A novel serine proteinase (HuTSP) isolated from a cloned human CD8⁺ cytolytic T cell line is expressed and secreted by activated CD4⁺ and CD8⁺ lymphocytes

Abstract

A novel proteinase, termed human T cell-associated serine proteinase (HuTSP), has been highly purified from a human CD8+ T lymphocyte clone. By using a panel of chromogenic model peptide substrates the enzyme was found to specifically recognize L-arginine and to cleave Tos-Gly-Pro-Arg-nitroanilide with high efficiency at a pH optimum of 10.5-11. Exposure to class-specific proteinase inhibitors revealed that HuTSP is a serine endopeptidase. The enzyme has a mol. mass of approximately 50 kDa (non-reduced) and of approximately 25-30 kDa (reduced) when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggesting HuTSP to be a disulfide-linked dimer. The enzyme is shown to be inducible by lectin in both CD4+ and CD8+ lymphocytes. Moreover, HuTSP was detected in a number of independent CD4+ and CD8+ T cell clones and was found to be released from effector cells upon ligand binding to the CD3-T cell receptor complex.

Activation of the Granzyme Pathway in Children With Severe Respiratory Syncytial Virus Infection

“…In addition to CTLs and NK cells, CD4 ϩ T cells and basophils may express Grs (31,32). Recently, neutrophils also were shown to express Grs (33), although this has been debated by others (34).…”

Interplay between Chromatin Remodeling and Epigenetic Changes during Lineage-Specific Commitment to Granzyme B Expression

“…The gzmB pathway is normally associated with NK cell and CD8 ϩ T cell responses, but not usually with CD4 ϩ Th cell function (9). Intriguingly, early experiments indicated that granzymes can sometimes be expressed in both murine CD4 ϩ and CD8 ϩ T lymphocytes, albeit at differing levels, depending on the conditions of stimulation and developmental stages of these T cell subsets (10). Recently, gzmB was shown to possess a second function besides its role in target cell killing, being possibly involved in regulating the homeostasis of activated Th2 T cells (11).…”

Activation of pro‐urokinase by the human T cell‐associated serine proteinase HuTSP‐1

“…After 24 h 29.6 IU/ml rpro-uPA or 56% of the melanoma cell-derived prouPA, respectively, were activated by 1 unit/ml HuTSP-1. The amount of HuTSP-1 used for the experiment (1 unit) is secreted by about 3 x lo5 activated UA B34.C7 cells per day [16].…”

“…The enzyme, which has also been demonstrated in inflammatory foci in vivo [17], is contained within intracellular storage granules and secreted by vectorially oriented exocytosis upon interaction of T effector cells with appropriate target cells [16]. Under pathophysiological conditions, secreted HuTSP-1 may thus induce the generation of both uPA and plasmin by activating pro-uPA, which has been found in a variety of tissues and cells, including those participating in inflammatory reactions such as macrophages [4].…”

“…The enzyme content of these cells is about 70 units HuTSP-i/IO6 cells [16]. One unit is defined as the amount of enzyme producing a AE.wt, of 0.01/h incubation at 37°C using the chromogenic substrate S-2288.…”