scholarly journals Interleukin-1 Receptor-Associated Kinase 4 Is Essential for Initial Host Control of Brucella abortus Infection

2011 ◽  
Vol 79 (11) ◽  
pp. 4688-4695 ◽  
Author(s):  
Fernanda S. Oliveira ◽  
Natália B. Carvalho ◽  
Ana Paula M. S. Brandão ◽  
Marco Túlio R. Gomes ◽  
Leonardo A. de Almeida ◽  
...  

ABSTRACTBrucella abortusis a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. Recent studies have revealed that Toll-like receptor (TLR)-initiated immune response toBrucellaspp. depends on myeloid differentiation factor 88 (MyD88) signaling. Therefore, we decided to study the role of the interleukin-1 receptor-associated kinase 4 (IRAK-4) in host innate immune response againstB. abortus. AfterBrucellainfection, it was shown that the number of CFU in IRAK-4−/−mice was high compared to that in IRAK-4+/−animals only at 1 week postinfection. At 3 and 6 weeks postinfection, IRAK-4−/−mice were able to control the infection similarly to heterozygous animals. Furthermore, the type 1 cytokine profile was evaluated. IRAK-4−/−mice showed lower production of systemic interleukin-12 (IL-12) and gamma interferon (IFN-γ). Additionally, a reduced percentage of CD4+and CD8+T cells expressing IFN-γ was observed compared to IRAK-4+/−. Further, the production of IL-12 and tumor necrosis factor alpha (TNF-α) by macrophages and dendritic cells from IRAK-4−/−mice was abolished at 24 h after stimulation withB. abortus. To investigate the role of IRAK-4 in mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways, macrophages were stimulated withB. abortus, and the signaling components were analyzed by protein phosphorylation. Extracellular signal-regulated kinase 1 (ERK1) and ERK2 and p38 as well as p65 NF-κB phosphorylation was profoundly impaired in IRAK-4−/−and MyD88−/−macrophages activated byBrucella. In summary, the results shown in this study demonstrated that IRAK-4 is critical to trigger the initial immune response againstB. abortusbut not at later phases of infection.

2013 ◽  
Vol 81 (12) ◽  
pp. 4392-4398 ◽  
Author(s):  
Wenpeng Gu ◽  
Xin Wang ◽  
Haiyan Qiu ◽  
Buyun Cui ◽  
Shiwen Zhao ◽  
...  

ABSTRACTBrucella abortusandYersinia enterocoliticaserotype O:9 serologically cross-react in the immune response with the host; therefore, our aim was to compare the immune responses to these two pathogens. We selected typicalB. abortusandY. enterocoliticaO:9 strains to study the cytokine immune response and the histopathological changes in livers and spleens of BALB/c mice. The data showed the cytokine responses to the two strains of pathogens were different, where the average levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), gamma interferon (IFN-γ), interleukin-12 (IL-12), and tumor necrosis factor alpha (TNF-α) were higher withB. abortusinfections than withY. enterocoliticaO:9 infections, especially for IFN-γ, while the IL-10 level was lower and the levels of IL-1β, IL-4, IL-5, and IL-6 were similar. The histopathological effects in the livers and spleens of the BALB/c mice withB. abortusandY. enterocoliticaO:9 infections were similar; however, the pathological changes in the liver were greater withB. abortusinfections, while damage in the spleen was greater withY. enterocoliticaO:9 infections. These observations show that different cytokine responses and histopathological changes occur withB. abortusandY. enterocoliticaO:9 infections.


2012 ◽  
Vol 80 (8) ◽  
pp. 2905-2913 ◽  
Author(s):  
Jessica Queen ◽  
Karla J. Fullner Satchell

ABSTRACTCholera is classically considered a noninflammatory diarrheal disease, in comparison to invasive enteric organisms, although there is a low-level proinflammatory response during early infection withVibrio choleraeand a strong proinflammatory reaction to live attenuated vaccine strains. Using an adult mouse intestinal infection model, this study examines the contribution of neutrophils to host defense to infection. Nontoxigenic El Tor O1V. choleraeinfection is characterized by the upregulation of interleukin-6 (IL-6), IL-10, and macrophage inflammatory protein 2 alpha in the intestine, indicating an acute innate immune response. Depletion of neutrophils from mice with anti-Ly6G IA8 monoclonal antibody led to decreased survival of mice. The role of neutrophils in protection of the host is to limit the infection to the intestine and control bacterial spread to extraintestinal organs. In the absence of neutrophils, the infection spread to the spleen and led to increased systemic levels of IL-1β and tumor necrosis factor alpha, suggesting the decreased survival in neutropenic mice is due to systemic shock. Neutrophils were found not to contribute to either clearance of colonizing bacteria or to alter the local immune response. However, when genes for secreted accessory toxins were deleted, the colonizing bacteria were cleared from the intestine, and this clearance is dependent upon neutrophils. Thus, the requirement for accessory toxins in virulence is negated in neutropenic mice, which is consistent with a role of accessory toxins in the evasion of innate immune cells in the intestine. Overall, these data support that neutrophils impact disease progression and suggest that neutrophil effectiveness can be manipulated through the deletion of accessory toxins.


2011 ◽  
Vol 79 (4) ◽  
pp. 1638-1646 ◽  
Author(s):  
Natália B. Carvalho ◽  
Fernanda S. Oliveira ◽  
Fernanda V. Durães ◽  
Leonardo A. de Almeida ◽  
Manuela Flórido ◽  
...  

ABSTRACTTo investigate the role of Toll-like receptor 9 (TLR9) in innate immunity toMycobacteriumavium, TLR9, TLR2, and MyD88 knockout (KO) mice were infected with this bacterium. Bacterial burdens were higher in the spleens, livers, and lungs of infected TLR9 KO mice than in those of C57BL/6 mice, indicating that TLR9 is required for efficient control ofM.aviuminfection. However, TLR9 KO or TLR2 KO spleen cells displayed normalM.avium-induced tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) responses. This finding was confirmed by determining the number of splenic CD4+T cells producing IFN-γ by flow cytometry. Furthermore, TLR2 and MyD88, but not TLR9, played a major role in interleukin-12 and TNF-α production byM.avium-infected macrophages and dendritic cells (DCs). We also found that major histocompatibility complex class II molecule expression on DCs is regulated by TLR2 and MyD88 signaling but not by TLR9. Finally, lack of TLR9, TLR2, or MyD88 reduced the numbers of macrophages, epithelioid cells, and lymphocytes inM.avium-induced granulomas but only MyD88 deficiency affected the number of liver granulomas. In summary, our data demonstrated that the involvement of TLR9 in the control ofM.aviuminfection is not related to the induction of Th1 responses.


2002 ◽  
Vol 9 (2) ◽  
pp. 348-351 ◽  
Author(s):  
Donato Torre ◽  
Filippo Speranza ◽  
Massimo Giola ◽  
Alberto Matteelli ◽  
Roberto Tambini ◽  
...  

