0
selected
-
1.
Nutrition Regulates Innate Immunity in Health and Disease.
Nobs, SP, Zmora, N, Elinav, E
Annual review of nutrition. 2020;:189-219
Abstract
Nutrient content and nutrient timing are considered key regulators of human health and a variety of diseases and involve complex interactions with the mucosal immune system. In particular, the innate immune system is emerging as an important signaling hub that modulates the response to nutritional signals, in part via signaling through the gut microbiota. In this review we elucidate emerging evidence that interactions between innate immunity and diet affect human metabolic health and disease, including cardiometabolic disorders, allergic diseases, autoimmune disorders, infections, and cancers. Furthermore, we discuss the potential modulatory effects of the gut microbiota on interactions between the immune system and nutrition in health and disease, namely how it relays nutritional signals to the innate immune system under specific physiological contexts. Finally, we identify key open questions and challenges to comprehensively understanding the intersection between nutrition and innate immunity and how potential nutritional, immune, and microbial therapeutics may be developed into promising future avenues of precision treatment.
-
2.
The role of plant-derived natural substances as immunomodulatory agents in carcinogenesis.
Samec, M, Liskova, A, Koklesova, L, Samuel, SM, Murin, R, Zubor, P, Bujnak, J, Kwon, TK, Büsselberg, D, Prosecky, R, et al
Journal of cancer research and clinical oncology. 2020;(12):3137-3154
Abstract
The role of immune system in carcinogenesis represents fundamental events associated with cancer eradication; however, tumor evolution is connected with various mechanisms of tumor evasion and progression of cancer. Based on recent evidence, phytochemicals are directly associated with immunomodulation of the innate and adaptive immunity via different mechanisms of action including stimulation and amplification of immune cells, humoral compartments, and associated molecules. This comprehensive study focuses on immunomodulating potential of phytochemicals (mixture in plants or separately such as individual phytochemical) and their impact on regulation of immune response during cancer development, immune tolerance, and immune escape. Clinical application of phytochemicals as modulators of host immunity against cancer may represent perspective approach in anticancer therapy.
-
3.
Vitamin D3 as Potential Treatment Adjuncts for COVID-19.
Malaguarnera, L
Nutrients. 2020;(11)
Abstract
Severe acute respiratory syndrome coronavirus type (SARS-CoV2, also known as COVID-19), which is the latest pandemic infectious disease, constitutes a serious risk to human health. SARS-CoV2 infection causes immune activation and systemic hyperinflammation which can lead to respiratory distress syndrome (ARDS). ARDS victims are characterized by a significant increase in IL-6 and IL-1. Macrophage activation, associated with the "cytokine storm", promotes the dysregulation of the innate immunity. So far, without vaccines or specific therapy, all efforts to design drugs or clinical trials are worthwhile. Vitamin D and its receptor vitamin D receptor (VDR) exert a critical role in infections due to their remarkable impact on both innate and adaptive immune responses and on the suppression of the inflammatory process. The protective properties of vitamin D supplementation have been supported by numerous observational studies and by meta-analysis of clinical trials for prevention of viral acute respiratory infection. In this review, we compare the mechanisms of the host immune response to SARS-CoV2 infection and the immunomodulatory actions that vitamin D exerts in order to consider the preventive effect of vitamin D supplementation on SARS-CoV2 viral infection.
-
4.
ER Stress Responses: An Emerging Modulator for Innate Immunity.
Di Conza, G, Ho, PC
Cells. 2020;(3)
Abstract
The endoplasmic reticulum (ER) is a critical organelle, storing the majority of calcium and governing protein translation. Thus, it is crucial to keep the homeostasis in all ER components and machineries. The ER stress sensor pathways, including IRE1/sXBP1, PERK/EIf2 and ATF6, orchestrate the major regulatory circuits to ensure ER homeostasis. The embryonic or postnatal lethality that occurs upon genetic depletion of these sensors reveals the essential role of the ER stress pathway in cell biology. In contrast, the impairment or excessive activation of ER stress has been reported to cause or aggravate several diseases such as atherosclerosis, diabetes, NAFDL/NASH, obesity and cancer. Being part of innate immunity, myeloid cells are the first immune cells entering the inflammation site. Upon entry into a metabolically stressed disease environment, activation of ER stress occurs within the myeloid compartment, leading to the modulation of their phenotype and functions. In this review, we discuss causes and consequences of ER stress activation in the myeloid compartment with a special focus on the crosstalk between ER, innate signaling and metabolic environments.
