scholarly journals Skin Immune Landscape: Inside and Outside the Organism

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Florence Abdallah ◽  
Lily Mijouin ◽  
Chantal Pichon
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Skin Surface ◽  
Negative Influence ◽  
Background Information ◽  
Symbiotic Relationship ◽  
Skin Microbiota ◽  
Effector Cells ◽  
Skin Immune System ◽  
The Impact

The skin is an essential organ to the human body protecting it from external aggressions and pathogens. Over the years, the skin was proven to have a crucial immunological role, not only being a passive protective barrier but a network of effector cells and molecular mediators that constitute a highly sophisticated compound known as the “skin immune system” (SIS). Studies of skin immune sentinels provided essential insights of a complex and dynamic immunity, which was achieved through interaction between the external and internal cutaneous compartments. In fact, the skin surface is cohabited by microorganisms recognized as skin microbiota that live in complete harmony with the immune sentinels and contribute to the epithelial barrier reinforcement. However, under stress, the symbiotic relationship changes into a dysbiotic one resulting in skin disorders. Hence, the skin microbiota may have either positive or negative influence on the immune system. This review aims at providing basic background information on the cutaneous immune system from major cellular and molecular players and the impact of its microbiota on the well-coordinated immune responses in host defense.

scholarly journals Contextual control of skin immunity and inflammation by Corynebacterium

2018 ◽  
Vol 215 (3) ◽  
pp. 785-799 ◽  
Author(s):  
Vanessa K. Ridaura ◽  
Nicolas Bouladoux ◽  
Jan Claesen ◽  
Y. Erin Chen ◽  
Allyson L. Byrd ◽  
...  
Keyword(s):  
Immune System ◽  
Cell Envelope ◽  
Γδ T Cells ◽  
Mycolic Acid ◽  
Dependent Manner ◽  
Skin Microbiota ◽  
Skin Immune System ◽  
Dominant Component ◽  
Skin Immunity ◽  
The Impact

How defined microbes influence the skin immune system remains poorly understood. Here we demonstrate that Corynebacteria, dominant members of the skin microbiota, promote a dramatic increase in the number and activation of a defined subset of γδ T cells. This effect is long-lasting, occurs independently of other microbes, and is, in part, mediated by interleukin (IL)-23. Under steady-state conditions, the impact of Corynebacterium is discrete and noninflammatory. However, when applied to the skin of a host fed a high-fat diet, Corynebacterium accolens alone promotes inflammation in an IL-23–dependent manner. Such effect is highly conserved among species of Corynebacterium and dependent on the expression of a dominant component of the cell envelope, mycolic acid. Our data uncover a mode of communication between the immune system and a dominant genus of the skin microbiota and reveal that the functional impact of canonical skin microbial determinants is contextually controlled by the inflammatory and metabolic state of the host.

Impact of gut microbiota on immune system

2021 ◽  
Author(s):  
Farhad Riazi-Rad ◽  
Ava Behrouzi ◽  
Hoora Mazaheri ◽  
Asal Katebi ◽  
Soheila Ajdary
Keyword(s):  
Immune System ◽  
Gut Microbiota ◽  
Immune Responses ◽  
Disease Susceptibility ◽  
Adaptive Immune System ◽  
Vital Role ◽  
Symbiotic Relationship ◽  
Adaptive Immune ◽  
Physiological Homeostasis ◽  
Environmental Antigens

AbstractThe commensal microflora collection known as microbiota has an essential role in maintaining the host's physiological homeostasis. The microbiota has a vital role in induction and regulation of local and systemic immune responses. On the other hand, the immune system involves maintaining microbiota compositions. Optimal microbiota-immune system cross-talk is essential for protective responses to pathogens and immune tolerance to self and harmless environmental antigens. Any change in this symbiotic relationship may cause susceptibility to diseases. The association of various cancers and auto-immune diseases with microbiota has been proven. Here we review the interaction of immune responses to gut microbiota, focusing on innate and adaptive immune system and disease susceptibility.

scholarly journals Platelets in Pulmonary Immune Responses and Inflammatory Lung Diseases

2016 ◽  
Vol 96 (4) ◽  
pp. 1211-1259 ◽  
Author(s):  
Elizabeth A. Middleton ◽  
Andrew S. Weyrich ◽  
Guy A. Zimmerman
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Blood Cells ◽  
Lung Diseases ◽  
Human Platelets ◽  
Effector Cells ◽  
Experimental Animals ◽  
Functional Capabilities ◽  
Health And Disease ◽  
Sense And Respond

Platelets are essential for physiological hemostasis and are central in pathological thrombosis. These are their traditional and best known activities in health and disease. In addition, however, platelets have specializations that broaden their functional repertoire considerably. These functional capabilities, some of which are recently discovered, include the ability to sense and respond to infectious and immune signals and to act as inflammatory effector cells. Human platelets and platelets from mice and other experimental animals can link the innate and adaptive limbs of the immune system and act across the immune continuum, often also linking immune and hemostatic functions. Traditional and newly recognized facets of the biology of platelets are relevant to defensive, physiological immune responses of the lungs and to inflammatory lung diseases. The emerging view of platelets as blood cells that are much more diverse and versatile than previously thought further predicts that additional features of the biology of platelets and of megakaryocytes, the precursors of platelets, will be discovered and that some of these will also influence pulmonary immune defenses and inflammatory injury.

scholarly journals Organization of the Skin Immune System and Compartmentalized Immune Responses in Infectious Diseases

2019 ◽  
Vol 32 (4) ◽  
Author(s):  
Juarez Antonio Simões Quaresma
Keyword(s):  
Immune System ◽  
Infectious Diseases ◽  
Immune Responses ◽  
Immune Cells ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Skin Immune System ◽  
Host Pathogen ◽  
Cellular Mediators ◽  
And Control

SUMMARY The skin is an organ harboring several types of immune cells that participate in innate and adaptive immune responses. The immune system of the skin comprises both skin cells and professional immune cells that together constitute what is designated skin-associated lymphoid tissue (SALT). In this review, I extensively discuss the organization of SALT and the mechanisms involved in its responses to infectious diseases of the skin and mucosa. The nature of these SALT responses, and the cellular mediators involved, often determines the clinical course of such infections. I list and describe the components of innate immunity, such as the roles of the keratinocyte barrier and of inflammatory and natural killer cells. I also examine the mechanisms involved in adaptive immune responses, with emphasis on new cytokine profiles, and the role of cell death phenomena in host-pathogen interactions and control of the immune responses to infectious agents. Finally, I highlight the importance of studying SALT in order to better understand host-pathogen relationships involving the skin and detail future directions in the immunological investigation of this organ, especially in light of recent findings regarding the skin immune system.

scholarly journals Coronavirus Disease 2019 (COVID-19) and Nutritional Status: The Missing Link?

2020 ◽  
Author(s):  
Renata Silverio ◽  
Daniela Caetano Gonçalves ◽  
Márcia Fábia Andrade ◽  
Marilia Seelaender
Keyword(s):  
Body Composition ◽  
Immune System ◽  
Nutritional Status ◽  
Immune Responses ◽  
Lean Mass ◽  
Severe Disease ◽  
Cytokine Storm ◽  
Risk Of Infection ◽  
Elderly Individuals ◽  
The Impact

ABSTRACT Coronavirus disease 2019 (COVID-19) is an emerging disease that has reached pandemic status by rapidly spreading worldwide. Elderly individuals and patients with comorbidities such as obesity, diabetes, and hypertension show a higher risk of hospitalization, severe disease, and mortality by acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. These patients frequently show exacerbated secretion of proinflammatory cytokines associated with an overreaction of the immune system, the so-called cytokine storm. Host nutritional status plays a pivotal role in the outcome of a variety of different infectious diseases. It is known that the immune system is highly affected by malnutrition, leading to decreased immune responses with consequent augmented risk of infection and disease severity. Body composition, especially low lean mass and high adiposity, has consistently been linked to worsened prognosis in many different diseases. In this review, evidence concerning the impact of nutritional status on viral infection outcomes is discussed.

scholarly journals Prenatal stress, anxiety and depression alter transcripts, proteins and pathways associated with immune responses at the maternal-fetal interface