ABSTRACT The relative balance between Th1 and Th2 cytokines appears crucial, since the role of cytokines has been evaluated in several studies by comparison of clinically heterogeneous groups of patients. The aim of this study is to determine the role of proinflammatory Th1 cytokines, interleukin-12 (IL-12) and gamma interferon (IFN-γ), and anti-inflammatory Th2 cytokines, IL-4 and IL-10, in a homogeneous group of patients with uncomplicated Plasmodium falciparum malaria. Levels of IL-12, IFN-γ, Il-4, and IL-10 in serum for 20 adult patients and 15 healthy control subjects were determined by an immunoenzymatic assay. Serum levels of Th1 cytokines, IL-12 (8.6 ± 2.8 pg/ml; controls, 3.2 ± 0.7 pg/ml) and IFN-γ (39.2 ± 67.6 pg/ml; controls, 8.4 ± 6.3 pg/ml), were significantly increased at admission; 3 days later, levels of IL-12 in serum remained significantly high (8.8 ± 2.6 pg/ml), whereas IFN-γ levels returned to control values. The anti-inflammatory response of Th2 cytokines (IL-10 and IL-4) was distinct. Levels of IL-10 in serum were not significantly increased at day 0 and day 3 (306.6 ± 200.4 pg/ml and 56.6 ± 38.4 pg/ml, respectively; controls, 17.4 ± 9.0 pg/ml). In contrast, levels of IL-4 in serum were not increased on admission (3.4 ± 1.2 pg/ml; controls, 2.4 ± 0.8 pg/ml), but at day 3 a moderate and significant increase of IL-4 levels was observed (4.5 ± 1.7 pg/ml). In conclusion, the increase of Th1 cytokine IL-12 and IFN-γ levels during the acute phase of uncomplicated P. falciparum malaria may reflect an early and effective immune response regulated by proinflammatory Th1 cytokines, and in particular IFN-γ may play a role in limiting progression from uncomplicated malaria to severe and life-threatening complications.


1998 ◽  
Vol 66 (1) ◽  
pp. 65-69 ◽  
Author(s):  
J. K. Brieland ◽  
D. G. Remick ◽  
M. L. LeGendre ◽  
N. C. Engleberg ◽  
J. C. Fantone

ABSTRACT The in vivo role of endogenous interleukin 12 (IL-12) in modulating intrapulmonary growth of Legionella pneumophila was assessed by using a murine model of replicative L. pneumophila lung infection. Intratracheal inoculation of A/J mice with virulent bacteria (106 L. pneumophilacells per mouse) resulted in induction of IL-12, which preceded clearance of the bacteria from the lung. Inhibition of endogenous IL-12 activity, via administration of IL-12 neutralizing antiserum, resulted in enhanced intrapulmonary growth of the bacteria within 5 days postinfection (compared to untreated L. pneumophila-infected mice). Because IL-12 has previously been shown to modulate the expression of cytokines, including gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and IL-10, which regulate L. pneumophila growth, immunomodulatory effects of endogenous IL-12 on intrapulmonary levels of these cytokines during replicative L. pneumophila lung infection were subsequently assessed. Results of these experiments demonstrated that TNF-α activity was significantly lower, while protein levels of IFN-γ and IL-10 in the lung were similar, in L. pneumophila-infected mice administered IL-12 antiserum, compared to similarly infected untreated mice. Together, these results demonstrate that IL-12 is critical for resolution of replicativeL. pneumophila lung infection and suggest that regulation of intrapulmonary growth of L. pneumophila by endogenous IL-12 is mediated, at least in part, by TNF-α.


2004 ◽  
Vol 11 (1) ◽  
pp. 106-110 ◽  
Author(s):  
Hajime Sasaki ◽  
Khaled Balto ◽  
Nobuyuki Kawashima ◽  
Jean Eastcott ◽  
Katsuaki Hoshino ◽  
...  

