scholarly journals Let There be Light—A Rare Glimpse Into the Lives of Our gut Bacteria

2021 ◽  
Vol 9 ◽  
Author(s):  
Anna Golberg ◽  
Naama Geva-Zatorsky

Our gut bacteria influence multiple physiological process including the immune response of our body. In this article, we describe a method for labeling anaerobic gut bacteria with a fluorescent marker that reflects light if it is illuminated, just like light reflectors on our bikes. This marker can be identified by a special microscope. Using this marker, we can act as detectives and track the activity of our gut bacteria in their natural environment. This method allowed us to see the interaction of bacteria with various immune system cells and where the bacteria chose to settle along the digestive system.

2021 ◽  
pp. jclinpath-2020-207337
Author(s):  
Claudia Núñez-Torrón ◽  
Ana Ferrer-Gómez ◽  
Esther Moreno Moreno ◽  
Belen Pérez-Mies ◽  
Jesús Villarrubia ◽  
...  

BackgroundSecondary haemophagocytic lymphohistiocytosis (sHLH) is characterised by a hyper activation of immune system that leads to multiorgan failure. It is suggested that excessive immune response in patients with COVID-19 could mimic this syndrome. Some COVID-19 autopsy studies have revealed the presence of haemophagocytosis images in bone marrow, raising the possibility, along with HScore parameters, of sHLH.AimOur objective is to ascertain the existence of sHLH in some patients with severe COVID-19.MethodsWe report the autopsy histological findings of 16 patients with COVID-19, focusing on the presence of haemophagocytosis in bone marrow, obtained from rib squeeze and integrating these findings with HScore parameters. CD68 immunohistochemical stains were used to highlight histiocytes and haemophagocytic cells. Clinical evolution and laboratory parameters of patients were collected from electronic clinical records.ResultsEleven patients (68.7%) displayed moderate histiocytic hyperplasia with haemophagocytosis (HHH) in bone marrow, three patients (18.7%) displayed severe HHH and the remainder were mild. All HScore parameters were collected in 10 patients (62.5%). Among the patients in which all parameters were evaluable, eight patients (80%) had an HScore >169. sHLH was not clinically suspected in any case.ConclusionsOur results support the recommendation of some authors to use the HScore in patients with severe COVID-19 in order to identify those who could benefit from immunosuppressive therapies. The presence of haemophagocytosis in bone marrow tissue, despite not being a specific finding, has proved to be a very useful tool in our study to identify these patients.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Tian-Yu Lei ◽  
Ying-Ze Ye ◽  
Xi-Qun Zhu ◽  
Daniel Smerin ◽  
Li-Juan Gu ◽  
...  

AbstractThrough considerable effort in research and clinical studies, the immune system has been identified as a participant in the onset and progression of brain injury after ischaemic stroke. Due to the involvement of all types of immune cells, the roles of the immune system in stroke pathology and associated effects are complicated. Past research concentrated on the functions of monocytes and neutrophils in the pathogenesis of ischaemic stroke and tried to demonstrate the mechanisms of tissue injury and protection involving these immune cells. Within the past several years, an increasing number of studies have elucidated the vital functions of T cells in the innate and adaptive immune responses in both the acute and chronic phases of ischaemic stroke. Recently, the phenotypes of T cells with proinflammatory or anti-inflammatory function have been demonstrated in detail. T cells with distinctive phenotypes can also influence cerebral inflammation through various pathways, such as regulating the immune response, interacting with brain-resident immune cells and modulating neurogenesis and angiogenesis during different phases following stroke. In view of the limited treatment options available following stroke other than tissue plasminogen activator therapy, understanding the function of immune responses, especially T cell responses, in the post-stroke recovery period can provide a new therapeutic direction. Here, we discuss the different functions and temporal evolution of T cells with different phenotypes during the acute and chronic phases of ischaemic stroke. We suggest that modulating the balance between the proinflammatory and anti-inflammatory functions of T cells with distinct phenotypes may become a potential therapeutic approach that reduces the mortality and improves the functional outcomes and prognosis of patients suffering from ischaemic stroke.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 380
Author(s):  
Ales Macela ◽  
Klara Kubelkova

SARS-CoV-2 infection induces the production of autoantibodies, which is significantly associated with complications during hospitalization and a more severe prognosis in COVID-19 patients. Such a response of the patient’s immune system may reflect (1) the dysregulation of the immune response or (2) it may be an attempt to regulate itself in situations where the non-infectious self poses a greater threat than the infectious non-self. Of significance may be the primary virus-host cell interaction where the surface-bound ACE2 ectoenzyme plays a critical role. Here, we present a brief analysis of recent findings concerning the immune recognition of SARS-CoV-2, which, we believe, favors the second possibility as the underlying reason for the production of autoantibodies during COVID-19.


