scholarly journals In Vitro Investigation of Host Resistance toToxoplasma gondii Infection in Microglia of BALB/c and CBA/Ca Mice

2001 ◽  
Vol 69 (2) ◽  
pp. 765-772 ◽  
Author(s):  
Yvonne R. Freund ◽  
Naunihal T. Zaveri ◽  
Harold S. Javitz

ABSTRACT Toxoplasmic encephalitis (TE) is a life-threatening disease of immunocompromised individuals and has increased in prevalence as a consequence of AIDS. TE has been modeled in inbred mice, with CBA/Ca mice being susceptible and BALB/c mice resistant to the development of TE. To better understand the innate mechanisms in the brain that play a role in resistance to TE, nitric oxide (NO)-dependent and NO-independent mechanisms were examined in microglia from BALB/c and CBA/Ca mice and correlated with the ability of these cells to inhibit Toxoplasma gondii replication. These parameters were measured 48 h after stimulation with lipopolysaccharide (LPS) gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), or combinations of these inducers in T. gondii-infected microglia isolated from newborn mice. CBA/Ca microglia consistently produced less NO than did BALB/c microglia after stimulation with LPS or with IFN-γ plus TNF-α, and they inhibitedT. gondii replication significantly less than did BALB/c microglia. Cells of both strains treated with IFN-γ alone significantly inhibited uracil incorporation by T. gondii, and N G-monomethyl-l-arginine (NMMA) treatment did not reverse this effect. In cells treated with IFN-γ in combination with other inducers, NMMA treatment resulted in only partial recovery of T. gondii replication. This IFN-γ-dependent inhibition of replication was not due to generation of reactive oxygen species or to increased tryptophan degradation. These data suggest that NO production and an IFN-γ-dependent mechanism contribute to the inhibition of T. gondii replication after in vitro stimulation with IFN-γ plus TNF-α or with LPS. Differences in NO production but not in IFN-γ-dependent inhibition of T. gondii replication were observed between CBA/Ca and BALB/c microglia.

2002 ◽  
Vol 70 (8) ◽  
pp. 4247-4253 ◽  
Author(s):  
A. Talvani ◽  
F. S. Machado ◽  
G. C. Santana ◽  
A. Klein ◽  
L. Barcelos ◽  
...  

ABSTRACT The production of nitric oxide (NO) by gamma interferon (IFN-γ)-activated macrophages is a major effector mechanism during experimental Trypanosoma cruzi infection. In addition to IFN-γ, chemoattractant molecules, such as platelet-activating factor (PAF) and CC chemokines, may also activate macrophages to induce NO and mediate the killing of T. cruzi in an NO-dependent manner. Here we investigated the ability of leukotriene B4 (LTB4) to induce the production of NO by macrophages infected with T. cruzi in vitro and whether NO mediated LTB4-induced parasite killing. The activation of T. cruzi-infected but not naive murine peritoneal macrophages with LTB4 induced the time- and concentration-dependent production of NO. In addition, low concentrations of LTB4 acted in synergy with IFN-γ to induce NO production. The NO produced mediated LTB4-induced microbicidal activity in macrophages, as demonstrated by the inhibitory effects of an inducible NO synthase inhibitor. LTB4-induced NO production and parasite killing were LTB4 receptor dependent and were partially blocked by a PAF receptor antagonist. LTB4 also induced significant tumor necrosis factor alpha (TNF-α) production, and blockade of TNF-α suppressed LTB4-induced NO release and parasite killing. A blockade of LTB4 or PAF receptors partially inhibited IFN-γ-induced NO and TNF-α production but not parasite killing. Finally, daily treatment of infected mice with CP-105,696 was accompanied by a significantly higher level of blood parasitemia, but not lethality, than that seen in vehicle-treated animals. In conclusion, our results suggest a role for LTB4 during experimental T. cruzi infection. Chemoattractant molecules such as LTB4 not only may play a major role in leukocyte migration into sites of inflammation in vivo but also, in the event of an infection, may play a relevant role in the activation of recruited leukocytes to kill the invading microorganism in an NO-dependent manner.


1999 ◽  
Vol 67 (4) ◽  
pp. 1929-1934 ◽  
Author(s):  
Damien Chaussabel ◽  
Frédérique Jacobs ◽  
Jan de Jonge ◽  
Marijke de Veerman ◽  
Yves Carlier ◽  
...  

ABSTRACT Because of the critical role of the CD40-CD40 ligand (CD40L) pathway in the induction and effector phases of immune responses, we investigated the effects of CD40 ligation on the control ofTrypanosoma cruzi infection. First, we observed that supernatants of murine spleen cells stimulated by CD40L-transfected 3T3 fibroblasts (3T3-CD40L transfectants) prevent the infection of mouse peritoneal macrophages (MPM) by T. cruzi. This phenomenon depends on de novo production of nitric oxide (NO) as it is prevented by the addition of N-nitro-l-arginine methyl ester, a NO synthase inhibitor. NO production requires interleukin (IL)-12-mediated gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) synthesis as demonstrated by inhibition experiments using neutralizing anti-IL-12, anti-IFN-γ, and anti-TNF-α monoclonal antibodies (MAb). We found that an activating anti-CD40 MAb also directly stimulates IFN-γ-activated MPM to produce NO and thereby to control T. cruzi infection. To determine the in vivo relevance of these in vitro findings, mice were injected with 3T3-CD40L transfectants or 3T3 control fibroblasts at the time ofT. cruzi inoculation. We observed that in vivo CD40 ligation dramatically reduced both parasitemia and the mortality rate of T. cruzi-infected mice. A reduced parasitemia was still observed when the injection of 3T3-CD40L transfectants was delayed 8 days postinfection. It was abolished by injection of anti-IL-12 MAb. Taken together, these data establish that CD40 ligation facilitates the control of T. cruzi infection through a cascade involving IL-12, IFN-γ, and NO.


2020 ◽  
Vol 7 (2) ◽  
pp. 79
Author(s):  
Erniati Erniati ◽  
Riri Ezraneti

AbstrakRumput laut merupakan sumber daya hayati perairan yang telah diteliti mengandung sejumlah komponen bioaktif untuk meningkatkan kesehatan manusia seperti meningkatkan sistem imun atau bersifat sebagai imunomodulator.Penulisan artikel ini bertujuan untuk menjelaskan lebih jauh tentang sifat imunomodulator rumput laut, diharapkan tulisan ini dapat memberikan informasi ilmiah tentang rumput laut sebagai imunomodulator, sehingga nantinya dapat dikembangkan lagi penelitian ilmiah tentang pemanfaatan rumput laut sebagai imunomodulator.Rumput laut dapat meningkatkan sistem imun spesifik dan non spesifik melalui berbagai sel imun seperti sel makrofag, monosit atau sel limfosit melalui berbagai mekanisme di tingkat seluler.Sifat imunomodulator rumput laut dalam meningkatkan aktivasi makrofag terjadi melalui peningkatan proliferasi makrofag, produksi NO dan sekresi sitokin. Rumput laut juga dapat memodulasi aktivitas makrofag secara in vitro dan in vivo yaitu melalui ekspresi reseptor dan sitokin inflamasi seperti tumor necrosis factor (TNF-α) dan interleukin-1β (IL-1β)., produksi NO dan PGE2 dan ekspresi gen NOS-2 dan COX-2. Sifat imunomodulator rumput laut juga terjadi melalui peningkatan fungsi dan aktivitas limfosit. Ekstrak atau komponen bioaktif rumput laut dapat meningkatkan aktivasi limfosit, diantaranya menstimulasi aktivitas sel limfosit B yaitu melalui peningkatan produksi antibodi imonoglobulin (Ig), meningkatkan proliferasi sel T dan produksi subset limfosit T seperti CD4 dan CD8. Ekstrak rumput laut juga telah diteliti  mempengaruhi ekspresi mRNA untuk meningkatkan produksi  sitokin oleh Th1 seperti TNF-α dan IFN-γ, dan menurunkan sitokin yang diproduksi oleh Th2 seperti  IL-4 dan IL-10 serta  meningkatkan produksi IL-2 pada sel limfosit T.Kata kunci: rumput laut; komponen bioaktif; imunomodulatori; makrofagAbstractSeaweed is one of the marine biological resources that is known to contain bioactive compounds to improve human health, such as enhancing the immune system or being as an immunomodulator. This study aims to explain more about the nature of seaweed immunomodulators so that scientific research could be developed in the use of seaweed as an immunomodulator later. Seaweed could increase specific and nonspecific immune systems by involving various immune cells such as macrophage cells, monocytes, or lymphocyte cells through various mechanisms at the cellular level. The role of Immunomodulatory properties of seaweed in increasing macrophage activation occurs through increasing macrophage proliferation, NO production, and cytokine secretion. Seaweed would modulate macrophage activity in vitro and in vivo through the expression of inflammatory receptors and cytokines such as tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β), NO and PGE2 production and NOS-gene expression 2 and COX-2. Seaweed immunomodulatory activity would also occur through increasing function and activity of lymphocytes that stimulate the activity of B lymphocyte cells, production of antibody immunoglobulin (Ig), T cell proliferation and production of T lymphocyte subsets such as CD4 and CD8. Seaweed extracts also have been investigated to be able to affect mRNA expression to increase cytokine production by Th1 such as TNF-α and IFN-γ, decrease cytokines produced by Th2 such as IL-4 and IL-10 and increase IL-2 production in T lymphocytes.Keywords: seaweed; bioactive components; immunomodulatory; macrophage 