ABSTRACT Periapical granulomas are induced by bacterial infection of the dental pulp and result in destruction of the surrounding alveolar bone. In previous studies we have reported that the bone resorption in this model is primarily mediated by macrophage-expressed interleukin-1 (IL-1). The expression and activity of IL-1 is in turn modulated by a network of Th1 and Th2 regulatory cytokines. In the present study, the functional roles of the Th1 cytokine gamma interferon (IFN-γ) and IFN-γ-inducing cytokines IL-12 and IL-18 were determined in a murine model of periapical bone destruction. IL-12−/−, IL-18−/−, and IFN-γ−/− mice were subjected to surgical pulp exposure and infection with a mixture of four endodontic pathogens, and bone destruction was determined by microcomputed tomography on day 21. The results indicated that all IL-12−/−, IL-18−/−, and IFN-γ−/− mice had similar infection-stimulated bone resorption in vivo as wild-type control mice. Mice infused with recombinant IL-12 also had resorption similar to controls. IFN-γ−/− mice exhibited significant elevations in IL-6, IL-10, IL-12, and tumor necrosis factor alpha in lesions compared to wild-type mice, but these modulations had no net effect on IL-1α levels. Recombinant IL-12, IL-18, and IFN-γ individually failed to consistently modulate macrophage IL-1α production in vitro. We conclude that, at least individually, endogenous IL-12, IL-18, and IFN-γ do not have a significant effect on the pathogenesis of infection-stimulated bone resorption in vivo, suggesting possible functional redundancy in proinflammatory pathways.


2018 ◽  
Vol 86 (10) ◽  
Author(s):  
Gabriela González-Espinoza ◽  
Elías Barquero-Calvo ◽  
Esteban Lizano-González ◽  
Alejandro Alfaro-Alarcón ◽  
Berny Arias-Gómez ◽  
...  

ABSTRACT Brucellosis is a bacterial disease of animals and humans. Brucella abortus barely activates the innate immune system at the onset of infection, and this bacterium is resistant to the microbicidal action of complement. Since complement stands as the first line of defense during bacterial invasions, we explored the role of complement in B. abortus infections. Brucella abortus-infected mice depleted of complement with cobra venom factor (CVF) showed the same survival rate as mice in the control group. The complement-depleted mice readily eliminated B. abortus from the spleen and did so more efficiently than the infected controls after 7 days of infection. The levels of the proinflammatory cytokines tumor necrosis factor alpha and interleukin-6 (IL-6) remained within background levels in complement-depleted B. abortus-infected mice. In contrast, the levels of the immune activator cytokine gamma interferon and the regulatory cytokine IL-10 were significantly increased. No significant histopathological changes in the liver and spleen were observed between the complement-depleted B. abortus-infected mice and the corresponding controls. The action exerted by Brucella on the immune system in the absence of complement may correspond to a broader phenomenon that involves several components of innate immunity.


2009 ◽  
Vol 77 (9) ◽  
pp. 3909-3918 ◽  
Author(s):  
Xiaoti Guo ◽  
Lisa Barroso ◽  
Steven M. Becker ◽  
David M. Lyerly ◽  
Thomas S. Vedvick ◽  
...  

ABSTRACT We have previously shown that vaccination with purified Entamoeba histolytica Gal/GalNAc lectin or recombinant subunits can protect mice from intestinal amebiasis upon intracecal challenge. In this study, we demonstrated with adoptive-transfer experiments that this lectin vaccine protection is mediated by T cells but not serum. The cell-mediated immune (CMI) response was characterized by significant gamma interferon (IFN-γ), interleukin 12 (IL-12), IL-2, IL-10, and IL-17 production. To move toward a human vaccine, we switched to a recombinant protein and tested a range of adjuvants and routes appropriate for humans. We found that subcutaneous delivery of LecA with IDRI's adjuvant system EM014 elicited a potent Th1-type CMI profile and provided significant protection, as measured by culture negativity (79% efficacy); intranasal immunization with cholera toxin provided 56% efficacy; and alum induced a Th2-type response that protected 62 to 68% of mice. Several antibody and CMI cytokine responses were examined for correlates of protection, and prechallenge IFN-γ+ or IFN-γ-, IL-2-, and tumor necrosis factor alpha-triple-positive CD4 cells in blood were statistically associated with protection. To test the role of IFN-γ in LecA-mediated protection, we neutralized IFN-γ in LecA-immunized mice and found that it abrogated the protection conferred by vaccination. These data demonstrate that CMI is sufficient for vaccine protection from intestinal amebiasis and reveal an important role for IFN-γ, even in the setting of alum.


