Effect of protein kinase C on T lymphocyte proliferation and apoptosis in acute idiopathic thrombocytopenic purpura.
Previous studies have shown that T lymphocyte proliferation and apoptosis are abnormal in idiopathic thrombocytopenic purpura (ITP) children; however, the underlying regulated mechanisms in signal transductions remain unknown. In this paper, we investigated the changes of protein kinase C (PKC) activity in peripheral blood T lymphocytes and the effect of PKC on the peripheral blood T lymphocyte proliferation and apoptosis in ITP children. We demonstrated that T lymphocytes from ITP children were more susceptible to the activator (phorbol myristate acetate) and the inhibitor (H-7) of PKC. In ITP children, phorbol myristate acetate and H-7 dramatically affected T lymphocyte proliferation and apoptosis, but altered little in healthy children. Compared with healthy children, PKC activity was significantly enhanced in ITP children, increasing the expressions of Fas ligand on CD3+, CD4+ and CD8+ T cells, indicating positive correlations between PKC activity and the expressions of Fas ligand on T cells, while the relations between PKC activity and platelet count showed negative correlations. Taken together, our findings suggest that PKC signal transductions may participate in the procedure of T lymphocyte proliferation and apoptosis in ITP children. PKC activation may enhance T lymphocyte activity, suppress T cell apoptosis, and be involved in thrombocyte damage, which can be related to the immunity pathogenesis of ITP.
Liu
Fang
F
Department of Microbiology and Immunology, Guangdong Medical College, Zhanjiang, Guangdong Province, China. liufang@gdmc.edu.cn
Wu
Chang-lin
CL
Xiao
Hong
H
Yang
Xiao-meng
XM
Lv
Xue-wen
XW
Chen
Qun
Q
D000208:Acute Disease; D000293:Adolescent; D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002648:Child; D002675:Child, Preschool; D004247:DNA / Q000032:analysis; D004587:Electrophoresis, Agar Gel; D053222:Fas Ligand Protein; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D011493:Protein Kinase C / Q000097:blood*; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000201:enzymology*; D015398:Signal Transduction / Q000502:physiology; D013601:T-Lymphocytes / Q000166:cytology*; D048069:Tumor Necrosis Factors / Q000378:metabolism
C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D048069:Tumor Necrosis Factors; D004247:DNA; D011493:Protein Kinase C