scholarly journals The Role of Mitochondria in Immune-Cell-Mediated Tissue Regeneration and Ageing

2021 ◽  
Vol 22 (5) ◽  
pp. 2668
Author(s):  
Yu-Jih Su ◽  
Pei-Wen Wang ◽  
Shao-Wen Weng

During tissue injury events, the innate immune system responds immediately to alarms sent from the injured cells, and the adaptive immune system subsequently joins in the inflammatory reaction. The control mechanism of each immune reaction relies on the orchestration of different types of T cells and the activators, antigen-presenting cells, co-stimulatory molecules, and cytokines. Mitochondria are an intracellular signaling organelle and energy plant, which supply the energy requirement of the immune system and maintain the system activation with the production of reactive oxygen species (ROS). Extracellular mitochondria can elicit regenerative effects or serve as an activator of the immune cells to eliminate the damaged cells. Recent clarification of the cytosolic escape of mitochondrial DNA triggering innate immunity underscores the pivotal role of mitochondria in inflammation-related diseases. Human mesenchymal stem cells could transfer mitochondria through nanotubular structures to defective mitochondrial DNA cells. In recent years, mitochondrial therapy has shown promise in treating heart ischemic events, Parkinson’s disease, and fulminating hepatitis. Taken together, these results emphasize the emerging role of mitochondria in immune-cell-mediated tissue regeneration and ageing.

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1280 ◽  
Author(s):  
Alessandro Maglione ◽  
Simona Rolla ◽  
Stefania Federica De Mercanti ◽  
Santina Cutrupi ◽  
Marinella Clerico

Multiple sclerosis (MS) is a chronic central nervous system inflammatory disease that leads to demyelination and neurodegeneration. The third trimester of pregnancy, which is characterized by high levels of estrogens, has been shown to be associated with reduced relapse rates compared with the rates before pregnancy. These effects could be related to the anti-inflammatory properties of estrogens, which orchestrate the reshuffling of the immune system toward immunotolerance to allow for fetal growth. The action of these hormones is mediated by the transcriptional regulation activity of estrogen receptors (ERs). Estrogen levels and ER expression define a specific balance of immune cell types. In this review, we explore the role of estradiol (E2) and ERs in the adaptive immune system, with a focus on estrogen-mediated cellular, molecular, and epigenetic mechanisms related to immune tolerance and neuroprotection in MS. The epigenome dynamics of immune systems are described as key molecular mechanisms that act on the regulation of immune cell identity. This is a completely unexplored field, suggesting a future path for more extensive research on estrogen-induced coregulatory complexes and molecular circuitry as targets for therapeutics in MS.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vikrant Rai ◽  
Megan B. Wood ◽  
Hao Feng ◽  
Nathan. M. Schabla ◽  
Shu Tu ◽  
...  

Abstract Cells of the immune system are present in the adult cochlea and respond to damage caused by noise exposure. However, the types of immune cells involved and their locations within the cochlea are unclear. We used flow cytometry and immunostaining to reveal the heterogeneity of the immune cells in the cochlea and validated the presence of immune cell gene expression by analyzing existing single-cell RNA-sequencing (scRNAseq) data. We demonstrate that cell types of both the innate and adaptive immune system are present in the cochlea. In response to noise damage, immune cells increase in number. B, T, NK, and myeloid cells (macrophages and neutrophils) are the predominant immune cells present. Interestingly, immune cells appear to respond to noise damage by infiltrating the organ of Corti. Our studies highlight the need to further understand the role of these immune cells within the cochlea after noise exposure.


Author(s):  
Azahara María García-Serna ◽  
Elena Martín-Orozco ◽  
Trinidad Hernández-Caselles ◽  
Eva Morales

It is suggested that programming of the immune system starts before birth and is shaped by environmental influences acting during critical windows of susceptibility for human development. Prenatal and perinatal exposure to physiological, biological, physical, or chemical factors can trigger permanent, irreversible changes to the developing immune system, which may be reflected in cord blood of neonates. The aim of this narrative review is to summarize the evidence on the role of the prenatal and perinatal environment, including season of birth, mode of delivery, exposure to common allergens, a farming environment, pet ownership, and exposure to tobacco smoking and pollutants, in shaping the immune cell populations and cytokines at birth in humans. We also discuss how reported disruptions in the immune system at birth might contribute to the development of asthma and related allergic manifestations later in life.


2020 ◽  
Vol 21 (10) ◽  
pp. 3665
Author(s):  
Wiwin Is Effendi ◽  
Tatsuya Nagano ◽  
Helmia Hasan ◽  
Resti Yudhawati

The innate immune system identifies exogenous threats or endogenous stress through germline-encoded receptors called pattern recognition receptors (PRRs) that initiate consecutive downstream signaling pathways to control immune responses. However, the contribution of the immune system and inflammation to fibrosing interstitial lung diseases (ILD) remains poorly understood. Immunoreceptor tyrosine-based motif-bearing C-type lectin-like receptors (CTLRs) may interact with various immune cells during tissue injury and wound repair processes. Dectin-1 is a CTLR with dominant mechanisms manifested through its intracellular signaling cascades, which regulate fibrosis-promoting properties through gene transcription and cytokine activation. Additionally, immune impairment in ILD facilitates microbiome colonization; hence, Dectin-1 is the master protector in host pulmonary defense against fungal invasion. Recent progress in determining the signaling pathways that control the balance of fibrosis has implicated immunoreceptor tyrosine-based motif-bearing CTLRs as being involved, either directly or indirectly, in the pathogenesis of fibrosing ILD.


2021 ◽  
Vol 22 (17) ◽  
pp. 9460
Author(s):  
Helmut Segner ◽  
Christyn Bailey ◽  
Carolina Tafalla ◽  
Jun Bo

The impact of anthropogenic contaminants on the immune system of fishes is an issue of growing concern. An important xenobiotic receptor that mediates effects of chemicals, such as halogenated aromatic hydrocarbons (HAHs) and polyaromatic hydrocarbons (PAHs), is the aryl hydrocarbon receptor (AhR). Fish toxicological research has focused on the role of this receptor in xenobiotic biotransformation as well as in causing developmental, cardiac, and reproductive toxicity. However, biomedical research has unraveled an important physiological role of the AhR in the immune system, what suggests that this receptor could be involved in immunotoxic effects of environmental contaminants. The aims of the present review are to critically discuss the available knowledge on (i) the expression and possible function of the AhR in the immune systems of teleost fishes; and (ii) the impact of AhR-activating xenobiotics on the immune systems of fish at the levels of immune gene expression, immune cell proliferation and immune cell function, immune pathology, and resistance to infectious disease. The existing information indicates that the AhR is expressed in the fish immune system, but currently, we have little understanding of its physiological role. Exposure to AhR-activating contaminants results in the modulation of numerous immune structural and functional parameters of fish. Despite the diversity of fish species studied and the experimental conditions investigated, the published findings rather uniformly point to immunosuppressive actions of xenobiotic AhR ligands in fish. These effects are often associated with increased disease susceptibility. The fact that fish populations from HAH- and PAH-contaminated environments suffer immune disturbances and elevated disease susceptibility highlights that the immunotoxic effects of AhR-activating xenobiotics bear environmental relevance.


2021 ◽  
Vol 12 ◽  
Author(s):  
Alecia M. Blaszczak ◽  
Anahita Jalilvand ◽  
Willa A. Hsueh

The role of adipose tissue (AT) inflammation in obesity and its multiple related-complications is a rapidly expanding area of scientific interest. Within the last 30 years, the role of the adipocyte as an endocrine and immunologic cell has been progressively established. Like the macrophage, the adipocyte is capable of linking the innate and adaptive immune system through the secretion of adipokines and cytokines; exosome release of lipids, hormones, and microRNAs; and contact interaction with other immune cells. Key innate immune cells in AT include adipocytes, macrophages, neutrophils, and innate lymphoid cells type 2 (ILC2s). The role of the innate immune system in promoting adipose tissue inflammation in obesity will be highlighted in this review. T cells and B cells also play important roles in contributing to AT inflammation and are discussed in this series in the chapter on adaptive immunity.


