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이 연구는 지금까지 경시되어 온 W. D. 하월즈의 여행기 『교외 소묘』를 논하는 것을 통해 미국 사실주의의 성립에 리듬 의식이 결부되어 있음에 주목한다. 삶을 구성하는 한 측면이자 소통을 위한 재현 형식의 구성적 요소 중 하나인 이 리듬은, 『교외 소묘』의 경우, 특히 출판 매체였던 『아틀랜틱 먼쓸리』와의 관계 속에서 형성되었다. 본고는 그 과정을 밝힘으로써 하월즈의 사실주의는 당대의 변화하는 소통의 미디어적 조건, 즉 페니 우편 등으로 가속된 소통의 템포를 반영하는 동시에 이를 재구성하려는 “우편적 무의식”이었음을 드러낸다.

Although strains of attenuated Salmonella typhimurium and wild-type Escherichia coli show similar tumor-targeting capacities, only S. typhimurium significantly suppresses tumor growth in mice. The aim of the present study was to examine bacteria-mediated immune responses by conducting comparative analyses of the cytokine profiles and immune cell populations within tumor tissues colonized by E. coli or attenuated Salmonellae. CT26 tumor-bearing mice were treated with two different bacterial strains: S. typhimurium defective in ppGpp synthesis (Delta ppGpp Salmonellae) or wild-type E. coli MG1655. Cytokine profiles and immune cell populations in tumor tissue colonized by these two bacterial strains were examined at two time points based on the pattern of tumor growth after Delta ppGpp Salmonellae treatment: 1) when tumor growth was suppressed ('suppression stage') and 2) when they began to re-grow ('re-growing stage'). The levels of IL-1 beta and TNF-alpha were markedly increased in tumors colonized by Delta ppGpp Salmonellae. This increase was associated with tumor regression; the levels of both IL-1 beta and TNF-alpha returned to normal level when the tumors started to re-grow. To identify the immune cells primarily responsible for Salmonellae-mediated tumor suppression, we examined the major cell types that produce IL-1 beta and TNF-alpha. We found that macrophages and dendritic cells were the main producers of TNF-alpha and IL-1 beta. Inhibiting IL-1 beta production in Salmonellae-treated mice restored tumor growth, whereas tumor growth was suppressed for longer by local administration of recombinant IL-1 beta or TNF-alpha in conjunction with Salmonella therapy. These findings suggested that IL-1 beta and TNF-alpha play important roles in Salmonella-mediated cancer therapy. A better understanding of host immune responses in Salmonella therapy may increase the success of a given drug, particularly when various strategies are combined with bacteriotherapy.