β-glucan-induced innate immune memory distinctively affects macrophage activation in response to differential environmental cues

AbstractAdvances in the field of immunological memory demonstrate that innate immune cells can recall a previous encounter – the innate immune memory. In vitro, exposure of human primary monocytes to the fungal ²-glucan enhances their pro-inflammatory responsiveness towards several pathogens. During infection, circulating monocytes infiltrate tissues where, following conditioning by local environment, they differentiate and polarise into different types of macrophages. Hence in vivo interaction of β-glucan with innate cells would occur in a complex environment. Understanding the potential of β-glucan to induce innate immune memory in complex physiological environments is crucial for future translational research.Recapitulating different physiological conditions in vitro we found that β-glucan imprinting does not always enhance responsiveness and function of macrophages but can also reduce it. In this study, we show that upon both GM-CSF- and M-CSF-mediated polarisation, imprinting by β-glucan leads to less differentiated macrophages with a convergent functional phenotype. Altogether, these observations provide insightful and crucial knowledge that will help apprehending the in vivo high potential of β-glucan-induced innate memory in different pathological contexts.

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Induction of Innate Immune Responses by SIV In Vivo and In Vitro: Differential Expression and Function of RIG-I and MDA5

The Journal of Infectious Diseases ◽

10.1093/infdis/jir469 ◽

2011 ◽

Vol 204 (7) ◽

pp. 1104-1114 ◽

Cited By ~ 15

Author(s):

Juliene G. Co ◽

Kenneth W. Witwer ◽

Lucio Gama ◽

M. Christine Zink ◽

Janice E. Clements

Keyword(s):

Immune Responses ◽

Differential Expression ◽

Innate Immune ◽

Innate Immune Responses ◽

And Function

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Hollow Fibers for Hepatocyte Encapsulation and Transplantation: Studies of Survival and Function in Rats

Cell Transplantation ◽

10.1177/096368979400300504 ◽

1994 ◽

Vol 3 (5) ◽

pp. 373-385 ◽

Cited By ~ 37

Author(s):

Michael B. Yang ◽

Joseph P. Vacanti ◽

Donald E. Ingber

Keyword(s):

Protein Synthesis ◽

Similar Rate ◽

Hollow Fibers ◽

Regenerated Cellulose ◽

Albumin Secretion ◽

Different Types ◽

And Function

In this study, the feasibility of transplanting hepatocytes using hollow fibers (HF) was investigated. Experiments were carried out in vitro and in vivo to determine the viability and function of hepatocytes encapsulated in four different types of commercially available HF: regenerated cellulose HF (RCHF), polysulfone HF of two different sizes (PSHF-1 and PSHF-2), and polyvinylidine HF (PVDF). Hepatocytes remained viable in all types of HF for at least 1 wk in vitro as measured by light microscopy and their ability to synthesize protein and secrete albumin. However, the levels of protein synthesis and albumin secretion in these cells varied significantly between different HF (RCHF > PSHF-2 > PVDF ã PSHF-1) and appeared to be inversely related to their internal diameters (215, 500, 1000, and 1100 μm for RCHF, PSHF-2, PVDF, and PSHF-1, respectively). While PSHF-2, PVDF, and PSHF-1 did not support long term viability in vivo, hepatocytes in RCHF survived after implantation in the mesentery. After 24 h in vivo, the hepatocytes appeared morphologically intact and exhibited a similar rate of protein synthesis when compared with cells cultured in parallel. The hepatocytes in RCHF also maintained the ability to synthesize protein after 7 days in vivo. These results suggest that HF of appropriate size may be useful for hepatocyte transplantation applications in which prevascularization is not possible.

