Effect of human polymorphonuclear and mononuclear leukocytes on chromosomal and plasmid DNA of Escherichia coli. Role of acid DNase.
Effect of human polymorphonuclear and mononuclear leukocytes on chromosomal and plasmid DNA of Escherichia coli. Role of acid DNase.
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人多形核和单核白细胞对大肠杆菌染色体和质粒 DNA 的影响。
DOI：
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发表时间：
1984
影响因子：
15.9
通讯作者：
J. Verhoef
中科院分区：
文献类型：
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作者：
M. Rozenberg‐Arska;J. V. van Strijp;W. P. Hoekstra;J. Verhoef
多形核白细胞和单核白细胞的吞噬和杀伤作用是宿主抵抗入侵微生物的重要因素。表明杀灭细菌后迅速降解细菌成分的证据有限。因此，我们研究了大肠杆菌DNA的命运后，吞噬E。多形核白细胞和单核白细胞。[3H]胸腺嘧啶标记的未包封E. coliPC2166和E. coli 048K1中培养，洗涤，并加入白细胞。测量细菌的摄取和杀灭以及DNA的降解。虽然单核白细胞的吞噬和杀伤作用不如多形核白细胞，但只有单核白细胞才能降解E。coliPC2166DNA。在2 h内，加入单核白细胞的60%放射性释放到上清液中，其中40%为酸溶性。E. coli 048K1不降解。进一步分析单核白细胞降解大肠杆菌的能力。从摄入的细菌中分离大肠杆菌DNA、染色体和质粒DNA，并进行琼脂糖凝胶电泳。只有染色体DNA被吞噬后降解。E.携带氨苄青霉素抗性编码基因的大肠杆菌在摄入后2小时内保持完整，并且仍然能够转化受体大肠杆菌。大肠杆菌细胞在此期间。虽然我们没有观察到DNA降解过程中吞噬的多形核白细胞，多形核白细胞和单核细胞的裂解物含有酸性DNA酶活性的最佳pH值为4.9。而单核白细胞的DNA酶活性比多形核白细胞高20倍。慢性肉芽肿病患者的多形核白细胞和单核白细胞的DNA酶活性与对照多形核白细胞和单核白细胞的DNA酶活性之间没有差异。
Phagocytosis and killing by polymorphonuclear and mononuclear leukocytes are important host resistance factors against invading microorganisms. Evidence showing that killing is rapidly followed by degradation of bacterial components is limited. Therefore, we studied the fate of Escherichia coli DNA following phagocytosis of E. coli by polymorphonuclear and mononuclear leukocytes. [3H]thymidine-labeled, unencapsulated E. coli PC2166 and E. coli 048K1 were incubated in serum, washed, and added to leukocytes. Uptake and killing of the bacteria and degradation of DNA were measured. Although phagocytosis and killing by mononuclear leukocytes was less efficient than that by polymorphonuclear leukocytes, only mononuclear leukocytes were able to degrade E. coli PC2166 DNA. Within 2 h, 60% of the radioactivity added to mononuclear leukocytes was released into the supernate, of which 40% was acid soluble. DNA of E. coli 048K1 was not degraded. To further analyze the capacity of mononuclear leukocytes to degrade E. coli DNA, chromosomal and plasmid DNA was isolated from ingested bacteria and subjected to agarose gel-electrophoresis. Only chromosomal DNA was degraded after phagocytosis. Plasmid DNA of E. coli carrying a gene coding for ampicillin resistance remained intact for a 2-h period after ingestion, and was still able to transform recipient E. coli cells after this period. Although we observed no DNA degradation during phagocytosis by polymorphonuclear leukocytes, lysates of both polymorphonuclear and mononuclear leukocytes contained acid-DNase activity with a pH optimum of 4.9. However, the DNase activity of mononuclear leukocytes was 20 times higher than that of polymorphonuclear leukocytes. No difference was observed between DNase activity from polymorphonuclear and mononuclear leukocytes from a chronic granulomatous disease patient with DNase activity from control polymorphonuclear and mononuclear leukocytes.