The role of Toll-like receptor 9 in a murine model of Cryptococcus gattii infection

AbstractToll-like receptor 9 (TLR9) is crucial to the host immune response against fungi, such as Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans, but its importance in Cryptococcus gattii infection is unknown. Our study aimed to understand the role of TLR9 during the course of experimental C. gattii infection in vivo, considering that the cryptococcal DNA interaction with the receptor could contribute to host immunity even in an extremely susceptible model. We inoculated C57BL/6 (WT) and TLR9 knock-out (TLR9−/−) mice intratracheally with 104C. gattii yeast cells. TLR9−/− mice had a higher mortality rate compared to WT mice and more yeast cells that had abnormal size, known as titan cells, in the lungs. TLR9−/− mice also had a greater number of CFUs in the spleen and brain than WT mice, in addition to having lower levels of IFN-γ and IL-17 in the lung. With these markers of aggressive cryptococcosis, we can state that TLR9−/− mice are more susceptible to C. gattii, probably due to a mechanism associated with the decrease of a Th1 and Th17-type immune response that promotes the formation of titan cells in the lungs. Therefore, our results indicate the participation of TLR9 in murine resistance to C. gattii infection.

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Differential Cytokine Pattern in the Spleens and Livers of BALB/c Mice Infected with Penicillium marneffei: Protective Role of Gamma Interferon

Infection and Immunity ◽

10.1128/iai.71.1.465-473.2003 ◽

2003 ◽

Vol 71 (1) ◽

pp. 465-473 ◽

Cited By ~ 36

Author(s):

Francesca Sisto ◽

Annarita Miluzio ◽

Orazio Leopardi ◽

Maurizio Mirra ◽

Johan R. Boelaert ◽

...

Keyword(s):

Immune Response ◽

Gamma Interferon ◽

Penicillium Marneffei ◽

Yeast Cells ◽

Interleukin 12 ◽

Type 2 Cytokines ◽

Ifn Γ

ABSTRACT Penicillium marneffei is an intracellular opportunistic fungus causing invasive mycosis in AIDS patients. T cells and macrophages are important for protection in vivo. However, the role of T-cell cytokines in the immune response against P. marneffei is still unknown. We studied by semiquantitative reverse transcription-PCR and biological assays the patterns of expression of Th1 and Th2 cytokines in the organs of wild-type (wt) and gamma interferon (IFN-γ) knockout (GKO) mice infected intravenously with P. marneffei conidia. At 3 × 105 conidia/mouse, a self-limiting infection developed in wt BALB/c mice, whereas all GKO mice died at day 18 postinoculation. Splenic and hepatic granulomas were present in wt mice, whereas disorganized masses of macrophages and yeast cells were detected in GKO mice. The infection resolved faster in the spleens than in the livers of wt mice and was associated with the local expression of type 1 cytokines (high levels of interleukin-12 [IL-12] and IFN-γ) but not type 2 cytokines (low levels of IL-4 and IL-10). Conversely, both type 1 and type 2 cytokines were detected in the livers of wt animals. Disregulation of the cytokine profile was seen in the spleens but not in the livers of GKO mice. The inducible nitric oxide synthase mRNA level was low and the TNF-α level was high in both spleens and livers of GKO mice compared to wt mice. These data suggest that the polarization of a protective type 1 immune response against P. marneffei is regulated at the level of individual organs and that the absence of IFN-γ is crucial for the activation of fungicidal macrophages and the development of granulomas.

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Activation of ASC Inflammasome Driven by Toll-Like Receptor 4 Contributes to Host Immunity against Rickettsial Infection

Infection and Immunity ◽

10.1128/iai.00886-19 ◽

2020 ◽

Vol 88 (4) ◽

Author(s):

Claire Rumfield ◽

Ilirjana Hyseni ◽

Jere W. McBride ◽

David H. Walker ◽

Rong Fang

Keyword(s):

Host Susceptibility ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Content Type ◽

