마우스에서 실험적 육아종이 Listeria monocytogenes감염에 대한 저항력에 미치는 영향

Abstract

[영문]

[한글]

육아종(granuloma)은 단핵탐식세포계 (mononuclear phagocyte series: MPS)의 세포들이

국소적으로 축적되어 결절성 병변을 형성하는 만성염증반응이다. Spector 및 Mariano(19

75)는 육아종을 조직반응기전에 의거한 기능적인 분류로서, anamnestic reactivity를 나

타내는 면역학적육아종과 화학적 매개의 활성화에 기인하는 비면역학적육아종으로 구분하

였다.

Sansonetti 및 Lagrange(1981)는 육아종이 획득세포성면역 (acquired cellular immunit

y)및 지연형과민반응(delayed hypersensitivity reaction)과 함께 이물질들에 대한 숙주

의 세포성매개면역방어기전의 하나로 설명하고 있다. 이와같이 육아종에 대한 형태학적

및 조직학적 반응에 관해서는 많은 보고가 있으나 실제 미생물 감염에 있어서 육아종이

숙주방어에 미치는 영향에 대해서는 거의 보고된 바가 없다.

따라서 BCG에 의한 면역학적육아종과 carrageenan에 의한 비면역학적육아종을 마우스

족저부 및 장기내에 유발하고 L.monocytogenes를 감염시켜 숙주의 저항성과 또한 거식세

포의 일반성질들을 비교하였다.

1. 국소적 및 전신적육아종 유발은 BCG 및 carrageenan군 모두 관찰되었으며 그 정도는

4주째가 가장 심하고 많은 단핵세포, 임파구 및 상피양세포로 구성되어 있었다.

2. 국소적 및 전신적육아종 유발은 listeria균 감염에 대한 숙주의 저항력을 증가시켰

으며 carrageenan에 비해 BCG 육아종유발군의 저항력이 다소 높은 것으로 나타났다.

3. BCG 및 carrageenan에 의한 전신적육아종 유발에 따른 마우스 장기무게와 거식세포

들의 형태학적 및 탐식소화능의 비교에서 육아종유발군은 모두 비종대 현상을 볼 수 있었

고 또한 비장 및 복강내의 거식세포들은 증가되어 있었다. 거식세포의 형태학적 및 탐식

소화능에서는 대조군 및 두실험군 모두 유의한 차이를 볼 수 없었다.

이상과 같은 결과를 종합하여 보면 마우스에 있어서 면역원 및 비면역원에 의한 국소

및 전신적육아종의 유발은 listeria감염에 대한 숙주의 저항력을 높일 수 있는 것으로 나

타났으며 육아종유발에 의한 마우스의 저항성 증가는 거식세포들의 활성화 및 탐식능에

기인하기 보다는 육아종 유발에서 비장내 거식세포의 축적 및 숫적 증가와 또한 거식세포

와 세균간의 접촉기회를 증가시킴으로써 좀더 효과적으로 거식세포의 식균작용에 도움을

주기 때문인 것으로 생각된다. 한편 carrageenan처리군에 비해 BCG 육아종유발군에서 다

소 저항성이 높은 것은 BCG 투여후 30일까지 마우스의 족저부내에 BCG가 존재하는 것으로

보아 BCG와 L.monocytogenes를 동시에 접종하였을 때 볼 수 있는 L.monocytogenes에 대

한 비특이방어에 의한 것으로 사료된다.

The Effect of Experimental Granuloma on Resistance to Listeria monocytogenes

Infection in the Mouse

Kyo sun Kim

Department of Medical Science The Graduate School, Yonsei University

(Directed by Professors Duk Jin Yun, M.D. and Joo Deuk Kim, M.D.)

Granuloma can be defined as a type of chronic inflammatory response which forms

focalized small mass(or tubercle) of mononuclear phagocytic cells. The granuloma

could be further classified by their functional differences in anamnestic

responses; immunologic granuloma and nonimmunologic granuloma(Spector and Mariano,

1975).

Sansonetti and Lagrange(1981) reported that granuloma is a final result of

cell-mediated host defence mechanism which includes acquired cellular resistance

and delayed hypersensitivity reaction. There had been numerous reports on the

attempts to classify granuloma by their differences in histopathologic feature.

However, reports on the effect of granuloma in the host upon microbial infection

are lacking.

In this experiment, differences in host defense of mice which had BCG induced

immunologic granuloma and carrageenan induced nonimmunologic granuloma were studied

by infecting the animals with L. monocytogenes. These granulomas were induced

locally in foot pad as well as systematically in the animals by inoculating the

inducers intradermally and intravenously.

Followings are the summary of the findings.

1. Local and systematic granulomas were successfully produced by inoculating the

inducers. The most distinctive granuloma were developed at the 4th week after

initial induction. The major population of the cells found in the granuloma were

mononuclear cells. lymphocytes and epithelioid cells.

2. Increaaed host resistance to the L. monocytogenes infection was observed in

both the animals with immunologic and nonimmunologic granuloma inducted by BCG and

carrageenan, Greater extent of enhanced resistance to the bacterial infection was

observed in animals with BCG induced granuloma than the animals with carrageenan

induced granuloma.

3. The changes in weights of the organs and in morphology and phagocytic activity

of phagocytes from the animals with granuloma were comparatively analyzed by the

inducers; BCG and carrageenan.

Enlargement of spleen which can be considered as splenomegaly was observed in

both the animals with BCG and carrageenan induced granuloma.

Although quantitative increase on splenic and peritoneal phagocytes was observed

in both the animals, the differences in phagocytic activity of the phagocytes from

the animals with BCG and carrageenan induced granuloma were not significant.

Thus it is tentatively concluded that host resistance of animals to L.

monocytogenes infection was appeared to be enhanced by inducing granuloma with both

the BCG and carrageenan.

The enhanced host resistance could be explained by the increased number of

phagocytes accumulated in the spleen not by the qualitative changes in phagocytic

activity of the cells involved.

Enhanced host defense in animals with granuloma could be also explained by

increasing the Chance of close contacts between invading organisms and phagocytic

cells, which was suggestible by the findings of splenomegaly and increased number

of phagocytes from the animals.

The long-term survival of BCG which was found in the sites up to 30 days after

inoculation, which might render non-specific defence mechanism was thought to be

responsible for the higher degree of enhancement in resistance of the animals with

BCG induced granuloma than that of the animals with carrageenan induced granuloma.