| abstract |
An experimental model animal by which type III allergic inflammation can be exclusively evaluated without affected by type I allergy, since it does not suffer from anaphylaxis (i.e., type I allergy) but can specifically undergo an Arthus reaction (i.e., type III allergy); and a method of screening a substance promoting or inhibiting a type III allergic reaction mediated by FcRIII by using this experimental model animal. To eliminate FcRIIB exerting an inhibitory effect on the FcRIII-mediated response, a mouse (LynIIB) carrying deletion mutations of Lyn and FcRIII as a homozygote is constructed by crossing a Lyn-knockout mouse (Lyn-/-) and an FcRIIB-knockout mouse (FcRI IB- /-). Thus, the defect in the Fc.gamma.RIII function in systemic passive anaphylaxis, lessening in the FcRIII function in bone marrow-origin mast cells, etc. are measured and evaluated. |