immune defense
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2022 ◽  
Vol 119 (3) ◽  
pp. e2108540119
Abdouramane Camara ◽  
Alice C. Lavanant ◽  
Jun Abe ◽  
Henri Lee Desforges ◽  
Yannick O. Alexandre ◽  

CD169+ macrophages reside in lymph node (LN) and spleen and play an important role in the immune defense against pathogens. As resident macrophages, they are responsive to environmental cues to shape their tissue-specific identity. We have previously shown that LN CD169+ macrophages require RANKL for formation of their niche and their differentiation. Here, we demonstrate that they are also dependent on direct lymphotoxin beta (LTβ) receptor (R) signaling. In the absence or the reduced expression of either RANK or LTβR, their differentiation is perturbed, generating myeloid cells expressing SIGN-R1 in LNs. Conditions of combined haploinsufficiencies of RANK and LTβR revealed that both receptors contribute equally to LN CD169+ macrophage differentiation. In the spleen, the Cd169-directed ablation of either receptor results in a selective loss of marginal metallophilic macrophages (MMMs). Using a RANKL reporter mouse, we identify splenic marginal zone stromal cells as a source of RANKL and demonstrate that it participates in MMM differentiation. The loss of MMMs had no effect on the splenic B cell compartments but compromised viral capture and the expansion of virus-specific CD8+ T cells. Taken together, the data provide evidence that CD169+ macrophage differentiation in LN and spleen requires dual signals from LTβR and RANK with implications for the immune response.

2022 ◽  
Vol 23 (2) ◽  
pp. 767
Stephenson B. Owusu ◽  
Sophie Dupré-Crochet ◽  
Tania Bizouarn ◽  
Chantal Houée-Levin ◽  
Laura Baciou

Neutrophils play a very key role in the human immune defense against pathogenic infections. The predominant players in this role during the activation of neutrophils are the release of cytotoxic agents stored in the granules and secretory vesicles and the massive production of reactive oxygen species (ROS) initiated by the enzyme NADPH oxidase. In addition, in living organisms, cells are continuously exposed to endogenous (inflammations, elevated neutrophil presence in the vicinity) and exogenous ROS at low and moderate levels (travels by plane, radiotherapy, space irradiation, blood banking, etc.). To study these effects, we used ROS induced by gamma radiation from low (0.2 Gy) to high (25 Gy) dose levels on PLB-985 cells from a myeloid cell line differentiated to neutrophil-like cells that are considered a good alternative to neutrophils. We determined a much longer lifetime of PLB-985 cells than that of neutrophils, which, as expected, decreased by increasing the irradiation dose. In the absence of any secondary stimulus, a very low production of ROS is detected with no significant difference between irradiated and non-irradiated cells. However, in phagocytosing cells, irradiation doses above 2 Gy enhanced oxidative burst in PLB-985 cells. Whatever the irradiation dose, NADPH oxidase devoid of its cytosolic regulatory units is observed at the plasma membrane in irradiated PLB-985 cells. This result is different from that observed for irradiated neutrophils in which irradiation also induced a translocation of regulatory subunits suggesting that the signal transduction mechanism or pathway operate differently in both cells.

2022 ◽  
pp. 41-46
N. B. Zakharova ◽  
A. N. Ponukalin ◽  
M. L. Chekhonatskaya ◽  
A. Y. Korolev ◽  
Y. M. Komyagina

The development of malignant tissue transformation is accompanied by the accumulation of immune system cells or tumor microenvironment cells (MCO) in it. Three variants of immune cell accumulation were identified: the ‘immune desert’ phenotype, ‘hot’ tumors, with a cytolytic T-cell response. The review presents immunotherapeutic strategies of exposure in order to enhance the ability of McO to initiate immune mechanisms capable of blocking the development of tumor tissue. The analysis of the presented data on the importance of immuno-oncological biomarkers as laboratory indicators of the therapeutic effectiveness of drug therapy aimed at restoring key immune defense pathways in oncourological diseases was carried out. The results of the study of the effectiveness of immuno-oncological biomarkers for assessing the state of antitumor immunity in malignant neoplasms of the bladder, kidneys, prostate gland are summarized.