Ifn Γ ◽

Human Infections ◽

Deficient Mice ◽

Dependent Mechanism

ABSTRACT Rickettsiae are cytosolically replicating, obligately intracellular bacteria causing human infections worldwide with potentially fatal outcomes. We previously showed that Rickettsia australis activates ASC inflammasome in macrophages. In the present study, host susceptibility of ASC inflammasome-deficient mice to R. australis was significantly greater than that of C57BL/6 (B6) controls and was accompanied by increased rickettsial loads in various organs. Impaired host control of R. australis in vivo in ASC−/− mice was associated with dramatically reduced levels of interleukin 1β (IL-1β), IL-18, and gamma interferon (IFN-γ) in sera. The intracellular concentrations of R. australis in bone marrow-derived macrophages (BMMs) of TLR4−/− and ASC−/− mice were significantly greater than those in BMMs of B6 controls, highlighting the important role of inflammasome and these molecules in controlling rickettsiae in macrophages. Compared to B6 BMMs, TLR4−/− BMMs failed to secrete a significant level of IL-1β and had reduced expression levels of pro-IL-1β in response to infection with R. australis, suggesting that rickettsiae activate ASC inflammasome via a Toll-like receptor 4 (TLR4)-dependent mechanism. Further mechanistic studies suggest that the lipopolysaccharide (LPS) purified from R. australis together with ATP stimulation led to cleavage of pro-caspase-1 and pro-IL-1β, resulting in TLR4-dependent secretion of IL-1β. Taken together, these observations indicate that activation of ASC inflammasome, most likely driven by interaction of TLR4 with rickettsial LPS, contributes to host protective immunity against R. australis. These findings provide key insights into defining the interactions of rickettsiae with the host innate immune system.

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Sarcoma IL-12 overexpression facilitates NK cell immunomodulation

Scientific Reports ◽

10.1038/s41598-021-87700-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mary Jo Rademacher ◽

Anahi Cruz ◽

Mary Faber ◽

Robyn A. A. Oldham ◽

Dandan Wang ◽

...

Keyword(s):

Immune Response ◽

Cell Lines ◽

Nk Cell ◽

Autologous Tumor ◽

Murine Models ◽

Lentiviral Transduction ◽

Ifn Γ ◽

Human Sarcoma

AbstractInterleukin-12 (IL-12) is an inflammatory cytokine that has demonstrated efficacy for cancer immunotherapy, but systemic administration has detrimental toxicities. Lentiviral transduction eliciting IL-12-producing human sarcoma for autologous reintroduction provides localized delivery for both innate and adaptive immune response augmentation. Sarcoma cell lines and primary human sarcoma samples were transduced with recombinant lentivirus engineering expression of human IL-12 (hu-IL-12). IL-12 expressing sarcomas were assessed in vitro and in vivo following implantation into humanized NSG and transgenic human IL-15 expressing (NSG.Tg(Hu-IL-15)) murine models. Lentiviral transduction (LV/hu-IL-12) of human osteosarcoma, Ewing sarcoma and rhabdomyosarcoma cell lines, as well as low-passage primary human sarcomas, engendered high-level expression of hu-IL-12. Hu-IL-12 demonstrated functional viability, eliciting specific NK cell-mediated interferon-γ (IFN-γ) release and cytotoxic growth restriction of spheroids in vitro. In orthotopic xenograft murine models, the LV/hu-IL-12 transduced human sarcoma produced detectable IL-12 and elicited an IFN-γ inflammatory immune response specific to mature human NK reconstitution in the NSG.Tg(Hu-IL-15) model while restricting tumor growth. We conclude that LV/hu-IL-12 transduction of sarcoma elicits a specific immune reaction and the humanized NSG.Tg(Hu-IL-15) xenograft, with mature human NK cells, can define in vivo anti-tumor effects and systemic toxicities. IL-12 immunomodulation through autologous tumor transduction and reintroduction merits exploration for sarcoma treatment.

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Knock out of tmem38b by CRISPR/Cas9 in zebrafish unveils the in vivo role of Trimeric intracellular cation (TRIC) channel B on cell homeostasis

Bone Reports ◽

10.1016/j.bonr.2021.101054 ◽

2021 ◽

Vol 14 ◽

pp. 101054

Author(s):

Laura Leoni ◽

Valentina Daponte ◽

Francesca Tonelli ◽

Roberta Gioia ◽

Silvia Cotti ◽

...

Keyword(s):

Cell Homeostasis ◽

Knock Out

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Arginase Activity in Eisenia andrei Coelomocytes: Function in the Earthworm Innate Response

International Journal of Molecular Sciences ◽

10.3390/ijms22073687 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3687

Author(s):

Joanna Homa ◽

Alina Klosowska ◽

Magdalena Chadzinska

Keyword(s):

