The utility of this assay lends itself to routine application in research and in clinical situations.