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Cytokine-Activated Endothelial Cells Delay Neutrophil Apoptosis in Vitro and in Vivo

Journal of Experimental Medicine ◽

10.1084/jem.190.7.923 ◽

1999 ◽

Vol 190 (7) ◽

pp. 923-934 ◽

Cited By ~ 111

Author(s):

Angela Coxon ◽

Tao Tang ◽

Tanya N. Mayadas

Keyword(s):

Endothelial Cells ◽

Peripheral Blood ◽

Neutrophil Apoptosis ◽

Wild Type ◽

Gm Csf ◽

Acute Meningitis ◽

Blood Neutrophils ◽

And Function

The activation of endothelium is important in recruiting neutrophils to sites of inflammation and in modulating their function. We demonstrate that conditioned medium from cultured, activated endothelial cells acts to significantly delay the constitutive apoptosis of neutrophils, resulting in their enhanced survival and increased phagocytic function. The antiapoptotic activity is, in part, attributable to granulocyte/macrophage colony-stimulating factor (GM-CSF) secreted by activated endothelial cells. The in vivo relevance of these findings was investigated in a cytokine-induced model of acute meningitis in mice. Peripheral blood neutrophils (PBNs) from mice with meningitis exhibited a delay in apoptosis compared with untreated mice. Furthermore, neutrophils recovered from the inflamed cerebrospinal fluid (CSF) exhibited enhanced survival compared with neutrophils isolated from the peripheral blood of the same animals. In unchallenged GM-CSF–deficient mice, the apoptosis of circulating PBNs was similar to wild-type animals; however, after cytokine-induced meningitis, the delay in neutrophil apoptosis typically observed in wild-type mice was attenuated. In contrast, the apoptosis of neutrophils recovered from the CSF of mice of both genotypes was comparable. Taken together, these studies suggest that neutrophil apoptosis is regulated during an inflammatory response, in both intravascular and extravascular compartments. GM-CSF released by activated endothelium can act to increase neutrophil survival and function in the peripheral blood, whereas other factor(s) appear to perform this function in the extravascular space.

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Systemic administration of β-glucan induces immune training in microglia

Journal of Neuroinflammation ◽

10.1186/s12974-021-02103-4 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Yang Heng ◽

Xiaoming Zhang ◽

Malte Borggrewe ◽

Hilmar R. J. van Weering ◽

Maaike L. Brummer ◽

...

Keyword(s):

Immune Tolerance ◽

Morphological Changes ◽

Innate Immune ◽

Cytokine Gene Expression ◽

Immune Memory ◽

Lps Challenge ◽

Lps Preconditioning ◽

Gene Expression Levels

Abstract Background An innate immune memory response can manifest in two ways: immune training and immune tolerance, which refers to an enhanced or suppressed immune response to a second challenge, respectively. Exposing monocytes to moderate-to-high amounts of bacterial lipopolysaccharide (LPS) induces immune tolerance, whereas fungal β-glucan (BG) induces immune training. In microglia, it has been shown that different LPS inocula in vivo can induce either immune training or tolerance. Few studies focused on impact of BG on microglia and were only performed in vitro. The aim of the current study was to determine whether BG activates and induces immune memory in microglia upon peripheral administration in vivo. Methods Two experimental designs were used. In the acute design, mice received an intraperitoneal (i.p.) injection with PBS, 1 mg/kg LPS or 20 mg/kg BG and were terminated after 3 h, 1 or 2 days. In the preconditioning design, animals were first challenged i.p. with PBS, 1 mg/kg LPS or 20 mg/kg BG. After 2, 7 or 14 days, mice received a second injection with PBS or 1 mg/kg LPS and were sacrificed 3 h later. Microglia were isolated by fluorescence-activated cell sorting, and cytokine gene expression levels were determined. In addition, a self-developed program was used to analyze microglia morphological changes. Cytokine concentrations in serum were determined by a cytokine array. Results Microglia exhibited a classical inflammatory response to LPS, showing significant upregulation of Tnf, Il6, Il1β, Ccl2, Ccl3 and Csf1 expression, three h after injection, and obvious morphological changes 1 and 2 days after injection. With an interval of 2 days between two challenges, both BG and LPS induced immune training in microglia. The training effect of LPS changed into immune tolerance after a 7-day interval between 2 LPS challenges. Preconditioning with BG and LPS resulted in increased morphological changes in microglia in response to a systemic LPS challenge compared to naïve microglia. Conclusions Our results demonstrate that preconditioning with BG and LPS both induced immune training of microglia at two days after the first challenge. However, with an interval of 7 days between the first and second challenge, LPS-preconditioning resulted in immune tolerance in microglia.

