TY - JOUR
T1 - Requirement for calcium ions in antibody-dependent complement-mediated cytolysis of toxoplasma gondii
AU - Suzuki, Yasuhiro
AU - Kobayashi, Akio
PY - 1985
Y1 - 1985
N2 - The mechanism of antibody-dependent complement-mediated cytolysis of Toxoplasma organisms was studied by using a selective chelating agent for Ca++, ethyleneglycol-bis (β-aminoethyl ether)-N,N-tetraacetic acid (EGTA). Toxoplasma organisms were lysed by treatment with human serum containing anti-Toxoplasma antibodies and with fresh human-plasma at 37°C for 1 h. The reaction was prevented by heat treatment of the fresh plasma at 56°C for 30 min, confirming that the cytolysis of Toxoplasma organisms had been mediated by an activation of complement. The lytic reaction was completely inhibited by an addition of EGTA at final concentrations of more than 2.5 mM. Addition of Ca++ cleared the inhibitory effect of EGTA on the reaction. These results demonstrate that the antibody-dependent complement-mediated cytolysis of Toxoplasma organisms requires the presence of Ca++, indicating that the reaction is mediated by an activation of the classical complement pathway.
AB - The mechanism of antibody-dependent complement-mediated cytolysis of Toxoplasma organisms was studied by using a selective chelating agent for Ca++, ethyleneglycol-bis (β-aminoethyl ether)-N,N-tetraacetic acid (EGTA). Toxoplasma organisms were lysed by treatment with human serum containing anti-Toxoplasma antibodies and with fresh human-plasma at 37°C for 1 h. The reaction was prevented by heat treatment of the fresh plasma at 56°C for 30 min, confirming that the cytolysis of Toxoplasma organisms had been mediated by an activation of complement. The lytic reaction was completely inhibited by an addition of EGTA at final concentrations of more than 2.5 mM. Addition of Ca++ cleared the inhibitory effect of EGTA on the reaction. These results demonstrate that the antibody-dependent complement-mediated cytolysis of Toxoplasma organisms requires the presence of Ca++, indicating that the reaction is mediated by an activation of the classical complement pathway.
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U2 - 10.1016/S0176-6724(85)80044-4
DO - 10.1016/S0176-6724(85)80044-4
M3 - Article
C2 - 4050198
AN - SCOPUS:0021797424
SN - 0176-6724
VL - 259
SP - 426
EP - 431
JO - International Journal of Medical Microbiology
JF - International Journal of Medical Microbiology
IS - 3
ER -