Abstract
Observations were made on the differences of cell-mediated responses in mice of three infectiorl groups di여erently scheduled in their severity with pathogenic Acanthamoeba culbertseni. Infections were done by dropping $5{\;}{\mu}l$ saline suspension containing $3{\times}10^3,{\;}1{\times}10^4,{\;}or{\;}1{\times}10^5$ trophosoites, respectively. Amoebae were cultured anenically in CGV medium and inoculated into the right nasal cavity of CSH/HeJ mice aging around 6∼8 weeks, under the anesthesia by intraperitoneal injection of secobarbital. Delayed type hypersensitivity (DTH) responses in footpad and blastogenlc responses of mouse spleen cells using ($^3H$)-thymidine and the serum antibody titer were measured up to day 14 after infection, and natural killer cell activities were measured up to day, i after infection. The results obtained in this study were as follows: 1. The mice infected with $3{\times}10^3$ trophosoites showed mortality rate of 17%, and 345 in the mice infected with $1{\times}10^4$ trophozoites and 65% with $1{\times}10^5$ trophozoites. 2. In regard to DTH responses in all experimental groups, the level increased on day 7 and declined on day 14 after infection, but their differences could not be noted between infected and control groups. 3. The blastogenic responses of splenocytes treated with amoeba Iysates and lipopolysaccharides (LPS) showed no difference from the control group. The blastogenic responses of splenocytes treated with concanavalin A were declined significantly in the experimental group as compared with the control group, but the blastogenic responses of splenocytes treated with polyinosinic acid were not different from the control group. There was also no difference among three infected groups. 4. The cytotoxic activity of the natural killer cells was activated on day 1 after infection and declined to the level of control group on day 2 in all experimental groups. On day 5 after infection, the natural killer cell cytotoxicity was significantly suppressed as compared with the control groups. 5. The serum antibody titers of the infected mice increased after day 7, but there was no statistical difference between the three infected groups. In summary of the results, there was no difference in cell-mediated immune responses of three experimental groups scheduled with different infection intensities. But there was a significant difference in cell$.$mediated immune responses between infected and control mice. It is considered that cell-mediated immune responses should be involved in murine model infected with A. culbertsoni.
병원성이 강한 Acanthamoeba culbertsoni에 감염된 마우스를 감염 정도에 따라 경(輕)감염, 중(中)등 감염, 중(重)감염 실험군으로 나누었을 때 감염 기간에 따라 발현되는 세포 매개성 면역반응의 차이를 지연형 과민반응, T와 B림프구의 아세포화 정도 및 자연 살세포의 독성을 통하여 곤찰하고 또한 혈청내 항체가를 측정하였다. 감염 마우스의 사망율은 $3{\times}10^3$개의 아메바 영양형을 감염시킨 경(輕) 감염군에서는 17%였으며, $1{\times}10^4$개를 감염시킨 중(中)등 감염군에서는 34%, $1{\times}10^5$개를 감염시킨 중(重) 감염군에서는 65%였다. 세포 매개성 면역을 관찰하기 위한 지연형 과민반응의 변동을보면 각 실험군 모두에서 감염 후 7일째 발바닥의 두께가 유의하게 증가하였으나 감염 후 14일째에는 감소하였고 각 실험군 간에 유의한 차이를 발견할 수 없었으며 각 실험군과 대조군 간에도 유의한 차이가 없었다. A. culbertsoni lysate 및 B 림프구 mitogen인 LPS에 의한 비장세포의 아세포화는 관찰되지 않았으며, T림프구 mitogen인 con. A로 처리한 비장세포의 아세포화 정도는 각 실험군 모두에서 감염 7일 이후 대조군에 비해 유의하게 감소하였으며 B림프구 mitogen인 poly I 처리시는 실험군 모두에게 대조군과 차이가 없었다. 그리고 con. A와 poly I에 의한 아세포화 정도에 있어서 각 실험군 간에 유의한 차이를 관찰할 수 없었다. 자연살세포의 세포 독성은 실험군 모두에게 대조군에 비해 감염 후 1일째에 증가되었고 감염 후 5일째에는 유의하게 감소하였다. 그러나 각 실험군 간에 세포독성의 유의한 차이는 발견할 수 없었다. 혈청내 항체가는 각 실험군 모두에서 감염 7일 이후부터 대조군에 비해 계속 증가하였으나 각 실험군 간에 유의한 차이를 발견할 수 없었다.