Search

In this paper, we study a delayed HIV infection model with nonmonotonic immune response and perform stability and bifurcation analysis. Our results show that the delayed HIV infection system with nonmonotonic immune response has bistability and stable periodic solution appear. We find that both the uninfected and immune-free equilibria are globally asymptotically stable under certain conditions which are not affected by time delay. However, the time delay makes one immune equilibrium always unstable for τ ≥ 0 and also makes another immune equilibrium appear stability switches; meanwhile, the system will exhibit local Hopf bifurcation, global Hopf bifurcation, and saddle-node-Hopf bifurcation. Numerical simulations are carried out to verify our results. [ABSTRACT FROM AUTHOR]

Background: Sexual dimorphism is observed in the occurrence, course, and severity of human disease. The difference in immune response between males and females can in part be attributed to sexual genotype. However, immunological differences can also be explained by endocrine–immune interactions. Specifically, androgens possess the ability of directly modulating the development and function of immune cells. Although androgens generally contribute to immunosuppressive effects, this is not necessarily always the case. Aim: The aim of the review is to uncover the role of androgens in shaping the innate immune response. Material & Methods: Authors included papers in this review which discussed the impact of androgens on specific innate immune cells. Results: Androgens modulate the innate immune response through various mechanisms. However, there is conflicting evidence in the literature regarding the interplay betwen androgens and the innate immune system. Discussion: Conflicting evidence presented in this review could in part be explained by the limitations present in interpreting results. Conclusion: This review is of great importance for our understanding of occurence and mechanism of human inflammatory disease. [ABSTRACT FROM AUTHOR]

Many of the reviews include discussion of diffusible molecules involved in cell-cell communication during the evolution of innate and adaptive responses (eg, interferons) and how these mediators influence the outcome of the dynamic processes visualized by optical methods. New data on tissue-resident T cells also fall in this category, as do recent observations of perivascular co-localization of effector lymphocytes and presenting cells at sites of effector function within tissues. Technologies are now emerging that will permit combining the protein and cell-based optical imaging methods used to date with recent advances in nucleic acid/genomic methods, especially single-cell sequencing. [Extracted from the article]

Innate immune adaptor proteins are critical components of the innate immune system that propagate pro‐inflammatory responses from their upstream receptors, and lead to pathogen clearance from the host. Bacterial pathogens have developed strategies to survive inside host cells without triggering the innate immune surveillance in ways that are still not fully understood. Here, it is reported that Pseudomonas aeruginosa induces its quorum sensing mechanism after macrophage engulfment. Further investigation of its secretome identified a quorum sensing regulated product, LasB, is responsible for innate immune suppression depending on the MyD88‐mediated signaling. Moreover, it is showed that this specific type of pathogen‐mediated innate immune suppression is due to the enzymatic digestion of the death domains of the innate immune adaptors, mainly MyD88, and attributed to LasB's large substrate binding groove. Lastly, it is demonstrated that the secretion of LasB from P. aeruginosa directly contributed to MyD88 degradation within macrophages. Hence, it is discovered an example of bacterial quorum sensing‐regulated cellular innate immune suppression by direct cleavage of immune adaptors. [ABSTRACT FROM AUTHOR]

We are frequently exposed to potentially harmful microbes of various types on a daily basis. Our immune system is an amazing collection of unique organs and cells that defends us from hazardous germs as well as certain diseases. It plays a crucial role in protecting the body against external invaders, including bacteria, viruses, and parasites. Maintaining a healthy immune system requires consuming a balanced diet that provides a variety of macro‐ and micronutrients. By consuming sufficient amounts of water, minerals such as zinc and magnesium, micronutrients, herbs, and foods rich in vitamins C, D, and E, and adopting a healthy lifestyle, one can enhance their health and immunity, and prevent infections. This article provides a comprehensive review of the scientific literature on common foods known for their potential to boost human immunity. The review begins by discussing the various components of the immune system and their functions. It then delves into the current understanding of how nutrition can influence immune response, highlighting the importance of a well‐balanced diet in supporting optimal immune function. The article presents an extensive analysis of a range of common foods that have been studied for their immune‐boosting properties. These foods include fruits, vegetables, whole grains, and animal‐based foods. Each food category is explored in terms of its specific nutrients and bioactive compounds that contribute to immune support. Foods such as milk, eggs, fruits, leafy greens, and spices like onion, garlic, and turmeric contain beneficial compounds that can enhance the immune system's function, activate and inhibit immune cells, and interfere with multiple pathways that eventually lead to improved immune responses and defense. The available literature on the issue was accessed via online resources and evaluated thoroughly as a methodology for preparing this manuscript. [ABSTRACT FROM AUTHOR]

Summary: Polymorphonuclear neutrophils are no longer considered as a homogeneous population of terminally differentiated and short‐lived cells that belong to the innate immune system only. In fact, data from the past decades have uncovered that neutrophils exhibit large phenotypic heterogeneity and functional versatility that render them more plastic than previously thought. Hence, their precise role as effector cells in inflammation, in immune response and in other pathophysiological processes, including tumors, needs to be better evaluated. In such a complex scenario, common knowledge of the differentiation of neutrophils in bone marrow refers to lineage precursors, starting from the still poorly defined myeloblasts, and proceeding sequentially to promyelocytes, myelocytes, metamyelocytes, band cells, segmented neutrophils, and mature neutrophils, with each progenitor stage being more mature and better characterized. Thanks to the development and utilization of cutting‐edge technologies, novel information about neutrophil precursors at stages earlier than the promyelocytes, hence closer to the hematopoietic stem cells, is emerging. Accordingly, this review discusses the main findings related to the very early precursors of human neutrophils and provides our perspectives on human neutropoiesis. [ABSTRACT FROM AUTHOR]

