Czop J K, Kadish J L, Zepf D M, Austen K F
J Immunol. 1985 Mar;134(3):1844-50.
The functional opsonic and monocyte adherence domains within the 180,000 m.w. opsonic fibronectin fragment (180K-opFnf) that selectively augments human monocyte phagocytosis of particulate activators of the alternative complement pathway were analyzed with Fab fragments of monoclonal anti-fibronectin antibodies BC7, CE9, BD4, AB3, and CPG1, and with fragments of intact human plasma fibronectin derived by cathepsin cleavage and isolated by affinity chromatography. Monoclonals AB3 and CPG1, which recognize epitopes within 40,000 daltons of the carboxy terminus of intact fibronectin, and the cathepsin D-derived, disulfide-linked fragments that contain these epitopes each inhibited the opsonic function of 180K-opFnf. Monoclonals AB3 and CPG1 inhibited monocyte ingestion of rabbit erythrocytes (Er) by 60 and 50%, respectively, when 180K-opFnf was pretreated with 20 micrograms of these monoclonals, but neither monoclonal affected the enhanced monocyte ingestion of Er pretreated with the fibronectin fragment. The pretreatment of Er with 5 micrograms and 40 micrograms of the disulfide-linked, cathepsin D derivatives isolated from high and low affinity heparin fractions, respectively, inhibited the proportion of ingesting monocytes by 60%, but these types of fragments had little effect when concurrently incubated with the opsonic fragment and Er. Monoclonals CE9 and BD4, which recognize epitopes located adjacent to or within the cell-adhesive domain of intact fibronectin, respectively, inhibited the monocyte adherence function of 180K-opFnf, as evidence by their comparable inhibitory effects when present before or after Er were opsonized with 180K-opFnf. When 20 micrograms of monoclonals CE9 and BD4 were each introduced before and after Er were opsonized with 180K-opFnf, monocyte ingestion was inhibited by 60 and 65% and by 51 and 60%, respectively. At 42 micrograms, cathepsin D-derived, non-gelatin-binding, low affinity heparin fragments that contained both BD4 and CE9 determinants or only the BD4 determinant inhibited monocyte ingestion by 53 and 74%, respectively, when concurrently incubated with 180K-opFnf and target Er, but were without effect when used to pretreat Er before the addition of 180K-opFnf. Thus, the inhibitory effects produced by monoclonals AB3 and CPG1 and by cathepsin D-derived, disulfide-linked fragments containing their corresponding epitopes demonstrated that the opsonic domain within 180K-opFnf is immunologically similar to regions within the carboxy terminus of intact plasma fibronectin.(ABSTRACT TRUNCATED AT 400 WORDS)
对分子量为180,000的调理素型纤连蛋白片段（180K-opFnf）内的功能性调理素和单核细胞黏附结构域进行了分析，该片段可选择性增强人单核细胞对替代补体途径颗粒激活剂的吞噬作用。使用抗纤连蛋白单克隆抗体BC7、CE9、BD4、AB3和CPG1的Fab片段，以及通过组织蛋白酶裂解并经亲和层析分离的完整人血浆纤连蛋白片段进行分析。识别完整纤连蛋白羧基末端40,000道尔顿以内表位的单克隆抗体AB3和CPG1，以及含有这些表位的组织蛋白酶D衍生的二硫键连接片段，均抑制了180K-opFnf的调理素功能。当用20微克这些单克隆抗体预处理180K-opFnf时，单克隆抗体AB3和CPG1分别抑制单核细胞对兔红细胞（Er）的摄取60%和50%，但两种单克隆抗体均不影响用纤连蛋白片段预处理的Er增强的单核细胞摄取。分别用5微克和40微克从高亲和力和低亲和力肝素组分中分离的二硫键连接的组织蛋白酶D衍生物预处理Er，抑制摄取单核细胞的比例达60%，但当与调理素片段和Er同时孵育时，这些类型的片段几乎没有作用。分别识别完整纤连蛋白细胞黏附结构域附近或内部表位的单克隆抗体CE9和BD4，抑制了180K-opFnf的单核细胞黏附功能，在用180K-opFnf调理Er之前或之后存在时，它们具有可比的抑制作用，这证明了这一点。当在用180K-opFnf调理Er之前和之后分别引入20微克单克隆抗体CE9和BD4时，单核细胞摄取分别被抑制60%和65%以及51%和60%。在42微克时，含有BD4和CE9决定簇或仅含BD4决定簇的组织蛋白酶D衍生的非明胶结合低亲和力肝素片段，在与180K-opFnf和靶标Er同时孵育时，分别抑制单核细胞摄取53%和74%，但在加入180K-opFnf之前用于预处理Er时则无作用。因此，单克隆抗体AB3和CPG1以及含有其相应表位的组织蛋白酶D衍生的二硫键连接片段产生的抑制作用表明，180K-opFnf内的调理素结构域在免疫学上与完整血浆纤连蛋白羧基末端的区域相似。（摘要截短至400字）
