Resialylation of sialidase-treated sheep and human erythrocytes by Trypanosoma cruzi trans-sialidase: restoration of complement resistance of desialylated sheep erythrocytes.
Trypanosoma cruzi trans-sialidase (TS) is a recently described enzyme which transfers alpha(2-3)-linked sialic acid from host-derived sialylated glycoconjugates to parasite surface molecules [Schenkman et al. (1991) Cell, 65, 1117]. We report here on the ability of TS to transfer sialic acid from donor sialyl-alpha(2-3)lactose to sialidase-treated sheep and human erythrocytes. Up to approximately 50% resialylation of both desialylated red cells could be attained. Resialylation of desialylated sheep erythrocytes restores their resistance to lysis by human complement. This ascribes a possible biological role for T. cruzi TS and demonstrates directly that sialic acid is solely responsible for preventing alternative pathway activation of human complement by sheep erythrocytes.
Tomlinson
S
S
Department of Pathology, New York University Medical Center, NY 10016.
Pontes de Carvalho
L
L
Vandekerckhove
F
F
Nussenzweig
V
V
D000818:Animals; D003165:Complement System Proteins / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D006023:Glycoproteins; D006461:Hemolysis; D006801:Humans; D019158:N-Acetylneuraminic Acid; D009439:Neuraminidase / Q000378:metabolism*; D011817:Rabbits; D012756:Sheep; D012794:Sialic Acids / Q000097:blood*; D014734:Vibrio cholerae / Q000201:enzymology
D006023:Glycoproteins; D012794:Sialic Acids; D003165:Complement System Proteins; C069715:trans-sialidase; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid