ヒト赤血球上のA型抗原局在に関する免疫電子顕微鏡学的観察

Abstract

Using immuno-electron microscopical method, the localization of the A antigen sites on human erythrocytes was demonstrated.It was shown that the A antigen sites are evenly distributed on a red cell. They are so numerous that no space seems to remain between adjacent antigen sites. In the examination using the diluted conjugates, however, the distribution of ferritin particles on the cells was diffuse and random. This suggests that the individual antigen sites on a cell were not equally capable to bind antibody.In the experiments on the subgroup or variant, it was noted that A2 cells have fewer than have A1 cells and Ax cells have fewer than have A2 cells, when A1 cells were compared with A2 or Ax cells in the degree of the A antigen sites, and that the attached ferritin particles indicating the A site positions conspicuously varied in number from cell to cell in the same specimen. This indicate that the different serological behaviour of A1, A2 and Ax cells in tests with anti-A reagents are due to both of a quantitative and a qualitative difference.In the umbilical cord blood, red cells in the same specimen were divided into four populations according to the number of the A antigen sites on the cell. It was perceived that the specimen from umbilical cord consists in the following ratio of red cell numbers in each population; I (possessing A antigen sites of about 5×105 or more) 18%, II (possessing 2×105-4×105 sites) 29%, III (possessing the sites of about 105) 28%, IV (possessing 0-104 sites) 25%.