Development of a sandwich ELISA for evaluating soluble OX40L (CD252) in human sera of different ages or with Graves' disease.
ABSTRACT OX40 ligand (CD252), a molecule originally identified as human gp34, is an important costimulatory molecule during immune response. Here, we describe a sandwich ELISA for the detection and quantification of soluble OX40L using anti-OX40L monoclonal antibodies 1G1 and 4C12 as capture and detecting antibody, respectively. With this ELISA, the existence and concentration of soluble forms of OX40L (sOX40L) was demonstrated for the first time. It was found that soluble OX40L is detectable in the sera of elderly persons (above 60 years old) and patients with Graves' disease which has the highest mean serum concentration of sOX40L, suggesting the potential diagnostic significance of sOX40L in the disease. Surprisingly, the quantitation of sOX40L was correlated with the age and among these subjects, those of 70s and 80s have much higher sOX40L concentration than those of 60s.
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ABSTRACT: Recently, we have demonstrated that human platelets carry preformed CD40 ligand (CD154) molecules, which rapidly appear on the platelet surface following stimulation by thrombin. Once on the surface, platelet CD154 induces an inflammatory reaction of CD40-bearing endothelial cells. This study shows that strong platelet agonists other than thrombin also lead to the expression of CD154 on the platelet surface. At the same time, several lines of evidence are presented that together indicate that thrombotic events in the vasculature are generally accompanied by activation of the inflammatory potential of platelet CD154. This study also reports the constitutive expression of CD40, the receptor for CD154, on platelets. The binding of CD154 to coexpressed CD40 in the platelet aggregate leads within minutes to hours to the cleavage of membrane-bound surface CD154 and the release of an 18-kd soluble form of the molecule. Soluble CD154 (sCD154), in contrast to transmembrane CD154, can no longer induce an inflammatory reaction of endothelial cells. These findings indicate that the interaction of platelet CD154 with CD40 on neighboring cells is temporally limited to prevent an uncontrolled inflammation at the site of thrombus formation. Thus, similar to the very tight regulation of the CD154-CD40 interaction in the immune system, an effective mechanism controls the inflammatory potential of platelet CD154 in the vascular system. (Blood. 2001;98:1047-1054)Blood 09/2001; 98(4):1047-54. · 9.06 Impact Factor
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ABSTRACT: Ath1 is a quantitative trait locus on mouse chromosome 1 that renders C57BL/6 mice susceptible and C3H/He mice resistant to diet-induced atherosclerosis. The quantitative trait locus region encompasses 11 known genes, including Tnfsf4 (also called Ox40l or Cd134l), which encodes OX40 ligand. Here we report that mice with targeted mutations of Tnfsf4 had significantly (P <or= 0.05) smaller atherosclerotic lesions than did control mice. In addition, mice overexpressing Tnfsf4 had significantly (P <or= 0.05) larger atherosclerotic lesions than did control mice. In two independent human populations, the less common allele of SNP rs3850641 in TNFSF4 was significantly more frequent (P <or= 0.05) in individuals with myocardial infarction than in controls. We therefore conclude that Tnfsf4 underlies Ath1 in mice and that polymorphisms in its human homolog TNFSF4 increase the risk of myocardial infarction in humans.Nature Genetics 05/2005; 37(4):365-72. · 35.21 Impact Factor
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ABSTRACT: To measure soluble CD40 ligand (sCD40L) in sera from patients with systemic lupus erythematosus (SLE) and to study the functional capacity of sCD40L in mediating B cell activation. A 2-site enzyme-linked immunosorbent assay (ELISA) was used to measure sCD40L in the sera of 66 SLE patients, 30 disease control patients, and 23 healthy subjects. Induction of B cell activation antigen expression was used to assess the functional capacity of sCD40L in SLE sera. The mean concentration of sCD40L was statistically significantly higher (P < 0.0001) in SLE patients than in disease controls or healthy subjects, and segregation of SLE patients by severe, moderate, or mild extent of disease showed a relationship between disease severity and sCD40L concentration. Western blot analysis demonstrated the presence of the 18-kd band of sCD40L in SLE sera, and the results of a 1-site ELISA protocol suggested that some of the product in SLE sera was present in dimer or trimer form. Functional studies showed that 10 ng/ml of recombinant CD40L, a level present in some SLE sera, induced increased expression of CD95 on B cells. Several SLE sera also induced CD95 or CD86 on Ramos B cells, a result that was inhibited by anti-CD40L monoclonal antibodies. The soluble form of CD40L is present in the sera of most patients with SLE and may have the capacity to mediate B cell activation. Aberrant expression of CD40L might be predicted to result in activation of bystander B cells, including those that have encountered self antigens, and to contribute to autoantibody secretion.Arthritis & Rheumatology 05/1999; 42(5):871-81. · 7.48 Impact Factor