Abstract: Antibodies, nucleic acid sequences, and methods for inhibition of lysis for a novel serine esterase produced by both murine and human cytotoxic T lymphocytes. The serine esterase has an apparent molecular weight of approximately 28,000-31,000, as determined by SDS gel electrophoresis under reducing conditions, and trypsin-like activity. Inhibition of the esterase correlates with inhibition of the cells' cytolytic activity. Specific inhibition of the serine esterase is useful as a method for immunosuppression as well as for the inhibition of cytolytic activity of T lymphocytes, both in vivo and in vitro. The genes encoding the murine and human serine esterase are homologous.

Abstract: A novel serine esterase produced by cytotoxic T lymphocytes is insolated and characterized. The protein appears to be membrane bound and has a reduced apparent molecular weight of about 28,000 daltons. Inhibition of the esterase correlates with inhibition of the cells' cytolytic activity. The serine esterase is useful in making antibody and as a target for the inhibition of cytolytic activity by T-lymphocytes, both in vivo and in vitro.