Demonstration, Purification, and Partial Characterization of Abnormal (HSL)1 Antigens in Stable Human Cell Lines3

Abstract

The existence of abnormal (HSL) human stable line antigens common to a number of stable human cell lines, but absent from normal human tissues and normal human diploid cell strains in tissue culture, has been demonstrated by agar gel microimmunodiffusion. HSL was detected in HeLa-SJ, HeLa-MBA, HeLa-S3, Chang conjunctiva, Syverton's embryo esophagus, Chang liver, and J-111. It was not detected in Henle's human intestine or Detroit-6. It was absent from two normal diploid strains, WI-38 and SJ-DHL, and was not found in a variety of concentrated extracts of fresh human organs. HSL was not associated with contamination by pleuropneumonia-like organisms (PPLO) of cell lines. The purest HSL preparations obtained from HeLa-SJ by ammonium sulfate fractionation yielded absorption spectra characteristic of protein and were inactivated by trypsin. Sephadex chromatography indicated a particle weight of approximately 150,000; HSL was not sedimented at 125,000 × g. In 0.02 M PO⁴ buffer, activity was virtually completely eliminated after 2 minutes at 50° C, 8 minutes at 45° C, or 80 minutes at 40° C. Preliminary studies with fluorescent anti-HSL globulin indicated that HSL was not a surface antigen; rabbit antisera to purified HSL fractions were not cytotoxic to Hela cells. The best preparations of HSL still contained a trace of common human antigen and appeared to consist of multiple components active in immunoprecipitation. Electrophoresis indicated the inhomogeneity of this material.