-
5.
Influenza A virus PB1-F2 protein: An ambivalent innate immune modulator and virulence factor.
Cheung, PH, Lee, TT, Chan, CP, Jin, DY
Journal of leukocyte biology. 2020;(5):763-771
Abstract
Influenza A virus (IAV) causes not only seasonal respiratory illness, but also outbreaks of more severe disease and pandemics when novel strains emerge as a result of reassortment or interspecies transmission. PB1-F2 is an IAV protein expressed from the second open reading frame of PB1 gene. Small as it is, PB1-F2 is a critical virulence factor. Multiple key amino acid residues and motifs of PB1-F2 have been shown to influence the virulence of IAV in a strain- and host-specific manner, plausibly through the induction of apoptotic cell death, modulation of type I IFN response, activation of inflammasome, and facilitation of secondary bacterial infection. However, the exact role of PB1-F2 in IAV pathogenesis remains unexplained. Through reanalysis of the current literature, we redefine PB1-F2 as an ambivalent innate immune modulator that determines IAV infection outcome through induction of immune cell death, differential modulation of early- and late-type I IFN response, and promotion of pathogenic inflammation. PB1-F2 functions both intracellularly and extracellularly. Further investigations of the mechanistic details of PB1-F2 action will shed new light on immunopathogenesis of IAV infection.
-
6.
Distinct and Orchestrated Functions of RNA Sensors in Innate Immunity.
Liu, G, Gack, MU
Immunity. 2020;(1):26-42
-
-
Free full text
-
Abstract
Faithful maintenance of immune homeostasis relies on the capacity of the cellular immune surveillance machinery to recognize "nonself", such as the presence of pathogenic RNA. Several families of pattern-recognition receptors exist that detect immunostimulatory RNA and then induce cytokine-mediated antiviral and proinflammatory responses. Here, we review the distinct features of bona fide RNA sensors, Toll-like receptors and retinoic-acid inducible gene-I (RIG-I)-like receptors in particular, with a focus on their functional specificity imposed by cell-type-dependent expression, subcellular localization, and ligand preference. Furthermore, we highlight recent advances on the roles of nucleotide-binding oligomerization domain (NOD)-like receptors and DEAD-box or DEAH-box RNA helicases in an orchestrated RNA-sensing network and also discuss the relevance of RNA sensor polymorphisms in human disease.
-
7.
Exposome and Immunity Training: How Pathogen Exposure Order Influences Innate Immune Cell Lineage Commitment and Function.
Adams, K, Weber, KS, Johnson, SM
International journal of molecular sciences. 2020;(22)
Abstract
Immune memory is a defining characteristic of adaptive immunity, but recent work has shown that the activation of innate immunity can also improve responsiveness in subsequent exposures. This has been coined "trained immunity" and diverges with the perception that the innate immune system is primitive, non-specific, and reacts to novel and recurrent antigen exposures similarly. The "exposome" is the cumulative exposures (diet, exercise, environmental exposure, vaccination, genetics, etc.) an individual has experienced and provides a mechanism for the establishment of immune training or immunotolerance. It is becoming increasingly clear that trained immunity constitutes a delicate balance between the dose, duration, and order of exposures. Upon innate stimuli, trained immunity or tolerance is shaped by epigenetic and metabolic changes that alter hematopoietic stem cell lineage commitment and responses to infection. Due to the immunomodulatory role of the exposome, understanding innate immune training is critical for understanding why some individuals exhibit protective phenotypes while closely related individuals may experience immunotolerant effects (e.g., the order of exposure can result in completely divergent immune responses). Research on the exposome and trained immunity may be leveraged to identify key factors for improving vaccination development, altering inflammatory disease development, and introducing potential new prophylactic treatments, especially for diseases such as COVID-19, which is currently a major health issue for the world. Furthermore, continued exposome research may prevent many deleterious effects caused by immunotolerance that frequently result in host morbidity or mortality.
