scholarly journals Dendritic Cells: Behind the Scenes of T-Cell Infiltration into the Tumor Microenvironment

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 433
Author(s):  
Valeria Lucarini ◽  
Ombretta Melaiu ◽  
Patrizia Tempora ◽  
Silvia D’Amico ◽  
Franco Locatelli ◽  
...  

Tumor-infiltrating CD8+ T cells have been shown to play a crucial role in controlling tumor progression. However, the recruitment and activation of these immune cells at the tumor site are strictly dependent on several factors, including the presence of dendritic cells (DCs), the main orchestrators of the antitumor immune responses. Among the various DC subsets, the role of cDC1s has been demonstrated in several preclinical experimental mouse models. In addition, the high density of tumor-infiltrating cDC1s has been associated with improved survival in many cancer patients. The ability of cDC1s to modulate antitumor activity depends on their interaction with other immune populations, such as NK cells. This evidence has led to the development of new strategies aimed at increasing the abundance and activity of cDC1s in tumors, thus providing attractive new avenues to enhance antitumor immunity for both established and novel anticancer immunotherapies. In this review, we provide an overview of the various subsets of DCs, focusing in particular on the role of cDC1s, their ability to interact with other intratumoral immune cells, and their prognostic significance on solid tumors. Finally, we outline key therapeutic strategies that promote the immunogenic functions of DCs in cancer immunotherapy.

2021 ◽  
Vol 22 (13) ◽  
pp. 7227
Author(s):  
Lai-San Wong ◽  
Yu-Ta Yen ◽  
Chih-Hung Lee

Atopic dermatitis (AD) is a prototypic inflammatory disease that presents with intense itching. The pathophysiology of AD is multifactorial, involving environmental factors, genetic susceptibility, skin barrier function, and immune responses. A recent understanding of pruritus transmission provides more information about the role of pruritogens in the pathogenesis of AD. There is evidence that pruritogens are not only responsible for eliciting pruritus, but also interact with immune cells and act as inflammatory mediators, which exacerbate the severity of AD. In this review, we discuss the interaction between pruritogens and inflammatory molecules and summarize the targeted therapies for AD.


Author(s):  
Sebastian Wawrocki ◽  
Magdalena Druszczynska

The development of effective innate and subsequent adaptive host immune responses is highly dependent on the production of proinflammatory cytokines that increase the activity of immune cells. The key role in this process is played by inflammasomes, multimeric protein complexes serving as a platform for caspase-1, an enzyme responsible for proteolytic cleavage of IL-1βand IL-18 precursors. Inflammasome activation, which triggers the multifaceted activity of these two proinflammatory cytokines, is a prerequisite for developing an efficient inflammatory response against pathogenicMycobacterium tuberculosis(M.tb). This review focuses on the role of NLRP3 and AIM2 inflammasomes inM.tb-driven immunity.


Blood ◽  
2009 ◽  
Vol 113 (1) ◽  
pp. 46-57 ◽  
Author(s):  
Bin Zhang ◽  
Rui Liu ◽  
Dan Shi ◽  
Xingxia Liu ◽  
Yuan Chen ◽  
...  

Abstract Mesenchymal stem cells (MSCs), in addition to their multilineage differentiation, exert immunomodulatory effects on immune cells, even dendritic cells (DCs). However, whether they influence the destiny of full mature DCs (maDCs) remains controversial. Here we report that MSCs vigorously promote proliferation of maDCs, significantly reduce their expression of Ia, CD11c, CD80, CD86, and CD40 while increasing CD11b expression. Interestingly, though these phenotypes clearly suggest their skew to immature status, bacterial lipopolysaccharide (LPS) stimulation could not reverse this trend. Moreover, high endocytosic capacity, low immunogenicity, and strong immunoregulatory function of MSC-treated maDCs (MSC-DCs) were also observed. Furthermore we found that MSCs, partly via cell-cell contact, drive maDCs to differentiate into a novel Jagged-2–dependent regulatory DC population and escape their apoptotic fate. These results further support the role of MSCs in preventing rejection in organ transplantation and treatment of autoimmune disease.


Blood ◽  
2010 ◽  
Vol 116 (26) ◽  
pp. 5875-5884 ◽  
Author(s):  
Hideaki Tanizaki ◽  
Gyohei Egawa ◽  
Kayo Inaba ◽  
Tetsuya Honda ◽  
Saeko Nakajima ◽  
...  

