scholarly journals Transient Neutralization of Tumor Necrosis Factor Alpha Can Produce a Chronic Fungal Infection in an Immunocompetent Host: Potential Role of Immature Dendritic Cells

2005 ◽  
Vol 73 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Amy C. Herring ◽  
Nicole R. Falkowski ◽  
Gwo-Hsiao Chen ◽  
Rod A. McDonald ◽  
Galen B. Toews ◽  
...  

ABSTRACT The mechanisms underlying induction of immune dysregulation and chronic fungal infection by a transient tumor necrosis factor alpha (TNF-α) deficiency remain to be defined. The objective of our studies was to determine the potential contribution of neutropenia and immature dendritic cells to the immune deviation. Administration of an anti-TNF-α monoclonal antibody at day 0 neutralized TNF-α only during the first week of a pulmonary Cryptococcus neoformans infection. Transient neutralization of TNF-α resulted in transient depression of interleukin-12 (IL-12), monocyte chemotactic protein 1 (MCP-1), and gamma interferon (IFN-γ) production but permanently impaired long-term clearance of the infection from the lungs even after the levels of these cytokines increased and a vigorous inflammatory response developed. Early neutrophil recruitment was defective in the absence of TNF-α. However, as demonstrated by neutrophil depletion studies, this did not account for the decrease in IL-12 and IFN-γ levels and did not play a role in establishing chronic pulmonary cryptococcal infection. Transient TNF-α neutralization also produced a deficiency in CD11c+ MHC II+ cells and IL-12 in the lymph nodes, potentially implicating a defect in mature dendritic cell trafficking. Transfer of cryptococcal antigen-pulsed immature dendritic cells into naïve mice prior to intratracheal challenge resulted in the development of a nonprotective immune response to C. neoformans that was similar to that observed in anti-TNF-α-treated mice (increased IL-4, IL-5, and IL-10 levels, pulmonary eosinophilia, and decreased clearance). Thus, stimulation of an antifungal response by immature dendritic cells can result in an immune deviation similar to that produced by transient TNF-α deficiency, identifying a new mechanism by which a chronic fungal infection can occur in an immunocompetent host.

2001 ◽  
Vol 69 (5) ◽  
pp. 2847-2852 ◽  
Author(s):  
Julia Y. Lee ◽  
Kathleen E. Sullivan

ABSTRACT Lipopolysaccharide (LPS) is a very potent inducer of tumor necrosis factor alpha (TNF-α) expression from monocytes and macrophages. Another inflammatory cytokine, gamma interferon (IFN-γ), can potentiate the effects of LPS, but the mechanism is not thoroughly understood. Previous reports emphasized the ability of IFN-γ to upregulate CD14 expression (the receptor for LPS), and nearly all studies have utilized sequential stimulation with IFN-γ followed by LPS to exploit this phenomenon. This study demonstrates that IFN-γ can upregulate the effect of LPS at the level of transcription. Human monoblastic Mono-Mac-6 cells produced up to threefold-greater levels of TNF-α when simultaneously stimulated with LPS and IFN-γ compared to treatment with LPS alone. RNase protection studies showed a similar increase in RNA beginning as early as within 30 min. The synthesis of TNF-α mRNA in IFN-γ- and LPS-treated Mono-Mac-6 cells was also temporally prolonged even though the message turnover rate was identical to that seen in LPS stimulated cells. The modulatory effect of IFN-γ may be mediated by Jak2.


2005 ◽  
Vol 73 (2) ◽  
pp. 849-858 ◽  
Author(s):  
Simone Korten ◽  
Richard J. Anderson ◽  
Carolyn M. Hannan ◽  
Eric G. Sheu ◽  
Robert Sinden ◽  
...  

ABSTRACT Understanding the protective mechanism in the liver induced by recombinant vaccines against the pre-erythrocytic stages of malaria is important for vaccine development. Most studies in mice have focused on splenic and peripheral blood T cells and identified gamma interferon (IFN-γ)-producing CD8+ T cells as correlates of protection, which can be induced by prime-boost vaccination with recombinant poxviruses. Invariant natural killer T (Vα14iNKT) cells can also protect against liver stage malaria, when activated, and are abundant in the liver. Since poxviruses have nonspecific immunomodulating effects, which are incompletely understood, we investigated whether recombinant poxviruses affect the protective properties of hepatic Vα14iNKT cells and thus vaccine efficacy. We show that intradermal vaccination with recombinant poxviruses activated Vα14iNKT cells and NK cells in the livers of BALB/c mice while inducing IFN-γ- and tumor necrosis factor alpha (TNF-α)-producing pre-erythrocytic stage antigen-specific CD8+ T cells. Greater numbers of hepatic Vα14iNKT cells secreted interleukin-4 than IFN-γ. Vaccinated Vα14iNKT-cell-deficient mice had lower, but still protective levels of hepatic and splenic IFN-γ+ and TNF-α+ CD8+ T cells and better protection rates later after challenge with Plasmodium berghei sporozoites. Therefore, vaccine-activated hepatic Vα14iNKT cells help in generating specific T cells but are not required for protection induced by recombinant poxviruses. Furthermore, double-positive INF-γ+/TNF-α+ CD8+ T cells were enriched in protected livers, suggesting that cells expressing both of these cytokines may be most relevant for protection.


