Karsten Hartmann

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The protein Lck (p56lck) has a relative molecular mass of 56,000 and belongs to the Src family of tyrosine kinases. It is expressed exclusively in lymphoid cells, predominantly in thymocytes and peripheral T cells. Lck associates specifically with the cytoplasmic domains of both CD4 and CD8 T-cell surface glycoproteins and interacts with the beta-chain of(More)
To analyze the tissue distribution of lymphocyte subsets of autoimmune MRL/Mp-lpr/lpr mice, we have studied cryostat sections of the lymphoid organs at different stages of the disease using monoclonal antibodies directed against Ly 1 (MAb 53-7.3), Ly 2 (MAb 53-6.7), B 220 (MAb 14.8), and mu heavy chain (MAb b.7.6). We have observed an increase of a(More)
Spleen cells of bone marrow chimeras (B cells) and of irradiated mice injected with thymus cells and heterologous erythrocytes (educated T cells) were mixed and cultured together (17). The number of PFC developing in these cultures was dependent both on the concentration of the B cells and of the educated T cells. In excess of T cells the number of(More)
Two monoclonal antibodies recognizing subpopulations of epithelial stroma cells of the embryonic mouse thymus are described. Antibody Th-115/7 reacts with epithelial cells of the thymus cortex: antibody Th-101/5 binds to stroma cells of the thymus medulla. In cryosections of whole embryos Th-115/7 bound in addition to mucosal epithelial cells of the(More)
The Fas/Apo-1 receptor is an integral membrane protein that transduces apoptotic signals upon binding to its natural ligand or to specific antibodies. Loss of Fas/Apo-1 receptor leads in (lpr,lpr) mice to a nonmalignant accumulation of abnormal T-cells very probably due to the lack of induction of apoptosis in peripheral T-cells. It has been reported that(More)
The murine gld mutation is targetted to the gene coding for the ligand of the Fas receptor for apoptosis. Gld mice display a lymphoproliferative and autoimmune syndrome that can be transferred in both irradiated euthymic wild and athymic beige (nubg) recipients. In order to test whether a supply of normal wild cells could correct the development of the gld(More)
Monoclonal antibodies (Mabs) were produced against C57B1/6 "nude" lymphoblast cells. They are IgG2a and do not react with mouse serum proteins. Five Mabs were characterized functionally by immunohistochemistry and immunofluorescence in spleen, lymph nodes and Peyer's patches from nude and normal mice, and normal mouse thymus. Two Mabs reacted with regions(More)