A cytotoxic proteinase isolated from human lymphocytes

V. B. Hatcher, M. S. Oberman, G. S. Lazarus, A. I. Grayzel

Research output: Contribution to journalArticlepeer-review

47 Scopus citations


A proteinase active at physiologic pH was isolated from unstimulated human peripheral blood lymphocytes with gel filtration and affinity chromatography. The proteinase with a molecular mass of approximately 30,000 daltons was completely inhibited by diisopropylfluorophosphate (DFP) and soybean trypsin inhibitor (STI). Incubation of the lymphocyte enzyme with 3H-proline labeled T24 human bladder carcinoma cells resulted in significant cytotoxicity of the target cells. Cytotoxicity was only observed with much higher concentrations of trypsin. Similar results were obtained with a 51Cr release assay. This investigation demonstrates that unstimulated human peripheral blood lymphocytes contain a cytotoxic proteinase capable of killing pre-labeled target cells. The proteinase may be involved in lymphocyte-mediated cytotoxicity.

Original languageEnglish (US)
Pages (from-to)665-670
Number of pages6
JournalJournal of Immunology
Issue number2
StatePublished - Jan 1 1978
Externally publishedYes

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology


Dive into the research topics of 'A cytotoxic proteinase isolated from human lymphocytes'. Together they form a unique fingerprint.

Cite this