Suppression of the immune response by microorganisms.

Schwab, J H

doi:10.1128/mmbr.39.2.121-143.1975

Cited by 92 publications

(58 citation statements)

References 55 publications

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“…The modulation of host immunity during infection is highly diverse, both in regard to the spectrum of infectious agents involved and in the immune functions which can be affected. Certain experimental systems and clinical studies have illustrated the immune dysfunction in infections by viruses [20], bacteria [21], metazoa and protozoa [22,23]. In experimental African trypanosomiasis, immune dysfunction is associated with abnormal cytokine response [5].…”

Section: Discussionmentioning

confidence: 99%

Interferon‐γ and Interleukin‐12 Genes are Preferentially Expressed During Early Experimental African Trypanosomiasis and Suppressed by Denervation of the Spleen

Liu

Ragaa

et al. 1999

Scand J Immunol

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The cross talk between the central nervous system (CNS) and the immune system includes among others, the modulation of immune responses by the autonomic nervous system. Here, we investigated the effects of a splenic denervation on cytokine induction in early experimental African trypanosomiasis. Profiles of the cytokine mRNA expression for interleukin (IL)‐4, interleukin (IL)‐6, interleukin (IL)‐10, interleukin (IL)‐12, tumour necrosis factor (TNF)‐α, tumour necrosis factor (TNF)‐β, transforming growth factor (TGF)‐β and interferon (IFN)‐γ were examined at 4 h, 8 h and 12 h postinfection (p.i.), and in noninfected controls. Only IFN‐γ and IL‐12 were significantly expressed over noninfected controls. Already at 4 h p.i. both cytokines were expressed and showed more increased levels at 12 h. Sympathetic denervation of the spleen markedly reduced the mRNA expression for both IFN‐γ and IL‐12. Con A was used as a positive control and showed an enhanced mRNA expression, which was also suppressed by a splenic denervation. To demonstrate that the mRNA expression had resulted in a cytokine production, we looked for the protein level of IFN‐γ at 4 h p.i. by immunohistochemistry and found increased levels of IFN‐γ, which was also inhibited by the denervation. Sham‐operated animals exhibited similar responses as the nondenervated controls. Our data present for the first time very early kinetics for a cytokine gene expression during an experimental African trypanosomiasis. Furthermore, the data suggest a regulatory role for the autonomic nervous system on cytokine responses at both the mRNA and the protein levels.

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Section: Discussionmentioning

confidence: 99%

Interferon‐γ and Interleukin‐12 Genes are Preferentially Expressed During Early Experimental African Trypanosomiasis and Suppressed by Denervation of the Spleen

Liu

Ragaa

et al. 1999

Scand J Immunol

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“…The fact that a certain time period was required before NK suppression became apparent after IV administration of C. parvurn suggested, among other alternatives, that suppressor cells for N K cells may have been induced. As " suppressor macrophages " have been found under such conditions in the mouse (Kirchner et al, 1975;Schwab, 1975;Scott, 1972a) we considered it relevant to remove adherent cells from spleen cells from Cp-treated mice followed by analysis for NK activity. As seen in Figure 7, we could not reconstitute the depressed N K activity by removing adherent cells.…”

mentioning

confidence: 99%

An analysis of conditions allowing corynebacterium parvum to cause either augmentation or inhibition of natural killer cell activity against tumor cells in mice

Ojo

Haller

Kimura

et al. 1978

Intl Journal of Cancer

101

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We have analyzed the impact of in vivo administration of Corynebacterium parvum on the mouse immune system against murine tumors, using the natural cytotoxic ability against tumors of normal mouse lymphoid cells as a baseline. A striking difference was found depending on the route of administration. Intravenous inoculation of bacteria would result in a significant decrease or sometimes complete abolition of natural cytotoxicity toward tumor cells of the spleen cells of treated mice. On the other hand, the intraperitoneal route of administration resulted in a dramatic increase in cytolytic ability of the peritoneal exudate cells. Both routes of treatment had the most significant impacts on the local cell population (IV = spleen, IP = peritoneal exudate cells) with only minor effects on other cell populations. Analysis of the spleen cell population from IV-treated mice did also demonstrate a significant reduction in the T lymphocyte function, but in contrast to the natural cytotoxicity this could be corrected for by the removal of suppressor cells of an adherent nature. The lytic cells induced in the peritoneal exudate by the Corynebacterium parvum bacteria were all found to be natural killer, NK, cells with no significant activity found amongst macrophages using short-term cytolytic assays.

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“…However, small numbers of PFC were generated in mice injected with the organisms 1 or 2 days before the immunization. One sometimes finds such suppressive effects on antibody response when microbial adjuvants are injected before immunization with an antigen (5,10). Furthermore, when these organisms were injected with SRBC together on day 0 and the PFC responses in the spleen of injected mice were examined on days 2 and 4, some adjuvant effects were observed (Table 1).…”

Section: Immunologicalmentioning

confidence: 99%