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Systemic administration of β-glucan induces immune training in microglia

10.21203/rs.3.rs-115993/v1 ◽

2020 ◽

Author(s):

Yang Heng ◽

Xiaoming Zhang ◽

Malte Borggrewe ◽

Hilmar R.J. van Weering ◽

Maaike L. Brummer ◽

...

Keyword(s):

Immune Tolerance ◽

Morphological Changes ◽

Innate Immune ◽

Cytokine Gene Expression ◽

Immune Memory ◽

Lps Challenge ◽

Lps Preconditioning ◽

Gene Expression Levels

Abstract BackgroundAn innate immune memory response can manifest in two ways: immune training and immune tolerance, which refers to an enhanced or suppressed immune response to a second challenge, respectively. Exposing monocytes to moderate-to-high amounts of bacterial lipopolysaccharide (LPS) induces immune tolerance, whereas fungal β-glucan (BG) induces immune training. In microglia, it has been shown that different LPS inocula in vivo can induce either immune training or tolerance. Few studies focused on impact of BG on microglia and were only performed in vitro. The aim of the current study was to determine whether BG activates and induces immune memory in microglia upon peripheral administration in vivo.MethodsTwo experimental designs were used. In the acute design, mice received an intraperitoneal (i.p.) injection with PBS, 1 mg/kg LPS or 20 mg/kg BG and were terminated after 3 h, 1 or 2 days. In the preconditioning design, animals were first challenged i.p. with PBS, 1 mg/kg LPS or 20 mg/kg BG. After 2, 7 or 14 days, mice received a second injection with PBS or 1 mg/kg LPS and were sacrificed 3 h later. Microglia were isolated by fluorescence-activated cell sorting, and cytokine gene expression levels were determined. In addition, a self-developed program was used to analyze microglia morphological changes. Cytokine concentrations in serum were determined by a cytokine array.ResultsMicroglia exhibited a classical inflammatory response to LPS, showing significant upregulation of Tnf, Il6, Il1β, Ccl2, Ccl3 and Csf1 expression, three h after injection, and obvious morphological changes 1 and 2 days after injection. With an interval of 2 days between two challenges, both BG and LPS induced immune training in microglia. The training effect of LPS changed into immune tolerance after a 7-day interval between 2 LPS challenges. Preconditioning with BG and LPS resulted in increased morphological changes in microglia in response to a systemic LPS challenge compared to naïve microglia.ConclusionsOur results demonstrate that preconditioning with BG and LPS both induced immune training of microglia at two days after the first challenge. However, with an interval of 7 days between the first and second challenge, LPS-preconditioning resulted in immune tolerance in microglia.

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Reversal of Tumor-induced Dendritic Cell Paralysis by CpG Immunostimulatory Oligonucleotide and Anti–Interleukin 10 Receptor Antibody

Journal of Experimental Medicine ◽

10.1084/jem.20020732 ◽

2002 ◽

Vol 196 (4) ◽

pp. 541-549 ◽

Cited By ~ 254

Author(s):

Alain P. Vicari ◽

Claudia Chiodoni ◽

Céline Vaure ◽

Smina Aït-Yahia ◽

Christophe Dercamp ◽

...

Keyword(s):

