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Circulating immune complexes (CIC) containing low density lipoprotein (LDL) were recently found in the blood of patients with coronary atherosclerosis. In the present study, we investigated the chemical composition and physical characteristics of the lipoprotein constituents of these CIC. CIC were isolated from the blood of atherosclerotic patients by affinity chromatography using anti-human immunoglobulin G-agarose. Low density lipoprotein of these complexes (CIC-LDL) was obtained by ultracentrifugation. CIC-LDL was compared with free circulating LDL isolated from the blood plasma of the same patients. Plasma LDL was fractionated by lectin-chromatography on RCA120-agarose to obtain desialylated LDL (atherogenic) and sialylated LDL (nonatherogenic). Both CIC-LDL and desialylated LDL, but not native (sialylated) lipoprotein, induced a 1.8- to 3-fold increase in the intracellular contents of free and esterified cholesterol of cells cultured from grossly normal areas of human aorta. The sialic acid level in CIC-LDL was 1.3- and 2.1-fold lower than in desialylated or native LDL, respectively. The neutral lipid and phospholipid contents of CIC-LDL and desialylated LDL were reduced as compared to native LDL. The levels of lipid-oxidation products, thiobarbituric acid-reactive substances and hydroperoxides, were similar in all lipoprotein preparations. However, desialylated LDL and CIC-LDL had an elevated oxysterol content. Gradient ultracentrifugation revealed that CIC-LDL particles had a higher density than native LDL. The mean diameters of native, desialylated and CIC-LDL accounted for 24.0, 21.3 and 19.5 nm, respectively. Like desialylated LDL, CIC-LDL displayed a higher electrophoretic mobility compared with that of native LDL. Thus, LDL obtained from circulating immune complexes appears to be a multiple-modified lipoprotein possessing many similarities to desialylated LDL. It was also found that the LDL content of circulating immune complexes correlates well with the desialylated LDL level in human plasma but not with the total LDL concentration. We believe that desialylated LDL predominately interacts with antibodies forming immune complexes. Taken together, our findings suggest that multiple-modified desialylated LDL is the circulating autoantigen for anti-LDL autoantibodies.
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
January 2013,
Journal of immunoassay & immunochemistry,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
January 2014,
BioMed research international,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
February 1985,
Mechanisms of ageing and development,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
February 2013,
Journal of clinical immunology,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
January 1993,
Neoplasma,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
August 1980,
Kardiologiia,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
July 2018,
Hormone molecular biology and clinical investigation,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
January 1976,
Acta biologica Academiae Scientiarum Hungaricae,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
September 1988,
The Journal of experimental medicine,
V V Tertov, and
I A Sobenin, and
A N Orekhov, and
O Jaakkola, and
T Solakivi, and
T Nikkari
July 2014,
International journal of molecular sciences,
