Local Resident Cells Research Articles

Single cell transcriptional zonation of human psoriasis skin identifies an alternative immunoregulatory axis conducted by skin resident cells

Psoriasis is the most common skin disease in adults. Current experimental and clinical evidences suggested the infiltrating immune cells could target local skin cells and thus induce psoriatic phenotype. However, recent studies indicated the existence of a potential feedback signaling loop from local resident skin cells to infiltrating immune cells. Here, we deconstructed the full-thickness human skins of both healthy donors and patients with psoriasis vulgaris at single cell transcriptional level, and further built a neural-network classifier to evaluate the evolutional conservation of skin cell types between mouse and human. Last, we systematically evaluated the intrinsic and intercellular molecular alterations of each cell type between healthy and psoriatic skin. Cross-checking with psoriasis susceptibility gene loci, cell-type based differential expression, and ligand-receptor communication revealed that the resident psoriatic skin cells including mesenchymal and epidermis cell types, which specifically harbored the target genes of psoriasis susceptibility loci, intensively evoked the expression of major histocompatibility complex (MHC) genes, upregulated interferon (INF), tumor necrosis factor (TNF) signalling and increased cytokine gene expression for primarily aiming the neighboring dendritic cells in psoriasis. The comprehensive exploration and pathological observation of psoriasis patient biopsies proposed an uncovered immunoregulatory axis from skin local resident cells to immune cells, thus provided a novel insight for psoriasis treatment. In addition, we published a user-friendly website to exhibit the transcriptional change of each cell type between healthy and psoriatic human skin.

Adult Stem Cell Functioning in the Tumor Micro-Environment.

Tumor progression from an expanded cell population in a primary location to disseminated lethal growths subverts attempts at cures. It has become evident that these steps are driven in a large part by cancer cell-extrinsic signaling from the tumor microenvironment (TME), one cellular component of which is becoming more appreciated for potential modulation of the cancer cells directly and the TME globally. That cell is a heterogenous population referred to as adult mesenchymal stem cells/multipotent stromal cells (MSCs). Herein, we review emerging evidence as to how these cells, both from distant sources, mainly the bone marrow, or local resident cells, can impact the progression of solid tumors. These nascent investigations raise more questions than they answer but paint a picture of an orchestrated web of signals and interactions that can be modulated to impact tumor progression.

Roles of exosomes in liver metastases: Novel diagnosis and treatment choices.

Tumors tend to metastasize to the liver. Premetastatic niche formation is a vital step in liver metastasis. Tumor-derived exosomes can influence premetastatic niche formation from three aspects: vascular leakiness and angiogenesis, recruitment of nonresident cells, and changes in local resident cells. Exosomes from other tissues, such as mesenchymal stem cell-derived exosomes and engineered exosomes, also have therapeutic potential, but further research on these exosomes is required. Based on the mechanism of premetastatic niche formation, we summarize the therapeutic and diagnostic potential of exosomes in inhibiting liver metastases in this review in an attempt to provide new avenues for the prevention and treatment of liver metastases.

MicroRNA in immunity and autoimmunity

MicroRNAs (miRNAs) are about 20-22 nucleotide conserved non-coding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3'-untranslated region of specific messenger RNAs (mRNAs) for degradation or translational repression. During the last two decades, miRNAs have emerged as critical regulators of a range of biological processes including immune cell lineage commitment, differentiation, maturation, and immune signaling pathways. The endoribonucleases such as Dicer, which is required for miRNA biogenesis, has also been shown to play an important role in inflammatory response and autoimmunity. Thus, dysregulated miRNA expression patterns have been documented in a broad range of human diseases including inflammatory and autoimmune diseases. In this review, we will discuss recent advances in miRNAs mediated regulation of inflammatory responses and autoimmune pathogenesis. Specifically, we will discuss how miRNAs regulate autoimmunity through affecting the development, differentiation, and function of various cell types such as innate immune cells, adaptive immune cells and local resident cells. The identification of distinct miRNA expression patterns, and a comprehensive understanding of the roles of those dysregulated miRNAs in inflammatory autoimmune pathogenesis offers inspirations of not only potential molecular diagnostic markers but also novel therapeutic strategies for treating inflammatory autoimmune diseases.