2012 ◽  
Vol 80 (3) ◽  
pp. 943-951 ◽  
Author(s):  
Duangjit Kanistanon ◽  
Daniel A. Powell ◽  
Adeline M. Hajjar ◽  
Mark R. Pelletier ◽  
Ilana E. Cohen ◽  
...  

Lipopolysaccharide (LPS) structural modifications have been shown to specifically affect the pathogenesis of many Gram-negative pathogens. InFrancisella, modification of the lipid A component of LPS resulted in a molecule with no to low endotoxic activity. The role of the terminal lipid A phosphates in host recognition and pathogenesis was determined using aFrancisella novicidamutant that lacked the 4′ phosphatase enzyme (LpxF). The lipid A of this strain retained the phosphate moiety at the 4′ position and the N-linked fatty acid at the 3′ position on the diglucosamine backbone. Studies were undertaken to determine the pathogenesis of this mutant strain via the pulmonary and subcutaneous routes of infection. Mice infected with thelpxF-nullF. novicidamutant by either route survived primary infection and subsequently developed protective immunity against a lethal wild-type (WT)F. novicidachallenge. To determine the mechanism(s) by which the host controlled primary infection by thelpxF-null mutant, the role of innate immune components, including Toll-like receptor 2 (TLR2), TLR4, caspase-1, MyD88, alpha interferon (IFN-α), and gamma interferon(IFN-γ), was examined using knockout mice. Interestingly, only the IFN-γ knockout mice succumbed to a primarylpxF-nullF. novicidamutant infection, highlighting the importance of IFN-γ production. To determine the role of components of the host adaptive immune system that elicit the long-term protective immune response, T- and B-cell deficient RAG1−/−mice were examined. All mice survived primary infection; however, RAG1−/−mice did not survive WT challenge, highlighting a role for T and B cells in the protective immune response.


2004 ◽  
Vol 72 (1) ◽  
pp. 176-186 ◽  
Author(s):  
Marco A. Campos ◽  
Gracia M. S. Rosinha ◽  
Igor C. Almeida ◽  
Xirlene S. Salgueiro ◽  
Bruce W. Jarvis ◽  
...  

ABSTRACT Initial host defense to bacterial infection is executed by innate immunity, and therefore the main goal of this study was to examine the contribution of Toll-like receptors (TLRs) during Brucella abortus infection. CHO reporter cell lines transfected with CD14 and TLRs showed that B. abortus triggers both TLR2 and TLR4. In contrast, lipopolysaccharide (LPS) and lipid A derived from Brucella rough (R) and smooth (S) strains activate CHO cells only through TLR4. Consistently, macrophages from C3H/HePas mice exposed to R and S strains and their LPS produced higher levels of tumor necrosis factor alpha (TNF-α) and interleukin-12 compared to C3H/HeJ, a TLR4 mutant mouse. The essential role of TLR4 for induction of proinflammatory cytokines was confirmed with diphosphoryl lipid A from Rhodobacter sphaeroides. Furthermore, to determine the contribution of TLR2 and TLR4 in bacterial clearance, numbers of Brucella were monitored in the spleen of C3H/HeJ, C3H/HePas, TLR2 knockout, and wild-type mice at 1, 3, and 6 weeks following B. abortus infection. Interestingly, murine brucellosis was markedly exacerbated at weeks 3 and 6 after infection in animals that lacked functional TLR4 (C3H/HeJ) compared to C3H/HePas that paralleled the reduced gamma interferon production by this mouse strain. Finally, by mass spectrometry analysis we found dramatic differences on the lipid A profiles of R and S strains. In fact, S lipid A was shown to be more active to trigger TLR4 than R lipid A in CHO cells and more effective in inducing dendritic cell maturation. In conclusion, these results indicate that TLR4 plays a role in resistance to B. abortus infection and that S lipid A has potent adjuvant activity.


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