Serum soluble interleukin-6 receptor in MRL/lpr mice is elevated with age and mediates the interleukin-6 signal.
The characteristics of soluble interleukin-6 receptor (sIL-6R) in murine sera were examined. To investigate a relationship between serum sIL-6R level and autoimmune diseases, quantitative analysis of serum sIL-6R in MRL/lpr mice was performed by an enzyme-linked immunosorbent assay. The serum sIL-6R level in MRL/lpr mice of both sexes was below the detection limit (< 1.0 ng/ml) at 8 weeks of age, but it increased in accordance with age and reached 42 +/- 9.3 ng/ml in female and 31 +/- 13 ng/ml in male mice at 30 weeks of age. In MRL/+ mice, although an age-associated increase in serum sIL-6R level was observed, it was much less extensive than that in MRL/lpr mice. Elevated serum sIL-6R level at the age of 30 weeks was observed in female and male (NZB x NZW)F1 mice (32 +/- 10 ng/ml and 17 +/- 5.0 ng/ml, respectively), and male BXSB/Mpj Yaa mice (42 +/- 18 ng/ml), suggesting that elevated serum sIL-6R in aged mice is one of the characteristics of autoimmune-prone mice. Quantitative analysis of serum IL-6 in MRL/lpr revealed that the serum sIL-6R level correlated well with the serum IL-6 level. We also showed that sIL-6R in the sera from MRL/lpr mice could mediate the IL-6 functions through the IL-6 signal-transducing receptor component gp130, suggesting that elevated production of sIL-6R may partly contribute to development of autoimmune disease in MRL/lpr mice.
Suzuki
H
H
Biotechnology Research Laboratory, Tosoh Corporation, Kanagawa, Japan.
Yasukawa
K
K
Saito
T
T
Narazaki
M
M
Hasegawa
A
A
Taga
T
T
Kishimoto
T
T
D000375:Aging / Q000276:immunology*; D000818:Animals; D001327:Autoimmune Diseases / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015850:Interleukin-6 / Q000097:blood / Q000494:pharmacology*; D008232:Lymphoproliferative Disorders / Q000097:blood*; D008297:Male; D051379:Mice; D008806:Mice, Inbred AKR; D008810:Mice, Inbred C57BL; D008814:Mice, Inbred NZB; D011971:Receptors, Immunologic / Q000032:analysis* / Q000502:physiology; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins / Q000494:pharmacology
D015850:Interleukin-6; D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins