Phagocytosis of bacteria by macrophages: changing the carbohydrate of lipopolysaccharide alters interaction with complement and macrophages.
Phagocytosis of bacteria by macrophages: changing the carbohydrate of lipopolysaccharide alters interaction with complement and macrophages.
复制标题
巨噬细胞对细菌的吞噬作用：改变脂多糖的碳水化合物会改变与补体和巨噬细胞的相互作用。
作者：
C. Liang;P. Mäkelä;L. Leive
沙门氏菌的转导子和重组子的脂多糖的O-抗原侧链不同，以不同的速率被鼠巨噬细胞样细胞系J774吸收。在O-抗原侧链中含有阿贝戈糖、甘露糖、鼠李糖和半乳糖的细菌以最慢的速率摄取;含有泰维糖而不是阿贝戈糖的细菌以中等速率摄取;含有甘露糖、N-乙酰葡糖胺和葡萄糖而不是上述序列的细菌以最高速率摄取。这些速率与这些菌株的已知毒力密切相关;毒性最强的是吸收最慢的，以中等速率吸收的是毒性较小的，而吸收最快的是毒性最小的。摄食率的差异反映了细菌对巨噬细胞的亲和力的差异，而不是相互作用发生后的摄食率，这表明了受体介导的过程。大多数摄取可能依赖于补体，如通过在56 ℃下加热或通过与酵母聚糖孵育破坏血清组分的需要所示。不需要特异性抗体。因此，我们推测，在体内的相对毒力可能反映了细菌脂多糖的多糖激活补体的相对能力，从而确定了通过吞噬细胞的补体受体摄取的细菌的易感性。
Salmonella transductants and recombinants differing the O-antigenic side chain of their lipopolysaccharide are taken up at different rates by the murine macrophage-like cell line J774. Bacteria containing abequose, mannose, rhamnose, and galactose in O-antigenic side chain were taken up at the slowest rate; the one containing tyvelose instead of abequose was taken up at an intermediate rate; and the one containing mannose, N-acetylglucosamine, and glucose, instead of the above sequence, was taken up at the highest rate. These rates correlate well with the known virulence of these strains; the most virulent is the one taken up slowest, the one taken up at an intermediate rate is less virulent, and the one taken up fastest is the least virulent. The differences in ingestion rates reflect differences in affinity of the bacteria for the macrophages and not in the rate of ingestion once interaction has occurred, suggesting a receptor-mediated process. The majority of uptake is probably dependent on complement, as shown by the requirement for a serum component(s) destroyed by heating at 56 degrees C or by incubation with zymosan. Specific antibody is not required. We therefore postulate that relative virulence in vivo may reflect the relative ability of the polysaccharide of bacterial lipopolysaccharide to activate complement, thus determining the susceptibility of the bacteria to ingestion via the complement receptor of phagocytic cells.