Crosslinking of ANCA-antigens stimulates superoxide release by human neutrophils.
Crosslinking of ANCA-antigens stimulates superoxide release by human neutrophils.
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发表时间：
1997-03
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通讯作者：
R. Kettritz;J. Jennette;R. Falk
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作者：
R. Kettritz;J. Jennette;R. Falk
抗中性粒细胞胞浆抗体（ANCA）在体外激活致敏的人多形核中性粒细胞（PMN），导致呼吸爆发和脱粒。在本研究中，探索了以下假设：该过程的启动需要ANCA的F（ab '）2部分的参与，以及ANCA靶抗原的交联对于触发超氧化物（O2-）释放是必要的。据推测，Fc γ受体结合是ANCA介导的活化的调节剂。流式细胞术证实完整的人ANCA免疫球蛋白（IG）、其相应的F（ab '）2和Fab片段以及针对人PR 3的鼠单克隆抗体及其F（ab'）2片段与用肿瘤坏死因子（TNF）α致敏的PMN表面上的ANCA抗原结合。PR 3-ANCA或MPO-ANCA患者的完整IG刺激TNF α致敏的正常PMN释放O2-（2.6 +/- 3.57至15.3 +/- 7.39 nmol O2-/2.5 x 10（6）PMN/30 min）。相应的F（ab '）2片段以剂量依赖性方式导致类似的O2-产生（10.2 +/- 4.34至36.9 nmol）。ANCA Fab片段不刺激O2-生成，直到这些片段与山羊抗人IG F（ab '）2的F（ab'）2交联，或当片段被生物素化并与抗生物素蛋白交联时。与这些人自身抗体数据相反，小鼠单克隆抗人PR 3抗体（25.7 +/- 8.55 nmol O2-），而不是其相应的F（ab '）2片段，激活TNF α处理的人PMN。当Fc γ IIa受体被阻断时，使用人PR 3-ANCA IG，超氧化物的产生减少了33%（P < 0.05）。总之，当完整的ANCA或ANCA F（ab '）2片段与中性粒细胞表面的靶抗原交联时，发生ANCA对PMN的活化。ANCA F（ab '）片段在与二级试剂交联时导致PMN活化。
Anti-neutrophil cytoplasmic antibodies (ANCA) activate primed human polymorphonuclear neutrophils (PMN) in vitro, resulting in a respiratory burst and degranulation. In this study, the hypotheses that the initiation of this process requires engagement of the F(ab')2 portion of ANCA, and that crosslinking of ANCA target antigens is necessary to trigger superoxide (O2-) release, were explored. It is speculated that Fc gamma receptor engagement is a modulator of ANCA-mediated activation. Flow cytometry demonstrated that intact human ANCA immunoglobulin (Ig), their corresponding F(ab')2 and Fab fragments, as well as a murine monoclonal to human PR3 and its F(ab')2 fragment, bind to ANCA antigens on the surface of PMN primed with tumor necrosis factor (TNF) alpha. Intact Ig of patients with PR3-ANCA or with MPO-ANCA stimulate O2- release from TNF alpha-primed normal PMN (2.6 +/- 3.57 to 15.3 +/- 7.39 nmol O2-/2.5 x 10(6) PMN/30 min). Corresponding F(ab')2 fragments result in similar O2- production (10.2 +/- 4.34 to 36.9 nmol) in a dose-dependent manner. ANCA Fab fragments do not stimulate O2- generation until these fragments are crosslinked with F(ab')2 of goat anti-human Ig F(ab')2, or when fragments are biotinylated and crosslinked with avidin. In contrast with these human autoantibody data, a mouse monoclonal anti-human PR3 antibody (25.7 +/- 8.55 nmol O2-), but not its corresponding F(ab')2 fragment, activates TNF alpha-treated human PMN. When the Fc gamma IIa receptors were blocked, superoxide production was reduced by 33% using human PR3-ANCA Ig (P < 0.05). In conclusion, PMN activation by ANCA occurs when intact ANCA or ANCA F(ab')2 fragments crosslink target antigens on the neutrophil cell surface. ANCA F(ab') fragments result in PMN activation when crosslinked by secondary reagents.