TNF-α Modulates TLR2-Dependent Responses During Mycobacterial Infection

Author(s):  
Sahana Holla ◽  
Jamma Trinath ◽  
Kithiganahalli Narayanaswamy Balaji
2021 ◽  
Vol 12 (1) ◽  
pp. 16-26
Author(s):  
Kimberly To ◽  
Ruoqiong Cao ◽  
Aram Yegiazaryan ◽  
James Owens ◽  
Kayvan Sasaninia ◽  
...  

Abstract Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tb) still remains a devastating infectious disease in the world. There has been a daunting increase in the incidence of Type 2 Diabetes Mellitus (T2DM) worldwide. T2DM patients are three times more vulnerable to M. tb infection compared to healthy individuals. TB-T2DM coincidence is a challenge for global health control. Despite some progress in the research, M. tb still has unexplored characteristics in successfully evading host defenses. The lengthy duration of treatment, the emergence of multi-drug-resistant strains and extensive-drug-resistant strains of M. tb have made TB treatment very challenging. Previously, we have tested the antimycobacterial effects of everolimus within in vitro granulomas generated from immune cells derived from peripheral blood of healthy subjects. However, the effectiveness of everolimus treatment against mycobacterial infection in individuals with T2DM is unknown. Furthermore, the effectiveness of the combination of in vivo glutathione (GSH) supplementation in individuals with T2DM along with in vitro treatment of isolated immune cells with everolimus against mycobacterial infection has never been tested. Therefore, we postulated that liposomal glutathione (L-GSH) and everolimus would offer great hope for developing adjunctive therapy for mycobacterial infection. L-GSH or placebo was administered to T2DM individuals orally for three months. Study subjects’ blood was drawn pre- and post-L-GSH/or placebo supplementation, where Peripheral Blood Mononuclear Cells (PBMCs) were isolated from whole blood to conduct in vitro studies with everolimus. We found that in vitro treatment with everolimus, an mTOR (membrane target of rapamycin) inhibitor, significantly reduced intracellular M. bovis BCG infection alone and in conjunction with L-GSH supplementation. Furthermore, we found L-GSH supplementation coupled with in vitro everolimus treatment produced a greater effect in inhibiting the growth of intracellular Mycobacterium bovis BCG, than with the everolimus treatment alone. We also demonstrated the functions of L-GSH along with in vitro everolimus treatment in modulating the levels of cytokines such as IFN-γ, TNF-α, and IL-2 and IL-6, in favor of improving control of the mycobacterial infection. In summary, in vitro everolimus-treatment alone and in combination with oral L-GSH supplementation for three months in individuals with T2DM, was able to increase the levels of T-helper type 1 (Th1) cytokines IFN-γ, TNF-α, and IL-2 as well as enhance the abilities of granulomas from individuals with T2DM to improve control of a mycobacterial infection.


2021 ◽  
Author(s):  
Elinor Hortle ◽  
Lam Vi Tran ◽  
Angela RM Fontaine ◽  
Natalia Pinello ◽  
Justin JL Wong ◽  
...  

Pathogenic mycobacteria inhibit inflammasome activation as part of their pathogenesis. While it is known that potassium efflux is a trigger for inflammasome activation, the interaction between mycobacterial infection, potassium efflux and inflammasome activation has not been investigated. Here we use Mycobacterium marinum infection of zebrafish embryos to demonstrate that pathogenic mycobacteria upregulate the host WNK signalling pathway kinases SPAK and OXSR1 which control intracellular potassium balance. We show that genetic depletion or inhibition of OXSR1 decreases bacterial burden and intracellular potassium levels. The protective effects of OXSR1 depletion are mediated by NLRP3 inflammasome activation and are dependent on caspase-mediated release of IL-1β and the downstream activation of protective TNF-α. The elucidation of this druggable pathway to potentiate inflammasome activation provides a new avenue for the development of host-directed therapies against intracellular infections.


