ヒトprotein Sに対するモノクローナル抗体NMC-PS/1およびNMC-PS/2の免疫学的特性

Abstract

Two monoclonal antibodies against human protein S (PS) were obtained. One (NMC-PS/1) belonged to IgM and the other (NMC-PS/2) was IgG₁. NMC-PS/1 did not interfere with the activity of PS but NMC-PS/2 did interfere. Both of the antibodies combined to PS, C₄bp-PS, and thrombin modified PS with or without Ca and EDTA. But after SDS treatment they did not react with PS, C₄bp-PS and thrombin-modified PS. About 50ml of PS deficient plasma was made from pooled plasma by immuno-depletion using 3 mg of NMC-PS/2. Enzyme-linked immunosorbent assays (ELISA) for total PS and PS antigen complexed with C₄bp using NMC-PS/2 monoclonal antibodies were established. The detection limit was approximately 0.4 U/dl. Using ELISA method by NMC-PS/2, chronological changes of levels of total PS and C₄bp-PS through the first 0-6 days of life were measured. On 0 day after birth the PS value was 24.68±4.49 U/dl and that of C₄bp-PS antigen was 16.55±14.02 U/dl. Both antigens increased gradually day by day. Plasma of neonatal melena were examined by the same method and no differnce from plasma of nomal neonates was found.