Adaptive innate immunity or innate adaptive immunity?

2019 ◽  
Vol 133 (14) ◽  
pp. 1549-1565 ◽  
Author(s):  
Jan Černý ◽  
Ilja Stříž
Keyword(s):  
Innate Immunity ◽  
Adaptive Immunity ◽  
Current Knowledge ◽  
Cell Receptor ◽  
Innate Immune ◽  
Lymphoid Cells ◽  
Immune Memory ◽  
Cytotoxic Lymphocytes ◽  
Black And White ◽  
Pathogen Invasion

Abstract The innate immunity is frequently accepted as a first line of relatively primitive defense interfering with the pathogen invasion until the mechanisms of ‘privileged’ adaptive immunity with the production of antibodies and activation of cytotoxic lymphocytes ‘steal the show’. Recent advancements on the molecular and cellular levels have shaken the traditional view of adaptive and innate immunity. The innate immune memory or ‘trained immunity’ based on metabolic changes and epigenetic reprogramming is a complementary process insuring adaptation of host defense to previous infections. Innate immune cells are able to recognize large number of pathogen- or danger- associated molecular patterns (PAMPs and DAMPs) to behave in a highly specific manner and regulate adaptive immune responses. Innate lymphoid cells (ILC1, ILC2, ILC3) and NK cells express transcription factors and cytokines related to subsets of T helper cells (Th1, Th2, Th17). On the other hand, T and B lymphocytes exhibit functional properties traditionally attributed to innate immunity such as phagocytosis or production of tissue remodeling growth factors. They are also able to benefit from the information provided by pattern recognition receptors (PRRs), e.g. γδT lymphocytes use T-cell receptor (TCR) in a manner close to PRR recognition. Innate B cells represent another example of limited combinational diversity usage participating in various innate responses. In the view of current knowledge, the traditional black and white classification of immune mechanisms as either innate or an adaptive needs to be adjusted and many shades of gray need to be included.

The natural history of defences

2021 ◽  
pp. 51-108
Author(s):  
Paul Schmid-Hempel
Keyword(s):  
Innate Immunity ◽  
Natural History ◽  
Adaptive Immunity ◽  
Immune Memory ◽  
History Of ◽  
Molecular Backbone ◽  
Somatic Diversification ◽  
Signalling Compounds ◽  
Immune Defences ◽  
Signalling Cascade

Hosts can avoid infections by behavioural changes and by body walls. After infection, hosts can change their behaviours to reduce the effects of parasitism. Immune defences have different arms (humoral or cellular), and organization (innate, adaptive). Innate immunity consists of a collection of different systems that are evolutionarily very old. Adaptive immunity, based on expansion of specific lymphocytes, evolved in the higher vertebrates. Immune defences are regulated tightly and based on receptors that can recognize parasites (or their activity). This triggers a complex signalling cascade that results in the production of further signalling compounds and effectors. Important protein families, e.g. the immunoglobulins, form the molecular backbone. A key to efficient defences is the diversification of receptors, such as the highly evolved somatic diversification processes of advanced adaptive immunity. The microbiota adds to defences in many ways. Immune memory and priming occur throughout the tree of life.

scholarly journals The Potential Effects of Short-Chain Fatty Acids on the Epigenetic Regulation of Innate Immune Memory

Challenges ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 25
Author(s):  
Raphael Watt ◽  
Kimberley Parkin ◽  
David Martino
Keyword(s):  
Fatty Acids ◽  
Innate Immunity ◽  
Epigenetic Regulation ◽  
Early Life ◽  
Short Chain Fatty Acids ◽  
Innate Immune ◽  
Short Chain ◽  
Immune Memory ◽  
Trained Immunity ◽  
Chain Fatty Acids

The regulation of innate immunity is substantially more ‘plastic’ than previously appreciated. Innate immune memory (manifested through trained immunity and tolerance) is a recently described epigenetic phenomenon that is a model example, with broad implications for infectious disease, allergy and autoimmunity. Training the innate immune system to combat infections and temper inappropriate responses in non-communicable diseases will likely be an area of intense research. Innate immunity is influenced by short chain fatty acids, which are the natural products of digestion by the intestinal microbiota that possess inherent histone deacetylase inhibitory properties. It therefore stands to reason that a healthy gut microbiome may well influence mucosal and systemic trained immunity via short chain fatty acids. There is a lack of data on this specific topic, and we discuss potential relationships based on available and preliminary evidence. Understanding the link between intestinal microbiome composition, capacity for short chain fatty acid production and downstream effects on innate immune memory in early life will have important implications for host immunobiology. In this review we explore the intersection between the gut microbiota, short chain fatty acids and epigenetic regulation of innate immunity with a focus on early life.