2004 ◽  
Vol 72 (5) ◽  
pp. 2477-2483 ◽  
Author(s):  
Naoko Aoki ◽  
Anna Zganiacz ◽  
Peter Margetts ◽  
Zhou Xing

ABSTRACT DAP12 and its associating molecules MDL-1, TREM-1, and TREM-2 are the recently identified immune regulatory molecules, expressed primarily on myeloid cells including monocytes/macrophages, dendritic cells, NK cells, and neutrophils. However, little is known about the regulation of their expression during host antimicrobial responses. We have investigated the effect of pulmonary mycobacterial infection and type 1 cytokines on the expression of these molecules both in vivo and in vitro. While DAP12 was constitutively expressed at high levels in the lungs, the MDL-1, TREM-1, and TREM-2 molecules were inducible during mycobacterial infection. Their kinetic expression was correlated with that of the type 1 cytokines tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ). In primary lung macrophage cultures, high constitutive levels of DAP12 and TREM-2 were not modulated by mycobacterial or type 1 cytokine exposure. In contrast, expression of both MDL-1 and TREM-1 was markedly induced by mycobacterial infection and such induction was inhibited by concurrent exposure to IFN-γ. On mycobacterial infection of TNF-α−/− and IFN-γ−/− mice in vivo or their lung macrophages in vitro, TNF-α was found to be critical for mycobacterially induced MDL-1, but not TREM-1, expression whereas IFN-γ negatively regulated mycobacterially induced MDL-1 and TREM-1 expression. Our findings thus suggest that DAP12 and its associating molecules are differentially regulated by mycobacterial infection and type 1 cytokines and that MDL-1- and TREM-1-triggered DAP12 signaling may play an important role in antimicrobial type 1 immunity.


2003 ◽  
Vol 71 (1) ◽  
pp. 254-259 ◽  
Author(s):  
Carrie J. Riendeau ◽  
Hardy Kornfeld

ABSTRACT We previously reported that Mycobacterium tuberculosis infection primes human alveolar macrophages (HAM) for tumor necrosis factor alpha (TNF-α)-mediated apoptosis and that macrophage apoptosis is associated with killing internalized bacilli. Virulent mycobacterial strains elicit much less apoptosis than attenuated strains, implying that apoptosis is a defense against intracellular infection. The present study evaluated the potential for phorbol myristate acetate-differentiated THP-1 cells to mimic this response of primary macrophages. Consistent with the behavior of alveolar macrophages, attenuated M. tuberculosis H37Ra and Mycobacterium bovis BCG strongly induce THP-1 apoptosis, which requires endogenous TNF. THP-1 apoptosis is associated with reduced viability of infecting BCG. In contrast, virulent wild-type M. tuberculosis H37Rv and M. bovis do not increase THP-1 apoptosis over baseline. BCG induced early activation of caspase 10 and 9, followed by caspase 3. In contrast, wild-type M. bovis infection failed to activate any caspases in THP-1 cells. BCG-induced THP-1 apoptosis is blocked by retroviral transduction with vectors expressing crmA but not bcl-2. We conclude that differentiated THP-1 cells faithfully model the apoptosis response of HAM. Analysis of the THP-1 cell response to infection with virulent mycobacteria suggests that TNF death signals are blocked proximal to initiator caspase activation, at the level of TNF receptor 1 or its associated intracytoplasmic adaptor complex. Interference with TNF death signaling may be a virulence mechanism that allows M. tuberculosis to circumvent innate defenses leading to apoptosis of infected host cells.


2000 ◽  
Vol 68 (12) ◽  
pp. 6954-6961 ◽  
Author(s):  
Linda-Gail Bekker ◽  
Andre L. Moreira ◽  
Amy Bergtold ◽  
Sherry Freeman ◽  
Bernard Ryffel ◽  
...  

ABSTRACT In experimental mycobacterial infection, tumor necrosis factor alpha (TNF-α) is required for control of bacillary growth and the protective granulomatous response, but may cause immunopathology. To directly examine the positive and detrimental effects of this cytokine, a murine model was used in which different amounts of TNF-α were delivered to the site of infection. Mice with a disruption in the TNF-α gene (TNF-KO) or wild-type mice were infected with low or high doses of recombinant Mycobacterium bovis BCG that secreted murine TNF-α (BCG-TNF). Infection of TNF-KO mice with BCG containing the vector (BCG-vector) at a low dose led to increased bacillary load in all organs and an extensive granulomatous response in the lungs and spleen. The mice succumbed to the infection by ∼40 days. However, when TNF-KO mice were infected with low doses of BCG-TNF, bacillary growth was controlled, granulomas were small and well differentiated, the spleen was not enlarged, and the mice survived. Infection with high inocula of BCG-TNF resulted in bacterial clearance, but was accompanied by severe inflammation in the lungs and spleen and earlier death compared to the results from the mice infected with high inocula of BCG-vector. Wild-type mice controlled infection with either recombinant strain, but showed decreased survival following high-dose BCG-TNF infection. The effects of TNF-α required signaling through an intact receptor, since the differential effects were not observed when TNF-α receptor-deficient mice were infected. The results suggest that the relative amount of TNF-α at the site of infection determines whether the cytokine is protective or destructive.


