IL-1 Receptor–Knockout Mice Develop Epidermal Cysts and Show an Altered Innate Immune Response after Exposure to UVB Radiation

Abstract mDia1, the diaphanous homolog 1 of Drosophila in mouse, is a formin protein involving in the linear actin polymerization. Recently, our group reported that patients with del(5q) myelodysplastic syndromes (MDS) showed a significantly decreased mDia1 expression. Mice with mDia1 deficiency developed age related hematologic features mimicking human MDS. In these mice, CD14 is aberrantly overexpressed on granulocytes, which sensitized the innate immune response upon the lipopolysaccharide(LPS) injection. Importantly, chronic LPS injection accelerated the development of MDS (Keerthivasan et al Blood 2014). Here we report that 1) the mDia1 knockout (KO) mice also have a hypersensitive innate immune response to damage-associated molecular pattern molecules (DAMPs), which can be partially blocked by CD14/Toll-like receptor 4(TLR4) signaling pathway inhibitors. This is significant since release of DAMPs from necrotic or senescent cells is a common age-related phenomenon. DAMPs are also detected in cancers including MDS. Thus our study may shed lights on how the deregulated innate immune responses get involved in the pathogenesis of MDS in a more pathophysiologically relevant etiology. 2) mDia1 KO mice have an increased Gr1/Mac1 expression on the granulocytes in peripheral blood. We demonstrate that the expression levels of Gr1/Mac1 were not changed in bone marrow granulocytes, suggesting a specific up-regulation of Gr1/Mac1 levels on circulating granulocytes in mDia1 knockout mice. Mac-1, as the predominant β2 integrin on granulocytes, plays key roles in the adhesion of leukocytes to the endothelium, and regulates the cell adhesion, migration, and chemotaxis. In this respect, the mDia1 knockout mice develop serve neutropenia, which could be due to the upregulation of Gr1/Mac1 and increased binding of the cells to intercellular adhesion molecule-1 (ICAM-1). Finally, we revealed the mechanism of Gr1/Mac1 upregulation by showing that loss of mDia1 significantly affected the endocytosis of Gr1 and Mac1 on granulocytes, however, the mRNA levels of Gr1 and Mac1 were not affected. Taken together, these studies reveal a significance of loss of mDia1 in the pathogenesis of del(5q) MDS through upregulation of innate immune response and accelerated granulocyte clearance. Disclosures No relevant conflicts of interest to declare.

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Aberrant Overexpression Of CD14 In Granulocytes Sensitizes Innate Immune Response In mDia1 Heterozygous Myelodysplastic Syndromes

Blood ◽

10.1182/blood.v122.21.1557.1557 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1557-1557

Author(s):

Ganesan Keerthivasan ◽

Baobing Zhao ◽

Chad E Harris ◽

Ling Zhang ◽

Juehua Gao ◽

...

Keyword(s):

Bone Marrow ◽

Immune Response ◽

Innate Immune Response ◽

Myelodysplastic Syndromes ◽

Knockout Mice ◽

Actin Polymerization ◽

Conflicts Of Interest ◽

Innate Immune ◽

Increased Risk ◽

A Cell

Abstract The myelodysplastic syndromes (MDS) are a group of pre-leukemic diseases characterized by increased risk of acute myeloid leukemia (AML). Heterozygous loss of chromosome 5q (5q-) is the most common cytogenetic abnormality in MDS. DIAPH1 is localized to 5q31 and encodes one of the formin family proteins, mDia1, involved in the regulation of linear actin polymerization. Mice with mDia1 deficiency develop hematologic features mimicking human myeloproliferative neoplasm, but its role in the pathogenesis of MDS is unclear. Here we report that mDia1 is largely dispensable for normal hematopoiesis. However, the committed or mature granulocytes in mDia1 heterozygous and knockout mice were activated and showed increased actin polarization. Strikingly, CD14 was aberrantly overexpressed in the bone marrow and peripheral granulocytes of mDia1 heterozygous and knockout mice in a cell-autonomous manner, leading to a hypersensitivity of the innate immune response to lipopolysaccharide (LPS) stimuli through CD14-Toll like receptor 4 (TLR4) signaling. Chronic stimulation with LPS accelerated the occurrence of MDS in mDia1 heterozygous and knockout mice. Similar findings of CD14 overexpression were observed in the bone marrow granulocytes of 5q- MDS patients, but not normal patients or MDS patients without 5q deletion. These patients exhibited relatively frequent infections with long duration of disease. Mechanistically, mDia1 was required for the endocytosis of CD14 upon LPS stimulation. Heterozygosity and loss of mDia1 led to diminished interferon expression that is dependent on CD14 endocytosis. Thus, our study revealed an essential role of the innate immune signaling in the pathogenesis of 5q- MDS. Specifically, heterozygosity or loss of mDia1 leads to a cell autonomous hypersensitivity of innate immune system in the granulocytes that causes myeloid dysplasia. Together with previous reported evidence of dyserythropoiesis due to loss of RPS14, and dysmegakaryopoiesis due to loss of mir-145/146a, these data fully recapitulate the pathogenesis of tri-lineage dysplasia in 5q- MDS. In addition, our study highlighted the significance of the activated CD14/TLR signaling pathway in the pathogenesis of MDS, which could serve as a novel target for therapeutic management. Disclosures: No relevant conflicts of interest to declare.