Abstract Dendritic cells (DCs) are essential for the initiation of acquired immune responses through antigen acquisition, migration, maturation, and T-cell stimulation. One of the critical mechanisms in this response is the process actin nucleation and polymerization, which is mediated by several groups of proteins, including mammalian Diaphanous-related formins (mDia). However, the role of mDia in DCs remains unknown. Herein, we examined the role of mDia1 (one of the isoforms of mDia) in DCs. Although the proliferation and maturation of bone marrow-derived DCs were comparable between control C57BL/6 and mDia1-deficient (mDia1−/−) mice, adhesion and spreading to cellular matrix were impaired in mDia1−/− bone marrow–derived DCs. In addition, fluorescein isothiocyanate-induced cutaneous DC migration to draining lymph nodes in vivo and invasive migration and directional migration to CCL21 in vitro were suppressed in mDia1−/− DCs. Moreover, sustained T-cell interaction and T-cell stimulation in lymph nodes were impaired by mDia1 deficiency. Consistent with this, the DC-dependent delayed hypersensitivity response was attenuated by mDia1-deficient DCs. These results suggest that actin polymerization, which is mediated by mDia1, is essential for several aspects of DC-initiated acquired immune responses.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chiel van Geffen ◽  
Astrid Deißler ◽  
Markus Quante ◽  
Harald Renz ◽  
Dominik Hartl ◽  
...  

The immune system is receiving increasing attention for interstitial lung diseases, as knowledge on its role in fibrosis development and response to therapies is expanding. Uncontrolled immune responses and unbalanced injury-inflammation-repair processes drive the initiation and progression of idiopathic pulmonary fibrosis. The regulatory immune system plays important roles in controlling pathogenic immune responses, regulating inflammation and modulating the transition of inflammation to fibrosis. This review aims to summarize and critically discuss the current knowledge on the potential role of regulatory immune cells, including mesenchymal stromal/stem cells, regulatory T cells, regulatory B cells, macrophages, dendritic cells and myeloid-derived suppressor cells in idiopathic pulmonary fibrosis. Furthermore, we review the emerging role of regulatory immune cells in anti-fibrotic therapy and lung transplantation. A comprehensive understanding of immune regulation could pave the way towards new therapeutic or preventive approaches in idiopathic pulmonary fibrosis.


2020 ◽  
Author(s):  
Jing Wu ◽  
Hang Cheng ◽  
Tete Li ◽  
Helei Wang ◽  
Guoxia Zang ◽  
...  

Abstract Background: Innate lymphoid cells (ILCs), so far studied mostly in mouse models, are important tissue-resident innate immune cells that play important roles in the colorectal cancer microenvironment and maintain the mucosal tissue homeostasis. Plasmacytoid dendritic cells (pDCs) present complexity in various tumour types and are correlated with poor prognosis. pDCs can promote HIV-1–induced group 3 ILC (ILC3) depletion through the CD95 pathway. However, the role of ILC3s in human colon cancer and their correlation with other immune cells, especially pDCs, remain unclear. Methods: We characterised ILCs and pDCs in the tumour microenvironment of 58 colon cancer patients by flow cytometry and selected three patients for RNA sequencing. Results: ILC3s were negatively correlated, and pDCs were positively correlated, with cancer pathological grade. There was a negative correlation between the numbers of ILC3s and pDCs in tumour tissues. RNA sequencing confirmed the correlations between ILC3s and pDCs and highlighted the potential function of many ILC- and pDC-associated differentially expressed genes in the regulation of tumour immunity. pDCs can induce apoptosis of ILC3s through the CD95 pathway in the tumour microenvironment. Conclusions: One of the interactions between ILC3s and pDCs is via the CD95 pathway, which may help explain the role of ILC3s in colon cancer.


2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A13.2-A14
Author(s):  
L Li ◽  
V Mussack ◽  
E Pepeldjiyska ◽  
A Hartz ◽  
A Rank ◽  
...  