2006 ◽  
Vol 75 (2) ◽  
pp. 820-829 ◽  
Author(s):  
Edhyana Sahiratmadja ◽  
Bachti Alisjahbana ◽  
Tjitske de Boer ◽  
Iskandar Adnan ◽  
Anugrah Maya ◽  
...  

ABSTRACT Pro- and anti-inflammatory cytokines and their signaling pathways play key roles in protection from and pathogenesis of mycobacterial infection, and their balance and dynamic changes may control or predict clinical outcome. Peripheral blood cells' capacity to produce proinflammatory (tumor necrosis factor alpha [TNF-α], interleukin-12/23p40 [IL-12/23p40], and gamma interferon [IFN-γ]) and anti-inflammatory (IL-10) cytokines in response to Mycobacterium tuberculosis or unrelated stimuli (lipopolysaccharide, phytohemagglutinin) was studied in 93 pulmonary tuberculosis (TB) patients and 127 healthy controls from Indonesia. Their cells' ability to respond to IFN-γ was examined to investigate whether M. tuberculosis infection can also inhibit IFN-γ receptor (IFN-γR) signaling. Although there was interindividual variability in the observed responses, the overall results revealed that M. tuberculosis-induced TNF-α and IFN-γ levels showed opposite trends. Whereas TNF-α production was higher in active-TB patients than in controls, IFN-γ production was strongly depressed during active TB, correlated inversely with TB disease severity, and increased during therapy. By contrast, mitogen-induced IFN-γ production, although lower in patients than in controls, did not change during treatment, suggesting an M. tuberculosis-specific and reversible component in the depression of IFN-γ. Depressed IFN-γ production was not due to decreased IL-12/IL-23 production. Importantly, IFN-γ-inducible responses were also significantly depressed during active TB and normalized during treatment, revealing disease activity-related and reversible impairment in IFN-γR signaling in TB. Finally, IFN-γ/IL-10 ratios significantly correlated with TB cure. Taken together, these results show that M. tuberculosis-specific stimulation of IFN-γ (but not TNF-α) production and IFN-γR signaling are significantly depressed in active TB, correlate with TB disease severity and activity, and normalize during microbiological TB cure. The depression of both IFN-γ production and IFN-γR signaling may synergize in contributing to defective host control in active TB.


2018 ◽  
Author(s):  
Lu Meng ◽  
Lingling Xie ◽  
Yuanqing Kan ◽  
Lixia Liu ◽  
Wenyue Dong ◽  
...  

Macrophages are the first-line host defense where the invading Mycobacterium tuberculosis (Mtb) encounters. It has been recently reported that host aerobic glycolysis was elevated post the infection by a couple of virulent mycobacterial species. However, whether this metabolic transition is required for host defense against intracellular pathogens and the underlying mechanisms remain to be further investigated. By analyzing carbon metabolism, we found that macrophages infected by M. marinum, a surrogate mycobacterial specie to Mtb, showed a strong elevation of glycolysis. Next, three glycolysis inhibitors were examined for their ability to inhibit mycobacterial proliferation inside RAW264.7, a murine macrophage-like cell line. Among them, a glucose analog, 2-deoxyglucose (2-DG) displayed a protective effect on assisting host to resist mycobacterial infection, which was further validated in zebrafish-infection model. The phagocytosis of M. marinum was significantly decreased in macrophages pre-treated with 2-DG at concentrations of 0.5 and 1 mM, at which no inhibitory effect was posed on M. marinum growth in vitro. Moreover, 2-DG pre-treatment exerted a significant protective effect on zebrafish larvae to limit the proliferation of M. marinum, and such effect was correlated to tumor necrosis factor alpha (TNF-α). On the contrary, the 2-DG treatment post infection did not restrain proliferation of M. marinum in WT zebrafish, and even accelerated bacterial replication in TNF-α-/- zebrafish. Together, modulation of glycolysis prior to infection boosts host immunity against M. marinum infection, indicating a potential intervention strategy to control mycobacterial infection.


