Verschuren, M.C.M. http://repub.eur.nl/res/aut/12998/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png RePub, Erasmus University Rotterdam http://repub.eur.nl PJA-BP expression and TCR delta deletion during human T cell differentiation (Article) http://repub.eur.nl/res/pub/8990/ 1998-01-01T00:00:00Z Recombination of deltaRec to psiJalpha will delete the TCR delta gene, which is thought to play an important role in the bifurcation of the TCR alphabeta versus TCR gammadelta differentiation lineages. We recently detected a DNA-binding protein in human thymocytes, the so-called PJA-BP, which recognizes the psiJalpha gene segment and might be one of the factors involved in the regulation of preferential deltaRec-psiJalpha rearrangements. We now investigate PJA-BP expression and its correlation with TCR delta gene deletion in thymocytes. Our electrophoretic mobility shift assay experiments showed that the PJA-BP is evolutionary conserved in human, murine and simian thymocytes. Using a large series of human hematopoietic malignancies (n = 30), we conclude that PJA-BP expression is thymocyte specific and seems to be restricted to thymocytes committed to the TCR alphabeta lineage. Analysis of seven well-defined human thymocyte subpopulations showed that preferential deltaRec-psiJalpha rearrangements as well as PJA-BP expression can be detected from the immature CD34-/CD1+/CD3-/CD4+/CD8alpha+beta- thymocyte differentiation stage onwards. These experiments indicate that expression of PJA-BP in human thymocytes starts simultaneously with preferential deltaRec-psiJalpha rearrangements, which supports our hypothesis that PJA-BP is one of the factors involved in the preferential recombination of deltaRec to psiJalpha. T cell receptor-o deletion in human T cells (Doctoral Thesis) http://repub.eur.nl/res/pub/21411/ 1996-12-04T00:00:00Z The immune system protects the body against pathogens such as bacteria, viruses, fungi, and parasites, when they pass the first line of body defence such as the skin or other epithelial and mucosal barriers. After penetration into the body, micro-organisms encounter the second line of defence. This concerns the so-called aspecitlc immune system, which consists of phagocytes, such as macrophages and granulocytes, complement factors, and natural killer cells. Generally, support by the third line of defence is needed, i.e. the socalled specific irrunune system.