Author(s):  
Luis Sánchez-del-Campo ◽  
Román Martí-Díaz ◽  
María F. Montenegro ◽  
Rebeca González-Guerrero ◽  
Trinidad Hernández-Caselles ◽  
...  

Abstract Background The application of immune-based therapies has revolutionized cancer treatment. Yet how the immune system responds to phenotypically heterogeneous populations within tumors is poorly understood. In melanoma, one of the major determinants of phenotypic identity is the lineage survival oncogene MITF that integrates diverse microenvironmental cues to coordinate melanoma survival, senescence bypass, differentiation, proliferation, invasion, metabolism and DNA damage repair. Whether MITF also controls the immune response is unknown. Methods By using several mouse melanoma models, we examine the potential role of MITF to modulate the anti-melanoma immune response. ChIP-seq data analysis, ChIP-qPCR, CRISPR-Cas9 genome editing, and luciferase reporter assays were utilized to identify ADAM10 as a direct MITF target gene. Western blotting, confocal microscopy, flow cytometry, and natural killer (NK) cytotoxicity assays were used to determine the underlying mechanisms by which MITF-driven phenotypic plasticity modulates melanoma NK cell-mediated killing. Results Here we show that MITF regulates expression of ADAM10, a key sheddase that cleaves the MICA/B family of ligands for NK cells. By controlling melanoma recognition by NK-cells MITF thereby controls the melanoma response to the innate immune system. Consequently, while melanoma MITFLow cells can be effectively suppressed by NK-mediated killing, MITF-expressing cells escape NK cell surveillance. Conclusion Our results reveal how modulation of MITF activity can impact the anti-melanoma immune response with implications for the application of anti-melanoma immunotherapies.


Pathobiology ◽  
2021 ◽  
pp. 1-17
Author(s):  
Ana Margarida Barbosa ◽  
Alexandra Gomes-Gonçalves ◽  
António G. Castro ◽  
Egídio Torrado

The immune system plays a critical role in preventing cancer development and progression. However, the complex network of cells and soluble factor that form the tumor microenvironment (TME) can dictate the differentiation of tumor-infiltrating leukocytes and shift the antitumor immune response into promoting tumor growth. With the advent of cancer immunotherapy, there has been a reinvigorated interest in defining how the TME shapes the antitumor immune response. This interest brought to light the microbiome as a novel player in shaping cancer immunosurveillance. Indeed, accumulating evidence now suggests that the microbiome may confer susceptibility or resistance to certain cancers and may influence response to therapeutics, particularly immune checkpoint inhibitors. As we move forward into the age of precision medicine, it is vital that we define the factors that influence the interplay between the triad immune system-microbiota-cancer. This knowledge will contribute to improve the therapeutic response to current approaches and will unravel novel targets for immunotherapy.


2021 ◽  
pp. 1-10
Author(s):  
Bader Alshehri

Breast cancer being the most malignant and lethal disease persistent among women globally. Immunotherapy as a new treatment modality has emerged in understanding the loopholes in the treatment of breast cancer which is mainly attributed to the potential of tumor cells to evade and survive the immune response by developing various strategies. Therefore, improved understanding of the immune evasion by cancer cells and the monoclonal antibodies against PD- and PD-L1 can help us in the diagnosis of this malignancy. Here in this article, I have highlighted that in addition to focusing on other strategies for breast cancer treatment, the involvement of immune system in breast cancer is vital for the understanding of this malignancy. Further, the complete involvement of immune system in the relapse or recurrence of the breast tumor and have also highlighted the role of vaccines, PD-1 and CTLA-4 with the recent advances in the field. Moreover, in addition to the application of immunotherapy as a sole therapy, combinations of immunotherapy with various strategies like targeting it with MEK inhibitors, Vaccines, chemotherapy and PARP inhibitor has shown to have significant benefits is also discussed in this article.


