Increased production of TGF-beta and Il-6 by aged spleen cells.
Aging is accompanied by a progressive decline in immunity in every species that has been studied. Despite its ubiquity, the causes of immunosenescence are unknown. Transforming growth factor beta (TGF-beta) is a cytokine with potent immunosuppressive properties. Cells from aged mice produce increased levels of TGF-beta in vitro along with similar increases in interleukin 6 (Il-6), a cytokine which is immunosuppressive at elevated concentrations. Il-6 does not upregulate TGF-beta production, but high concentrations of Il-6 increase the percentage of cells expressing the TGF-beta receptor. Increased TGF-beta production and Il-6-induced upregulation of the TGF-beta receptor may be factors contributing to age-associated immunosuppression.
Johns Hopkins School of Medicine, Asthma and Allergy Center, Baltimore, MD.
D
D
Zhou
F J
FJ
Chrest
W
W
Adler
A
A
Munster
R A
RA
Winchurch
D000375:Aging / Q000276:immunology*; D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D007109:Immunity; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D008213:Lymphocyte Activation / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000378:metabolism; D018125:Receptors, Transforming Growth Factor beta; D013154:Spleen / Q000166:cytology / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics; D015854:Up-Regulation
D015850:Interleukin-6; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta