Effects of lysolecithin and synthetic analogs on concanavalin A induced agglutination of chicken, human and bovine erythrocytes

Abstract

The influence of sublytic amounts of lysolecithin upon the agglutinability of chicken, human and bovine erythrocytes by concanavalin A (Con A) has been investigated. The following results have been obtained: 1. 1. Of the 3 cell types tested, only chicken red cells can be stimulated by lysolecithin treatment to agglutinate faster than control cells. 2. 2. Human and bovine red cells in their native state are not affected by lysolecithin with respect to Con A agglutinability. Both of these cells, however, become highly sensitive to lysolecithin when they are pretreated with trypsin or, as in the case of human red cells, with neuraminidase from V. cholerae. 3. 3. The effects of lysolecithin may be imitated by synthetic analogs which are unaffected by membrane enzymes, involved in the lysolecithin turnover. The observed membrane-effects must hence be due to a direct physical interaction of the lysolecithin molecule with the erythrocyte membrane. 4. 4. The lysophosphatide induced membrane alterations are highly dose dependent with an optimal acceleration of agglutination rates at lysolecithin concentrations as low as 1 nmole/10 8 cells. Con A binding to the cells is unaltered in the presence or absence of lysophosphatide. The data are discussed in relation to the current hypothesis that the cellular agglutinability by Con A may be related to the degree of mobility of Con A membrane receptors.