Visser L G, Annema A, van Furth R
Department of Infectious Diseases, University Hospital Leiden, The Netherlands.
Infect Immun. 1995 Jul;63(7):2570-5. doi: 10.1128/iai.63.7.2570-2575.1995.
The virulence plasmid of Yersinia enterocolitica codes for the production of the outer membrane protein YadA and the secretion of several proteins, called Yops, which may play a role in the interaction between granulocytes and this bacterium. We investigated whether the expression of YadA or the secretion of Yops affected the phagocytosis and killing of opsonized Y. enterocolitica by human granulocytes. The rates of phagocytosis and killing of Y. enterocolitica by granulocytes in suspension in the presence of rabbit Yersinia antibodies and complement were determined by microbiological assays. In addition, noningested cell-adherent bacteria were differentiated from ingested yersiniae by immunofluorescence microscopy. Plasmid-bearing opsonized Y. enterocolitica was able to inhibit phagocytosis and killing by human granulocytes. The inhibition of phagocytosis was specific for the plasmid-bearing strain of Y. enterocolitica, since granulocytes were still able to phagocytose and kill Staphylococcus aureus in the presence of Y. enterocolitica. Plasmid-cured Y. enterocolitica was readily phagocytosed and killed by these cells. To investigate the role of YadA or Yops in the inhibition of phagocytosis by granulocytes, the phagocytosis of mutant strains unable to express YadA or to secrete Yops was studied. A Y. enterocolitica mutant unable to secrete Yops lost its ability to inhibit phagocytosis; a mutant expressing only YadA was readily ingested by granulocytes. These results indicate that after attachment of opsonized Y. enterocolitica to granulocytes, Yops play an important role in inhibiting the ingestion of Y. enterocolitica by human granulocytes.
小肠结肠炎耶尔森氏菌的毒力质粒编码外膜蛋白YadA的产生以及几种被称为Yops的蛋白质的分泌，这些蛋白质可能在粒细胞与这种细菌的相互作用中发挥作用。我们研究了YadA的表达或Yops的分泌是否会影响人粒细胞对调理过的小肠结肠炎耶尔森氏菌的吞噬和杀伤作用。通过微生物学测定法确定了在存在兔耶尔森氏菌抗体和补体的情况下，悬浮的粒细胞对小肠结肠炎耶尔森氏菌的吞噬和杀伤率。此外，通过免疫荧光显微镜将未摄取的细胞粘附细菌与摄取的耶尔森氏菌区分开来。携带质粒的调理过的小肠结肠炎耶尔森氏菌能够抑制人粒细胞的吞噬和杀伤作用。吞噬作用的抑制对携带质粒的小肠结肠炎耶尔森氏菌菌株具有特异性，因为在存在小肠结肠炎耶尔森氏菌的情况下，粒细胞仍然能够吞噬和杀伤金黄色葡萄球菌。质粒消除的小肠结肠炎耶尔森氏菌很容易被这些细胞吞噬和杀伤。为了研究YadA或Yops在粒细胞抑制吞噬作用中的作用，研究了无法表达YadA或分泌Yops的突变菌株的吞噬作用。无法分泌Yops的小肠结肠炎耶尔森氏菌突变体失去了抑制吞噬作用的能力；仅表达YadA的突变体很容易被粒细胞摄取。这些结果表明，在调理过的小肠结肠炎耶尔森氏菌附着于粒细胞后，Yops在抑制人粒细胞摄取小肠结肠炎耶尔森氏菌中起重要作用。