2021 ◽  
Vol 10 (5) ◽  
pp. 1131
Author(s):  
Magdalena Chmielińska ◽  
Marzena Olesińska ◽  
Katarzyna Romanowska-Próchnicka ◽  
Dariusz Szukiewicz

Haptoglobin (Hp) is an acute phase protein which supports the immune response and protects tissues from free radicals. Its concentration correlates with disease activity in spondyloarthropathies (SpAs). The Hp polymorphism determines the functional differences between Hp1 and Hp2 protein products. The role of the Hp polymorphism has been demonstrated in many diseases. In particular, the Hp 2-2 phenotype has been associated with the unfavorable course of some inflammatory and autoimmune disorders. Its potential role in modulating the immune system in SpA is still unknown. This article contains pathophysiological considerations on the potential relationship between Hp, its polymorphism and SpA.


Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Yuntian Shen ◽  
Qiang Zhao ◽  
Jiangbo Wu ◽  
Zhuoran Wang ◽  
Wei Yang

Introduction: Cardiac arrest (CA) is associated with high mortality and morbidity, which is in part due to infectious complications developed in CA patients. Infection complications, particularly pneumonia, occur in approximately 60% of CA patients. Given this high incidence, we hypothesized that after CA, the immune system is impaired, which increases the susceptibility of CA patients to potential infections. Therefore, in this study, we systematically examined the immune response in the brain and peripheral immune organs after CA. Methods: Mice were subjected to CA and cardiopulmonary resuscitation (CA/CPR). Flow cytometry, ELISA, immunohistochemistry, and quantitative PCR were used to analyze the immune response in various post-CA organs. Results: First, we characterized the time course of the immune response in the spleen after CA/CPR. CA/CPR induced significant changes in all major immune cell populations. Notably, B cell frequencies decreased, while T cell frequencies increased, in various organs on day 3 post-CA. Further, the levels of pro-inflammatory cytokines, eg IL-6, were markedly increased in the blood and brain after CA. Critically, we found that the lymphocyte counts in the spleen and thymus were dramatically lower in CA mice than in sham mice. Interestingly, CA/CPR caused progressive atrophy of the spleen and thymus. Since it has been shown that CA/CPR alters activity of the hypothalamic-pituitary-adrenal (HPA) axis, we speculated that CA-induced atrophy of lymphoid organs is mediated by the HPA axis. Thus, we treated CA mice with RU486, a glucocorticoid receptor antagonist. Indeed, this treatment reversed CA-induced organ atrophy and mitigated immune cell depletion, both in the thymus and spleen. Conclusions: We provided for the first time evidence that CA/CPR rapidly induced a systemic inflammatory response followed by impairment of the immune system, which eventually led to a massive loss of immune cells in the peripheral immune organs. This CA-induced immunodeficiency appears to be mediated by dysregulation of the HPA axis. Our findings here may be of high clinical significance, considering the high incidence of infectious complications in CA patients and their detrimental effects on CA outcome.


ChemViews ◽  
2020 ◽  
Author(s):  
Michael Breuer ◽  
Melanie Weingarten

2014 ◽  
Vol 281 (1790) ◽  
pp. 20140333 ◽  
Author(s):  
Crystal M. Vincent ◽  
Darryl T. Gwynne

Sex differences in immunity are often observed, with males generally having a weaker immune system than females. However, recent data in a sex-role-reversed species in which females compete to mate with males suggest that sexually competitive females have a weaker immune response. These findings support the hypothesis that sexual dimorphism in immunity has evolved in response to sex-specific fitness returns of investment in traits such as parental investment and longevity, but the scarcity of data in sex-reversed species prevents us from drawing general conclusions. Using an insect species in which males make a large but variable parental investment in their offspring, we use two indicators of immunocompetence to test the hypothesis that sex-biased immunity is determined by differences in parental investment. We found that when the value of paternal investment was experimentally increased, male immune investment became relatively greater than that of females. Thus, in this system, in which the direction of sexual competition is plastic, the direction of sex-biased immunity is also plastic and appears to track relative parental investment.


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