Bacterial secreted proteins are required for the internalization of Campylobacter jejuni into cultured mammalian cells
Bacterial secreted proteins are required for the internalization of Campylobacter jejuni into cultured mammalian cells
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DOI：
10.1046/j.1365-2958.1999.01376.x
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发表时间：
1999-05-01
影响因子：
3.6
通讯作者：
Garvis, SG
中科院分区：
文献类型：
--
作者：
Konkel, ME;Kim, BJ;Garvis, SG
这里提供的第一个证据表明空肠弯曲杆菌在与宿主细胞共培养并在 INT 407 细胞条件培养基中分泌蛋白质。使用差异筛选技术鉴定了空肠弯曲菌基因，称为弯曲杆菌入侵抗原 B 的 ciaB，该技术是该分泌过程和该细菌有效进入宿主细胞所必需的。空肠弯曲菌 ciaB 基因编码 610 个氨基酸的蛋白质，计算分子量为 73 154 Da。推导的 CiaB 蛋白氨基酸序列与与其他更广泛表征的细菌病原体入侵宿主细胞相关的 III 型分泌蛋白具有相似性。体外结合和内化测定表明，空肠弯曲菌ciaB无效突变体的结合与亲本分离株的结合无法区分，而内化却显着降低。对空肠弯曲菌感染的细胞进行共聚焦显微镜检查发现，CiaB 易位到宿主细胞的细胞质中。用 INT 407 细胞或在 INT 407 条件培养基中培养空肠弯曲菌，导致至少八种蛋白质（大小范围为 12.8 至 108 kDa）分泌到培养基中。空肠弯曲菌 ciaB 无效突变体在所有八种蛋白质的分泌方面均存在缺陷，表明分泌过程需要 CiaB。空肠弯曲菌ciaB基因的鉴定代表了理解空肠弯曲菌内化的分子机制和空肠弯曲菌介导的肠炎发病机制的重大进展。
Presented here is the first evidence that Campylobacter jejuni secrete proteins upon co-cultivation with host cells and in INT 407 cell-conditioned medium. A C. jejuni gene designated ciaB for Campylobacter Invasion antigen B was identified, using a differential screening technique, which is required for this secretion process and the efficient entry of this bacterium into a host cell. The C. jejuni ciaB gene encodes a protein of 610 amino acids with a calculated molecular mass of 73 154 Da. The deduced amino acid sequence of the CiaB protein shares similarity with type III secreted proteins associated with the invasion of host cells from other more extensively characterized bacterial pathogens. In vitro binding and internalization assays revealed that the binding of C. jejuni ciaB null mutants was indistinguishable from that of the parental isolate, whereas a significant reduction was noted in internalization. Confocal microscopic examination of C. jejuni-infected cells revealed that CiaB was translocated into the cytoplasm of the host cells. Culturing C. jejuni with INT 407 cells or in INT 407-conditioned medium resulted in the secretion of at least eight proteins, ranging in size from 12.8 to 108 kDa, into the culture medium. C. jejuni ciaB null mutants were deficient in the secretion of all eight proteins, indicating that CiaB is required for the secretion process. The identification of the C. jejuni ciaB gene represents a significant advance in understanding the molecular mechanism of C, jejuni internalization and the pathogenesis of C. jejuni-mediated enteritis.