De Novo ◽

Interleukin 10 ◽

Interferon Γ ◽

Immune Memory ◽

Mouse Tumor ◽

Tumor Associated Antigen ◽

Functional Defect ◽

And Function

Progressing tumors in man and mouse are often infiltrated by dendritic cells (DCs). Deficient antitumor immunity could be related to a lack of tumor-associated antigen (TAA) presentation by tumor-infiltrating DCs (TIDCs) or to a functional defect of TIDCs. Here we investigated the phenotype and function of TIDCs in transplantable and transgenic mouse tumor models. Although TIDCs could encompass various known DC subsets, most had an immature phenotype. We observed that TIDCs were able to present TAA in the context of major histocompatibility complex class I but that they were refractory to stimulation with the combination of lipopolysaccharide, interferon γ, and anti-CD40 antibody. We could revert TIDC paralysis, however, by in vitro or in vivo stimulation with the combination of a CpG immunostimulatory sequence and an anti-interleukin 10 receptor (IL-10R) antibody. CpG or anti–IL-10R alone were inactive in TIDCs, whereas CpG triggered activation in normal DCs. In particular, CpG plus anti–IL-10R enhanced the TAA-specific immune response and triggered de novo IL-12 production. Subsequently, CpG plus anti–IL-10R treatment showed robust antitumor therapeutic activity exceeding by far that of CpG alone, and elicited antitumor immune memory.

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Murine Stromal Cells Counteract the Loss of Long-Term Culture-Initiating Cell Potential Induced by Cytokines in CD34+CD38low/neg Human Bone Marrow Cells

Blood ◽

10.1182/blood.v94.2.529 ◽

1999 ◽

Vol 94 (2) ◽

pp. 529-538 ◽

Cited By ~ 62

Author(s):

Annelise Bennaceur-Griscelli ◽

Cristina Tourino ◽

Brigitte Izac ◽

William Vainchenker ◽

Laure Coulombel

Keyword(s):

Stromal Cells ◽

Bone Marrow Cells ◽

Cell Potential ◽

Self Renewal ◽

Gm Csf ◽

High Concentrations ◽

And Function

Abstract Evidence has been provided recently that shows that high concentrations of cytokines can fulfill functions previously attributed to stromal cells, such as promote the survival of, and led to a net increase in human primitive progenitors initiating long-term cultures in vitro (LTC-IC) or engrafting NOD-SCID (nonobese diabetic severe-combined immunodeficient) recipients in vivo. These data prompted us to re-evaluate whether stromal cells will further alter the properties of primitive progenitor cells exposed to cytokines. Single CD34+CD38low and CD38neg cells were incubated 10 days in serum-containing or serum-free medium in the presence or in the absence of murine marrow-derived stromal cells (MS-5). Recombinant human cytokines stem cell factor (SCF), pegylated-megakaryocyte growth and differentiation factor (PEG–MGDF), FLT3-L, Interleukin (IL)-3, IL-6, and granulocyte-macrophage colony-stimulating factor (GM–CSF) were systematically added at various concentrations (10 to 300 ng/mL). Cell proliferation and LTC-IC potential were evaluated in each clone after 10 days. A striking and consistent observation was the retention of a high LTC-IC potential in clones exposed to cytokines in the presence of stromal feeders, whereas clones exposed to cytokines alone in the absence of stromal feeders rapidly lost their LTC-IC potential as they proliferated. This was reflected both by the higher proportion of wells containing LTC-IC and by the high numbers of CFC produced after 5 weeks in clones grown with MS-5 during the first 10 days. We further showed by analyzing multiple replicates of a single clone at day 10 that MS-5 cells promoted a net increase in the LTC-IC compartment through self-renewal divisions. Interestingly, these primitive LTC-IC were equally distributed among small and large clones, as counted at day 10, indicating that active proliferation and loss of LTC-IC potential could be dissociated. These observations show that, in primitive cells, stromal cells counteract differentiation events triggered by cytokines and promoted self-renewal divisions. Furthermore, the almost identical distribution of the size of the clones with or without MS-5 suggests that proliferation and function of human primitive cells may be independently regulated by external signals, and that the former is primarily under the control of cytokines.

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Murine Stromal Cells Counteract the Loss of Long-Term Culture-Initiating Cell Potential Induced by Cytokines in CD34+CD38low/neg Human Bone Marrow Cells

Blood ◽

10.1182/blood.v94.2.529.414k21_529_538 ◽

1999 ◽

Vol 94 (2) ◽

pp. 529-538 ◽

Cited By ~ 1

Author(s):

Annelise Bennaceur-Griscelli ◽

Cristina Tourino ◽

Brigitte Izac ◽

William Vainchenker ◽

Laure Coulombel

Keyword(s):

