Heterogeneous responses and cross reactivity between the major peanut allergens Ara h 1, 2,3 and 6 in a mouse model for peanut allergy.

Background: The relative contribution and the relation between individual peanut allergens in peanut allergic responses is still matter of debate. We determined the individual contribution of peanut proteins to B, T cell and allergic effector responses in a mouse model for peanut allergy.

Methods: Mice were immunized and challenged by oral gavage with peanut protein extract or isolated allergens Ara h 1, 2, 3 and 6 followed by assessment of food allergic manifestations.

Optimisation of lupus anticoagulant tests: should test samples always be mixed with normal plasma?

Coagulation factor deficiencies are thought to interfere with the detection of the phospholipid-dependent coagulation inhibitor known as lupus anticoagulant (LA). Treatment with vitamin K antagonists (VKA) in particular, is thought to preclude accurate LA assessment. For this reason, the procedure to detect LA includes a mixing test, in which coagulation factor deficiencies are corrected by mixing samples with an equal volume of normal plasma.

Apolipoprotein E receptor 2 is involved in the thrombotic complications in a murine model of the antiphospholipid syndrome.

Antiphospholipid (aPL)/anti-β(2) glycoprotein I (anti-β(2)GPI) antibodies stimulates tissue factor (TF) expression within vasculature and in blood cells, thereby leading to increased thrombosis. Several cellular receptors have been proposed to mediate these effects, but no convincing evidence for the involvement of a specific one has been provided. We investigated the role of Apolipoprotein E receptor 2 (ApoER2') on the pathogenic effects of a patient-derived polyclonal aPL IgG preparation (IgG-APS), a murine anti-β(2)GPI monoclonal antibody (E7) and of a constructed dimeric β(2)GPI I (dimer), which in vitro mimics β(2)GPI-antibody immune complexes, using an animal model of thrombosis, and ApoER2-deficient (-/-) mice.

Pathogenic anti-beta2-glycoprotein I antibodies recognize domain I of beta2-glycoprotein I only after a conformational change.

Recently, we published the existence of 2 populations of anti-beta2-glycoprotein I (beta2-GPI) IgG antibodies. Type A antibodies recognize epitope G40-R43 in domain I of beta2-GPI and are strongly associated with thrombosis. Type B antibodies recognize other parts of beta2-GPI and are not associated with thrombosis.

The binding site in {beta}2-glycoprotein I for ApoER2' on platelets is located in domain V.

The antiphospholipid syndrome is caused by autoantibodies directed against beta(2)-glycoprotein I (beta(2)GPI). Dimerization of beta(2)GPI results in an increased platelet deposition to collagen. We found that apolipoprotein E receptor 2' (apoER2'), a member of the low density lipoprotein receptor family, is involved in activation of platelets by dimeric beta(2)GPI.