Background: So far, limited studies have focused on the role of Macrophages (MQs) in the development or progression of celiac disease (CD). Researchers believe that increasing knowledge about the function of MQs in inflammatory disorders plays a critical role in finding a new treatment for these kinds of diseases. Main body: CD is a permanent autoimmune intestinal disorder triggered by gluten exposure in predisposed individuals. This disorder happens due to the loss of intestinal epithelial barrier integrity characterized by dysregulated innate and adaptive immune responses. MQs are known as key players of the innate immune system that link innate and adaptive immunity. MQs of human intestinal lamina propria participate in maintaining tissue homeostasis, and also intestinal inflammation development. Previous studies suggested that gliadin triggers a proinflammatory phenotype (M1 MQ) in human primary MQs. Moreover, M2‐related immunosuppressive mediators are also present in CD. In fact, CD patients present an impaired transition from pro‐inflammatory to anti‐inflammatory responses due to inappropriate responses to gliadin peptides. Conclusion: The M1/M2 MQs polarization balancing regulators can be considered novel therapeutic targets for celiac disease. [ABSTRACT FROM AUTHOR]

Immunoprotection and oxygen supply are vital in implementing a cell therapy for type 1 diabetes (T1D). Without these features, the transplanted islet cell clusters will be rejected by the host immune system, and necrosis will occur due to hypoxia. The use of anti‐rejection drugs can help protect the transplanted cells from the immune system; yet, they also may have severe side effects. Cell delivery systems (CDS) have been developed for islet transplantation to avoid using immunosuppressants. CDS provide physical barriers to reduce the immune response and chemical coatings to reduce host fibrotic reaction. In some CDS, there is architecture to support vascularization, which enhances oxygen exchange. In this review, we discuss the current clinical and preclinical studies using CDS without immunosuppression as a cell therapy for T1D. We find that though CDS have been demonstrated for their ability to support immunoisolation of the grafted cells, their functionality has not been fully optimized. Current advanced methods in clinical trials demonstrate the systems are partly functional, physically complicated to implement or inefficient. However, modifications are being made to overcome these issues. [ABSTRACT FROM AUTHOR]

COVID‐19, caused by SARS‐CoV‐2, has emerged as a global pandemic. While immune responses of the adaptive immune system have been in the focus of research, the role of NK cells in COVID‐19 remains less well understood. Here, we characterized NK cell‐mediated SARS‐CoV‐2 antibody‐dependent cellular cytotoxicity (ADCC) against SARS‐CoV‐2 spike‐1 (S1) and nucleocapsid (NC) protein. Serum samples from SARS‐CoV‐2 resolvers induced significant CD107a‐expression by NK cells in response to S1 and NC, while serum samples from SARS‐CoV‐2‐negative individuals did not. Furthermore, serum samples from individuals that received the BNT162b2 vaccine induced strong CD107a expression by NK cells that increased with the second vaccination and was significantly higher than observed in infected individuals. As expected, vaccine‐induced responses were only directed against S1 and not against NC protein. S1‐specific CD107a responses by NK cells were significantly correlated to NK cell‐mediated killing of S1‐expressing cells. Interestingly, screening of serum samples collected prior to the COVID‐19 pandemic identified two individuals with cross‐reactive antibodies against SARS‐CoV‐2 S1, which also induced degranulation of NK cells. Taken together, these data demonstrate that antibodies induced by SARS‐CoV‐2 infection and anti‐SARS‐CoV‐2 vaccines can trigger significant NK cell‐mediated ADCC activity, and identify some cross‐reactive ADCC‐activity against SARS‐CoV‐2 by endemic coronavirus‐specific antibodies. [ABSTRACT FROM AUTHOR]

Immune checkpoint inhibitors (ICIs) have revolutionised oncology and are now standard‐of‐care for the treatment of a wide variety of solid neoplasms. However, tumour responses remain unpredictable, experienced by only a minority of ICI recipients across malignancy types. Therefore, there is an urgent need for better predictive biomarkers to identify a priori the patients most likely to benefit from these therapies. Despite considerable efforts, only three such biomarkers are FDA‐approved for clinical use, and all rely on the availability of tumour tissue for immunohistochemical staining or genomic assays. There is emerging evidence that host factors – for example, genetic, metabolic, and immune factors, as well as the composition of one's gut microbiota – influence the response of a patient's cancer to ICIs. Tantalisingly, some of these factors are modifiable, paving the way for co‐therapies that may enhance the therapeutic index of these treatments. Herein, we review key host factors that are of potential biomarker value for response to ICI therapy, with a particular focus on the proposed mechanisms for these influences. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

During the last 15 years, a significant amount of data related to the crustacean immune system has been generated, mainly led by the advances made in the field of transcriptomic analysis through massive mRNA sequencing technology. In order to shed new light on the genes and metabolic pathways associated with the immune system in shrimp species, we have carried out a meta‐analysis using the current literature and the Sequence Read Archive (SRA) database of the National Center for Biotechnology Information (NCBI), which has 1195 published transcriptomic data sets until 31 December 2020, from different tissues and 14 Penaeus species. The transcriptomic analyses published so far have explored the effects of the challenge from viral and bacterial pathogens, as well as abiotic stressors, such as ammonia, temperature, salinity, oxygen deprivation and pH. They have also explored the effect of dietary factors and beneficial microbes (pre‐ and probiotics) in the immune response. In order to harness the vast amount of information available, multidisciplinary efforts have to generate better genomic tools to overcome the complexity of the genome and to implement the knowledge gained into commercial applications for the improvement of the culture conditions, adaptation of more sustainable feeds and producing strains showing more resilience/tolerance to diseases. [ABSTRACT FROM AUTHOR]