Alteration of ganglioside composition in the erythrocytes associated with Theileria sergenti infection.

The changes in ganglioside composition of bovine erythrocytes associated with Theileria sergenti infection were investigated using the erythrocytes before and after the infection. The erythrocytes before infection with T. sergenti had GM3, sialosylparagloboside (SPG), i-active, and I-active ganglioside as predominant gangliosides. After infection with T. sergenti merozoites, the contents of SPG and i-active ganglioside were slightly less, and I-active ganglioside content was much less in the erythrocytes, though GM3 content did not so vary. The decreased I-active ganglioside content showed a recovery as the parasitemia waned to low level in the infected cattle. The total amount of lipid-bound sialic acid also decreased in the erythrocytes after the infection. Similar changes were also caused by the incubation of liposomes containing ganglioside fraction obtained from bovine erythrocytes with T. sergenti piroplasms. These results suggest that the reduction of the contents of SPG, i-active, and I-active ganglioside on the erythrocytes was related to the T. sergenti infection.