Mice lacking serum amyloid P component do not necessarily develop severe autoimmune disease.
Serum amyloid P component (SAP) is a major acute-phase reactant in mice. Recently, it was reported that SAP-deficient mice spontaneously developed anti-nuclear antibodies and severe glomerulonephritis. Because the SAP-deficient mice we generated display no obvious phenotypic abnormalities, we investigated whether our SAP-deficient mice would also spontaneously develop autoimmune responses. In accordance with the report, our mice produced high titers of anti-nuclear antibody but did not develop severe glomerulonephritis. On the other hand, it was recently reported that SAP bound to gram-negative bacteria via lipopolysaccharide (LPS) prevented LPS-mediated activation of a classical complement pathway. Thus, we asked if SAP-deficient mice would show altered responses to an intraperitoneal injection of LPS from Salmonella typhimirium. SAP-deficiency did afford resistance to lethality induced by high-dose LPS. Our experiments clearly showed that contrary to documented data, SAP-deficient mice do not develop serious autoimmune disease and we suggest that SAP has a critical role in LPS toxicity.
Soma
M
M
First Department of Biochemistry, Yamanashi Medical University, 1110 Shimokato, Tamaho-cho, Nakakoma-gun, Yamanashi 409-3898, Japan.
Tamaoki
T
T
Kawano
H
H
Ito
S
S
Sakamoto
M
M
Okada
Y
Y
Ozaki
Y
Y
Kanba
S
S
Hamada
Y
Y
Ishihara
T
T
Maeda
S
S
D000818:Animals; D001327:Autoimmune Diseases / Q000235:genetics / Q000503:physiopathology*; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D008070:Lipopolysaccharides / Q000008:administration & dosage; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D012486:Salmonella typhimurium / Q000378:metabolism; D000683:Serum Amyloid P-Component / Q000235:genetics / Q000502:physiology*
D017931:DNA Primers; D008070:Lipopolysaccharides; D000683:Serum Amyloid P-Component