Johnson E, Eskeland T, Bertheussen K
Scand J Immunol. 1984 Jan;19(1):31-9. doi: 10.1111/j.1365-3083.1984.tb00897.x.
The phagocytosis of particles activating the alternative pathway of complement by human monocytes cultured under serum-free conditions was studied. In contrast to native zymosan particles, which were easily ingested, rabbit erythrocytes and agarose beads had to be coated with C3b or C3bi to be engulfed by the monocytes. The binding and ingestion by monocytes of particles coated with C3bi were greater than for the same particles coated with the equivalent amount of C3b. The binding and uptake of rabbit erythrocytes and agarose beads were proportional to the amount of C3b or C3bi on the particles. In contrast to the complement activator particles, C3b- and C3bi-coated sheep erythrocytes, which are non-activators, were not ingested by the monocytes, although attachment to the monocytes took place. The presence of methylamine or cobra venom factor, which are complement inhibitors, strongly reduced the ingestion of native zymosan by the monocytes, whereas the uptake of C3b- or C3bi-coated zymosan particles were only weakly affected. This suggests that the binding of native zymosan to monocytes is sensitive to interference from a cell-derived alternative pathway C3 convertase (C3bBb). Binding and uptake of activators by human monocytes via complement receptor(s) are discussed.
研究了在无血清条件下培养的人单核细胞对激活补体替代途径的颗粒的吞噬作用。与易于摄取的天然酵母聚糖颗粒不同，兔红细胞和琼脂糖珠必须用C3b或C3bi包被才能被单核细胞吞噬。单核细胞对包被有C3bi的颗粒的结合和摄取大于对包被等量C3b的相同颗粒的结合和摄取。兔红细胞和琼脂糖珠的结合和摄取与颗粒上C3b或C3bi的量成正比。与补体激活剂颗粒不同，作为非激活剂的包被有C3b和C3bi的绵羊红细胞虽然会与单核细胞发生附着，但不会被单核细胞摄取。补体抑制剂甲胺或眼镜蛇毒因子的存在强烈降低了单核细胞对天然酵母聚糖的摄取，而包被有C3b或C3bi的酵母聚糖颗粒的摄取仅受到微弱影响。这表明天然酵母聚糖与单核细胞的结合对细胞源性替代途径C3转化酶（C3bBb）的干扰敏感。讨论了人单核细胞通过补体受体对激活剂的结合和摄取。
