Although it is now well established that cells of the immune system express most of the exopeptidases described so far, little information is available concerning the identification and the characterization of the peptidases associated with the surface of human thymocytes. In the present study we have focused on CD10 expression on thymocytes using both FACS and enzymatic analysis. Unfractionated intact human thymocytes were shown to express significant levels of CD10-specific enzymatic activity, as assessed by the hydrolysis of the neutral endopeptidase (NEP) substrate Suc-Ala-Ala-Phe-pNA and of D-Ala2-Leu-enkephalin, a typical NEP substrate. CD10 activity was abolished by specific NEP inhibitors, including thiorphan, retrothiorphan and phosphoramidon. Moreover, high performance liquid chromatography (HPLC) analysis showed that intact thymocytes and purified NEP hydrolysed thymopentin, a thymic factor known to induce the maturation of prothymocytes into thymocytes. Finally, CD 10/NEP was preferentially associated with CD3- CD3low and immature CD4- CD8- thymocytes. The data demonstrate for the first time that human thymocytes express functional NEP and suggest a role for this enzyme in the maturation of human thymocytes.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1414883PMC

Publication Analysis

Top Keywords

human thymocytes
20
thymocytes
9
cd10 activity
8
thymocytes express
8
nep substrate
8
human
5
nep
5
high levels
4
levels functional
4
functional endopeptidase
4

Similar Publications

The assembly of Tcrb and Tcra genes require double negative (DN) thymocytes to undergo multiple rounds of programmed DNA double-strand breaks (DSBs), followed by their efficient repair. However, mechanisms governing cell cycle checkpoints and specific survival pathways during the repair process remain unclear. Here, we report high-resolution scRNA-seq analyses of individually sorted mouse DN3 and DN4 thymocytes, which reveals a G2M cell cycle checkpoint, in addition to the known G1 checkpoint, during Tcrb and Tcra recombination.

View Article and Find Full Text PDF

Association Between Early Immunosuppression Center Variability and One-Year Outcomes After Pediatric Liver Transplant.

Pediatr Transplant

February 2025

Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of California San Francisco, San Francisco, California, USA.

Background: Despite the existence of institutional protocols, liver transplant centers often have variability in early immunosuppression practices. We aimed to measure within-center variability in early immunosuppression after pediatric liver transplant (LT) and examine its association with one-year outcomes.

Methods: We analyzed pediatric LTs from 2013 to 2018 in the United Network for Organ Sharing registry, with data aggregated by center.

View Article and Find Full Text PDF

Tribbles homolog 2 (TRIB2), a pseudoserine/threonine kinase, is a member of the TRIB family. TRIB2 primarily regulates cell proliferation through its scaffold or adaptor effect on promoting the degradation of target proteins by E3 ligase-dependent ubiquitination and regulating mitogen-activated protein kinase (MAPK) and protein kinase B (AKT) signaling pathways. TRIB2 is not only involved in the physiological proliferation of cells (granulosa cells, myoblasts, naive T cells, and thymocytes) during normal development but also in the pathological proliferation of vascular smooth muscle cells and a variety of cancer cells (lung cancer cells, liver cancer cells, leukemia cells, pancreatic cancer cells, gastric cancer cells, prostate cancer cells, thyroid cancer cells, cervical cancer cells, melanoma cells, colorectal cancer cells, ovarian cancer cells and osteosarcoma cells) under disease conditions.

View Article and Find Full Text PDF

The effect of conditioned medium from human amniotic membrane-derived mesenchymal stem cells on thymus involution.

Life Sci

January 2025

3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Guimarães, Portugal; ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal. Electronic address:

Aims: The development and selection of T cells occur within the thymus. This organ involutes throughout life, compromising the generation of T cells and, consequently, the efficacy of the immune system. Mesenchymal stem cells (MSC) have beneficial effects on the immune system.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!