Molecular mechanism of infection and growth of endonuclear symbiotic bacterium.

(1)在4ﾟC下，携带钝顶青霉繁殖短型的草履虫细胞的存活率高于非共生细胞，这是首次证明钝顶草履虫和草履虫之间存在相互作用。这一现象可能是携带全孢子虫的草履虫仅在寒冷地区发现的原因。(2)霍洛孢菌的GroEL同源物是一种热休克蛋白。(3)研制了三种针对钝顶螺旋体感染性长形的单抗。4.宿主消化液泡的酸化是细菌逃逸空泡和感染宿主细胞核所必需的早期事件。在刀豆素A或B存在的情况下，V-ATPase的抑制剂、空泡的酸化和细胞核的感染都被抑制。此外，当感染的长形细菌悬浮在PH3缓冲液中时，细菌表达活化的形态特异抗原，并显示活化的形态特异的形态。因此，宿主消化液泡中的酸化似乎是细菌从空泡中逃逸和活性形式分化的触发因素。(5)为纯化的钝顶螺旋体67K蛋白而产生的单抗与各种生物收缩的空泡-放射管和线粒体质子泵发生交叉反应。(6)当生殖短形分化为具有感染性的长形时，产生的过量细胞壁物质被排出细菌外并聚集在大核被膜周围，导致被膜的低通透性。这可能是感染型草履虫分裂率较低的原因。(7)在-85ﾟC条件下，分离的直肠草履虫的冻存成功，至少127d的感染性和重复性没有损失。

(1).Paramecium caudatum cells bearing the reproductive short forms of Holospora obtusa show high servival ratio compared with aposymbiotic cells at 4ﾟC.This is the first evidence showing a presence of mutual interaction between H.obtusa and P.caudatum. This phonomenon may be a cause why the Holospora-bearing paramecia is found only in cold area.(2).Horospora's groEL homologue is a heat-shock protein.(3).Three monoclonal antibodies specific for infectious long from of H.obtusa were developed. Two of them was found to react with periplasm by immunoelectron microscopy.(4).Acidification of the host digestive vacuole is an early event required for the bacterial escape from the vacuole and for infection of the host nucleus. In the presence of concanamycin A or B,inhibitors of V-ATPase, both acidification of the vacuoles and infection of the nucleus were inhibited. In addition, when the infectious long forms were suspended in pH3 buffer, the bacteria expressed the activated form specifc antigen and showed activated forms specific morphology. Thus, it seems that acidification in the host digestive vacuole is a trigger for the escape of the bacteris from the vacuole and for differentiation of the activated form.(5).Monoclonal antibody raised for purified 67 K protein of H.obtusa cross-reacted with a proton pump of the contractile vacuole-radial canals and mitochondoria of various organisms.(6).When the reproductive short form differentiated into the infectious lonf form, cell-wall materials produced excess amount were excreted outside the bacteria and accumulated around the macronuclear envelope and induced low permeability of the envelope. This may be a cause of low fission ratio of the infectious form-bearing paramecia.(7).Cryopreservation of the isolated H.recta was succeeded without loss of the infectivity and reproducebility at-85ﾟC at least 127 days.