P083 Increased IL-27 cytokine levels in the cerebrospinal fluid of patients with multiple sclerosis

Introduction IL-27 is a heterodimeric cytokine with both pro- and anti-inflammatory properties involved in the pathogenesis of autoimmune diseases. IL-27 can be produced directly at the inflammation sites by local resident cells and antigen presenting cells (APC). IL-27 can be secreted by resident cells of the central nervous system (CNS) [1] . In Experimental Autoimmune Encephalomyelitis (EAE) a mouse model of multiple sclerosis (MS), IL-27 has potent anti-inflammatory properties and mediate the protective effects of IFN- β treatment [2] , [3] . Finally at the mechanistic levels, IL-21 is critical for the anti-inflammatory properties if IL-27 [4] . However, it is not known whether IL-27 or IL-21 levels are modified in the cerebrospinal fluid or blood of MS patients. Methods We performed a cases study analysis. Protein levels of IL-27 and IL-21 were measured by ELISA from (1) the cerebrospinal fluid (CSF) of untreated patients with relapsing remitting MS (RRMS; n = 56), with optic neuritis (ON; n = 29) or with non inflammatory neurological diseases (NIND; n = 42) (2) the serum of healthy controls ( n = 23), patients with RRMS without treatment ( n = 30) or treated with Interferon beta 1a ( n = 28), Glatiramer acetate ( n = 24) or Natalizumab ( n = 12), Differences in variables were analyzed using ANOVA and Student t tests (for normally distributed data) or Kruskal–Wallis and Mann–Whitney U tests (for non-normally distributed data) as appropriate. Results We found that IL-27 levels were significantly elevated in the CSF of patients with RRMS but not with isolated ON compared with patient with NIND ( p Conclusion Our results show that increased level of IL-27 cytokine is detected in the CSF but not in the serum of RRMS patients compared to controls. This points toward a local secretion of IL-27 in the brain that is increased during autoimmune processes. It is increasingly accepted that IL-27 has anti-inflammatory properties during autoimmune diseases and we propose that local production of IL-27 could sign the induction of a regulatory response that promotes the inflammation’s resolution. The effect of new immunodulatory therapies on cerebral IL-27 production could be used to understand the biology of IL-27 in MS disease.

Increased IL-27 Cytokine Levels in the Cerebrospinal Fluid but Not in the Blood of Multiple Sclerosis Patients (P02.083)

Objective: To measure Interleukin (IL)-27 levels in blood and cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients compared to healthy controls (HC) or patients suffering from non inflammatory neurological diseases (NIND). Background IL-27, an heterodimeric cytokine with both pro- and anti-inflammatory properties, is involved in autoimmune diseases pathogenesis. IL-27 can be produced directly at the inflammation sites by local resident cells and Antigen Presenting Cells (APC). In vitro, IL-27 can be secreted by resident cells of the central nervous system such as astrocytes or microglia. However, it is not known whether IL-27 levels are modified in blood or CSF of MS patients. Design/Methods: We performed a cases study analysis. Protein levels of IL-27 were measured by ELISA from A) the blood of HC (n=23), patients with relapsing remitting (RR)MS without treatment (n=30) or treated with Interferon beta (n=28), Glatiramer acetate (n=24) or Natalizumab (n=12), B) the CSF of untreated patients with RRMS (n=56), optic neuritis (ON) (n=29) or NIND (n=42). Differences in variables were analyzed using Student t tests (for normally distributed data) or MannWhitney U tests (for non-normally distributed data). Results: IL-27 levels were significantly elevated in the CSF of patients with RRMS but not with isolated ON compared with patient with NIND. By contrast, IL-27 plasma levels of RRMS patients were equivalent to HC and were not influenced by immunomodulatory drugs. Conclusions: Our results show increased levels of IL-27 cytokine in the CSF but not in the blood of MS patients compared to controls. Those results highlight the importance of IL-27 during autoimmune disease in human. IL-27 has anti-inflammatory properties and local production of IL-27 in the brain could sign the induction of a regulatory response. The effect of new immunodulatory therapies on cerebral IL-27 production should be investigated and could help understand the biology of IL-27 in MS. Supported by: Swiss National Foundation, Novartis Foundation, FP7 Marie Curie. Disclosure: Dr. Pot Kreis has nothing to disclose. Dr. Juillard-Mochon has nothing to disclose. Dr. LaLive has nothing to disclose.