2022 ◽  
Vol 12 ◽  
Ximei Liu ◽  
Jiani Liu ◽  
Kai Xiong ◽  
Caoqi Zhang ◽  
James Kar-Hei Fang ◽  

Anthropogenic elevation of atmospheric carbon dioxide (CO2) drives global-scale ocean acidification (OA), which has aroused widespread concern for marine ecosystem health. The tri-spine horseshoe crab (HSC) Tachypleus tridentatus has been facing the threat of population depletion for decades, and the effects of OA on the physiology and microbiology of its early life stage are unclear. In this study, the 1st instar HSC larvae were exposed to acidified seawater (pH 7.3, pH 8.1 as control) for 28 days to determine the effects of OA on their growth, molting, oxidative stress, and gut microbiota. Results showed that there were no significant differences in growth index and molting rate between OA group and control group, but the chitinase activity, β-NAGase activity, and ecdysone content in OA group were significantly lower than those of the control group. Compared to the control group, reactive oxygen species (ROS) and malondialdehyde (MDA) contents in OA group were significantly increased at the end of the experiment. Superoxide dismutase (SOD), catalase (CAT), and alkaline phosphatase (AKP) activities increased first and then decreased, glutathione peroxidase (GPX) decreased first and then increased, and GST activity changed little during the experiment. According to the result of 16S rRNA sequencing of gut microbiota, microbial-mediated functions predicted by PICRUSt showed that “Hematopoietic cell lineage,” “Endocytosis,” “Staphylococcus aureus infection,” and “Shigellosis” pathways significantly increased in OA group. The above results indicate that OA had no significant effect on growth index and molting rate but interfered with the activity of chitinolytic enzymes and ecdysone expression of juvenile horseshoe crabs, and caused oxidative stress. In addition, OA had adverse effects on the immune defense function and intestinal health. The present study reveals the potential threat of OA to T. tridentatus population and lays a foundation for the further study of the physiological adaptation mechanism of juvenile horseshoe crabs to environmental change.

Carlos A. Antolínez ◽  
Krzysztof Szejbak ◽  
Kerry E. Mauck ◽  
Monique J. Rivera

AbstractThe Asian citrus psyllid (ACP) Diaphorina citri (Hemiptera:Liviidae), vector of huanglongbing disease, displays a high degree of color polyphenism. In the adult stage, ACP exhibits abdominal colors that can be separated into three color groupings: blue-green, grey-brown and orange-yellow. Color morphology has been shown to influence important and energetically costly psyllid life traits including reproduction, dispersion, immune defense and resistance to insecticides. Despite this, it remains unclear how color morphology is correlated with feeding behavior. Understanding variation in feeding behavior of the ACP color morphs is critical to better understanding how ACP populations utilize host-plants and to assess potential risk for transmission of the causal agent of huanglongbing disease. We compared the feeding behavior of the three ACP color morphs by using electropenetrography (EPG). We did not detect differences in the feeding behavior activities at phloem or xylem tissues when comparing the three-color morphs. Furthermore, there were no differences in feeding behavioral parameters before reaching phloem or xylem tissues. Our results suggest energy requirements are similar between color morphs and feeding behavior parameters associated with CLas transmission are potentially similar between color morphs.

2022 ◽  
Zhiwen Qian ◽  
Tingxiang Chang ◽  
Tingting Zhang ◽  
Jing Wang ◽  
Hanming Gu

Zinc finger with KRAB and SCAN domain 3 (ZKSCAN3) is associated with cell differentiation, cell proliferation and apoptosis, which has been reported as a critical driver of colorectal cancer. However, the mechanism and function of ZKSCAN3 in colorectal cancer is still unclear. Here, our objective is to identify the functional molecules and signaling by analyzing the RNA-seq data. The GSE172201 was created by the Illumina NovaSeq 6000 (Homo sapiens). The KEGG and GO analyses indicated the immune defense response to virus and transcription activity are major processes in the ZKSCAN3 KO colorectal cancer cells. Moreover, we determined ten key molecules including STAT1, MX1, DDX58, PPARG, EGFR, APP, BST2, DLG4, OASL, and IFIT2. Therefore, our study may provide the novel knowledge of ZKSCAN3 mediated colorectal cancer.

2021 ◽  
Wei Li ◽  
Fahim Syed ◽  
Richard X Yu ◽  
Jing Yang ◽  
Ying Xia ◽  

Immune checkpoints (ICPs) consist of paired receptor-ligand molecules that exert inhibitory or stimulatory effects on immune defense, surveillance, regulation, and self-tolerance. ICPs exist in both membrane and soluble forms in vivo and in vitro. Imbalances between inhibitory and stimulatory membrane-bound ICPs (mICPs) in malignant cells and immune cells in the tumor immune microenvironment (TIME) have been well documented. Blockades of inhibitory mICPs have emerged as an immense breakthrough in cancer therapeutics. However, the origin, structure, production regulation, and biological significance of soluble ICPs (sICPs) in health and disease largely remains elusive. Soluble ICPs can be generated through either alternative mRNA splicing and secretion or protease-mediated shedding from mICPs. Since sICPs are found in the bloodstream, they likely form a circulating immune regulatory system. In fact, there is increasing evidence that sICPs exhibit biological functions including (1) regulation of antibacterial immunity, (2) interaction with their mICP compartments to positively or negatively regulate immune responses, and (3) competition with their mICP compartments for binding to the ICP blocking antibodies, thereby reducing the efficacy of ICP blockade therapies. Here, we summarize current data of sICPs in cancer and infectious diseases. We particularly focus on sICPs in COVID-19 and HIV infection as they are the two ongoing global pandemics and have created the world's most serious public health challenges. A storm of sICPs occurs in the peripheral circulation of COVID-19 patients and is associated with the severity of COVID-19. Similarly, sICPs are highly dysregulated in people living with HIV (PLHIV) and some sICPs remain dysregulated in PLHIV on antiretroviral therapy (ART), indicating these sICPs may serve as biomarkers of incomplete immune reconstitution in PLHIV on ART. We reveal that HIV infection in the setting of alcohol abuse exacerbates sICP dysregulation as PLHIV with heavy alcohol consumption have significantly elevated plasma levels of many sICPs. Thus, both stimulatory and inhibitory sICPs are present in the bloodstream of healthy people and their balance can be disrupted under pathophysiological conditions such as cancer, COVID-19, HIV infection, and alcohol abuse. There is an urgent need to study the role of sICPs in immune regulation in health and disease.

2021 ◽  
Vol 23 (1) ◽  
pp. 382
Tingting Zhu ◽  
Han Liu ◽  
Li Su ◽  
Ali Dawood ◽  
Changmin Hu ◽  

Although Mycobacterium tuberculosis (MTB) has existed for thousands of years, its immune escape mechanism remains obscure. Increasing evidence signifies that microRNAs (miRNAs) play pivotal roles in the progression of tuberculosis (TB). RNA sequencing was used to sequence miRNAs in human acute monocytic leukemia cells (THP-1) infected by the virulent MTB-1458 strain and the avirulent vaccine strain Mycobacterium bovis Bacillus Calmette-Guérin (BCG). Sets of differentially expressed miRNAs (DE-miRNAs) between MTB-1458/BCG-infected groups and uninfected groups were identified, among which 18 were differentially expressed only in the MTB-1458-infected THP-1 group. Then, 13 transcription factors (TFs) and 81 target genes of these 18 DE-miRNAs were matched. Gene Ontology classification as well as Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the candidate targets were predominantly involved in apoptotic-associated and interferon-γ-mediated signaling pathways. A TF-miRNA-mRNA interaction network was constructed to analyze the relationships among these 18 DE-miRNAs and their targets and TFs, as well as display the hub miRNAs, TFs, and target genes. Considering the degrees from network analysis and the reported functions, this study focused on the BHLHE40-miR-378d-BHLHE40 regulation axis and confirmed that BHLHE40 was a target of miR-378d. This cross-talk among DE-miRNAs, mRNAs, and TFs might be an important feature in TB, and the findings merited further study and provided new insights into immune defense and evasion underlying host-pathogen interactions.

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