Author(s):  
NELLY MARISSA ◽  
NUR RAMADHAN ◽  
SARI HANUM ◽  
MARLINDA ◽  
EKA FITRIA ◽  
...  

Objective: This study aimed to determine the decreased immune response of tuberculosis (TB) with diabetes mellitus (DM) patients. Methods: A total of 105 TB patients who were undergoing treatment at health centers and hospitals in Banda Aceh and Aceh Besar were included in this study. Data collection was carried out by interviewed to obtained demographic and respondent categories based on the diagnosis. Measurements of height and weight were also conducted to obtain body mass index data. 5 mL peripheral blood was taken from each respondent group into a TB with DM (TB+DM) and TB without DM (TB-DM). The blood tested usage tumor necrosis factor-alpha (TNF-α) level using enzyme-linked immunosorbent assay and interferon-gamma (IFN-γ) using IFN-γ release assay. Results: The average concentration of both TNF-α and IFN-γ was higher in TB-DM group (TNF-a 5.2 pg/mL; IFN-g 1.5 IU/mL) than in TB+DM group (TNF-a 2.06 pg/mL; IFN-g 2.86 IU/mL). There were significant differences in TNF-α between the two groups but no significant differences in IFN-γ protein concentration. Conclusion: The immune response of TB patients with DM symptoms was markedly reduced by the decreased expression of TNF-α and IFN-γ.


2004 ◽  
Vol 72 (3) ◽  
pp. 1725-1732 ◽  
Author(s):  
Ravi Jotwani ◽  
Christopher W. Cutler

ABSTRACT Porphyromonas gingivalis is a fimbriated mucosal pathogen implicated in chronic periodontitis (CP). The fimbriae are required for invasion of the gingival mucosa and for induction of CP in animal models of periodontitis. CP is associated with infection of immature dendritic cells (DCs) by P. gingivalis in situ and with increased numbers of dermal DCs (DDCs) and mature DCs in the lamina propria. The role of fimbriae in gaining entry into human DCs and how this modulates the inflammatory and effector immune responses, however, have not been explored. To address this, we generated monocyte-derived DCs (MDDCs) in vitro which phenotypically and functionally resemble DDCs. We show here that virulent fimbriated P. gingivalis 381, in contrast to its fimbria-deficient mutant, P. gingivalis DPG3, efficiently gains entry to MDDCs in a manner dependent on active cell metabolism and cytoskeletal rearrangement. In addition, uptake of 381, unlike DPG3, induces DCs to undergo maturation, upregulate costimulatory molecules, and secrete inflammation cytokines interleukin-1β (IL-1β), IL-6, tumor necrosis factor alpha, IL-10, and IL-12. Moreover, MDDCs pulsed with 381 also stimulated a higher autologous mixed lymphocyte reaction and induced a Th1-type response, with gamma interferon (IFN-γ) being the main cytokine. Monocytes used as controls demonstrated fimbria-dependent uptake of 381 as well but produced low levels of inflammatory cytokines compared to MDDCs. When MDDCs were pulsed with recombinant fimbrillin of P. gingivalis (10 μg/ml), maturation of MDDCs was also induced; moreover, matured MDDCs induced proliferation of autologous CD4+ T cells and release of IFN-γ. Thus, these results establish the significance of P. gingivalis fimbriae in the uptake of P. gingivalis by MDDCs and in induction of immunostimulatory Th1 responses.


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.