Defining the molecular role of gp91phox in the immune manifestation of acute allergic asthma using a preclinical murine model

ObjectiveThe phenomena manifested during inflammation require interplay between circulating effector cells, local resident cells, soluble mediators and genetic host factors to establish, develop and maintain itself. Of the molecues involed in the initiation and perpetuation of acute allergic inflammation in asthma, the involvement of effector cells in redox reactions for producing O2- (superoxide anion) through the mediation of NADPH oxidase is a critical step. Prior data suggest that reactive oxygen species (ROS) produced by NADPH oxidase homologues in non-phagocytic cells play an important role in the regulation of signal transduction, while macrophages use a membrane-associated NADPH oxidase to generate an array of oxidizing intermediates which inactivate MMPs on or near them.Materials and Methods and TreatmentTo clarify the role of gp91phox subunit of NADPH oxidase in the development and progression of an acute allergic asthma phenotype, we induced allergen dependent inflammation in a gp91phox-/- single knockout and a gp91phox-/-MMP-12-/- double knockout mouse models.ResultsIn the knockout mice, both inflammation and airway hyperreactivity were more extensive than in wildtype mice post-OVA. Although OVA-specific IgE in plasma were comparable in wildtype and knockout mice, enhanced inflammatory cell recruitment from circulation and cytokine release in lung and BALf, accompanied by higher airway resistance as well as Penh in response to methacholine, indicate a regulatory role for NADPH oxidase in development of allergic asthma. While T cell mediated functions like Th2 cytokine secretion, and proliferation to OVA were upregulated synchronous with the overall robustness of the asthma phenotype, macrophage upregulation in functions such as proliferation, and mixed lymphocyte reaction indicate a regulatory role for gp91phox and an overall non-involvement or synergistic involvement of MMP12 in the response pathway (comparing data from gp91phox-/- and gp91phox-/-MMP-12-/- mice).

Identifying the TLR4 bearing target cell in experimental arthritis

PurposeThe interleukin 1 (IL-1) receptor antagonist (IL-1Ra) knockout mice spontaneously develop T cell driven arthritis due to excessive IL-1 signalling. Joint destruction is accompanied by increased Th17 cells and elevated...

Origin of neointimal cells in arteriovenous fistulae: bone marrow, artery, or the vein itself?

To elucidate the source of neointimal cells, experimental fistulas were created in Lewis wild-type (WT) and transgenic rats that constitutively expressed the green fluorescent protein (GFP) in all tissues. Arteriovenous fistula (AVFs) were created by anastomosing the left renal vein to the abdominal aorta. The contribution of bone marrow (BM)-derived cells to the AVF neointima was examined in lethally irradiated WT rats that had been rescued with GFP BM cells. Neointimal cells in these chimeric rats were mostly GFP negative indicating the non-BM origin of those cells. Then, the contribution of arterial cells to the AVF neointima was assessed in a fistula made with a GFP aorta that had been implanted orthotopically into a WT rat. Most of the neointimal cells were also GFP negative demonstrating that AVF neointimal cells are not derived from the feeding artery. Finally to study local resident cells contribution to the formation of neointimal lesions, a composite fistula was created by interposing a GFP vein between the renal vein and the aorta in a WT recipient rat. GFP neointimal cells were only found in the transplanted vein. This study suggests that neointimal cells originate from the local resident cells in the venous limb of the fistula.

