β2-glycoprotein I complexed with MHC class II molecules are involved in the pathogenesis of antiphospholipid syndrome

β2-Glycoprotein I/HLA class II complexes are novel autoantigens in antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thrombosis and/or pregnancy complications. β2-glycoprotein I (β2GPI) complexed with phospholipid is recognized as a major target for autoantibodies in APS; however, less than half the patients with clinical manifestations of APS possess autoantibodies against the complexes. Therefore, the range of autoantigens involved i...

Structural Changes in β2-Glycoprotein I and the Antiphospholipid Syndrome

Revisiting Beta 2 Glycoprotein I, the Major Autoantigen in the Antiphospholipid Syndrome

Beta 2 glycoprotein I (β2GPI) is a single chain 50 kDa highly glycosylated glycoprotein at an approximate concentration of 4 μM in cells. The abundance of this protein in plasma and its high state of preservation indicate the important role of this protein in mammalian. In addition, β2GPI has a particular structure in the fifth domain, and is categorized as the major antigen recognized by autoa...

IgG Autoantibodies against β2-Glycoprotein I Complexed with a Lipid Ligand Derived from Oxidized Low-Density Lipoprotein are Associated with Arterial Thrombosis in Antiphospholipid Syndrome

We recently reported [J. Lipid Res. 42 (2001), 697; 43 (2002), 1486; 44 (2003), 716] that [beta2-glycoprotein I (beta2GPI) forms complexes with oxidized LDL (oxLDL) and autoantibodies against these complexes are present in patients with SLE and antiphospholipid syndrome (APS). The relationship of beta2GPI/oxLDL complexes and IgG autoantibodies against beta2GPI complexed with oxLig-1 (an oxLDL-d...

Reconstitution of class I MHC molecules expressed in E. coli and complexed with single antigenic peptides.

The HLA-Cw3 heavy chain has been expressed at high level as insoluble protein aggregates in E. coli. The protein aggregates dissolved in strong denaturant solution were efficiently reconstituted by removal of denaturant in the presence of an HLA-Cw3 binding peptide (FAM) and beta 2m. The reconstituted HLA-Cw3/FAM protein binds specifically to a p58 natural killer cell inhibitory receptor, a nat...