immune mechanism
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2022 ◽  
Vol 12 ◽  
Author(s):  
Wael Bahnan ◽  
Sebastian Wrighton ◽  
Martin Sundwall ◽  
Anna Bläckberg ◽  
Olivia Larsson ◽  
...  

Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focused on antibodies that neutralize the ACE2-Spike interaction but not on non-neutralizing antibodies. Antibody-dependent phagocytosis is an immune mechanism enhanced by opsonization, where typically, more bound antibodies trigger a stronger phagocyte response. Here, we show that Spike-specific antibodies, dependent on concentration, can either enhance or reduce Spike-bead phagocytosis by monocytes independently of the antibody neutralization potential. Surprisingly, we find that both convalescent patient plasma and patient-derived monoclonal antibodies lead to maximum opsonization already at low levels of bound antibodies and is reduced as antibody binding to Spike protein increases. Moreover, we show that this Spike-dependent modulation of opsonization correlate with the outcome in an experimental SARS-CoV-2 infection model. These results suggest that the levels of anti-Spike antibodies could influence monocyte-mediated immune functions and propose that non-neutralizing antibodies could confer protection to SARS-CoV-2 infection by mediating phagocytosis.


Author(s):  
Bart J. M. Grijmans ◽  
Sander B. van der Kooij ◽  
Monica Varela ◽  
Annemarie H. Meijer

Cells of the innate immune system continuously patrol the extracellular environment for potential microbial threats that are to be neutralized by phagocytosis and delivery to lysosomes. In addition, phagocytes employ autophagy as an innate immune mechanism against pathogens that succeed to escape the phagolysosomal pathway and invade the cytosol. In recent years, LC3-associated phagocytosis (LAP) has emerged as an intermediate between phagocytosis and autophagy. During LAP, phagocytes target extracellular microbes while using parts of the autophagic machinery to label the cargo-containing phagosomes for lysosomal degradation. LAP contributes greatly to host immunity against a multitude of bacterial pathogens. In the pursuit of survival, bacteria have developed elaborate strategies to disarm or circumvent the LAP process. In this review, we will outline the nature of the LAP mechanism and discuss recent insights into its interplay with bacterial pathogens.


2021 ◽  
pp. 089719002110647
Author(s):  
Widyati ◽  
Nurul Latifah ◽  
Maya Ramadhani

Introduction Pantoprazole is a proton pump inhibitor (PPI) class drug that is widely used in the treatment of SRMD (stress-related mucosal disease in critical ill patients. PPI are one class of drugs used commonly both for treatment and prophylactic therapy for stress ulcers in intensive care unit (ICU). Case We report a case of a 51-year old male who was referred to PKU Hospital. He was admitted to ICU with diagnosis of Hyperosmolar Hyperglymic State and bronchopneumonia. Thrombocytopenia was noted in admission. There was more than 70% decrease in platelet count after initiation of pantoprazole. Patient received Thrombocyte Concentrate (TC) transfusion and corticosteroid iv for several days, but only had minor increase in platelet count. The platelets recovered after stopping pantoprazole. Discussion In the present case report, another exposures to parenteral pantoprazole in a dose of 40 mg once daily reproduced the same adverse drug reaction. In comparison to lansoprazole, thrombocytopenia from pantoprazole is more severe that necessitate TC transfusion and corticosteroid trial. However, in the present case, TC transfusion and corticosteroid fail to escalate platelet count. This finding suggests probability of non-immune mechanism of pantoprazole-induced thrombocytopenia. Conclusion Pantoprazole may induce thrombocytopenia with new features that were immediately developed, resulting a decrease in platelet count >70%. The mechanism found in this case may be non-immune. Drug-induced thrombocytopenia is one of the rare complications that has to be kept in mind with the use of pantoprazole.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yi Zhou ◽  
Weili Xia ◽  
Shengping Peng

Based on the analysis of bacterial parasitic behavior and biological immune mechanism, this paper puts forward the basic idea and implementation method of an embedding adaptive dynamic probabilistic parasitic immune mechanism into a particle swarm optimization algorithm and constructs particle swarm optimization based on an adaptive dynamic probabilistic parasitic immune mechanism algorithm. The specific idea is to use the elite learning mechanism for the parasitic group with a strong parasitic ability to improve the ability of the algorithm to jump out of the local extreme value, and the host will generate acquired immunity against the parasitic behavior of the parasitic group to enhance the diversity of the host population’s particles. Parasitic behavior occurs when the number of times reaches a predetermined algebra. In this paper, an example simulation is carried out for the prescheduling and dynamic scheduling of immune inspection. The effectiveness of prescheduling for immune inspection is verified, and the rules constructed by the adaptive dynamic probability particle swarm algorithm and seven commonly used scheduling rules are tested on two common dynamic events of emergency task insertion and subdistributed immune inspection equipment failure. In contrast, the experimental data was analyzed. From the analysis of experimental results, under the indicator of minimum completion time, the overall performance of the adaptive dynamic probability particle swarm optimization algorithm in 20 emergency task insertion instances and 20 subdistributed immune inspection equipment failure instances is better than that of seven scheduling rules. Therefore, in the two dynamic events of emergency task insertion and subdistributed immune inspection equipment failure, the adaptive dynamic probabilistic particle swarm algorithm proposed in this paper can construct effective scheduling rules for the rescheduling of the system when dynamic events occur and the constructed scheduling. The performance of the rules is better than that of the commonly used scheduling rules. Among the commonly used scheduling rules, the performance of the FIFO scheduling rules is also better. In general, the immune inspection scheduling multiagent system in this paper can complete the prescheduling of immune inspection and process dynamic events of the inspection process and realize the prereactive scheduling of the immune inspection process.


Author(s):  
Chenchen Bi ◽  
Geqiong Xiao ◽  
Chunyan Liu ◽  
Junwei Yan ◽  
Jiaqi Chen ◽  
...  

Intestinal microorganisms are closely associated with immunity, metabolism, and inflammation, and play an important role in health and diseases such as inflammatory bowel disease, diabetes, cardiovascular disease, Parkinson’s disease, and cancer. Liver cancer is one of the most fatal cancers in humans. Most of liver cancers are slowly transformed from viral hepatitis, alcoholic liver disease, and non-alcoholic fatty liver disease. However, the relationship between intestinal microbiota and their metabolites, including short-chain fatty acids, bile acids, indoles, and ethanol, and liver cancer remains unclear. Here, we summarize the molecular immune mechanism of intestinal microbiota and their metabolites in the occurrence and development of liver cancer and reveal the important role of the microbiota-gut-liver axis in liver cancer. In addition, we describe how the intestinal flora can be balanced by antibiotics, probiotics, postbiotics, and fecal bacteria transplantation to improve the treatment of liver cancer. This review describes the immunomolecular mechanism of intestinal microbiota and their metabolites in the occurrence and development of hepatic cancer and provides theoretical evidence support for future clinical practice.


2021 ◽  
Vol 10 (23) ◽  
pp. 5610
Author(s):  
Tomoyo Matsuda-Taniguchi ◽  
Masaki Takemura ◽  
Takeshi Nakahara ◽  
Akiko Hashimoto-Hachiya ◽  
Ayako Takai-Yumine ◽  
...  

Psoriasis is a chronic inflammatory skin disease, and its immune mechanism has been profoundly elucidated. Biologics targeting interleukin (IL)-23 have prevented the development of psoriasis. As major sources of IL-23, dendritic cells (DCs) play a pivotal role in psoriasis; however, the regulatory mechanism of IL-23 in DCs remains unclear. IL-36γ was reported to reflect the disease activity of psoriasis. Therefore, we hypothesized that IL-36γ may affect IL-23 production in DCs. To reveal the mechanism by which IL-36γ controls IL-23 production in DCs, we analyzed murine bone marrow-derived DCs (BMDCs) stimulated with IL-36γ. IL-36γ stimulation upregulated the mRNA and protein expression of Nfkbiz in BMDCs. Nfkbiz knockdown using siRNA transfection partially inhibited the upregulation of IL-23 mRNA expression induced by IL-36γ stimulation. Since NF-κB signaling regulates Nfkbiz expression and the anti-diabetic agent metformin reportedly modulates NF-κB signaling, we examined the effect of metformin treatment on IL-36γ-induced IL-23 production. Metformin treatment impaired the phosphorylation of NF-κB induced by IL-36γ stimulation with the subsequent downregulation of Nfkbiz, resulting in the inhibition of IL-23 production in BMDCs. These data provided evidence that metformin treatment can inhibit IL-36γ-mediated IL-23 production in BMDCs, which might contribute to the prevention of psoriasis.


2021 ◽  
Vol 5 (2.1) ◽  
pp. 72
Author(s):  
Ying Song ◽  
Yufang Qiu ◽  
Weiyou Liu ◽  
Xiaoliang Yuan

Whether infection of Cryptococcus causes disease in host or not depends on the virulence of the pathogen and the immune defense ability of the host. Cryptococcus neoformans (C. neoformans) mainly causes opportunistic infections in the immunocompromised or immunodeficient patients. In contrast, Cryptococcus gattii (C. gattii) mainly attacks the immunocompetent individuals. On the one hand, the host immune cells can eliminate the invasive Cryptococcus through a complex immune mechanism; on the other hand, Cryptococcus can evade the clearance of host immune cells by adopting various strategies (immune escape). This review mainly focuses on the pathogenic mechanism of Cryptococcus, and the host’s immune defense mechanism against cryptococcal infection.


2021 ◽  
Author(s):  
Wael Bahnan ◽  
Sebastian Wrighton ◽  
Martin Sundwall ◽  
Anna Bläckberg ◽  
Olivia Larsson ◽  
...  

Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focused on antibodies that neutralize the ACE2-Spike interaction but not on non-neutralizing antibodies. Antibody-dependent phagocytosis is an immune mechanism enhanced by opsonization, where typically, more bound antibodies trigger a stronger phagocyte response. Here, we show that Spike-specific antibodies, dependent on concentration, can either enhance or reduce Spike-bead phagocytosis by monocytes independently of the antibody neutralization potential. Surprisingly, we find that both convalescent patient plasma and patient-derived monoclonal antibodies lead to maximum opsonization already at low levels of bound antibodies and is reduced as antibody binding to Spike protein increases. Moreover, we show that this Spike-dependent modulation of opsonization seems to affect the outcome in an experimental SARS-CoV-2 infection model. These results suggest that the levels of anti-Spike antibodies could influence monocyte-mediated immune functions and propose that non-neutralizing antibodies could confer protection to SARS-CoV-2 infection by mediating phagocytosis.


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