哪个句子正确？

1、Sialylated Fc, present in low quantities in intravenous immune globulin, binds to SIGN-R1 on macrophages, resulting in the release of soluble mediators. These mediators bind to effector macrophages and increase expression of the inhibitory FcγR receptors, which compete with antigen–antibody complex binding to activating FcγRs.

2、Sialylated Fc, present in low quantities in intravenous immune globulin, binds to SIGN-R1 on macrophages, resulting in the release of soluble mediators. These mediators bind to effector macrophages and increase expression of the inhibitory FcγRIIB receptors, which compete with activating FcγRs binding to antigen–antibody complex

1、2两句的红字部分内容完全不同。

1、它与抗原-抗体复合物竞争结合激活的 FcγR。

2、它与激活的 FcγR竞争结合抗原-抗体复合物。

1是原文，2是我修改的。抗原-抗体复合是指抗体与抗原形成的复合物，在此复合物中，抗体的Fc段可与 FcγR及 FcγRIIB受体结合。 而句子1中说 FcγRIIB受体与抗原-抗体复合物竞争结合激活的 FcγR受体。这不符合医学知识吧。你认为呢？请指正。