Abstract
Peripheral T cells are resistant to Fas receptor (FasR/CD95)-mediated apoptosis. After prolonged treatment with interleukin-2 (IL-2), these T cells develop a Fas-sensitive phenotype. To clarify the molecular mechanism of apoptosis susceptibility, mRNA expression of FasR-associated proteins [Fas-associating protein with death domain (FADD), receptor-interacting protein (RIP), and Fas-associated phosphatase-1 (FAP-1)] has been investigated in IL-2 activated T cells. Competitive reverse transcriptase-polymerase chain reaction analysis revealed that FADD and RIP mRNA were equally expressed in freshly isolated resting T cells and IL-2-activated T cells. In contrast, FAP-1 mRNA was produced more abundantly by Fas-resistant resting T cells than by Fas-sensitive activated T cells. These findings suggested that sensitivity to FasR-mediated apoptosis in T cells could be correlated with down-regulation of FAP-1 expression. Additionally, CD45RO+ memory T cells expressed a larger amount of FAP-1 mRNA than did CD45RA+ naive T cells.
MeSH terms
- Adaptor Proteins, Signal Transducing*
- Apoptosis
- Carrier Proteins / biosynthesis*
- Carrier Proteins / genetics
- Cells, Cultured
- Down-Regulation*
- Fas Ligand Protein
- Fas-Associated Death Domain Protein
- Gene Expression
- Humans
- Interleukin-2 / pharmacology*
- Lymphocyte Activation / physiology*
- Membrane Glycoproteins / metabolism
- Mitogens / pharmacology
- Protein Phosphatase 1
- Protein Tyrosine Phosphatase, Non-Receptor Type 13
- Protein Tyrosine Phosphatases / biosynthesis*
- Protein Tyrosine Phosphatases / genetics
- Proteins / genetics
- RNA, Messenger
- Receptor-Interacting Protein Serine-Threonine Kinases
- T-Lymphocytes / drug effects
- T-Lymphocytes / metabolism*
Substances
- Adaptor Proteins, Signal Transducing
- Carrier Proteins
- FADD protein, human
- FASLG protein, human
- Fas Ligand Protein
- Fas-Associated Death Domain Protein
- Interleukin-2
- Membrane Glycoproteins
- Mitogens
- Proteins
- RNA, Messenger
- RIPK1 protein, human
- Receptor-Interacting Protein Serine-Threonine Kinases
- Protein Phosphatase 1
- PTPN13 protein, human
- Protein Tyrosine Phosphatase, Non-Receptor Type 13
- Protein Tyrosine Phosphatases