Effect of Neisserial Porin in Immune Cell Apoptosis

奈瑟氏球菌孔蛋白对免疫细胞凋亡的影响

• 批准号: 6758513
• 负责人: LEE Mark WETZLER
• 金额: $ 33.42万
• 依托单位: BOSTON MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6758513
• 关键词: B lymphocyte; HeLa cells; Neisseriaceae; antigen antibody reaction; antigen presenting cell; apoptosis; bacteria infection mechanism; bacterial proteins; bacterial toxins; clone cells; confocal scanning microscopy; cytoprotection; electrophysiology; flow cytometry; gel electrophoresis; immunoprecipitation; intracellular transport; laboratory mouse; leukocyte activation /transformation; ligands; mitochondrial membrane; pore forming protein; protein protein interaction; protein transport; tissue /cell culture; western blottings

Neisserial porins (gonococcal Protein I [PIA or PIB] or meningococcal class 1 [PorA], 2 or 3 [PorB] proteins) are the major protein constituents of the Neisserial outer membrane. We have previously demonstrated that the Neisserial porins activate B lymphocytes, increasing the surface expression of the costimulatory ligand B7-2, which improves the B cell's ability to "costimulate" T lymphocytes. The induction of B7-2 expression is directly related to the porins' adjuvant ability. During the course of this work, we have discovered that the porins, when activating B cells, decreased the susceptibility of these B cells to activation induced cell death (AICD) or apoptosis. We found that the anti-apoptotic effect is due to a direct interaction of the porin with mitochondria (a central control point for apoptotic cell death). Immunoprecipitation experiments revealed that PorB interacts with the mitochondrial porin, VDAC. We hypothesize that this VDAC-Neisserial porin protein-protein interaction, which is similar to that of VDAC with the anti- apoptotic molecule Bcl-2, is responsible for the anti-apoptotic effect of the porins. This interaction results in an enhancement of cell survival and continued activation of B cells, which would potentiate the B cells' involvement in specific immune responses. Therefore, it is possible that this anti-apoptotic effect is a potential additional mechanism of the porins' immunopotentiating ability. This proposal will investigate the effect of Neisserial porins on the susceptibility of B cells, epithelial cells and other cell types to apoptosis. The basic aims include 1) examining the interaction of Neisserial porin with mitochondria and mitochondrial VDAC, 2) determining if alterations in cell culture conditions (especially serum withdrawal) can alter the effect of porins on apoptosis and whether this could be related to changes in cellular ATP levels and 3) determining the effect of intact Neisserial organisms on apoptosis and whether porin might play a role in this effect. These studies will yield significant findings that could both elucidate the immune stimulatory effect of Por (and potentially other bacterial components), allowing for the better use of Por as a vaccine adjuvant. In addition, these results can have significant implications in Neisserial pathogenesis, especially since we have new preliminary data that intact live meningococci can also protect cells from apoptosis.

Neisserial Porin（淋球菌蛋白I [PIA或PIB]或脑膜炎球菌1 [Pora]，2或3 [PORB]蛋白是奈瑟氏外膜的主要蛋白质成分。 我们先前已经证明，奈瑟氏菌孔蛋白激活B淋巴细胞，从而增加了共刺激配体B7-2的表面表达，从而提高了B细胞“ costimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimimine”。 B7-2表达的诱导与孔蛋白的辅助能力直接相关。 在这项工作过程中，我们发现孔蛋白激活B细胞时，这些B细胞对激活诱导的细胞死亡（AICD）或凋亡的敏感性降低了。 我们发现抗凋亡作用是由于孔蛋白与线粒体的直接相互作用（凋亡细胞死亡的中心控制点）。 免疫沉淀实验表明，PORB与线粒体Porin VDAC相互作用。 我们假设这种VDAC神性孔蛋白蛋白 - 蛋白质相互作用与抗凋亡分子Bcl-2相似，这是孔蛋白的抗凋亡作用的原因。 这种相互作用导致细胞存活的增强和B细胞的持续激活，这将增强B细胞参与特定的免疫反应。因此，这种抗凋亡效应可能是孔蛋白免疫术能力的潜在附加机制。 该提案将研究奈瑟氏孔孔蛋白对B细胞，上皮细胞和其他细胞类型凋亡的敏感性的影响。 基本目的包括1）检查奈瑟氏骨与线粒体和线粒体VDAC的相互作用，2）确定细胞培养条件的改变（尤其是血清戒断）是否会改变孔蛋白对凋亡的影响，以及这是否可能与细胞ATP水平的变化以及3）在por neisersial Organism上的作用以及是否可以与por neisersial Organism and Ansosiss效应相关。 这些研究将产生重要的发现，这些发现既可以阐明POR的免疫刺激作用（以及潜在的其他细菌成分），从而可以更好地利用POR作为疫苗佐剂。 此外，这些结果可能对奈瑟氏病发病具有重要意义，尤其是因为我们有新的初步数据，即完整的活脑膜炎球菌也可以保护细胞免受凋亡。