TNF-alpha-induced apoptosis in neonatal lymphocytes: TNFRp55 expression and downstream pathways of apoptosis.
Previously we have shown decreased Fas-mediated apoptosis in cord blood lymphocyte subsets. In this study, we compared tumor necrosis factor (TNF)-alpha-induced apoptosis in T lymphocytes and their subsets between cord blood and peripheral blood from healthy young controls. The expression of TNF receptor I (TNFR-I) was assessed by flow cytometry and quantitative RT-PCR. The expression of adapter molecules TNF receptor-associated death domain (TRADD), Fas-associated death domain (FADD) and TNF-associated factor-2 (TRAF-2) and caspase 3 was analyzed by Western blotting. The activity of caspase 3 and caspase 8 was measured by colorimetric assay. The susceptibility of CD4+ and CD8+ T cells to TNF-alpha-induced apoptosis was measured by terminal deoxytidyl transferase-mediated dUTP nick end labelling (TUNEL) assay. Both CD4+ and CD8+ T cell subsets from cord blood demonstrated decreased susceptibility to TNF-alpha-induced apoptosis that was associated with decreased activation of both caspase 8 and caspase 3 as compared to T cell subsets in peripheral blood. Furthermore, expression of TNFR-I, TRADD and caspase 3 was decreased in cord blood lymphocytes as compared to peripheral blood lymphocytes. The significance of these observations is discussed.
Aggarwal
S
S
Molecular Immunology Laboratory, Division of Basic and Clinical Immunology, University of California, Irvine, CA 92697-4069, USA.
Gollapudi
S
S
Yel
L
L
Gupta
A S
AS
Gupta
S
S
D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D015703:Antigens, CD / Q000096:biosynthesis / Q000502:physiology*; D017209:Apoptosis; D017252:CD3 Complex / Q000378:metabolism; D002352:Carrier Proteins / Q000096:biosynthesis; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D053200:Fas-Associated Death Domain Protein; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D014176:Protein Biosynthesis; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis / Q000502:physiology*; D047888:Receptors, Tumor Necrosis Factor, Type I; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D047990:TNF Receptor-Associated Factor 1; D047992:TNF Receptor-Associated Factor 2; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; D017252:CD3 Complex; D002352:Carrier Proteins; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D047990:TNF Receptor-Associated Factor 1; D047992:TNF Receptor-Associated Factor 2; D014409:Tumor Necrosis Factor-alpha; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases