scholarly journals Retinal microglia initiate neuroinflammation in ocular autoimmunity

2019 ◽  
Vol 116 (20) ◽  
pp. 9989-9998 ◽  
Author(s):  
Yoko Okunuki ◽  
Ryo Mukai ◽  
Takeshi Nakao ◽  
Steven J. Tabor ◽  
Oleg Butovsky ◽  
...  

Autoimmune uveitis is a sight-threatening ocular inflammatory condition in which the retina and uveal tissues become a target of autoreactive immune cells. While microglia have been studied extensively in autoimmune uveitis, their exact function remains uncertain. The objective of the current study was to determine whether resident microglia are necessary and sufficient to initiate and amplify retinal inflammation in autoimmune uveitis. In this study, we clearly demonstrate that microglia are essential for initiating infiltration of immune cells utilizing a murine model of experimental autoimmune uveoretinitis (EAU) and the recently identified microglia-specific marker P2ry12. Initiating disease is the primary function of microglia in EAU, since eliminating microglia during the later stages of EAU had little effect, indicating that the function of circulating leukocytes is to amplify and sustain destructive inflammation once microglia have triggered disease. In the absence of microglia, uveitis does not develop, since leukocytes cannot gain entry through the blood-retinal barrier, illustrating that microglia play a critical role in regulating infiltration of inflammatory cells into the retina.

Author(s):  
Chang Liu ◽  
Zecheng Jiang ◽  
Zhongjie Pan ◽  
Liang Yang

Atherosclerosis is a chronic progressive inflammatory vascular disease, which is an important pathological basis for inducing a variety of cardio-cerebrovascular diseases. As a kind of inflammatory cells, macrophages are the most abundant immune cells in atherosclerotic plaques and participate in the whole process of atherosclerosis and are the most abundant immune cells in atherosclerotic plaques. Recent studies have shown that programmed cell death plays a critical role in the progression of many diseases. At present, it is generally believed that the programmed death of macrophages can affect the development and stability of atherosclerotic vulnerable plaques, and the intervention of macrophage death may become the target of atherosclerotic therapy. This article reviews the role of macrophage programmed cell death in the progression of atherosclerosis and the latest therapeutic strategies targeting macrophage death within plaques.


2020 ◽  
Vol 11 ◽  
Author(s):  
Courtney B. Johnson ◽  
Jizhou Zhang ◽  
Daniel Lucas

Hematopoiesis in the bone marrow (BM) is the primary source of immune cells. Hematopoiesis is regulated by a diverse cellular microenvironment that supports stepwise differentiation of multipotent stem cells and progenitors into mature blood cells. Blood cell production is not static and the bone marrow has evolved to sense and respond to infection by rapidly generating immune cells that are quickly released into the circulation to replenish those that are consumed in the periphery. Unfortunately, infection also has deleterious effects injuring hematopoietic stem cells (HSC), inefficient hematopoiesis, and remodeling and destruction of the microenvironment. Despite its central role in immunity, the role of the microenvironment in the response to infection has not been systematically investigated. Here we summarize the key experimental evidence demonstrating a critical role of the bone marrow microenvironment in orchestrating the bone marrow response to infection and discuss areas of future research.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 823
Author(s):  
Jian Tan ◽  
Duan Ni ◽  
Rosilene V. Ribeiro ◽  
Gabriela V. Pinget ◽  
Laurence Macia

Cell survival, proliferation and function are energy-demanding processes, fuelled by different metabolic pathways. Immune cells like any other cells will adapt their energy production to their function with specific metabolic pathways characteristic of resting, inflammatory or anti-inflammatory cells. This concept of immunometabolism is revolutionising the field of immunology, opening the gates for novel therapeutic approaches aimed at altering immune responses through immune metabolic manipulations. The first part of this review will give an extensive overview on the metabolic pathways used by immune cells. Diet is a major source of energy, providing substrates to fuel these different metabolic pathways. Protein, lipid and carbohydrate composition as well as food additives can thus shape the immune response particularly in the gut, the first immune point of contact with food antigens and gastrointestinal tract pathogens. How diet composition might affect gut immunometabolism and its impact on diseases will also be discussed. Finally, the food ingested by the host is also a source of energy for the micro-organisms inhabiting the gut lumen particularly in the colon. The by-products released through the processing of specific nutrients by gut bacteria also influence immune cell activity and differentiation. How bacterial metabolites influence gut immunometabolism will be covered in the third part of this review. This notion of immunometabolism and immune function is recent and a deeper understanding of how lifestyle might influence gut immunometabolism is key to prevent or treat diseases.


Author(s):  
Mingyi Zhou ◽  
Zhuo Yang ◽  
Danbo Wang ◽  
Peng Chen ◽  
Yong Zhang

Abstract Background As a novel type of non-coding RNA, circular RNAs (circRNAs) play a critical role in the initiation and development of various diseases, including cancer. However, the exact function of circRNAs in human cervical cancer remains largely unknown. Methods We identified the circRNA signature of upregulated circRNAs between cervical cancer and paired adjacent normal tissues. Using two different cohorts and GEO database, a total of six upregulated circRNAs were identified with a fold change > 2, and P < 0.05. Among these six circRNAs, hsa_circ_0072088 (circZFR) was the only exonic circRNA significantly overexpressed in cervical cancer. Functional experiments were performed to investigate the biological function of circZFR. CircRNA pull-down, circRNA immunoprecipitation (circRIP) and Co-immunoprecipitation (Co-IP) assays were executed to investigate the molecular mechanism underlying the function of circZFR. Results Functionally, circZFR knockdown represses the proliferation, invasion, and tumor growth. Furthermore, circRNA pull-down experiments combined with mass spectrometry unveil the interactions of circZFR with Single-Stranded DNA Binding Protein 1 (SSBP1). Mechanistically, circZFR bound with SSBP1, thereby promoting the assembly of CDK2/cyclin E1 complexes. The activation of CDK2/cyclin E1 complexes induced p-Rb phosphorylation, thus releasing activated E2F1 leading to cell cycle progression and cell proliferation. Conclusion Our findings provide the first evidence that circZFR is a novel onco-circRNA and might be a potential biomarker and therapeutic target for cervical cancer patients.


Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582095135
Author(s):  
Michael I. Koukourakis

Low dose radiotherapy has been used in the pre-antibiotic era for the treatment of all kind of pneumonia, with relative success. The unimaginable daily death toll of thousands of victims dying from COVID-19 pneumonia and the marginal therapeutic value of agents tested, brings forward the re-evaluation of the position of radiotherapy in the treatment of late stage lethal COVID-induced respiratory failure. A sound biological rationale supports this idea. Immunopathology studies show that excessive inflammation and infiltration of the lung parenchyma by immune cells is the cause of death. Mice lacking IFNαβ receptors remain unaffected by the virus. Radiotherapy at doses of 50-200cG may exert an intense anti-inflammatory effect and reduce the burden of inflammatory cells infiltrating the lungs. Whether radiotherapy, in conjunction with remdesivir and/or macrolides can reduce the dramatic death rates related to COVID-19 is an open challenge, under the absence of an alternative solution.


2021 ◽  
Vol 22 (13) ◽  
pp. 6878
Author(s):  
Yaser Hosny Ali Elewa ◽  
Mahmoud Mansour Abd Elwakil ◽  
Osamu Ichii ◽  
Teppei Nakamura ◽  
Sherif Kh. A. Mohamed ◽  
...  

Recently, we clarified the function of mediastinal fat-associated lymphoid clusters (MFALCs) in the progression of several respiratory diseases. However, their role has not yet been identified in the lung asthmatic condition. Hence, we compared the immune cells in lung and MFALCs of C57BL/6N mice on days 3 and 7 following intranasal instillation of either papain (papain group “PG”) or phosphate buffer saline (PBS) (vehicle group “VG”). The PG showed significantly prominent MFALCs, numerous goblet cells (GCs), and higher index ratios of different immune cells (macrophages, natural helper cells (NHC), B- and T-lymphocytes) within the MFALCs and lung than in the VG on both days 3 and 7. Interestingly, a tendency of decreased size of MFALCs and a significant reduction in the number of GCs and immune cells were observed within the MFALCs and lung in the PG on day 7 than on day 3. Furthermore, the quantitative parameters of these immune cells in MFALCs were significantly and positively correlated with the size of MFALCs and immune cells in the lung. This suggested that the possible crosstalk between immune cells within MFALCs and the lung could play a critical role in the progression and recovery of the acute inflammatory lung asthma.


Endocrinology ◽  
2004 ◽  
Vol 145 (3) ◽  
pp. 1331-1341 ◽  
Author(s):  
Shaaban A. Mousa ◽  
Mehdi Shakibaei ◽  
Nicolle Sitte ◽  
Michael Schäfer ◽  
Christoph Stein

Abstract The opioid peptide β-endorphin (END) as well as mRNA for its precursor proopiomelanocortin (POMC) are found not only in the pituitary gland, but also within various types of immune cells infiltrating inflamed sc tissue. During stressful stimuli END is released and interacts with peripheral opioid receptors to inhibit pain. However, the subcellular pathways of POMC processing and END release have not yet been delineated in inflammatory cells. The aim of the present study was to examine the presence of POMC, carboxypeptidase E, the prohormone convertases 1 (PC1), and 2 (PC2), PC2-binding protein 7B2, and the release of END from inflammatory cells in rats. Using immunohistochemistry we detected END and POMC alone or colocalized with PC1, PC2, carboxypeptidase E, and 7B2 in macrophages/monocytes, granulocytes, and lymphocytes of the blood and within inflamed sc paw tissue. Immunoelectron microscopy revealed that END is localized within secretory granules packed in membranous structures in macrophages, monocytes, granulocytes, and lymphocytes. Finally, END is released by noradrenaline from immune cells in vitro. Taken together, our results indicate that immune cells express the entire machinery required for POMC processing into functionally active peptides such as END and are able to release these peptides from secretory granules.