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 868
Author(s):  
Fabiana Albani Zambuzi ◽  
Priscilla Mariane Cardoso-Silva ◽  
Ricardo Cardoso Castro ◽  
Caroline Fontanari ◽  
Flavio da Silva Emery ◽  
...  

Decitabine is an approved hypomethylating agent used for treating hematological malignancies. Although decitabine targets altered cells, epidrugs can trigger immunomodulatory effects, reinforcing the hypothesis of immunoregulation in treated patients. We therefore aimed to evaluate the impact of decitabine treatment on the phenotype and functions of monocytes and macrophages, which are pivotal cells of the innate immunity system. In vitro decitabine administration increased bacterial phagocytosis and IL-8 release, but impaired microbicidal activity of monocytes. In addition, during monocyte-to-macrophage differentiation, treatment promoted the M2-like profile, with increased expression of CD206 and ALOX15. Macrophages also demonstrated reduced infection control when exposed to Mycobacterium tuberculosis in vitro. However, cytokine production remained unchanged, indicating an atypical M2 macrophage. Furthermore, when macrophages were cocultured with lymphocytes, decitabine induced a reduction in the release of inflammatory cytokines such as IL-1β, TNF-α, and IFN-γ, maintaining IL-10 production, suggesting that decitabine could potentialize M2 polarization and might be considered as a therapeutic against the exacerbated immune response.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haidy A. Saleh ◽  
Eman Ramdan ◽  
Mohey M. Elmazar ◽  
Hassan M. E. Azzazy ◽  
Anwar Abdelnaser

AbstractDoxorubicin (DOX) chemotherapy is associated with the release of inflammatory cytokines from macrophages. This has been suggested to be, in part, due to DOX-mediated leakage of endotoxins from gut microflora, which activate Toll-like receptor 4 (TLR4) signaling in macrophages, causing severe inflammation. However, the direct function of DOX on macrophages is still unknown. In the present study, we tested the hypothesis that DOX alone is incapable of stimulating inflammatory response in macrophages. Then, we compared the anti-inflammatory effects of curcumin (CUR), resveratrol (RES) and sulforaphane (SFN) against lipopolysaccharide/interferon-gamma (LPS/IFN-γ)-mediated inflammation in the absence or presence of DOX. For this purpose, RAW 264.7 cells were stimulated with LPS/IFN-γ (10 ng/mL/10 U/mL) in the absence or presence of DOX (0.1 µM). Our results showed that DOX alone is incapable of stimulating an inflammatory response in RAW 264.7 macrophages. Furthermore, after 24 h of incubation with LPS/IFN-γ, a significant increase in tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS) mRNA levels was observed. Similarly, nitric oxide (NO) production and TNF-α and IL-6 protein levels were significantly upregulated. Moreover, in LPS/IFN-γ-treated macrophages, the microRNAs (miRNAs) miR-146a, miR-155, and miR-21 were significantly overexpressed. Interestingly, upon testing CUR, RES, and SFN against LPS/IFN-γ-mediated inflammation, only SFN was able to significantly reverse the LPS/IFN-γ-mediated induction of iNOS, TNF-α and IL-6 and attenuate miR-146a and miR-155 levels. In conclusion, SFN, at the transcriptional and posttranscriptional levels, exhibits potent immunomodulatory action against LPS/IFN-γ-stimulated macrophages, which may indicate SFN as a potential treatment for DOX-associated inflammation.


