Using histochemical and immunological methods, the development of lymphocyte-tissue complexes in the distal part of human fetal intestine (appendix, Peyer's patch) was studied in relation to the changes taking place in the ileocecal lymph nodes. It was found that this autonomous gut immune system started to function in the second trimester of fetal development. It is dominated by T-cell system of the immunity. After the appearance of meconium in the intestinal lumen, the phenotypical diversity of lymphocytes within the organ was increased, but it did not reach the level found in mature organism. The ileocecal lymph nodes are distinguished by their lymphocyte composition as a T-cell depot in this interorgan and intertissue system, which provides essential homeostasis of the developing fetus.
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Using histochemical and immunological methods, the development of lymphocyte-tissue complexes in the distal part of human fetal intestine (appendix, Peyer's patch) was studied in relation to the changes taking place in the ileocecal lymph nodes. It was found that this autonomous gut immune system started to function in the second trimester of fetal development. It is dominated by T-cell system of the immunity.
View Article and Find Full Text PDFCancer Res
March 2000
Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
In the complex microenvironment where they evolve, developing cells undergo rapid programmed cell death (PCD) when cytokines that support them become limiting. The transcriptional mechanisms of cytokine-withdrawal apoptosis are poorly understood. In this report, we used early B-lymphocyte tissue culture and transgenic cells to demonstrate that nuclear factor-kappaB (NF-kappaB) promotes apoptosis during cytokine withdrawal-induced PCD.
View Article and Find Full Text PDFJ Biol Chem
September 1999
Max-Planck-Institute of Neurobiology, Department of Neuroimmunology, Department of Structural Biology, Am Klopferspitz 18A, D-82152 Martinsried, Germany.
Granzymes are granule-stored lymphocyte serine proteases that are implicated in T- and natural killer cell-mediated cytotoxic defense reactions after target cell recognition. A fifth human granzyme (granzyme 3, lymphocyte tryptase-2), renamed as granzyme K (gene name GZMK), has recently been cloned from lymphocyte tissue. For its further characterization we successfully generated catalytically active enzyme in milligram quantities per liter of Escherichia coli culture.
View Article and Find Full Text PDFTissue Antigens
November 1979
Department of Surgery, University of Cambridge, Addenbrooke's Hospital, Cambridge, England.
Cultured porcine non-lymphoid cells, characterized by biochemical and morphological criteria, were derived from different tissues of individuals typed by serological and mixed lymphocyte culture methods for gene products of the major histocompatibility complex. These cultured cells have been used as stimulators in mixed lymphocyte-tissue cell cultures in order to investigate (1) the magnitude, kinetics and dose-dependence of lymphocyte transformation caused by tissue cells compared with that caused by lymphocytes as stimulators; (2) the relationship between the expression of serologically detected Ia-like antigens by tissue cells and their ability to cause lymphocyte transformation; (3) the genetic control of stimulation by tissue cells and by lymphocytes and (4) the expression and genetic control of lymphocyte stimulatory properties restricted to tissue cells and absent from lymphocytes. It has been shown that some but not all kinds of tissue cells can stimulate allogeneic lymphocytes strongly and that the characteristics of such stimulation are similar to those observed in mixed lymphocyte cultures.
View Article and Find Full Text PDFThe sera of 20 random human heart transplant recipients, drawn before the administration of immunosuppressive medications, were screened for the presence of factors that might inhibit the mixed lymphocyte reaction. The donors for the lymphocyte cultures were unrelated both to one another and to the heart donor and recipient. Inhibition was defined as a reduction of the number of transformed cells produced in vitro to less than one-third of that produced in autologous serum.
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