Induction of tumor necrosis factor alpha expression in human T lymphocytes following ionizing gamma irradiation.
In this work, we present evidence that enriched human peripheral blood T lymphocytes, depleted of contaminating monocytes, rapidly express tumor necrosis factor alpha (TNF-alpha) mRNA when exposed to low doses of gamma-irradiation. In total PBL, TNF-alpha mRNA accumulation increased threefold as early as 30 minutes following exposure to 4 Gy and then declined to the baseline level by 3-5 h, as measured by the reverse transcriptase-polymerase chain reaction (RT-PCR). The increase in TNF-alpha mRNA was also observed in populations of enriched T cells and decreased when the dose of irradiation was increased to 10 Gy, strongly suggesting that T lymphocytes, the most radiosensitive cells of the body, contributed directly to the increase of TNF-alpha mRNA. A good correlation was found between mRNA expression and TNF-alpha protein secretion. Interestingly, a eightfold increase in glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA accumulation was also detected in both PBL and enriched T cells irradiated at 4 Gy for 3 h compared with unirradiated cells. This irradiation effect was almost completely abolished, however, following exposure to 10 Gy. Together these data suggest that T cells are responsible for the irradiation-induced expression of TNF-alpha and GAPDH.
Weill
D
D
Laboratoire de Génétique Moléculaire et Biologie du Développement, Villejuif, France.
Gay
F
F
Tovey
M G
MG
Chouaib
S
S
D001483:Base Sequence; D002478:Cells, Cultured; D005720:Gamma Rays; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis; D012016:Reference Values; D013601:T-Lymphocytes / Q000378:metabolism / Q000528:radiation effects*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases