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PubMed1997

TCR alpha beta+ CD4- CD8- T cells differentiate extrathymically in an lck-independent manner and participate in early response against Listeria monocytogenes infection through interferon-gamma production.

T-cell receptor (TCR) alpha beta+ CD4- CD8- (double-negative; DN) T cells appear in the peritoneal cavity at an early stage of intraperitoneal (i.p.) infection with the intracellular pathogen Listeria monocytogenes. In the present report, we analysed the developmental pathway and functions of the TCR alpha beta+ DN T cells using the L. monocytogenes infection system. The TCR alpha beta+ DN T cells appeared in the peritoneal cavity after L. monocytogenes i.p. infection in adult-thymectomized lethally irradiated bone marrow chimeras and p56lck-deficient mice. The results demonstrated that the TCR alpha beta+ DN T cells can develop extrathymically in a p56lck-independent manner. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that the TCR alpha beta+ DN T cells expressed genes for interferon-gamma (IFN-gamma), the macrophage chemotactic factors MCP-1 and Eta-1, and granulocyte-macrophage colony-stimulating factor (GM-CSF) but lacked expression of genes for interleukin-2 (IL-2), IL-4 and IL-10. As expected from the RT-PCR analysis, the TCR alpha beta+ DN T cells produced IFN-gamma in response to anti-TCR beta monoclonal antibody (mAb), anti-CD3 mAb and L. monocytogenes-infected macrophages but IL-4 was undetectable after the stimulation. Furthermore, the intracellular cytokine staining analysis demonstrated that approximately half of the TCR alpha beta+ DN T cells detectable at the early stage of L. monocytogenes infection were IFN-gamma-producing cells. All of the results suggest that the TCR alpha beta+ DN T cells develop through a unique extrathymic p56lck-independent pathway and participate in early protection against bacterial infection through activation and accumulation of macrophages.

Animals↗
PubMed2007

The role of the activated macrophage in clearing Listeria monocytogenes infection.

Macrophage activation often contributes to the strong immune response elicited upon infection. The ability of macrophages to become activated was discovered when sub-lethal primary infections of mice with the bacterium Listeria monocytogenes provided protection against secondary infections through non-humoral immunity. L. monocytogenes infect and propagate in macrophages by escaping the phagosome into the cytosol, where they avoid humoral immune mediators. Activated macrophages kill L. monocytogenes by blocking phagosomal escape. The timing of the antimicrobial activities within the phagosome is crucial to the outcome. In non-activated macrophages, bacterial factors generally prevail, and L. monocytogenes can escape from the vacuoles and grow within cytoplasm. Activated macrophages generate reactive oxygen or nitrogen intermediates early after bacterial uptake, which prevent the bacteria from escaping vacuoles into cytoplasm. The heterogeneity in the interactions between L. monocytogenes and the macrophage indicate a complex relationship between the host and the pathogen governed by chemistries that promote and inhibit escape from vacuoles. This review examines the mechanisms used by activated and non-activated macrophages to kill microbes, and how those mechanisms are employed against L. monocytogenes.

Animals↗
PubMed1996

Transforming growth factor beta is protective in host resistance against Listeria monocytogenes infection in mice.

The role of transforming growth factor beta (TGF-beta) in host resistance against Listeria monocytogenes infection was studied with mice. The constitutive expression of TGF-beta 1 mRNA was observed in the spleens and livers of mice before and after infection. Injecting the mice with anti-TGF-beta 1 peptide serum resulted in diminished antilisterial resistance, whereas the administration of human platelet-derived TGF-beta 1 enhanced the resistance. Moreover, mice were protected against lethal infection when treated with TGF-beta 1. These results suggest the TGF-beta 1 might be involved in antilisterial resistance. On the other hand, injecting the mice with TGF-beta 1 resulted in a decrease in the titers of endogenous gamma interferon, tumor necrosis factor alpha, and interleukin-6, which are crucial in antilisterial resistance, in sera and in extracts of spleen and liver. Thus, a complicated mechanism might be involved in the role of TGF-beta 1 in host resistance against L. monocytogenes infection.

Animals↗
PubMed1995

Influence of ibuprofen on the infection with Listeria monocytogenes.

Listeria monocytogenes is a bacterial infection, which is facultatively localized in monocytes and macrophages. The influence of ibuprofen (CAS 15687-27-1), a nonsteroidal anti-inflammatory drug (NSAID), on this bacterial infection in balb/c mice was investigated. One day prior to sublethal infection, balb/c mice were treated intravenously with various therapeutic concentrations of ibuprofen alone or ibuprofen in combination with a suboptimal dosage of murine recombinant interferon gamma, a lymphokine produced by T-helper cells. Three days post-infection, parasite burdens of the mainly infected organs, spleen and liver, were determined by the colony-forming unit assay. It was shown that the prophylactic treatment with ibuprofen in a concentration of 4 mg/kg body weight resulted in a more than 10-fold reduction of viable Listeria monocytogenes in the spleen, whereas in liver 12 mg/kg Ibuprofen was necessary for a comparable kill of viable bacteria. A higher concentration of ibuprofen did not resulted in a higher antibacterial efficacy. In order to clarify the mechanism of ibuprofen action, molecular-biological experiments were performed to measure the messenger RNA (mRNA) induced by ibuprofen. It is presented here that therapeutic concentrations of ibuprofen induced significant higher amounts of mRNA for interleukin-1 in human monocytes compared to untreated cells. These findings support the hypothesis that ibuprofen influences the complex immune system to overcome a bacterial infection.

Animals↗
PubMed2001

Intestinal and splenic T cell responses to enteric Listeria monocytogenes infection: distinct repertoires of responding CD8 T lymphocytes.

Listeria monocytogenes is an intracellular bacterium that causes systemic infections after traversing the intestinal mucosa. Clearance of infection and long term protective immunity are mediated by L. monocytogenes-specific CD8 T lymphocytes. In this report, we characterize the murine CD8 T cell response in the lamina propria and intestinal epithelium after enteric L. monocytogenes infection. We find that the frequency of MHC class Ia-restricted, L. monocytogenes-specific T cells is approximately 4- to 5-fold greater in the lamina propria than in the spleen of mice after oral or i.v. infection. Although the kinetics of T cell expansion and contraction are similar in spleen, lamina propria, and intestinal epithelium, high frequencies of Ag-specific T cells are detected only in the lamina propria 1 mo after infection. In contrast to MHC class Ia-restricted T cells, the frequency of H2-M3-restricted, L. monocytogenes-specific T cells is decreased in the intestinal mucosa relative to that found in the spleen. In addition to this disparity, we find that MHC class Ia-restricted CD8 T cells specific for a dominant L. monocytogenes epitope have different TCR V beta repertoires in the spleen and intestinal mucosa of individual mice. These findings indicate that the intestinal mucosa is a depot where L. monocytogenes-specific effector CD8 T cells accumulate during and after infection irrespective of immunization route. Furthermore, our results demonstrate that CD8 T cell populations in these two sites, although overlapping in Ag specificity, are distinct in terms of their repertoire.

Animals↗
PubMed1985

Induction of alpha/beta interferon and gamma interferon in mice infected with Listeria monocytogenes during pregnancy.

Alpha/beta interferon (IFN-alpha/beta) was induced in the bloodstream of mice 48 h after intravenous infection with Listeria monocytogenes, whereas IFN-gamma was induced in the bloodstream 6 h after stimulation with specific antigen on day 5 of infection in virgin mice. In contrast, no IFN-alpha/beta or IFN-gamma was produced in the bloodstream of pregnant mice after L. monocytogenes infection. However, unusual acid-labile IFN-alpha/beta instead of IFN-gamma was produced in some of the pregnant mice in response to specific antigen. The bacterial growth in the organs of pregnant mice in the early stage of infection was normal, but resulted in the delay of T-cell-dependent elimination of bacteria from the organs of pregnant animals in the late stage, and numerous bacteria were detected in both the placenta and the fetus. The significance of the IFN system induced by L. monocytogenes infection in pregnant mice is discussed.

Animals↗
PubMed1989

Evidence that tumor necrosis factor has an important role in antibacterial resistance.

TNF is produced in the spleens of Listeria-infected mice during the first 3 days of a sublethal immunizing infection. The production of Listeria-induced TNF coincides with the time when peak numbers of bacteria are present in the liver and spleen. Evidence suggesting that TNF produced in Listeria-infected organs functions in a T cell-independent resistance mechanism comes from results showing that listeriosis is exacerbated in both T cell-intact mice and T cell-deficient (athymic nude) mice treated with a monospecific anti-murine TNF IgG. Listeriosis is exacerbated, however, only if the anti-TNF IgG is given during the first 3 days of infection, i.e., at the time when TNF is being produced in the spleen. Anti-TNF IgG administered on the first day of infection neutralized all the cytotoxic activity of endogenously produced TNF in the spleen. Additional evidence that TNF plays an important role in antibacterial defenses was obtained by showing that administration of pure murine rTNF protects mice against a normally lethal Listeria challenge given 1 to 24 h later.

Animals↗
PubMed2003

Influence of cadmium and zinc on the mice resistance to Listeria monocytogenes infection.

UNLABELLED: The objective of this study was to examine the effect of chronic exposure to cadmium and zinc on the mice resistance to experimental Listeria monocytogenes infection. MATERIALS AND METHODS: At the day beginning of experiment outbred mice were injected with suspension of bacteria and 8 weeks were given the following oral intake treatment: control group (n=28) deionized drinking water, Cd- group (n=37) water containing CdCl2 10 mg/l and Cd+Zn- group (n=33) water containing CdCl2 10 mg/l and ZnSO4 100 mg/l. The delayed type hypersensitivity was evaluated by the inflammatory response during so-called "foot" test. Listerial proteins solution was injected under plantare of lower aponeurosis of rear foot of experimental animals. Survival of L. monocytogenes in organs of experimental animals was evaluated by the presence of bacteria colonies after 30 days incubation of livers homogenates in broth medium at +4 degrees C and inoculation on CASO-agar. Kidneys, liver and spleen were used for metals analysis. Differences were significant if the P value was below 0.05. RESULTS: Chronic exposure to Cd or to Cd with Zn for 8 weeks caused influence on survival of mice: Cd- and Cd+Zn groups mice died more rapidly than control group ones. Bacterial growth in organs was observed for all groups until fourth week. From sixth-week, control and Cd+Zn- group's mice more rapidly eliminated bacteria from organs, demonstrating that Zn- treated mice were more resistant to listerial infection than Cd- intoxicated ones. On the other hand, mice from Cd+Zn- group had significantly decreased spleen index (up to 74%, p<0.01) as compared to control group. Chronic poisoning of mice with low doses cadmium and zinc during infection significantly affected (p<0.05) their growth rate from fourth week in both experimental groups. Cadmium and zinc insignificantly decreased the delayed type hypersensitivity response to L. monocytogenes allergens in Cd+Zn- group of mice, and no differences were observed in Cd- group, as compared with control group. CONCLUSIONS: 1. Cadmium-exposed mice are more susceptible to Listeria monocytogenes and to other opportunistic infections than not intoxicated mice. 2. Zinc significantly reduces the negative effect of cadmium on the antimicrobial defense of mice. 3. Cadmium and zinc no significantly decrease the delayed type hypersensitivity response to L. monocytogenes allergens as compared with control.

Animals↗
PubMed1994

CD4+ T cell associated cytokine gene expression during experimental infection with Listeria monocytogenes: the mRNA phenotype of granuloma formation.

In murine listeriosis, elimination of bacteria and immunity to re-infection critically depend on Thy-1+CD4- cells, while cell-mediated inflammatory phenomena like delayed-type hypersensitivity and granuloma formation are mediated by CD4+ T cells. In an attempt to correlate T cell phenotype and function with a particular set of cytokines produced in vivo, we examined the cytokine gene expression profile associated with the presence or absence of CD4+ and/or CD8+ cells in the livers of mice during experimental infection with Listeria monocytogenes. T cell subset depletion was achieved by i.p. administration of saturating amounts of the appropriate mAbs, and mRNA detection was carried out using a qualitative and semi-quantitative polymerase chain reaction-based mRNA amplification protocol. In both primary and secondary infection, the presence of CD4+ cells was a prerequisite for granuloma formation, and was found to be closely associated with mRNA expression for IL-2, IL-3 and IL-4, a 5-fold increase in expression of tumor necrosis factor (TNF)-alpha and granulocyte macrophage colony stimulating factor, and a 25-fold increase in expression of IFN-gamma and TNF-beta mRNAs, suggesting a role for these cytokines in granuloma formation. In striking contrast, depletion of CD8+ cells did not result in reduced mRNA expression for any one of the cytokines studied, implying that CD8+ T cell mediated cure and prevention of listeriosis may operate via qualitatively distinct mechanisms.

Animals↗
PubMed1976

Effect of pretreatment with Bacillus Calmette-Guerin on the course of a Listeria monocytogenes infection in normal and congenitally athymic (nude) mice.

The effect of pretreatment with BCG on the course of a Listeria monomcytogenes infection was studied in nu/nu mice and in their heterozygous littermates (+/nu). First, evidence was presented that the nu/nu mice used lacked functional T cells, since BCG treatment resulted only in skin reactivity to tuberculin in +/nu mice and not in nu/nu mice. Acquired resistance to Listeria (based on lower spleen counts) was only obtained in BCG pretreated +/nu mice. Evidence was presented that BCG pretreatment in nu/nu mice failed to increase non-specific resistance, both in terms of spleen counts and survival rate. These results seem to imply that functional T cells are required for this type of non-specific resistance to heterologous antigens. In this connection attention has been drawn to the possible implication of BCG treatment in man.

Animals↗
PubMed1992

The appearance and role of gamma delta T cells in the peritoneal cavity and liver during primary infection with Listeria monocytogenes in rats.

We have previously reported that gamma delta T cells play important roles in protection during the early stage of infection with Listeria monocytogenes in mice. To generalize the protective roles of gamma delta T cells in listerial infection to different species, we examined the appearance of gamma delta T cells during infection with L. monocytogenes in Fisher F344 rats. The numbers of bacteria in the peritoneal cavity and liver increased to a maximum level on day 3 and then decreased to an undetectable level by day 10 after an intraperitoneal infection with a sublethal dose (1 x 10(8)) of viable L. monocytogenes in rats. CD3+ alpha beta- T cells in the peritoneal cavity and liver began to increase on day 3, reached a maximum level on day 6, and thereafter decreased gradually by day 10 after infection. Northern blot analysis confirmed that the CD3+ alpha beta- T cells expressed TCR delta and gamma gene messages. In vivo treatment with anti-TCR alpha beta mAb, which suppressed most of the alpha beta T cells in the periphery and impaired resistance during the late stage of listerial infection, did not affect the host defense by day 6 after infection. A significantly increased number of gamma delta T cells was detected in the peritoneal cavity of the TCR alpha beta-suppressed rats on day 6 after infection. These results suggest that the early appearing gamma delta T cells may contribute to the host defense at a relatively early stage during listeriosis in rats.

Animals↗
PubMed2006

The role of macrophage migration inhibitory factor in lethal Listeria monocytogenes infection in mice.

Macrophage migration inhibitory factor (MIF) has been characterized as a proinflammatory cytokine. Previous studies have indicated that MIF may play a beneficial role or a detrimental role in microbial infections, depending on pathogens. In this study, we investigated the role of MIF in Listeria monocytogenes infection. The MIF titers increased 6h after lethal L. monocytogenes infection but not in the sublethal infection. The elimination of bacteria from the spleens and livers was not affected by anti-MIF antibody (Ab) injection in the sublethal infection, whereas anti-MIF Ab treatment rescued mice from the lethal infection, suggesting that MIF plays a deteriorating role in lethal L. monocytogenes infection. Anti-MIF Ab treatment significantly augmented interleukin (IL)-10 production in the spleens and livers 24h after infection, suggesting that MIF might down-regulate IL-10 production. Although the administration of anti-IL-10 monoclonal Ab showed no significant effect on the bacterial growth in the organs, the bacterial infection was deteriorated by the combined administration of Abs against MIF and IL-10. On the other hand, anti-MIF Ab treatment also increased in the serum cortisol titer 6h after infection compared with the control immunoglobulin G-injected group. Depletion of endogenous IL-10 decreased serum cortisol titers. These results suggested that IL-10 and cortisol might be involved in the deteriorating effect of MIF on lethal L. monocytogenes infection.

Animals↗
PubMed1994

Intercellular adhesion molecule-1 and leukocyte function-associated antigen-1 are involved in protection mediated by CD3+TCR alpha beta- T cells at the early stage after infection with Listeria monocytogenes in rats.

To investigate the significance of intercellular adhesion molecule-1 (ICAM-1) and leukocyte function-associated antigen-1 (LFA-1) in host defense against infection with intracellular parasites, we examined the effects of in vivo pretreatment with mAbs to ICAM-1 (1A29) and LFA-1 alpha (WT-1) on the protection against infection with Listeria monocytogenes in Fisher F344/N rats. Expression of ICAM-1 and LFA-1 alpha molecules on T cells in spleen, liver and peritoneal cavity of rats was down-regulated after i.p. administration with daily doses of 300 micrograms of either 1A29 or WT-1 for 10 days. The survival rate of rats inoculated with viable Listeria was significantly reduced by in vivo pretreatment with 1A29 together with WT-1 for 10 days but not by in vivo pretreatment with control mAb. The numbers of bacteria in the spleen in rats pretreated with both 1A29 and WT-1 were significantly increased on day 3 and day 6 after infection with 1 x 10(7) of viable Listeria corresponding to 1/30 of LD50 to normal rats. Thus, the resistance against listerial infection was severely impaired by combinational pretreatment with mAbs in ICAM-1 and LFA-1 alpha. As shown in our previous report, the early appearance of CD3+TCR alpha beta- T cells, presumably TCR gamma delta T cells, was evident in the peritoneal cavity and liver of control rats at the early stage after listerial infection, while this was suppressed at this stage in rats pretreated with both 1A29 and WT1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Antibody response of dairy cattle experimentally infected with Listeria monocytogenes.

The purpose of our study was to monitor the humoral immune response of 34 lactating dairy cattle experimentally infected with Listeria monocytogenes (strain Scott A, serotype 4b). Twenty-seven animals were inoculated with 10(6) to 10(7) c.f.u./ml of L. monocytogenes via the intramammary route at ten day intervals for one month and 7 were inoculated with 4 x 10(2) to 4 x 10(3) c.f.u./ml. Preinfection and weekly-post infection serum and whey samples were prepared during acute infection. Antibody titres of serum and whey were evaluated in agglutination tests using whole-cell formalin-fixed L. monocytogenes suspensions. Preinfection agglutination titres ranged from 1:20 to 1:320. At least four-dilution increase over pre-infection titres were apparent by the 8th week of infection. Eighty per cent of the bovine sera (26/34) exhibited titres of greater than or equal to 1:20, 480. Whey titres, which reflected the local humoral response to L. monocytogenes, rarely exceeded 1:256 which may be ascribed in part to the lower immunoglobulin concentration in milk vs. blood. Antibody levels indicate active listeriosis but could not be used to predict the magnitude of the recovery of Listeria (c.f.u./ml) in milk.

Agglutination Tests↗
PubMed2004

Changes in the immune functions and susceptibility to Listeria monocytogenes infection in mice fed dietary lipids.

The direct examination of the effects that fish oil diets (composed of long-chain n-3 polyunsaturated fatty acids) exert on immune system function indicates a reduction of host natural resistance to infectious diseases mainly because of a suppression of immune function generated by the fatty acids contained in this diet. Here, we evaluated the concentration of IL-12, IL-4, prostaglandin E2 and leukotriene B4 in the serum from BALB/c mice receiving four different diets. Each group was fed a diet that differed only in the source of fat: a low-fat diet (2.5% by weight), an olive oil diet (20% by weight), a fish oil diet (20% by weight) or a hydrogenated coconut oil diet (20% by weight). Mice were fed for 4 weeks and then infected with the intracellular pathogen Listeria monocytogenes. An initial reduction in the Th1-type response as a result of a decrease in IL-12p70 secretion, an inefficient action of IL-4 (Th2-type response) and no modification of pro-inflammatory lipid-mediator production could be, at least in part, the key events responsible for the inadequate elimination of L. monocytogenes from the spleens of mice fed a fish oil diet. Furthermore, our results suggest that the type of dietary lipids may affect the circulating concentration of IL-12p70 and IL-4, leading to a modulation in the protective cellular immune response to L. monocytogenes infection.

Animals↗