Local Mesenchymal Stem/Progenitor Cells Are a Preferential Target for Initiation of Adult Soft Tissue Sarcomas Associated with p53 and Rb Deficiency

The cell of origin and pathogenesis of the majority of adult soft tissue sarcomas (STS) remains poorly understood. Because mutations in both the P53 and RB tumor suppressor genes are frequent in STS in humans, we inactivated these genes by Cre-loxP-mediated recombination in mice with floxed p53 and Rb. Ninety-three percent of mice developed spindle cell/pleomorphic sarcomas after a single subcutaneous injection of adenovirus carrying Cre-recombinase. Similar to human STS, these sarcomas overexpress Cxcr4, which contributes to their invasive properties. Using irradiation chimeras generated by transplanting bone marrow cells from mice carrying either the Rosa26StoploxPLacZ or the Z/EG reporter, as well as the floxed p53 and Rb genes, into irradiated p53loxP/loxPRbloxP/loxP mice, it was determined that sarcomas do not originate from bone marrow-derived cells, such as macrophages, but arise from the local resident cells. At the same time, dermal mesenchymal stem cells isolated by strict plastic adherence and low levels of Sca-1 expression (Sca-1low, CD31negCD45neg) have shown enhanced potential for malignant transformation according to soft agar, invasion, and tumorigenicity assays, after the conditional inactivation of both p53 and Rb. Sarcomas formed after transplantation of these cells have features typical for undifferentiated high-grade pleomorphic sarcomas. Taken together, our studies indicate that local Sca-1low dermal mesenchymal stem/progenitor cells are preferential targets for malignant transformation associated with deficiencies in both p53 and Rb.

Abstract 4183: Modeling soft tissue sarcomas by conditional inactivation of p53 and Rb tumor suppressor genes

Abstract Soft tissue sarcomas, particularly its most common type, undifferentiated pleomorphic sarcomas (also known as malignant fibrous histiocytomas), frequently carry mutations in p53 and Rb tumor suppressor genes. We have established the sarcoma mouse model using conditional inactivation of p53 and Rb by a single subcutaneous injection of adenovirus carrying Cre-recombinase into transgenic mice with floxed copies of p53 and Rb genes. The majority of sarcomas in this model are malignant fibrous histiocytomas, which is a neoplasm consisting of intermixed fibroblast- and histiocyte-like cells. By using irradiation chimeras that have been generated by transplanting bone marrow cells from mice carrying the Rosa26StopLacZ or the Z/EG reporter, as well as floxed p53 and Rb genes, to irradiated p53loxP/loxPRbloxP/loxP mice, we have determined that sarcomas in this model do not originate from hematopoietic cells but arise from the local resident cells. Although the majority of dermal cells infected with AdCMVCre-eGFP have shown expression of fibroblast marker procollagen type I or macrophage marker F4/80, we have observed that cells expressing stem cell markers Sca-1 and nestin also have been targeted by adenovirus. Notably, isolated mesenchymal multipotent cells characterized by strict plastic adherence and low levels of Sca-1 expression have shown enhanced potential for malignant transformation according to proliferation, invasion, and soft agar assays, following conditional inactivation of p53 and Rb. Additionally, we have determined that sarcomas have increased expression of CXCR4, while its ligand SDF-1 is expressed by infiltrating macrophages. Treatment of sarcoma cells with SDF-1 leads to their increased invasion in Boyden chamber assay while CXCR4 knockdown with siRNA abrogates this effect. Taken together, our results indicate that local Sca-1low multipotent dermal stem/progenitor cells may be a preferential target for malignant transformation associated with p53 and Rb deficiency. Furthermore, accumulation of SDF-1 producing macrophages may stimulate sarcomagenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4183.