Stromal Cells ◽

Bone Marrow Cells ◽

Cell Potential ◽

Self Renewal ◽

Gm Csf ◽

High Concentrations ◽

And Function

Evidence has been provided recently that shows that high concentrations of cytokines can fulfill functions previously attributed to stromal cells, such as promote the survival of, and led to a net increase in human primitive progenitors initiating long-term cultures in vitro (LTC-IC) or engrafting NOD-SCID (nonobese diabetic severe-combined immunodeficient) recipients in vivo. These data prompted us to re-evaluate whether stromal cells will further alter the properties of primitive progenitor cells exposed to cytokines. Single CD34+CD38low and CD38neg cells were incubated 10 days in serum-containing or serum-free medium in the presence or in the absence of murine marrow-derived stromal cells (MS-5). Recombinant human cytokines stem cell factor (SCF), pegylated-megakaryocyte growth and differentiation factor (PEG–MGDF), FLT3-L, Interleukin (IL)-3, IL-6, and granulocyte-macrophage colony-stimulating factor (GM–CSF) were systematically added at various concentrations (10 to 300 ng/mL). Cell proliferation and LTC-IC potential were evaluated in each clone after 10 days. A striking and consistent observation was the retention of a high LTC-IC potential in clones exposed to cytokines in the presence of stromal feeders, whereas clones exposed to cytokines alone in the absence of stromal feeders rapidly lost their LTC-IC potential as they proliferated. This was reflected both by the higher proportion of wells containing LTC-IC and by the high numbers of CFC produced after 5 weeks in clones grown with MS-5 during the first 10 days. We further showed by analyzing multiple replicates of a single clone at day 10 that MS-5 cells promoted a net increase in the LTC-IC compartment through self-renewal divisions. Interestingly, these primitive LTC-IC were equally distributed among small and large clones, as counted at day 10, indicating that active proliferation and loss of LTC-IC potential could be dissociated. These observations show that, in primitive cells, stromal cells counteract differentiation events triggered by cytokines and promoted self-renewal divisions. Furthermore, the almost identical distribution of the size of the clones with or without MS-5 suggests that proliferation and function of human primitive cells may be independently regulated by external signals, and that the former is primarily under the control of cytokines.

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GM-CSF differentiation of human monocytes stabilizes macrophage state via oxidative signaling

10.1101/2020.09.29.318352 ◽

2020 ◽

Author(s):

Christopher Y Itoh ◽

Cal Gunnarsson ◽

Gregory H Babunovic ◽

Armel Nibasumba ◽

Ngomu Akeem Akilimali ◽

...

Keyword(s):

Experimental Approach ◽

Dominant Role ◽

Human Monocyte ◽

Transcriptional Networks ◽

Gm Csf ◽

Oxidative Signaling ◽

Inflammatory Phenotype ◽

And Function

AbstractMacrophages are central mediators of immunity that integrate diverse signals derived from differentiation cues, tissue location, and disease. Controlling macrophage state and function is an appealing therapeutic objective across many diseases including cancer, atherosclerosis, and tuberculosis. Despite the growing appreciation for the in vivo complexity of macrophage state, existing in vitro models of human monocyte-derived macrophages have used a limited number of individual perturbations to explore the complex phenotypic space that macrophages can occupy. Here, we leverage a tiered differentiation, activation, and stimulation strategy to generate libraries of in vitro monocyte-derived macrophages and examine the in vitro state space of macrophage function using high-dimensional technologies. Our tiered experimental approach further revealed a striking relationship between GM-CSF differentiation and IL-10 production. Cells that were differentiated with GM-CSF produced very low or undetectable levels of IL-10 independent of activation or stimulation condition. To nominate candidate regulators of this IL-10 response, we leverage unbiased single-cell mRNA sequencing to identify transcriptional networks associated with GM-CSF-derived cells. Using these data, we identify oxidative signaling pathways as upregulated in GM-CSF derived cells and demonstrate that scavenging of oxidative radicals can enhance IL-10 production in these cells. Collectively, these data underscore the complexity of monocyte-derived macrophage state over time and highlight a dominant role for GM-CSF in tuning macrophage inflammatory phenotype, metabolic state, and plasticity.

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