2009 ◽  
Vol 77 (12) ◽  
pp. 5537-5542 ◽  
Author(s):  
M. Djavad Mossalayi ◽  
Ioannis Vouldoukis ◽  
Maria Mamani-Matsuda ◽  
Tina Kauss ◽  
Jean Guillon ◽  
...  

ABSTRACT Engagement of surface receptors contributes to the antimicrobial activity of human immune cells. We show here that infection of human monocyte-derived macrophages (MDM) with live Mycobacterium avium induced the expression of CD23 on their membrane. Subsequent cross-linking of surface CD23 by appropriate ligands induced a dose-dependent antibacterial activity of MDM and the elimination of most infected cells. The stimulation of inducible nitric oxide synthase-dependent generation of NO from MDM after CD23 activation played a major role during their anti-M. avium activity. CD23 activation also induced tumor necrosis factor alpha (TNF-α) production from MDM. Mycobacteria reduction was partially inhibited by the addition of neutralizing anti-TNF-α antibody to cell cultures without affecting NO levels, which suggested the role of this cytokine for optimal antimicrobial activity. Finally, interleukin-10, a Th2 cytokine known to downregulate CD23 pathway, is shown to decrease NO generation and mycobacteria elimination by macrophages. Therefore, (i) infection with M. avium promotes functional surface CD23 expression on human macrophages and (ii) subsequent signaling of this molecule contributes to the antimicrobial activity of these cells through an NO- and TNF-α-dependent pathway. This study reveals a new human immune response mechanism to counter mycobacterial infection involving CD23 and its related ligands.


Apmis ◽  
2008 ◽  
Vol 109 (7-8) ◽  
pp. 533-540
Author(s):  
Hideki Kitaura ◽  
Naoya Ohara ◽  
Kazuhide Kobayashi ◽  
Takeshi Yamada

2020 ◽  
Vol 8 (11) ◽  
pp. 1804
Author(s):  
Dania AlQasrawi ◽  
Saleh A. Naser

Recently, we reported that cigarette smoking, and especially nicotine, increases susceptibility to mycobacterial infection and exacerbates inflammation in patients with Crohn’s disease (CD). The macrophagic response to Mycobacterium avium subspecies paratuberculosis (MAP) in CD and Mycobacteria tuberculosis (MTB) continues to be under investigation. The role of toll-like-receptors (TLRs) and cytoplasmic adaptor protein (MyD88) in proinflammatory response during Mycobacterial infection has been suggested. However, the mechanism of how nicotine modulates macrophage response during infection in CD and exacerbates inflammatory response remain unclear. In this study, we elucidated the mechanistic role of nicotine in modulating MyD88-dependent/TLR pathway signaling in a macrophage system during mycobacterial infection. The data demonstrated that MAP infection in THP-1 derived macrophages was mediated through TLR2 and MyD88 leading to increase in IL-8 in expression and production. On the other hand, LPS-representing, Gram-negative bacteria mediated macrophage response through TLR4. Blocking TLR2 and TLR4 with antagonists voided the effect of MAP, and LPS, respectively in macrophages and reversed response with decrease in expression of iNOS, TNF-α and IL-8. Interestingly, nicotine in infected macrophages significantly (1) downregulated TLR2 and TLR4 expression, (2) activated MyD88, (3) increased M1/M2 ratio, and (4) increased expression and secretion of proinflammatory cytokines especially IL-8, as seen in CD smokers. We also discovered that blocking macrophages during MAP infection with MyD88 antagonist significantly decreased response which illustrates the key role for MyD88 during infection. Surprisingly, dual treatment of MAP-infected macrophages with MyD88 antagonist and nicotine absolutely impaired immune response and decreased MAP viability, which clearly validate the inflammatory role of nicotine in macrophages through TLR2/MyD88 pathway during infection. This is the first report to describe the mechanism by which nicotine modulates TLR2/MyDD88 and exacerbates inflammation in CD smokers associated with infection.


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