2021 ◽  
Vol 8 ◽  
Author(s):  
Mohammed M. Almutairi ◽  
Farzane Sivandzade ◽  
Thamer H. Albekairi ◽  
Faleh Alqahtani ◽  
Luca Cucullo

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical manifestations of COVID-19 include dry cough, difficult breathing, fever, fatigue, and may lead to pneumonia and respiratory failure. There are significant gaps in the current understanding of whether SARS-CoV-2 attacks the CNS directly or through activation of the peripheral immune system and immune cell infiltration. Although the modality of neurological impairments associated with COVID-19 has not been thoroughly investigated, the latest studies have observed that SARS-CoV-2 induces neuroinflammation and may have severe long-term consequences. Here we review the literature on possible cellular and molecular mechanisms of SARS-CoV-2 induced-neuroinflammation. Activation of the innate immune system is associated with increased cytokine levels, chemokines, and free radicals in the SARS-CoV-2-induced pathogenic response at the blood-brain barrier (BBB). BBB disruption allows immune/inflammatory cell infiltration into the CNS activating immune resident cells (such as microglia and astrocytes). This review highlights the molecular and cellular mechanisms involved in COVID-19-induced neuroinflammation, which may lead to neuronal death. A better understanding of these mechanisms will help gain substantial knowledge about the potential role of SARS-CoV-2 in neurological changes and plan possible therapeutic intervention strategies.


2020 ◽  
Author(s):  
David A Swan ◽  
Morgane Rolland ◽  
Joshua Herbeck ◽  
Joshua T Schiffer ◽  
Daniel B Reeves

AbstractModern HIV research depends crucially on both viral sequencing and population measurements. To directly link mechanistic biological processes and evolutionary dynamics during HIV infection, we developed multiple within-host phylodynamic (wi-phy) models of HIV primary infection for comparative validation against viral load and evolutionary dynamics data. The most parsimonious and accurate model required no positive selection, suggesting that the host adaptive immune system reduces viral load, but does not drive observed viral evolution. Rather, random genetic drift primarily dictates fitness changes. These results hold during early infection, and even during chronic infection when selection has been observed, viral fitness distributions are not largely different from in vitro distributions that emerge without adaptive immunity. These results highlight how phylogenetic inference must consider complex viral and immune-cell population dynamics to gain accurate mechanistic insights.One sentence summaryThrough the lens of a unified population and phylodynamic model, current data show the first wave of HIV mutations are not driven by selection by the adaptive immune system.


2019 ◽  
Vol 11 ◽  
pp. 251584141986812
Author(s):  
Tanima Bose

Pemphigoid disease is classified according to the phenotypical location of the disease and the presence of different types of antibodies. The ocular distribution of pemphigoid mainly occurs in patients with bullous pemphigoid and mucous membrane pemphigoid. Several immune cells, including the cells of the innate immune system (neutrophils and γδ T cells) and the adaptive immune system (T and B cells), are involved in pemphigoid disease. The treatment of pemphigoid is still wide-ranging, and the most utilized treatment is the use of immunosuppressants and corticosteroids. In this scenario, it is absolutely important to screen the immune cells that are involved in this group of diseases and to determine if a targeted treatment approach is plausible. In conclusion, this review will identify some newer treatment possibilities for the whole spectrum of pemphigoid diseases.


2019 ◽  
Vol 5 (1) ◽  
pp. 205521731881924 ◽  
Author(s):  
Jeffrey A Cohen ◽  
Amit Bar-Or ◽  
Bruce A C Cree ◽  
Yang Mao-Draayer ◽  
May H Han ◽  
...  

Background Fingolimod is a sphingosine 1-phosphate receptor modulator for the treatment of patients with relapsing forms of multiple sclerosis (RMS). Fingolimod sequesters lymphocytes within lymphoid tissue thereby reducing the counts of circulating lymphocytes. However, fingolimod’s effects on the innate and adaptive components of the immune system are incompletely understood. Objective The FLUENT study will investigate temporal changes in circulating immune cell subsets in patients with RMS treated with fingolimod. Secondary objectives include examining the association between anti-John Cunningham virus (JCV) antibody status/index and phenotypic changes in innate and T and B cell subsets in patients on fingolimod therapy, and the association between serum neurofilament levels and clinical outcomes. Methods FLUENT is a prospective, multicenter, two-cohort, nonrandomized, open-label Phase IV study. Cohort 1 will include fingolimod-naïve patients and Cohort 2 will include patients who have received fingolimod 0.5 mg/day continuously for ≥2 years. Changes in the cellular components of the innate and adaptive immune system will be characterized over 12 months. Results The study is ongoing. Conclusion FLUENT may provide evidence for the use of immunologic profiling in predicting efficacy and risk of infection in patients with RMS treated with fingolimod.


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