BackgroundAntileukemic responses of immune reactive cells in AML-patients need to be improved. Combinations of blast-modulatory kitM (GM-CSF+PGE1) (vs control) convert myeloid blasts into dendritic cells of leukemic origin (DCleu), that effectively activate immune-cells against leukemic blasts. Exosomes are small (30–150 nm) membranous vesicles of endocytic origin produced by all cells under physiological and pathological conditions. Their involvement in nearly all aspects of malignant transformation has generated much interest in their biology, mechanisms responsible for information transfer and their role in immune-surveillance as well as -escape.Exosomes secreted by dendritic cells (DCs) have been shown to allow efficient activation of T lymphocytes, displaying potential as promoters of adaptive immune responses.Materials and Methods1)DC/DCleu-culture of blast containing AML patients’ whole blood (WB) (n=10) and of healthy volunteers(n=8) with kits, T-cell enriched mixed lymphocyte culture (MLC) with kit- vs un-treated WB, functional blast-cytotoxicity and, leukemia-specificity assays (Degranulation/intracellular cytokine-assays), Flowcytometric evaluation of blast-,DC- and lymphocyte composition before or after cultures. 2)Exosomes were isolated by immunoaffinity from serum, DC- and MLC-culture supernatants of 3 AML patients and 3 healthy volunteers. Exosomes were negatively stained and characterized by transmission electron microscopy (TEM). Fluorescence nanoparticle tracking analysis (fNTA) was performed to determine exosomal size and -concentration. Obtained results were compared in AML and healthy volunteers.ResultsAddition of kitM to blast-containing WB significantly increased frequencies of mature DC/DCleu and their subtypes compared to untreated WB without induction of blasts’ proliferation. Immune monitoring showed a continuous increase ofactivated/proliferating cells of the adaptive and innate immune system after Tcell-enriched MLC using kitM pretreated vs -untreated WB, suggesting a production/activation of (potentially leukemia-specific) cells after kit-stimulation. Moreover kit-pretreated WB regularly and significantly improved provision, activation as well as antileukemic and leukemia-specifically directed immune reactive cells after MLC. TEM showed exosome-like structures with a typically cup-shaped appearance without any differences between healthy and AML samples. fNTA revealed average vesicle sizes of 177±23 nm (healthy) and 178±17 nm (AML). Higher levels of EVs were detectable in AML samples compared to healthy controls in serum and after DC-culture, but lower levels after MLC independent of culture conditions.Interestingly, the number of EVs increased during cultivation of DC of AML and healthy samples, but not in AML-derived MLC samples.ConclusionsWe will provide data in AML patients and healthy volunteers about a potential role of DCs- and MLC-derived exosomes as biomarkers in immune responses, malignant progression or as potential therapeutic targets for AML patients.Disclosure InformationL. li: None. V. Mussack: None. E. Pepeldjiyska: None. A. Hartz: None. A. Rank: None. C. Schmid: None. E. Özkaya: None. S. Ugur: None. M. Pfaffl: None. H. Schmetzer: None.


Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3044 ◽  
Author(s):  
Peter Kok-Ting Wan ◽  
Michelle Kwan-Yee Siu ◽  
Thomas Ho-Yin Leung ◽  
Xue-Tang Mo ◽  
Karen Kar-Loen Chan ◽  
...  

Nuclear receptor related-1 protein (Nurr1), coded by an early response gene, is involved in multiple cellular and physiological functions, including proliferation, survival, and self-renewal. Dysregulation of Nurr1 has been frequently observed in many cancers and is attributed to multiple transcriptional and post-transcriptional mechanisms. Besides, Nurr1 exhibits extensive crosstalk with many oncogenic and tumor suppressor molecules, which contribute to its potential pro-malignant behaviors. Furthermore, Nurr1 is a key player in attenuating antitumor immune responses. It not only potentiates immunosuppressive functions of regulatory T cells but also dampens the activity of cytotoxic T cells. The selective accessibility of chromatin by Nurr1 in T cells is closely associated with cell exhaustion and poor efficacy of cancer immunotherapy. In this review, we summarize the reported findings of Nurr1 in different malignancies, the mechanisms that regulate Nurr1 expression, and the downstream signaling pathways that Nurr1 employs to promote a wide range of malignant phenotypes. We also give an overview of the association between Nurr1 and antitumor immunity and discuss the inhibition of Nurr1 as a potential immunotherapeutic strategy.


Metabolites ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 372 ◽  
Author(s):  
Karl J. Harber ◽  
Kyra E. de Goede ◽  
Sanne G. S. Verberk ◽  
Elisa Meinster ◽  
Helga E. de Vries ◽  
...  

Immunometabolism revealed the crucial role of cellular metabolism in controlling immune cell phenotype and functions. Macrophages, key immune cells that support progression of numerous inflammatory diseases, have been well described as undergoing vast metabolic rewiring upon activation. The immunometabolite succinate particularly gained a lot of attention and emerged as a crucial regulator of macrophage responses and inflammation. Succinate was originally described as a metabolite that supports inflammation via distinct routes. Recently, studies have indicated that succinate and its receptor SUCNR1 can suppress immune responses as well. These apparent contradictory effects might be due to specific experimental settings and particularly the use of distinct succinate forms. We therefore compared the phenotypic and functional effects of distinct succinate forms and receptor mouse models that were previously used for studying succinate immunomodulation. Here, we show that succinate can suppress secretion of inflammatory mediators IL-6, tumor necrosis factor (TNF) and nitric oxide (NO), as well as inhibit Il1b mRNA expression of inflammatory macrophages in a SUCNR1-independent manner. We also observed that macrophage SUCNR1 deficiency led to an enhanced inflammatory response without addition of exogenous succinate. While our study does not reveal new mechanistic insights into how succinate elicits different inflammatory responses, it does indicate that the inflammatory effects of succinate and its receptor SUCNR1 in macrophages are clearly context dependent.


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