2021 ◽  
Author(s):  
Cristina A Martinez ◽  
Ina Marteinsdottir ◽  
Ann Josefsson ◽  
Gunilla Sydsjö ◽  
Elvar Theodorsson ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Psychiatric Symptoms ◽  
Anxiety And Depression ◽  
Cytokine Signaling ◽  
Control Group ◽  
Index Group ◽  
Immune Related Genes ◽  
The Impact ◽  
Maternal Fetal Interface

Abstract During pregnancy, the immune system is modified to allow developmental developmental tolerance of the semi-allogeneic fetus and placenta to term. Pregnant women suffering from stress, anxiety and depression show dysfunctions of their immune system that may be responsible for fetal and/or newborn disorders, provided that provided that placental gene regulation is compromised. The present study explored the effects of maternal chronic self-perceived stress, anxiety and depression during pregnancy on the expression of immune related-genes and pathways in term placenta. Pregnancies were clinically monitored with the Beck’s Anxiety Inventory (BAI) and Edinburgh Postnatal Depression Scale (EPDS). A cutoff threshold for BAI/EPDS of 10 divided patients into two groups: Index group (≥10, n = 11) and a Control group (<10, n = 11), whose placentae were sampled at delivery. The placental samples were subjected to RNA-Sequencing, demonstrating that stress, anxiety and depression during pregnancy induced a major downregulation of placental transcripts related to immune processes such as T-cell regulation, interleukin and cytokine signaling or innate immune responses. Expression differences of main immune related genes such as CD46, CD15, CD8α & β ILR7α and CCR4 among others, were found in the index group (P < 0.05). Moreover, the key immune-like pathway involved in humoral and cellular immunity named “Primary immunodeficiency” was significantly downregulated in the index group compared to controls. Our results show that mechanisms ruling immune system functions are compromised at the maternal-fetal interface following self-perceived depressive symptoms and anxiety during pregnancy. These findings may help unveil mechanisms ruling the impact of maternal psychiatric symptoms and lead to new prevention/intervention strategies in complicated pregnancies.

scholarly journals Antibiotics Against COVID-19 and Mitochondria? Urgent Thinking Out of the Box

2020 ◽  
Author(s):  
Jaroslaw Tyszka ◽  
Karolina Kobos ◽  
Aleksandra Tyszka
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Viral Infections ◽  
Treatment Strategies ◽  
Local Health ◽  
Antiviral Immune Response ◽  
Health Authorities ◽  
Treatment Data ◽  
The Moment ◽  
The Impact

Italian, Spanish, French vs German, Austrian or Norwegian COVID-19 tracks? Antibiotics might have a partial impact on COVID-19 death rates in various countries. Our working hypotheses based on recent publications is that that antibiotics may be a major factor that negatively affects patients’ immune system during viral infections. We are all aware that there is no specific and effective medical treatment for COVID-19 so far. However, we know that our immune system is the only efficient weapon that fights against this syndrome right now. In fact, antibiotics are very often prescribed to prevent secondary infections following an antiviral immune response. Various antibiotic therapies have also been commonly applied to support COVID-19 treatments in China and Italy. Unfortunately, the frequent antibiotic off-site targets include mitochondria that are genetically and evolutionary closely linked to bacteria. Mitochondria are multifunctional organelles responsible for bioenergetics in nearly all our cells, acting as signaling hubs in antiviral and antibacterial immune responses. Several studies have demonstrated that mitochondria are vulnerable to antibacterial treatments, interrupting their physiology. Inhibition of these processes by antibiotics might render the immune system less capable of fighting acute COVID-19 viral infections. Some antibiotics, including those prescribed for COVID-19 in Wuhan, have been shown to inhibit the synthesis of mitochondrial DNA. The question is whether antibiotics support such a treatment or weaken patient immune responses in this case. This hypothesis should be evaluated based on comparative clinical data that seem to be unavailable at the moment. Possibly the COVID-19 risk group should be extended to all patients being treated with antibiotics, including those who finished antibiotic therapies days up to several months before SARS-CoV-2 infection. We therefore urge health service response groups to evaluate the impact of antibiotics on COVID-19 recovery vs death retrospective data. We would like to motivate international, national and local health authorities to share available clinical treatment data, discuss and optimize treatment strategies.

scholarly journals Avian gut-associated lymphoid tissues and intestinal immune responses to Eimeria parasites.

