Sorvillo J M, Gigli I, Pearlstein E
J Immunol. 1986 Feb 1;136(3):1023-6.
In the past several years, it has been demonstrated that plasma fibronectin (Fn) binds to the C1q subunit of the complement system. The effect of Fn on the processing of immune complexes containing C1q and C3b by human peripheral blood monocytes was investigated. Preincubation of monocytes with Fn causes a significant increase in attachment of sheep erythrocytes coated with IgM and C1q (EIg-MC1q), but does not mediate their ingestion. EIg-MC1q attach to the Fn-treated monocytes via the C1q receptor because Fab anti-Fn antibodies do not inhibit their attachment to the monocytes. In addition, Fn-treated monocytes exhibit no change in C1q receptor number or affinity compared with monocytes treated with buffer. Fn mediates the phagocytosis of C3b/bi-coated particles, and C1q can enhance this process in two ways. First, phagocytosis of particles bearing C3b/bi and Fn is enhanced by the presence of C1q on the immune complex. Second, monocytes on Fn-coated surfaces ingest more particles if they are coated with both C3b/bi and C1q, compared with particles coated with either C3b/bi or C1q alone.
在过去几年中，已证实血浆纤连蛋白（Fn）可与补体系统的C1q亚基结合。研究了Fn对人外周血单核细胞处理含C1q和C3b免疫复合物的影响。单核细胞与Fn预孵育会导致包被有IgM和C1q的绵羊红细胞（EIg-MC1q）的黏附显著增加，但不介导其摄取。EIg-MC1q通过C1q受体附着于经Fn处理的单核细胞，因为抗Fn抗体的Fab片段不抑制其与单核细胞的黏附。此外，与用缓冲液处理的单核细胞相比，经Fn处理的单核细胞在C1q受体数量或亲和力方面没有变化。Fn介导C3b/bi包被颗粒的吞噬作用，C1q可通过两种方式增强这一过程。第一，免疫复合物上存在C1q可增强携带C3b/bi和Fn颗粒的吞噬作用。第二，与仅包被有C3b/bi或C1q的颗粒相比，在Fn包被表面的单核细胞摄取同时包被有C3b/bi和C1q的颗粒更多。