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Toll-Like Receptor 2-Mediated Innate Immune Responses against Junín Virus in Mice Lead to Antiviral Adaptive Immune Responses during Systemic Infection and Do Not Affect Viral Replication in the Brain

Journal of Virology ◽

10.1128/jvi.00050-14 ◽

2014 ◽

Vol 88 (14) ◽

pp. 7703-7714 ◽

Cited By ~ 20

Author(s):

Christian D. Cuevas ◽

Susan R. Ross

Keyword(s):

Immune Response ◽

Virus Infection ◽

Innate Immune Response ◽

Knockout Mice ◽

Cytokine Response ◽

Innate Immune ◽

Wild Type ◽

Junin Virus ◽

The Brain ◽

Junín Virus

ABSTRACTSuccessful adaptive immunity to virus infection often depends on the initial innate response. Previously, we demonstrated that Junín virus, the etiological agent responsible for Argentine hemorrhagic fever (AHF), activates an early innate immune response via an interaction between the viral glycoprotein and Toll-like receptor 2 (TLR2). Here we show that TLR2/6 but not TLR1/2 heterodimers sense Junín virus glycoprotein and induce a cytokine response, which in turn upregulates the expression of the RNA helicases RIG-I and MDA5. NF-κB and Erk1/2 were important in the cytokine response, since both proteins were phosphorylated as a result of the interaction of virus with TLR2, and treatment with an Erk1/2-specific inhibitor blocked cytokine production. We show that the Junín virus glycoprotein activates cytokine production in a human macrophage cell line as well. Moreover, we show that TLR2-mediated immune response plays a role in viral clearance because wild-type mice cleared Candid 1 (JUNV C1), the vaccine strain of Junín virus, more rapidly than did TLR2 knockout mice. This clearance correlated with the generation of Junín virus-specific CD8+T cells. However, infected wild-type and TLR2 knockout mice developed TLR2-independent blocking antibody responses with similar kinetics. We also show that microglia and astrocytes but not neurons are susceptible to infection with JUNV C1. Although JUNV C1 infection of the brain also triggered a TLR2-dependent cytokine response, virus levels were equivalent in wild-type and TLR2 knockout mice.IMPORTANCEJunín virus is transmitted by rodents native to Argentina and is associated with both systemic disease and, in some patients, neurological symptoms. Humans become infected when they inhale aerosolized Junín virus. AHF has a 15 to 30% mortality rate, and patients who clear the infection develop a strong antibody response to Junín virus. Here we investigated what factors determine the immune response to Junín virus. We show that a strong initial innate immune response to JUNV C1 determines how quickly mice can clear systemic infection and that this depended on the cellular immune response. In contrast, induction of an innate immune response in the brain had no effect on virus infection levels. These findings may explain how the initial immune response to Junín virus infection could determine different outcomes in humans.

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Aberrant overexpression of CD14 on granulocytes sensitizes the innate immune response in mDia1 heterozygous del(5q) MDS

Blood ◽

10.1182/blood-2014-01-552463 ◽

2014 ◽

Vol 124 (5) ◽

pp. 780-790 ◽

Cited By ~ 26

Author(s):

Ganesan Keerthivasan ◽

Yang Mei ◽

Baobing Zhao ◽

Ling Zhang ◽

Chad E. Harris ◽

...

Keyword(s):

Immune Response ◽

Innate Immunity ◽

Innate Immune Response ◽

Knockout Mice ◽

Innate Immune ◽

Chronic Stimulation ◽

Key Points ◽

Age Dependent ◽

A Cell ◽

Stimulation Of

Key Points mDia1 deficiency led to a cell-autonomous overexpression of CD14 on granulocytes and a hypersensitive innate immune response. mDia1 heterozygous and knockout mice developed age-dependent MDS that was accelerated by chronic stimulation of the innate immunity.

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Oral Immune Activation by Disgust and Disease-Related Pictures

Journal of Psychophysiology ◽

10.1027/0269-8803/a000143 ◽

2015 ◽

Vol 29 (3) ◽

pp. 119-129 ◽

Cited By ~ 4

Author(s):

Richard J. Stevenson ◽

Deborah Hodgson ◽

Megan J. Oaten ◽

Luba Sominsky ◽

Mehmet Mahmut ◽

...

Keyword(s):

Immune Response ◽

Immune Responses ◽

Innate Immune Response ◽

Negative Control ◽

Innate Immune ◽

Innate Immune Responses ◽

Immune Markers ◽

Before And After ◽

Secondary Analyses ◽

Image Set

Abstract. Both disgust and disease-related images appear able to induce an innate immune response but it is unclear whether these effects are independent or rely upon a common shared factor (e.g., disgust or disease-related cognitions). In this study we directly compared these two inductions using specifically generated sets of images. One set was disease-related but evoked little disgust, while the other set was disgust evoking but with less disease-relatedness. These two image sets were then compared to a third set, a negative control condition. Using a wholly within-subject design, participants viewed one image set per week, and provided saliva samples, before and after each viewing occasion, which were later analyzed for innate immune markers. We found that both the disease related and disgust images, relative to the negative control images, were not able to generate an innate immune response. However, secondary analyses revealed innate immune responses in participants with greater propensity to feel disgust following exposure to disease-related and disgusting images. These findings suggest that disgust images relatively free of disease-related themes, and disease-related images relatively free of disgust may be suboptimal cues for generating an innate immune response. Not only may this explain why disgust propensity mediates these effects, it may also imply a common pathway.

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