Autoimmunity as the body's defense mechanism against the enemy within: Development of therapeutic vaccines for neurodegenerative disorders.

Insults to the central nervous system (CNS), whether of microbial or microbe-free origin, result in tissue damage. Until recently, it was generally believed that only microbe-related damage elicits an adaptive immune response, the purpose of which is to eliminate the offending microorganisms. Recent studies in the author's laboratory suggest, however, that the body exhibits an adaptive immune response to microbe-free injuries as well. The immune response in this case is directed against dominant self-antigens residing in the damaged site, where such an adaptive anti-self immune response reinforces the protective activity of local resident cells by providing them with factors that can augment and regulate their capacity for buffering troublemakers such as destructive self-compounds emerging from the injured neural tissue. Because the specificity of this autoimmune response apparently depends not on the type but on the site of lesion, the response can be boosted by therapeutic vaccination for acute and chronic neurodegenerative conditions irrespective of their primary etiology. The results have far-reaching implications, both for microbial infections and for neurodegenerative diseases of the CNS.

Rat Tracheal Epithelial Cells Produce Granulocyte/Macrophage Colony-stimulating Factor

It is unknown whether local resident cells of the upper airway are able to regulate the number and function of phagocytic cells by the secretion of cytokines. We undertook to determine if tracheal epithelial cells (TEC) produce the potent cytokine granulocyte/macrophage colony-stimulating factor (GM-CSF) and how TEC-derived GM-CSF might be regulated. Conditioned media (TEC-CM) from 7- to 21-day-old primary cultures of rat TEC contained material with bioactivity similar to GM-CSF. This bioactivity was increased in conditioned medium from lipopolysaccharide (LPS)-treated (1 microgram/ml) TEC. Molecular characterization of bioactivity revealed a molecular weight of 27 to 44 kD by gel-filtration high performance liquid chromatography (HPLC), and elution at 44 to 50% acetonitrile by reverse-phase HPLC, similar to that of authentic GM-CSF. The biologic activity of TEC-CM was completely blocked by a goat polyclonal anti-GM-CSF antibody. With in situ hybridization using a murine GM-CSF cDNA probe, more than 95% of the adherent TEC population expressed GM-CSF transcripts, and the number of transcripts was significantly increased by LPS (1 microgram/ml, 48 h). TEC appear to produce a cytokine that is functionally, biochemically, and antigenically indistinguishable from GM-CSF. The ability of TEC to produce GM-CSF suggests that these cells may play a role in modulating the inflammatory response in the airway.

Mechanism of replacement of non-parenchymal liver cells (NPLC) in murine radiation chimeras

The mechanism of cell replacement of non-parenchymal liver cells (NPLC) was investigated in an attempt to answer the question: to what extend are NPLC replaced by proliferation of local resident cells and to what extend by cells originating from the bone-marrow. The bone-marrow of mice was used, and H2k positive cells from F1 (B10.BR X B10.D2) hybrid mice were transplanted into irradiated H2k negative parent animals. Their NPLC were isolated and tested immunocytochemically with a monoclonal anti-H2k antibody for the presence of H2k positive cells. During the whole of the experiment (from the 5th to the 20th week following transplantation) H2k positive cells (macrophages and non-macrophages) were present, and made up an average of nearly one third of the NPLC. The H2k positive (immigrant) non-macrophages showed essentially more active DNA synthesis than these H2k negative cells. To increase cell turnover, we injected one group of animals with endotoxin. At the time of maximum replacement, more than 50% of the NPLC (macrophages and non-macrophages) were recruited from cells of bone-marrow origin. Note-worthy here was the proportionate level of the H2k positive macrophages (more than 70% of all liver macrophages). The DNA synthesis of both the H2k positive macrophages and non-macrophages was more than twice that of the H2k negative NPLC during the regeneration process following administration of endotoxin. Our observations suggest that the bone-marrow contributes significantly to the replacement of macrophages and non-macrophages of NPLC in both health and disease.