Innate immune memory of tissue‐resident macrophages and trained innate immunity: Re‐vamping vaccine concept and strategies

2020 ◽  
Vol 108 (3) ◽  
pp. 825-834 ◽  
Author(s):  
Zhou Xing ◽  
Sam Afkhami ◽  
Jegarubee Bavananthasivam ◽  
Dominik K. Fritz ◽  
Michael R. D'Agostino ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Innate Immune ◽  
Immune Memory

scholarly journals A trade-off switch of two immunological memories in Caenorhabditis elegans reinfected by bacterial pathogens

2020 ◽  
Vol 295 (50) ◽  
pp. 17323-17336
Author(s):  
Jinyuan Yan ◽  
Ninghui Zhao ◽  
Zhongshan Yang ◽  
Yuhong Li ◽  
Hua Bai ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Caenorhabditis Elegans ◽  
Pathogenic Bacteria ◽  
Immunological Memory ◽  
Innate Immune ◽  
Microbial Pathogens ◽  
Immune Memory ◽  
Microbial Infection ◽  
Trade Off ◽  
Chemosensory Neurons

Recent studies have suggested that innate immune responses exhibit characteristics associated with memory linked to modulations in both vertebrates and invertebrates. However, the diverse evolutionary paths taken, particularly within the invertebrate taxa, should lead to similarly diverse innate immunity memory processes. Our understanding of innate immune memory in invertebrates primarily comes from studies of the fruit fly Drosophila melanogaster, the generality of which is unclear. Caenorhabditis elegans typically inhabits soil harboring a variety of fatal microbial pathogens; for this invertebrate, the innate immune system and aversive behavior are the major defensive strategies against microbial infection. However, their characteristics of immunological memory remains infantile. Here we discovered an immunological memory that promoted avoidance and suppressed innate immunity during reinfection with bacteria, which we revealed to be specific to the previously exposed pathogens. During this trade-off switch of avoidance and innate immunity, the chemosensory neurons AWB and ADF modulated production of serotonin and dopamine, which in turn decreased expression of the innate immunity-associated genes and led to enhanced avoidance via the downstream insulin-like pathway. Therefore, our current study profiles the immune memories during C. elegans reinfected by pathogenic bacteria and further reveals that the chemosensory neurons, the neurotransmitter(s), and their associated molecular signaling pathways are responsible for a trade-off switch between the two immunological memories.

scholarly journals Evolving Perspectives on Innate Immune Mechanisms of IPF

2021 ◽  
Vol 8 ◽  
Author(s):  
Genta Ishikawa ◽  
Angela Liu ◽  
Erica L. Herzog
Keyword(s):  
Innate Immunity ◽  
Genetic Factors ◽  
Suppressor Cells ◽  
Innate Immune ◽  
Lymphoid Cells ◽  
Animal Modeling ◽  
Myeloid Suppressor Cells ◽  
Disease Outcomes ◽  
Molecular Patterns

While epithelial-fibroblast interactions are viewed as the primary drivers of Idiopathic Pulmonary Fibrosis (IPF), evidence gleaned from animal modeling and human studies implicates innate immunity as well. To provide perspective on this topic, this review synthesizes the available data regarding the complex role of innate immunity in IPF. The role of substances present in the fibrotic microenvironment including pathogen associated molecular patterns (PAMPs) derived from invading or commensal microbes, and danger associated molecular patterns (DAMPs) derived from injured cells and tissues will be discussed along with the proposed contribution of innate immune populations such as macrophages, neutrophils, fibrocytes, myeloid suppressor cells, and innate lymphoid cells. Each component will be considered in the context of its relationship to environmental and genetic factors, disease outcomes, and potential therapies. We conclude with discussion of unanswered questions and opportunities for future study in this area.

scholarly journals NK Cell Memory to Cytomegalovirus: Implications for Vaccine Development

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 394
Author(s):  
Calum Forrest ◽  
Ariane Gomes ◽  
Matthew Reeves ◽  
Victoria Male
Keyword(s):  
Immune System ◽  
Nk Cells ◽  
Innate Immune System ◽  
Vaccine Development ◽  
Nk Cell ◽  
Innate Immune ◽  
Lymphoid Cells ◽  
Murine Cytomegalovirus ◽  
Immune Memory ◽  
Cell Memory

Natural killer (NK) cells are innate lymphoid cells that recognize and eliminate virally-infected and cancerous cells. Members of the innate immune system are not usually considered to mediate immune memory, but over the past decade evidence has emerged that NK cells can do this in several contexts. Of these, the best understood and most widely accepted is the response to cytomegaloviruses, with strong evidence for memory to murine cytomegalovirus (MCMV) and several lines of evidence suggesting that the same is likely to be true of human cytomegalovirus (HCMV). The importance of NK cells in the context of HCMV infection is underscored by the armory of NK immune evasion genes encoded by HCMV aimed at subverting the NK cell immune response. As such, ongoing studies that have utilized HCMV to investigate NK cell diversity and function have proven instructive. Here, we discuss our current understanding of NK cell memory to viral infection with a focus on the response to cytomegaloviruses. We will then discuss the implications that this will have for the development of a vaccine against HCMV with particular emphasis on how a strategy that can harness the innate immune system and NK cells could be crucial for the development of a vaccine against this high-priority pathogen.

