| Autor: |
Rijkers, Ger T, Scharenberg, John G M, Van Dongen, Jacques J M, Neijens, Herman J, Zegers, Ben J M |
| Zdroj: |
Pediatric Research; March 1991, Vol. 29 Issue: 3 p306-309, 4p |
| Abstrakt: |
ABSTRACT: We have studied an 8-yr-old male patient with adenosine deaminase-positive severe combined immunodeficiency disease with a normal number of peripheral CD3+, T cell receptor-aß+T cells. The majority of these T cells expressed the CD8 molecule and were oligoclonal in nature as proven by Southern blot analysis of the T cell receptor genes. T cells failed to proliferate in vitro either upon stimulation with T cell mitogens or when stimulated with a combination of the phorbol ester phorbol myristate acetate and the Ca-ionophore ionomycin. High doses of recombinant IL-2, when added to in vitro cultures, were able to restore proliferation induced by phorbol myristate acetate and ionomycin but the response to concanavalin A remained severely defective. However, activation of the patient's T cells with phytohemagglutinin or concanavalin A induced an increase of free cytoplasmic Ca++, which was 2- to 5-fold higher than in normal CD8+T cells. Furthermore, phorbol myristate acetate or phytohemagglutinin induced the translocation of protein kinase C from cytosol to plasma membrane. Analysis of membrane phospholipid composition of the patient's T cells disclosed that the ratio of phosphatidylcholine to phosphatidylserine was 5-fold higher than in normal T cells. The abnormal Ca++response after activation with T cell raitogens as well as the high phosphatidylcholine/phosphatidylserine ratio may be causally linked to the defective in vitro T cell proliferation. Because the capacity of T lymphocytes to produce or respond to IL-2 may vary, the oligoclonality of the T cells of the patient should be considered as well in the explanation of defective cell proliferation. |
| Databáze: |
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