scholarly journals HIV-1 Primarily Targets the Innate Immune System and Only Secondarily Modulates Adaptive Immune Cell Depletion

2012 ◽  
Vol 02 (03) ◽  
pp. 226-231
Author(s):  
Lawrence M. Agius
2020 ◽  
Vol 128 (3) ◽  
pp. 473-482 ◽  
Author(s):  
Andrew C. Noah ◽  
Thomas M. Li ◽  
Leandro M. Martinez ◽  
Susumu Wada ◽  
Jacob B. Swanson ◽  
...  

Tendon injuries are a common clinical condition with limited treatment options. The cellular components of the innate immune system, such as neutrophils and macrophages, have been studied in tendon injuries. However, the adaptive immune system, comprising specialized lymphocytes, plays an important role in orchestrating the healing of numerous tissues, but less is known about these cells in tendon healing. To gain a greater understanding of the biological processes that regulate tendon healing, we determined how the cellular components of the adaptive and innate immune system respond to a tendon injury using two-month-old male mice. We observed that lymphatic vasculature is present in the epitenon and superficial regions of Achilles tendons, and that the lymphatics drain into the popliteal lymph node. We then created an acute Achilles tenotomy followed by repair, and collected tendons and popliteal lymph nodes 1, 2, and 4 wk after injury. Tendon injury resulted in a robust adaptive immune cell response that followed an initial innate immune cell response in tendons and lymph nodes. Monocytes, neutrophils, and macrophages initially accumulated at 1 wk after injury in tendons, while dendritic cells and CD4+ T cells peaked at 2 wk after injury. B cells and CD8+ T cells progressively increased over time. In parallel, immune cells of the popliteal lymph node demonstrated a similarly coordinated response to the injury. These results suggest that there is an adaptive immune response to tendon injury, and adaptive immune cells may play a role in regulating tendon healing. NEW & NOTEWORTHY While the innate immune system, consisting of macrophages and related hematopoietic cells, has been studied in tendon injury, less is known about the adaptive immune system. Using a mouse model of Achilles tendon tenotomy and repair, we observed an adaptive immune cell response, consisting of CD4+ and CD8+ T cells, and B cells, which occur through 4 wk after tendon injury. This response appeared to be coordinated by the draining popliteal lymph node.


Microbiology ◽  
2006 ◽  
Vol 152 (2) ◽  
pp. 285-293 ◽  
Author(s):  
Gavin K. Paterson ◽  
Tim J. Mitchell

The innate immune system provides a non-specific first line of defence against microbes and is crucial both in the development and effector stages of subsequent adaptive immune responses. Consistent with its importance, study of the innate immune system is a broad and fast-moving field. Here we provide an overview of the recent key advances made in this area with relation to the important pathogen Streptococcus pneumoniae (the pneumococcus).


2017 ◽  
Vol 131 (8) ◽  
pp. 625-634 ◽  
Author(s):  
Marc Weidenbusch ◽  
Onkar P. Kulkarni ◽  
Hans-Joachim Anders

Although the role of adaptive immune mechanisms, e.g. autoantibody formation and abnormal T-cell activation, has been long noted in the pathogenesis of human systemic lupus erythematosus (SLE), the role of innate immunity has been less well characterized. An intricate interplay between both innate and adaptive immune elements exists in protective anti-infective immunity as well as in detrimental autoimmunity. More recently, it has become clear that the innate immune system in this regard not only starts inflammation cascades in SLE leading to disease flares, but also continues to fuel adaptive immune responses throughout the course of the disease. This is why targeting the innate immune system offers an additional means of treating SLE. First trials assessing the efficacy of anti-type I interferon (IFN) therapy or modulators of pattern recognition receptor (PRR) signalling have been attempted. In this review, we summarize the available evidence on the role of several distinct innate immune elements, especially neutrophils and dendritic cells as well as the IFN system, as well as specific innate PRRs along with their signalling pathways. Finally, we highlight recent clinical trials in SLE addressing one or more of the aforementioned components of the innate immune system.


2010 ◽  
Vol 16 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Nades Palaniyar

Soluble pattern-recognition innate immune proteins functionally resemble the antibodies of the adaptive immune system. Two major families of such proteins are ficolins and collectins or collagenous lectins (e.g. mannose-binding lectin [MBL], surfactant proteins [SP-A and SP-D] and conglutinin). In general, subunits of ficolins and collectins recognize the carbohydrate arrays of their targets via globular trimeric carbohydrate-recognition domains (CRDs) whereas IgG, IgM and other antibody isotypes recognize proteins via dimeric antigen-binding domains (Fab). Considering the structure and functions of these proteins, ficolins and MBL are analogous to molecules with the complement activating functions of C1q and the target recognition ability of IgG. Although the structure of SP-A is similar to MBL, it does not activate the complement system. Surfactant protein-D and conglutinin could be considered as the collagenous non-complement activating giant IgMs of the innate immune system. Proteins such as peptidoglycan-recognition proteins, pentraxins and agglutinin gp-340/DMBT1 are also pattern-recognition proteins. These proteins may be considered as different isotypes of antibody-like molecules. Proteins such as defensins, cathelicidins and lactoferrins directly or indirectly alter microbes or microbial growth. These proteins may not be considered as antibodies of the innate immune system. Hence, ficolins and collectins could be considered as specialized ‘antibodies of the innate immune system’ instead of ‘ante-antibody’ innate immune molecules. The discovery, structure, functions and future research directions of many of these soluble proteins and receptors such as Toll-like and NOD-like receptors are discussed in this special issue of Innate Immunity.


Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2350
Author(s):  
Martina Montanari ◽  
Julien Royet

Like all invertebrates, flies such as Drosophila lack an adaptive immune system and depend on their innate immune system to protect them against pathogenic microorganisms and parasites. In recent years, it appears that the nervous systems of eucaryotes not only control animal behavior but also cooperate and synergize very strongly with the animals’ immune systems to detect and fight potential pathogenic threats, and allow them to adapt their behavior to the presence of microorganisms and parasites that coexist with them. This review puts into perspective the latest progress made using the Drosophila model system, in this field of research, which remains in its infancy.


2021 ◽  
Vol 8 ◽  
Author(s):  
Colm Keane ◽  
Matthew Coalter ◽  
Ignacio Martin-Loeches

Equilibrium within the immune system can often determine the fate of its host. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the coronavirus disease 2019 (COVID-19) pandemic. Immune dysregulation remains one of the main pathophysiological components of SARS-CoV-2-associated organ injury, with over-activation of the innate immune system, and induced apoptosis of adaptive immune cells. Here, we provide an overview of the innate immune system, both in general and relating to COVID-19. We specifically discuss “NETosis,” the process of neutrophil release of their extracellular traps, which may be a more recently described form of cell death that is different from apoptosis, and how this may propagate organ dysfunction in COVID-19. We complete this review by discussing Stem Cell Therapies in COVID-19 and emerging COVID-19 phenotypes, which may allow for more targeted therapy in the future. Finally, we consider the array of potential therapeutic targets in COVID-19, and associated therapeutics.


2017 ◽  
Author(s):  
Grant C. O’Connell ◽  
Connie S. Tennant ◽  
Noelle Lucke-Wold ◽  
Yasser Kabbani ◽  
Abdul R. Tarabishy ◽  
...  

AbstractCD163 is a scavenger receptor expressed on innate immune cell populations which can be shed from the plasma membrane via the metalloprotease ADAM17 to generate a soluble peptide with lympho-inhibitory properties. The purpose of this study was to investigate CD163 as a possible effector of stroke-induced adaptive immune system suppression. Liquid biopsies were collected from ischemic stroke patients (n=39), neurologically asymptomatic controls (n=20), and stroke mimics (n=20) within 24 hours of symptom onset. Peripheral blood ADAM17 activity and soluble CD163 levels were elevated in stroke patients relative to non-stroke control groups, and negatively associated with post-stroke lymphocyte counts. Subsequent in vitro experiments suggested that this stroke-induced elevation in circulating soluble CD163 likely originates from activated monocytic cells, as serum from stroke patients stimulated ADAM17-dependant CD163 shedding from healthy donor-derived monocytes. Additional in vitro experiments demonstrated that stroke-induced elevations in circulating soluble CD163 can elicit direct suppressive effects on the adaptive immune system, as serum from stroke patients inhibited the proliferation of healthy donor-derived lymphocytes, an effect which was attenuated following serum CD163 depletion. Collectively, these observations provide novel evidence that the innate immune system employs protective mechanisms aimed at mitigating the risk of post-stroke autoimmune complications driven by adaptive immune system overactivation, and that CD163 is key mediator of this phenomenon.


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Betty Diamond ◽  
Bruce T. Volpe ◽  
Sonya VanPatten ◽  
Yousef Al Abed

Abstract The response to viral infection generally includes an activation of the adaptive immune response to produce cytotoxic T cells and neutralizing antibodies. We propose that SARS-CoV-2 activates the innate immune system through the renin-angiotensin and kallikrein-bradykinin pathways, blocks interferon production and reduces an effective adaptive immune response. This model has therapeutic implications.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Danielle Minns ◽  
Katie Jane Smith ◽  
Emily Gwyer Findlay

Neutrophils are the most abundant leukocytes in peripheral blood and respond rapidly to danger, infiltrating tissues within minutes of infectious or sterile injury. Neutrophils were long thought of as simple killers, but now we recognise them as responsive cells able to adapt to inflammation and orchestrate subsequent events with some sophistication. Here, we discuss how these rapid responders release mediators which influence later adaptive T cell immunity through influences on DC priming and directly on the T cells themselves. We consider how the release of granule contents by neutrophils—through NETosis or degranulation—is one way in which the innate immune system directs the phenotype of the adaptive immune response.


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