-
8.
Immunoregulatory Sensory Circuits in Group 3 Innate Lymphoid Cell (ILC3) Function and Tissue Homeostasis.
Domingues, RG, Hepworth, MR
Frontiers in immunology. 2020;:116
Abstract
Recent years have seen a revolution in our understanding of how cells of the immune system are modulated and regulated not only via complex interactions with other immune cells, but also through a range of potent inputs derived from diverse and varied biological systems. Within complex tissue environments, such as the gastrointestinal tract and lung, these systems act to orchestrate and temporally align immune responses, regulate cellular function, and ensure tissue homeostasis and protective immunity. Group 3 Innate Lymphoid Cells (ILC3s) are key sentinels of barrier tissue homeostasis and critical regulators of host-commensal mutualism-and respond rapidly to damage, inflammation and infection to restore tissue health. Recent findings place ILC3s as strategic integrators of environmental signals. As a consequence, ILC3s are ideally positioned to detect perturbations in cues derived from the environment-such as the diet and microbiota-as well as signals produced by the host nervous, endocrine and circadian systems. Together these cues act in concert to induce ILC3 effector function, and form critical sensory circuits that continually function to reinforce tissue homeostasis. In this review we will take a holistic, organismal view of ILC3 biology and explore the tissue sensory circuits that regulate ILC3 function and align ILC3 responses with changes within the intestinal environment.
-
9.
MECHANISMS IN ENDOCRINOLOGY: Vitamin D and COVID-19.
Bilezikian, JP, Bikle, D, Hewison, M, Lazaretti-Castro, M, Formenti, AM, Gupta, A, Madhavan, MV, Nair, N, Babalyan, V, Hutchings, N, et al
European journal of endocrinology. 2020;(5):R133-R147
-
-
Free full text
-
Abstract
The SARS-CoV-2 virus responsible for the COVID-19 pandemic has generated an explosion of interest both in the mechanisms of infection leading to dissemination and expression of this disease, and in potential risk factors that may have a mechanistic basis for disease propagation or control. Vitamin D has emerged as a factor that may be involved in these two areas. The focus of this article is to apply our current understanding of vitamin D as a facilitator of immunocompetence both with regard to innate and adaptive immunity and to consider how this may relate to COVID-19 disease. There are also intriguing potential links to vitamin D as a factor in the cytokine storm that portends some of the most serious consequences of SARS-CoV-2 infection, such as the acute respiratory distress syndrome. Moreover, cardiac and coagulopathic features of COVID-19 disease deserve attention as they may also be related to vitamin D. Finally, we review the current clinical data associating vitamin D with SARS-CoV-2 infection, a putative clinical link that at this time must still be considered hypothetical.
-
10.
The Potential Role of Trained Immunity in Autoimmune and Autoinflammatory Disorders.
Arts, RJW, Joosten, LAB, Netea, MG
Frontiers in immunology. 2018;:298
Abstract
During induction of trained immunity, monocytes and macrophages undergo a functional and transcriptional reprogramming toward increased activation. Important rewiring of cellular metabolism of the myeloid cells takes place during induction of trained immunity, including a shift toward glycolysis induced through the mTOR pathway, as well as glutaminolysis and cholesterol synthesis. Subsequently, this leads to modulation of the function of epigenetic enzymes, resulting in important changes in chromatin architecture that enables increased gene transcription. However, in addition to the beneficial effects of trained immunity as a host defense mechanism, we hypothesize that trained immunity also plays a deleterious role in the induction and/or maintenance of autoimmune and autoinflammatory diseases if inappropriately activated.