Immune Response ◽

Wound Healing ◽

Arginase Activity ◽

Eisenia Andrei ◽

Heavy Metals Ions ◽

First Time ◽

Important Marker

Arginase is the manganese metalloenzyme catalyzing the conversion of l-arginine to l-ornithine and urea. In vertebrates, arginase is involved in the immune response, tissue regeneration, and wound healing and is an important marker of alternative anti-inflammatory polarization of macrophages. In invertebrates, data concerning the role of arginase in these processes are very limited. Therefore, in the present study, we focused on the changes in arginase activity in the coelomocytes of Eisenia andrei. We studied the effects of lipopolysaccharide (LPS), hydrogen peroxide (H2O2), heavy metals ions (e.g., Mn2+), parasite infection, wound healing, and short-term fasting (5 days) on arginase activity. For the first time in earthworms, we described arginase activity in the coelomocytes and found that it can be up-regulated upon in vitro stimulation with LPS and H2O2 and in the presence of Mn2+ ions. Moreover, arginase activity was also up-regulated in animals in vivo infected with nematodes or experiencing segment amputation, but not in fasting earthworms. Furthermore, we confirmed that the activity of coelomocyte arginase can be suppressed by l-norvaline. Our studies strongly suggest that similarly to the vertebrates, also in the earthworms, coelomocyte arginase is an important element of the immune response and wound healing processes.

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The Extracellular Small Leucine-Rich Proteoglycan Biglycan Is a Key Player in Gastric Cancer Aggressiveness

Cancers ◽

10.3390/cancers13061330 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1330

Author(s):

Filipe Pinto ◽

Liliana Santos-Ferreira ◽

Marta T. Pinto ◽

Catarina Gomes ◽

Celso A. Reis

Keyword(s):

Clinical Value ◽

Knock Out ◽

Angiogenic Potential ◽

In Vivo Experiments ◽

Cancer Aggressiveness ◽

Advanced Stages ◽

Oncogenic Gene

Biglycan (BGN gene), an extracellular proteoglycan, has been described to be associated with cancer aggressiveness. The purpose of this study was to clarify the clinical value of biglycan as a biomarker in multiple independent GC cohorts and determine the in vitro and in vivo role of biglycan in GC malignant features. We found that BGN is commonly over-expressed in all analyzed cohorts, being associated with disease relapse and poor prognosis in patients with advanced stages of disease. In vitro and in vivo experiments demonstrated that biglycan knock-out GC cells display major phenotypic changes with a lower cell survival, migration, and angiogenic potential when compared with biglycan expressing cells. Biglycan KO GC cells present increased levels of PARP1 and caspase-3 cleavage and a decreased expression of mesenchymal markers. Importantly, biglycan deficient GC cells that were supplemented with exogenous biglycan were able to restore biological features, such as survival, clonogenic and migratory capacities. Our in vitro and in vivo findings were validated in human GC samples, where BGN expression was associated with several oncogenic gene signatures that were associated with apoptosis, cell migration, invasion, and angiogenesis. This study provided new insights on biglycan role in GC that should be taken in consideration as a key cellular regulator with major impact in tumor progression and patients’ clinical outcome.

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Essential role of IRAK-4 protein and its kinase activity in Toll-like receptor–mediated immune responses but not in TCR signaling

Journal of Experimental Medicine ◽

10.1084/jem.20061523 ◽

2007 ◽

Vol 204 (5) ◽

pp. 1013-1024 ◽

Cited By ~ 120

Author(s):

Tatsukata Kawagoe ◽

Shintaro Sato ◽

Andreas Jung ◽

Masahiro Yamamoto ◽

Kosuke Matsui ◽

...

Keyword(s):

Immune Responses ◽

Kinase Activity ◽

Interleukin 1 ◽

Cell Receptor ◽

Nuclear Factor Κb ◽

Toll Like Receptor ◽

Tcr Signaling ◽

Mitogen Activated Protein

Interleukin-1 receptor–associated kinase 4 (IRAK-4) was reported to be essential for the Toll-like receptor (TLR)– and T cell receptor (TCR)–mediated signaling leading to the activation of nuclear factor κB (NF-κB). However, the importance of kinase activity of IRAK family members is unclear. In this study, we investigated the functional role of IRAK-4 activity in vivo by generating mice carrying a knockin mutation (KK213AA) that abrogates its kinase activity. IRAK-4KN/KN mice were highly resistant to TLR-induced shock response. The cytokine production in response to TLR ligands was severely impaired in IRAK-4KN/KN as well as IRAK-4−/− macrophages. The IRAK-4 activity was essential for the activation of signaling pathways leading to mitogen-activated protein kinases. TLR-induced IRAK-4/IRAK-1–dependent and –independent pathways were involved in early induction of NF-κB–regulated genes in response to TLR ligands such as tumor necrosis factor α and IκBζ. In contrast to a previous paper (Suzuki, N., S. Suzuki, D.G. Millar, M. Unno, H. Hara, T. Calzascia, S. Yamasaki, T. Yokosuka, N.J. Chen, A.R. Elford, et al. 2006. Science. 311:1927–1932), the TCR signaling was not impaired in IRAK-4−/− and IRAK-4KN/KN mice. Thus, the kinase activity of IRAK-4 is essential for the regulation of TLR-mediated innate immune responses.