2019 ◽  
Vol 20 (2) ◽  
pp. 377 ◽  
Author(s):  
Giulia Franzolin ◽  
Luca Tamagnone

The inflammatory and immune response elicited by the growth of cancer cells is a major element conditioning the tumor microenvironment, impinging on disease progression and patients’ prognosis. Semaphorin receptors are widely expressed in inflammatory cells, and their ligands are provided by tumor cells, featuring an intense signaling cross-talk at local and systemic levels. Moreover, diverse semaphorins control both cells of the innate and the antigen-specific immunity. Notably, semaphorin signals acting as inhibitors of anti-cancer immune response are often dysregulated in human tumors, and may represent potential therapeutic targets. In this mini-review, we provide a survey of the best known semaphorin regulators of inflammatory and immune cells, and discuss their functional impact in the tumor microenvironment.


2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii24-iii24
Author(s):  
Q Chang ◽  
L Zhu ◽  
N Li

Abstract BACKGROUND Medulloblastoma (MB) is the most common malignant paediatric brain tumor. Recent studies show that M2 cells were relative more abundant in Shh subtype of MBs compared with other three subtypes. It’s known that M2 cells have close relationship with many tumors’ progression. But if they play any role in the progression of Shh subtype of MB is not yet clear. Many studies demonstrate that exosomes carring miRNAs have close relationship with tumor invasion. The aim of present study is to clarify the role of exosome miRNA between tumor cells and microglias during the progression of Shh subtype of medulloblastoma. MATERIAL AND METHODS Immunofluerescence staining using iNOS and Arg1, which is M1 and M2 specific marker, respectively, was performed in four subtypes of MBs. After coculture of exosomes extracted from Shh subtype of MB cell (DAOY) with microglia cell (BV2), Q-PCR and ELISA assay were done to evaluate the polarization status of the microglia. Transwell and scratch assay were then performed to detect the migration ability of DAOY cell after treatment of exosomes from polirized M2 cells. MiRNA sequencing by Ion Proton technology was then done to analyze the miRNAs expression level between Shh subtype and other subtype of MBs. Transformation assay was used to overexpress and inhibit the expression of these miRNAs respectively to further clarify the role of exosome miRNA in the polarization of BV2 cells. RESULTS M2 cells were observed more abundant than other three subtypes of tumors, supporting that M2 cells play some role in this subtype of MBs. Exosomes of DAOY cells can induce the polarization of M2 cells. The polarized M2 cells can improved the migration and invasion ability of DAOY cell. Dozens of miRNAs were identified with different expression level between Shh subtype of MBs and other subtype of MB cells. Among them, 4 miRNAs were reported to be related with polariztion of M2 in many other lesions. Three of the 4 miRNAs can induce the polarization of M2 in present study. CONCLUSION Our study demonstrated exosome miRNA play a critical role between tumor cells and microglias during the progression of Shh subtype of medulloblastoma.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hee Young Na ◽  
Yujun Park ◽  
Soo Kyung Nam ◽  
Jiwon Koh ◽  
Yoonjin Kwak ◽  
...  

Abstract Background Natural killer (NK) cells mediate the anti-tumoral immune response as an important component of innate immunity. The aim of this study was to investigate the prognostic significance and functional implication of NK cell-associated surface receptors in gastric cancer (GC) by using multiplex immunohistochemistry (mIHC). Methods We performed an mIHC on tissue microarray slides, including 55 GC tissue samples. A total of 11 antibodies including CD57, NKG2A, CD16, HLA-E, CD3, CD20, CD45, CD68, CK, SMA, and ki-67 were used. CD45 + CD3-CD57 + cells were considered as CD57 + NK cells. Results Among CD45 + immune cells, the proportion of CD57 + NK cell was the lowest (3.8%), whereas that of CD57 + and CD57- T cells (65.5%) was the highest, followed by macrophages (25.4%), and B cells (5.3%). CD57 + NK cells constituted 20% of CD45 + CD57 + immune cells while the remaining 80% were CD57 + T cells. The expression of HLA-E in tumor cells correlated with that in tumoral T cells, B cells, and macrophages, but not CD57 + NK cells. The higher density of tumoral CD57 + NK cells and tumoral CD57 + NKG2A + NK cells was associated with inferior survival. Conclusions Although the number of CD57 + NK cells was lower than that of other immune cells, CD57 + NK cells and CD57 + NKG2A + NK cells were significantly associated with poor outcomes, suggesting that NK cell subsets play a critical role in GC progression. NK cells and their inhibitory receptor, NKG2A, may be potential targets in GC.


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