Author(s):  
Mohamed A. Salama ◽  
Mohamed A. Younis ◽  
Roba M. Talaat

AbstractObjectiveThe present study aimed to evaluate cytotoxic, apoptotic, and anti-inflammatory properties of bee venom (BV) as well as changes in cytokine secretion levels and nitric oxide (NO) production using three different cancer cell lines [liver (Hep-G2), breast (MCF-7), and cervical (HPV-18 infected HeLa cells)] and two normal cells (splenocytes and macrophages (MQ).MethodsCytotoxic activity of BV against tumor cell lines and normal splenocytes/MQ was tested by MTT assay. By ELISA (ELISA); Tumor necrosis factor (TNF-α), Interleukine (IL-10) and interferon (IFN-γ) were measured. Caspase three expressions was evaluated using reverse transcription-polymerase chain reaction (RT-PCR). Nitric oxide (NO) was estimated using a colorimetric assay.ResultsBV has a significant cytotoxic effect on all cell lines in a dose- and time-dependent manner; none of them was toxic for normal cells. Treating Hep-G2 cells with BV showed a reduction in IL-10, elevation in TNF-α with no change in IFN-γ level. MCF-7 cells have low IL-10 and TNF-α and high IFN-γ production level. Elevation of IL-10 and IFN-γ coincides with a reduction in TNF-α level was demonstrated in HeLa cells. The expression of Caspase three was dramatically increased with elevation in BV concentration in all tested cancer cell lines. A gradual decrease in NO production by MQ with increasing BV dose was observed.ConclusionTaken together, our results stressed on the importance of BV as a potent anti-tumor agent against various types of cancers (Liver, Breast, and Cervix). Further steps towards the use of BV for pharmacological purposes must be done.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1230
Author(s):  
Sumin Pyeon ◽  
Ok-Kyung Kim ◽  
Ho-Geun Yoon ◽  
Shintae Kim ◽  
Kyung-Chul Choi ◽  
...  

Atopic dermatitis (AD) is a chronic inflammatory skin disease caused by immune hypersensitivity reaction. The cause of AD is unclear, but its symptoms have a negative effect on quality of life; various treatment methods to alleviate these symptoms are underway. In the present study, we aimed to evaluate in vitro antioxidant and anti-inflammatory effects of Rubus coreanus water extract (RCW) on AD. Total phenolic compounds and flavonoid content of RCW were 4242.40 ± 54.84 mg GAE/g RCE and 1010.99 ± 14.75 mg CE/g RCW, respectively. RCW reduced intracellular reactive oxygen species level and increased the action of antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase in tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-stimulated HaCaT cells. Moreover, mRNA expression of the pro-inflammatory cytokines, including TNF-α, interleukin-1β, and interleukin-6, was downregulated by RCW in the TNF-α/IFN-γ-stimulated cells. The levels of inflammatory chemokines (thymus- and activation-regulated chemokine; eotaxin; macrophage-derived chemokine; regulated on activation, normal T-cell expressed and secreted; and granulocyte-macrophage colony-stimulating factor) and intercellular adhesion molecule-1 were decreased in the TNF-α/IFN-γ-stimulated HaCaT cells after RCW treatment. Additionally, the mRNA expression levels of filaggrin and involucrin, proteins that form the skin, were increased by RCW. Furthermore, RCW inhibited the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway in the TNF-α/IFN-γ-stimulated HaCaT cells. Collectively, the present investigation indicates that RCW is a potent substance that inhibits AD.