1996 ◽  
Vol 9 (3) ◽  
pp. 349-360 ◽  
Author(s):  
H S Lillehoj ◽  
J M Trout
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Minor Role ◽  
Lymphoid Tissues ◽  
Cell Mediated Immunity ◽  
Limited Information ◽  
Effector Cells ◽  
Intestinal Immune System ◽  
Eimeria Spp ◽  
Coccidial Infection

Coccidiosis, an intestinal infection caused by intracellular protozoan parasites belonging to several different species of Eimeria, seriously impairs the growth and feed utilization of livestock and poultry. Host immune responses to coccidial infection are complex. Animals infected with Eimeria spp. produce parasite-specific antibodies in both the circulation and mucosal secretions. However, it appears that antibody-mediated responses play a minor role in protection against coccidiosis. Furthermore, there is increasing evidence that cell-mediated immunity plays a major role in resistance to infection. T lymphocytes appear to respond to coccidial infection through both cytokine production and a direct cytotoxic attack on infected cells. The exact mechanisms by which T cells eliminate the parasites, however, remain unclear. Although limited information is available on the intestinal immune system of chickens, gut lymphoid tissues have evolved specialized features that reflect their role as the first line of defense at mucosal surfaces, including both immunoregulatory cells and effector cells. This review summarizes our current understanding of the avian intestinal immune system and mucosal immune responses to Eimeria spp., providing an overview of the complex cellular and molecular events involved in intestinal immune responses to enteric pathogens.

scholarly journals The Impact of the Myeloid Response to Radiation Therapy

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Michael J. Gough ◽  
Kristina Young ◽  
Marka Crittenden
Keyword(s):  
Radiation Therapy ◽  
Immune Responses ◽  
Adaptive Immunity ◽  
Residual Cancer ◽  
Effector Cells ◽  
Adaptive Immune ◽  
Treatment Site ◽  
Inflammatory Damage ◽  
Cancer Models ◽  
The Impact

Radiation therapy is showing potential as a partner for immunotherapies in preclinical cancer models and early clinical studies. As has been discussed elsewhere, radiation provides debulking, antigen and adjuvant release, and inflammatory targeting of effector cells to the treatment site, thereby assisting multiple critical checkpoints in antitumor adaptive immunity. Adaptive immunity is terminated by inflammatory resolution, an active process which ensures that inflammatory damage is repaired and tissue function is restored. We discuss how radiation therapy similarly triggers inflammation followed by repair, the consequences to adaptive immune responses in the treatment site, and how the myeloid response to radiation may impact immunotherapies designed to improve control of residual cancer cells.

scholarly journals Directing T-Cell Immune Responses for Cancer Vaccination and Immunotherapy

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1392
Author(s):  
Peter Lawrence Smith ◽  
Katarzyna Piadel ◽  
Angus George Dalgleish
Keyword(s):  
Immune System ◽  
T Cell ◽  
Immune Responses ◽  
Cell Function ◽  
Effector Cells ◽  
Cancer Vaccination ◽  
Cell Responses ◽  
T Cell Immune Responses ◽  
Health And Disease ◽  
Primary Effector

Cancer vaccination and immunotherapy revolutionised the treatment of cancer, a result of decades of research into the immune system in health and disease. However, despite recent breakthroughs in treating otherwise terminal cancer, only a minority of patients respond to cancer immunotherapy and some cancers are largely refractive to immunotherapy treatment. This is due to numerous issues intrinsic to the tumour, its microenvironment, or the immune system. CD4+ and CD8+ αβ T-cells emerged as the primary effector cells of the anti-tumour immune response but their function in cancer patients is often compromised. This review details the mechanisms by which T-cell responses are hindered in the setting of cancer and refractive to immunotherapy, and details many of the approaches under investigation to direct T-cell function and improve the efficacy of cancer vaccination and immunotherapy.

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