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Resistance to Acute Babesiosis Is Associated with Interleukin-12- and Gamma Interferon-Mediated Responses and Requires Macrophages and Natural Killer Cells

Infection and Immunity ◽

10.1128/iai.71.4.2002-2008.2003 ◽

2003 ◽

Vol 71 (4) ◽

pp. 2002-2008 ◽

Cited By ~ 43

Author(s):

Irma Aguilar-Delfin ◽

Peter J. Wettstein ◽

David H. Persing

Keyword(s):

Nk Cells ◽

Gamma Interferon ◽

Interleukin 12 ◽

No Production ◽

Cytokine Responses ◽

Early Production ◽

Ifn Γ ◽

Crucial Part

ABSTRACT We examined the role of the cytokines gamma interferon (IFN-γ) and interleukin-12 (IL-12) in the model of acute babesiosis with the WA1 Babesia. Mice genetically deficient in IFN-γ-mediated responses (IFNGR2KO mice) and IL-12-mediated responses (Stat4KO mice) were infected with the WA1 Babesia, and observations were made on the course of infection and cytokine responses. Levels of IFN-γ and IL-12 in serum increased 24 h after parasite inoculation. The augmented susceptibility observed in IFNGR2KO and Stat-4KO mice suggests that the early IL-12- and IFN-γ-mediated responses are involved in protection against acute babesiosis. Resistance appears to correlate with an increase in nitric oxide (NO) production. In order to assess the contribution of different cell subsets to resistance against the parasite, we also studied mice lacking B cells, CD4+ T cells, NK cells, and macrophages. Mice genetically deficient in B lymphocytes or CD4+ T lymphocytes were able to mount protective responses comparable to those of immunosufficient mice. In contrast, in vivo depletion of macrophages or NK cells resulted in elevated susceptibility to the infection. Our observations suggest that a crucial part of the response that protects from the pathogenic Babesia WA1 is mediated by macrophages and NK cells, probably through early production of IL-12 and IFN-γ, and induction of macrophage-derived effector molecules like NO.

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RESPIRATORY SYNCYTIAL VIRUS LUNG INFECTION IN INFANTS: IMMUNOREGULATORY ROLE OF INFECTED ALVEOLAR MACROPHAGES

PEDIATRICS ◽

10.1542/peds.96.2.391 ◽

1995 ◽

Vol 96 (2) ◽

pp. 391-391

Author(s):

Leon S. Greos

Keyword(s):

Immune Response ◽

Respiratory Syncytial Virus ◽

Lung Injury ◽

Alveolar Macrophages ◽

Lung Infection ◽

Local Immune Response ◽

Rsv Infection ◽

Syncytial Virus

Alveolar macrophages are infected by RSV in vivo and coexpress potent immunomodulatory molecules that potentially regulate local immune response or lung injury caused by RSV infection.

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Temperature-dependence of the DnaA–DNA interaction and its effect on the autoregulation of dnaA expression

Biochemical Journal ◽

10.1042/bj20120876 ◽

2012 ◽

Vol 449 (2) ◽

pp. 333-341 ◽

Cited By ~ 6

Author(s):

Chiara Saggioro ◽

Anne Olliver ◽

Bianca Sclavi

Keyword(s):

Temperature Dependence ◽

Binding Sites ◽

Dna Interaction ◽

Bacterial Dna ◽

Dnaa Protein ◽

High Affinity ◽

Key Factor

The DnaA protein is a key factor for the regulation of the timing and synchrony of initiation of bacterial DNA replication. The transcription of the dnaA gene in Escherichia coli is regulated by two promoters, dnaAP1 and dnaAP2. The region between these two promoters contains several DnaA-binding sites that have been shown to play an important role in the negative auto-regulation of dnaA expression. The results obtained in the present study using an in vitro and in vivo quantitative analysis of the effect of mutations to the high-affinity DnaA sites reveal an additional effect of positive autoregulation. We investigated the role of transcription autoregulation in the change of dnaA expression as a function of temperature. While negative auto-regulation is lost at dnaAP1, the effects of both positive and negative autoregulation are maintained at the dnaAP2 promoter upon lowering the growth temperature. These observations can be explained by the results obtained in vitro showing a difference in the temperature-dependence of DnaA–ATP binding to its high- and low-affinity sites, resulting in a decrease in DnaA–ATP oligomerization at lower temperatures. The results of the present study underline the importance of the role for autoregulation of gene expression in the cellular adaptation to different growth temperatures.

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