2009 ◽  
Vol 78 (3) ◽  
pp. 1012-1021 ◽  
Author(s):  
Rosane M. B. Teles ◽  
Rose B. Teles ◽  
Thais P. Amadeu ◽  
Danielle F. Moura ◽  
Leila Mendonça-Lima ◽  
...  

ABSTRACT Gelatinases A and B (matrix metalloproteinase 2 [MMP-2] and MMP-9, respectively) can induce basal membrane breakdown and leukocyte migration, but their role in leprosy skin inflammation remains unclear. In this study, we analyzed clinical specimens from leprosy patients taken from stable, untreated skin lesions and during reactional episodes (reversal reaction [RR] and erythema nodosum leprosum [ENL]). The participation of MMPs in disease was suggested by (i) increased MMP mRNA expression levels in skin biopsy specimens correlating with the expression of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α), (ii) the detection of the MMP protein and enzymatic activity within the inflammatory infiltrate, (iii) increased MMP levels in patient sera, and (iv) the in vitro induction of MMP-9 by Mycobacterium leprae and/or TNF-α. It was observed that IFN-γ, TNF-α, MMP-2, and MMP-9 mRNA levels were higher in tuberculoid than lepromatous lesions. In contrast, interleukin-10 and tissue inhibitor of MMP (TIMP-1) message were not differentially modulated. These data correlated with the detection of the MMP protein evidenced by immunohistochemistry and confocal microscopy. When RR and ENL lesions were analyzed, an increase in TNF-α, MMP-2, and MMP-9, but not TIMP-1, mRNA levels was observed together with stronger MMP activity (zymography/in situ zymography). Moreover, following in vitro stimulation of peripheral blood cells, M. leprae induced the expression of MMP-9 (mRNA and protein) in cultured cells. Overall, the present data demonstrate an enhanced MMP/TIMP-1 ratio in the inflammatory states of leprosy and point to potential mechanisms for tissue damage. These results pave the way toward the application of new therapeutic interventions for leprosy reactions.


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.


2002 ◽  
Vol 11 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Vera L. Petricevich

The purpose of this study was to investigate the effects ofTityus serrulatusvenom (TSV) on murine peritoneal macrophages evaluated in terms of activation. The effects of crude TSV were analysed by detection of cytokines, oxygen intermediate metabolites (H2O2) and nitric oxide (NO) in supernatants of peritoneal macrophages. Several functional bioassays were employed including anin vitromodel for envenomating: cytotoxicity of TSV was assessed using the lyses percentage. Tumor necrosis factor (TNF) activity was assayed by measuring its cytotoxic activity on L-929 cells, and interleukin-6 (IL-6) and interferon-γ (IFN-γ) were assayed by enzyme-linked immunosorbent assay, whereas NO levels were detected by Griess colorimetric reactions in culture supernatant of macrophages incubated with TSV and subsequently exposed to either lipopolysaccharide or IFN-γ. Incubation of macrophages with TSV increased production of IL-6 and IFN-γ in a dose-dependent manner. TNF production was not detected in supernatants treated with TSV at any concentration. The increase in IL-6 secretion was not associated with concentration-dependent cytoxicity of TSV on these cells. These data suggest that the cytotoxicity does not appear to be the main cause of an increased cytokine production by these cells. Although NO is an important effector molecule in macrophage microbicidal activity, the inducing potential of the test compounds for its release was found to be very moderate, ranging from 125 to 800 mM. Interestingly, NO levels of peritoneal macrophages were increased after IFN-γ. Moreover, NO production had an apparent effect on macrophage activity. The results obtained here also shown that the TSV induces an important elevation in H2O2release. These results combined with NO production suggest that TSV possesses significant immunomodulatory activities capable of stimulating immune functionsin vitro.


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