Coelomocytes: Biology and Possible Immune Functions in Invertebrates with Special Remarks on Nematodes

All metazoans are exposed to a wide range of microbes and have evolved complex immune defenses used to repel infectious agents. Coelomocytes play a key role in the defense reactions of most invertebrates. They are involved in important immune functions, such as phagocytosis, encapsulation, graft rejection, and inflammation, as well as the synthesis and secretion of several humoral factors especially in annelids and echinoderms. Coelomocytes in nematodes are variable in shapes from round, ovoid, cuboidal, and spindle-shaped to stellate or branched cells that are found usually at fixed positions in the pseudocoelom. Their number usually varies from 2 to 6. The model nematode,C. eleganslacks an adaptive immune system and the coelomocytes are capable of endocytosis, but their involvement in phagocytosis of bacteria seems unlikely. The aim of this review is to evaluate current knowledge on coelomocytes of invertebrates with special reference to nematodes. The morphology and structure of these coelomocytes are discussed along with their origin. Their relative positions and diversity in different nematode groups have also been discussed and illustrated.

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Immune Aging and Immunotherapy in Cancer

International Journal of Molecular Sciences ◽

10.3390/ijms22137016 ◽

2021 ◽

Vol 22 (13) ◽

pp. 7016

Author(s):

Melanie Kaiser ◽

Maria Donatella Semeraro ◽

Markus Herrmann ◽

Gudrun Absenger ◽

Armin Gerger ◽

...

Keyword(s):

T Cells ◽

Immune System ◽

Current Knowledge ◽

Adaptive Immune System ◽

Predictive Biomarkers ◽

Immune Checkpoint Blockade ◽

Cell Aging ◽

Immune Functions ◽

Adaptive Immune ◽

Age Related

Immune functions decline as we age, while the incidence of cancer rises. The advent of immune checkpoint blockade (ICB) has not only revolutionized cancer therapy, but also spawned great interest in identifying predictive biomarkers, since only one third of patients show treatment response. The aging process extensively affects the adaptive immune system and thus T cells, which are the main target of ICB. In this review, we address age-related changes regarding the adaptive immune system with a focus on T cells and their implication on carcinogenesis and ICB. Differences between senescence, exhaustion, and anergy are defined and current knowledge, treatment strategies, and studies exploring T cell aging as a biomarker for ICB are discussed. Finally, novel approaches to improve immunotherapies and to identify biomarkers of response to ICB are presented and their potential is assessed in a comparative analysis.

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The neuropeptide receptor NMUR-1 regulates the specificity of C. elegans innate immunity against pathogen infection

10.1101/2021.05.06.442992 ◽

2021 ◽

Author(s):

Phillip Wibisono ◽

Shawndra Wibisono ◽

Jan Watteyne ◽

Chia-Hui Chen ◽

Durai Sellegounder ◽

...

Keyword(s):

Innate Immunity ◽

Immune System ◽

Immune Responses ◽

Adaptive Immune System ◽

Innate Immune ◽

Innate Immune Responses ◽

Immune Genes ◽

C Elegans ◽

Adaptive Immune ◽

Functional Assays

A key question in current immunology is how the innate immune system generates high levels of specificity. Like most invertebrates, Caenorhabditis elegans does not have an adaptive immune system and relies solely on innate immunity to defend itself against pathogen attacks, yet it can still differentiate different pathogens and launch distinct innate immune responses. Here, we have found that functional loss of NMUR-1, a neuronal GPCR homologous to mammalian receptors for the neuropeptide neuromedin U, has diverse effects on C. elegans survival against various bacterial pathogens. Transcriptomic analyses and functional assays revealed that NMUR-1 modulates C. elegans transcription activity by regulating the expression of transcription factors, which, in turn, controls the expression of distinct immune genes in response to different pathogens. Our study has uncovered a molecular basis for the specificity of C. elegans innate immunity that could provide mechanistic insights into understanding the specificity of vertebrate innate immunity.

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Persistent anti-heart autoimmunity causes cardiomyocyte damage in chronic heart failure

10.1101/542597 ◽

2019 ◽

Cited By ~ 1

Author(s):

Amalia Sintou ◽

Sarah el Rifai ◽

Catherine Mansfield ◽

Jose L. Sanchez Alonso ◽

Stephen M. Rothery ◽

...

Keyword(s):

Heart Failure ◽

Immune System ◽

Chronic Heart Failure ◽

Adaptive Immune System ◽

Tissue Destruction ◽

Humoral Factors ◽

Adaptive Immune ◽

Promising Target ◽

Self Tolerance

AbstractAlthough clinicians and researchers have long appreciated the detrimental effects of excessive acute inflammation after myocardial infarction (MI), less is known about the role of the adaptive immune system in MI complications including heart failure. Yet, abundant cardiac self-antigens released from necrotic cardiomyocytes in a highly inflammatory environment are likely to overwhelm peripheral mechanisms of immunological self-tolerance and adaptive auto-reactivity against the heart may cause ongoing tissue destruction and exacerbate progression to chronic heart failure (CHF).Here, we confirm that the adaptive immune system is indeed persistently active in CHF due to ischemic heart disease triggered by MI in rats. Heart draining mediastinal lymph nodes contain active secondary follicles with mature class-switched IgG2a positive cells, and mature anti-heart auto-antibodies binding to cardiac epitopes are still present in serum as late as 16 weeks after MI. When applied to healthy cardiomyocytes in vitro, humoral factors present in CHF serum promoted apoptosis, cytotoxicity and signs of hypertrophy.These findings directly implicate post-MI autoimmunity as an integral feature of CHF progression, constituting a roadblock to effective regeneration and a promising target for therapeutic intervention.

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Functions of the immune system

10.1093/med/9780199568741.003.0293 ◽

2018 ◽

Author(s):

Malini Bhole

Keyword(s):

Immune System ◽

Adaptive Immune System ◽

Innate Immune ◽

Central Feature ◽

Humoral Factors ◽

Adaptive Immune ◽

System P ◽

The Common ◽

Physical And Chemical ◽

Adaptive Immune Systems

This chapter reviews the functions of the immune system, which has evolved to provide a defence mechanism against microbial challenges, and is divided into two main branches, innate and adaptive. In addition, there are physical and chemical barriers, including skin, mucous membrane, mucous secretions, saliva, and various enzymes, and these contribute to the first line of defence against pathogens. The innate immune system provides the initial quick response for rapid recognition and elimination of pathogens, as opposed to the adaptive immune system, which has evolved to provide a more definitive and finely tuned response. The common central feature of both of these systems is the ability to distinguish between self and non-self. The recognition of non-self or ‘foreign’ pathogens and the subsequent immune response is orchestrated by a whole range of cells and soluble (humoral) factors in both innate and adaptive immune systems.

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