scholarly journals Self-harm caused by an insect's innate immunity

2006 ◽  
Vol 273 (1600) ◽  
pp. 2571-2574 ◽  
Author(s):  
Ben M Sadd ◽  
Michael T Siva-Jothy
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Life History ◽  
Immune System ◽  
Innate Immune System ◽  
Innate Immune ◽  
Pathogen Invasion ◽  
Potential Disadvantage ◽  
Self Harm ◽  
Fast Acting

It has been a long-held assumption that the innate immune system of insects causes self-harm when used to combat an immune insult. We show empirically that this assumption is correct. Invertebrate innate immunity relies heavily on effector systems which, on activation, produce cytotoxins that kill pathogens. Reliance on these robust, fast-acting, generic killing mechanisms ensures a potent and rapid response to pathogen invasion, but has the potential disadvantage of causing self-damage. We show that the innate immune response against an immune insult produces measurable phenotypic and functional damage to self-tissue in the beetle Tenebrio molitor . This type of self-harm (autoreactivity) and the life-history implications that arise from it are important to understand evolutionary phenomena such as the dynamics between hosts and parasites as well as the nature of immune system costs.

scholarly journals Botryllus schlosseri as a Unique Colonial Chordate Model for the Study and Modulation of Innate Immune Activity

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 454
Author(s):  
Oron Goldstein ◽  
Edna Ayerim Mandujano-Tinoco ◽  
Tom Levy ◽  
Shani Talice ◽  
Tal Raveh ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Adaptive Immunity ◽  
Adaptive Immune Response ◽  
Allogeneic Transplantation ◽  
Innate Immune ◽  
Botryllus Schlosseri ◽  
Proinflammatory Response ◽  
Hematopoietic Stem ◽  
Loss Of Tolerance ◽  
Cellular Pathways

Understanding the mechanisms that sustain immunological nonreactivity is essential for maintaining tissue in syngeneic and allogeneic settings, such as transplantation and pregnancy tolerance. While most transplantation rejections occur due to the adaptive immune response, the proinflammatory response of innate immunity is necessary for the activation of adaptive immunity. Botryllus schlosseri, a colonial tunicate, which is the nearest invertebrate group to the vertebrates, is devoid of T- and B-cell-based adaptive immunity. It has unique characteristics that make it a valuable model system for studying innate immunity mechanisms: (i) a natural allogeneic transplantation phenomenon that results in either fusion or rejection; (ii) whole animal regeneration and noninflammatory resorption on a weekly basis; (iii) allogeneic resorption which is comparable to human chronic rejection. Recent studies in B. schlosseri have led to the recognition of a molecular and cellular framework underlying the innate immunity loss of tolerance to allogeneic tissues. Additionally, B. schlosseri was developed as a model for studying hematopoietic stem cell (HSC) transplantation, and it provides further insights into the similarities between the HSC niches of human and B. schlosseri. In this review, we discuss why studying the molecular and cellular pathways that direct successful innate immune tolerance in B. schlosseri can provide novel insights into and potential modulations of these immune processes in humans.

scholarly journals Trained Immunity and Cardiometabolic Disease

2020 ◽  
Author(s):  
Ioannis Mitroulis ◽  
George Hajishengallis ◽  
Triantafyllos Chavakis
Keyword(s):  
Innate Immunity ◽  
Progenitor Cells ◽  
Immune Cells ◽  
Innate Immune ◽  
Hematopoietic Progenitor Cells ◽  
Immune Memory ◽  
Cardiometabolic Disease ◽  
Innate Immune Cells ◽  
Hematopoietic Progenitor ◽  
Functional Changes

Until recently, immunologic memory was considered an exclusive characteristic of adaptive immunity. However, recent advances suggest that the innate arm of the immune system can also mount a type of nonspecific memory responses. Innate immune cells can elicit a robust response to subsequent inflammatory challenges after initial activation by certain stimuli, such as fungal-derived agents or vaccines. This type of memory, termed trained innate immunity (also named innate immune memory), is associated with epigenetic and metabolic alterations. Hematopoietic progenitor cells, which are the cells responsible for the generation of mature myeloid cells at steady-state and during inflammation, have a critical contribution to the induction of innate immune memory. Inflammation-triggered alterations in cellular metabolism, the epigenome and transcriptome of hematopoietic progenitor cells in the bone marrow promote long-lasting functional changes, resulting in increased myelopoiesis and consequent generation of trained innate immune cells. In the present brief review, we focus on the involvement of hematopoietic progenitors in the process of trained innate immunity and its possible role in cardiometabolic disease.

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