2005 ◽  
Vol 73 (4) ◽  
pp. 2175-2183 ◽  
Author(s):  
Anton Pernthaner ◽  
Sally-Ann Cole ◽  
Lilian Morrison ◽  
Wayne R. Hein

ABSTRACT Cytokine gene expression in cells migrating in afferent and efferent intestinal lymph was monitored for extended time periods in individual sheep experimentally infected with the nematode Trichostrongylus colubriformis. Animals from stable selection lines with increased levels of either genetic resistance (R) or susceptibility (S) to nematode infection were used. Genes for interleukin-5 (IL-5), IL-13, and tumor necrosis factor alpha (TNF-α), but not for IL-4, IL-10, or gamma interferon (IFN-γ), were consistently expressed at higher levels in both afferent and efferent lymph cells of R sheep than in S sheep. However, only minor differences were observed in the surface phenotypes and antigenic and mitogenic responsiveness of cells in intestinal lymph between animals from the two selection lines. The IL-4 and IL-10 genes were expressed at higher levels in afferent lymph cells than in efferent lymph cells throughout the course of the nematode infection in animals of both genotypes, while the proinflammatory TNF-α gene was relatively highly expressed in both lymph types. These relationships notwithstanding, expression of the IL-10 and TNF-α genes declined significantly in afferent lymph cells but not in efferent lymph cells during infection. Collectively, the results showed that R-line sheep developed a strong polarization toward a Th2-type cytokine profile in immune cells migrating in lymph from sites where the immune response to nematodes was initiated, although the IFN-γ gene was also expressed at moderate levels. Genes or alleles that predispose an animal to develop this type of response appear to have segregated with the R selection line and may contribute to the increased resistance of these animals.


2003 ◽  
Vol 10 (5) ◽  
pp. 960-966 ◽  
Author(s):  
W. R. Waters ◽  
M. V. Palmer ◽  
D. L. Whipple ◽  
M. P. Carlson ◽  
B. J. Nonnecke

ABSTRACT Bovine tuberculosis in the United States has proven costly to cattle producers as well as to government regulatory agencies. While in vivo responsiveness to mycobacterial antigens is the current standard for the diagnosis of tuberculosis, in vitro assays are gaining acceptance, especially as ancillary or complementary tests. To evaluate in vitro indices of cellular sensitization, antigen-induced gamma interferon (IFN-γ), nitric oxide (NO), and tumor necrosis factor alpha (TNF-α) responses by blood mononuclear cells from Mycobacterium bovis-infected cattle were quantified and compared. Using an aerosol model of infection, two doses of each of two strains of M. bovis (95-1315 and HC-2045T) were used to induce a range of IFN-γ, NO, and TNF-α responses. Infection-specific increases in NO, but not in IFN-γ or TNF-α, were detected in nonstimulated cultures at 48 h, a finding that is indicative of nonspecific activation and spontaneous release of NO. The infective dose of M. bovis organisms also influenced responses. At 34 days postinfection, IFN-γ, NO, and TNF-α responses in antigen-stimulated cells from cattle receiving 105 CFU of M. bovis organisms were greater than responses of cells from cattle infected with 103 CFU of M. bovis organisms. The NO response, but not the IFN-γ and TNF-α responses, was influenced by infective strains of M. bovis. The TNF-α, NO, and IFN-γ responses followed similar kinetics, with strong positive associations among the three readouts. Overall, these findings indicate that NO and TNF-α, like IFN-γ, may prove useful as indices for the diagnosis of bovine tuberculosis.


2001 ◽  
Vol 69 (11) ◽  
pp. 6912-6922 ◽  
Author(s):  
Annette Kolb-Mäurer ◽  
Alexandra Unkmeir ◽  
Ulrike Kämmerer ◽  
Claudia Hübner ◽  
Thomas Leimbach ◽  
...  

ABSTRACT Infection with Neisseria meningitidis serogroup B is responsible for fatal septicemia and meningococcal meningitis. The severity of disease directly correlates with the production of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), IL-6, and IL-8. However, the source of these cytokines has not been clearly defined yet. Since bacterial infection involves the activation of dendritic cells (DCs), we analyzed the interaction of N. meningitidis with monocyte-derived DCs. Using N. meningitidis serogroup B wild-type and unencapsulated bacteria, we found that capsule expression significantly impaired neisserial adherence to DCs. In addition, phagocytic killing of the bacteria in the phagosome is reduced by at least 10- to 100-fold. However, all strains induced strong secretion of proinflammatory cytokines TNF-α, IL-6, and IL-8 by DCs (at least 1,000-fold at 20 h postinfection [p.i.]), with significantly increased cytokine levels being measurable by as early as 6 h p.i. Levels of IL-1β, in contrast, were increased only 200- to 400-fold at 20 h p.i. with barely measurable induction at 6 h p.i. Moreover, comparable amounts of cytokines were induced by bacterium-free supernatants of Neisseria cultures containing neisserial lipooligosaccharide as the main factor. Our data suggest that activated DCs may be a significant source of high levels of proinflammatory cytokines in neisserial infection and thereby may contribute to the pathology of meningococcal disease.


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