Studios on the cell-mediated immunity in experimental Nnegleria spp. infections

실험적 Naegleria 감염에 있어서 세포매개성 면역에 관한 연구

Observations were made on the differences in cell-mediated immune responses in the mice infected with strongly pathogenic Naegleria fewleyi ITMAP 359, weakly pathogenic Naegzeria jadini 0400, or non.pathogenic Naegleria gruberi EGB, respectively. Variations in cell-mediated responses and changes in antibody titers according to the duration after infection wore noted. Infections were done by dropping $5{\;}{\mu}l$ saline suspension containing $10{\times}10^4$ trophozoites cultured Bxenically in the CGVS medium into the right nasal cavity of ICR mice aging about 6~7 weeks, under the anesthesia by intraperitoneal injection of'secobarbital. Following infection, delayed type hypersensitivity(DTH) iesponses in the footpad and blastogenic responses of the mouse spleen cells using [$^3H$]-thymidine were observed on the day 1, 4, 7, 10 and 14 after infection. For the preparation of amoeba Iysates, each of cultured trophosoites were homogenized with an ultrasonicator, and centrifugated at 20,000 g. The supernatants of amoeba Iysates were used as the mitogen'and antigen for ELISA. Confanavalin A(Con. A) and lipopolysaccharide(LPS) were also used as mitogens in the blastogenic response. 1. The mice infected with N, fowleri showed the mortality rate of 75.7%. The rate was 6.2% for the N. jadini infected group, while no dead mouse was observed for N. gruberi infections. 2. In regard to DTH responses in the H. fewleri infected mice, the level increased in com- parison to the control group but declined after 7 days. An increase was also noted for the JV. jadini group after 1 day, but gradual decreases were observed through the infection period. In addition, no difference was noted between the N. gruberi infected and control groups. 3. Concerning the blastogenic response of the splenocytes, it increased after 10 days in the experimental group of N, fcwleri infection, but the differences ware not statistically significant compared with control group. It was evident that N. jadini group was not different from control group either, while there was a tendency of decrease in SV. gruberi infected group. In regard to the blastogenic response of the splenocytes by LPS, it was found that the N. fowlgri, N. jadini and N. gruberi infected groups had no differences from the control group. 4. The serum antibody titer of N. fcwleri and N. jadini infected mice increased from the day 7 and 14 after infection respectively, while the N. gruberi infected mice showed no increase. In summary of the results, it was observed that there were differences in the cell-mediated immune responses and serum antibody titers in the mice infected with strongly pathogenic JV. fowleri, weakly pathogenic N. jadini, or non.pathogenic N. gruberi, respectively.

병원성이 강한 Naegleria fowleri ITMAP 359, 병원성이 약한 Naegleria jadini 0400, 비병원성인 Naegleria gruberi EGB를 ICR마우스에 각각 감염시켰을 때 세포매개 성 면역반응의 차이를 관찰하고 이들 아메바를 감염시킨 후 경과된 감염 시간에 따른 세포매개 성 면역반응과 혈청내 항체가의 변동을 관찰하였다. N. fowleri를 감염시킨 마우스의 사망률은 75.7%, N. jadini를 감염시킨 실험군에서는 6.2%, N. gruberi 감염에 의한 마우스의 사망은 전혀 관찰되지 않았다. 지연형 과민반응은 N. fowleri, 감염시에 감염 초부터 대조군에 비해 반응이 증가하였으나 7일 후에는 감소하였다. N. jadini 감염 시에도 감염 후 1일째부터 과민반응이 증가하였으며 감염기간이 지나갈수록 점차 감소하였다. 또 N. gruberi 감염시에는 대조군과 비교할 때 변화를 나타내지 않았다. 7림프구의 아세포화 정도는 N. fowleri 감염시 감염 10일 후 증가하였으나 대조군에 비해 유의한 차이는 없었다. N. jadini에 감염된 경우는 대조군과 차이가 없음을 알 수 있었고, N. gruberi 감염시에는 감염 후 감소하는 경향이 있었다. B림프구의 아세포화 정도는 N. fowleri 감염군, N. gadini 감염군 및 N. gruberi 감염군에서 대조군과 차이가 없었다. N. fowleri에 감염된 마우스의 혈청내 항체가는 감염 7일 후부터 증가하였고, N. jadini 감염시에는 14일 후 증가하였으며, N, gruberi게 감염된 마우스의 항체가는 대조군과 차이가 없었다.