The Role of Eosinophil Chemokine Receptors in Allergic Inflammation in Vivo

1998 ◽  
Vol 95 (s39) ◽  
pp. 13P-13P
Author(s):  
I Sabroe ◽  
A Hartnell ◽  
D Conroy ◽  
PD Collins ◽  
NP Gerard ◽  
...  
Author(s):  
Tiziana Schioppa ◽  
Francesca Sozio ◽  
Ilaria Barbazza ◽  
Sara Scutera ◽  
Daniela Bosisio ◽  
...  

CCRL2 is a seven-transmembrane domain receptor that belongs to the chemokine receptor family. At difference from other members of this family, CCRL2 does not promote chemotaxis and shares structural features with atypical chemokine receptors (ACKRs). However, CCRL2 also differs from ACKRs since it does not bind chemokines and is devoid of scavenging functions. The only commonly recognized CCRL2 ligand is chemerin, a non-chemokine chemotactic protein. CCRL2 is expressed both by leukocytes and non-hematopoietic cells. The genetic ablation of CCRL2 has been instrumental to elucidate the role of this receptor as positive or negative regulator of inflammation. CCRL2 modulates leukocyte migration by two main mechanisms. First, when CCRL2 is expressed by barrier cells, such endothelial, and epithelial cells, it acts as a presenting molecule, contributing to the formation of a non-soluble chemotactic gradient for leukocytes expressing CMKLR1, the functional chemerin receptor. This mechanism was shown to be crucial in the induction of NK cell-dependent immune surveillance in lung cancer progression and metastasis. Second, by forming heterocomplexes with other chemokine receptors. For instance, CCRL2/CXCR2 heterodimers were shown to regulate the activation of β2-integrins in mouse neutrophils. This mini-review summarizes the current understanding of CCRL2 biology, based on experimental evidence obtained by the genetic deletion of this receptor in in vivo experimental models. Further studies are required to highlight the complex functional role of CCRL2 in different organs and pathological conditions.


Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5174
Author(s):  
Santosh R. Alluri ◽  
Yusuke Higashi ◽  
Kun-Eek Kil

Chemokines and chemokine receptors have been recognized as critical signal components that maintain the physiological functions of various cells, particularly the immune cells. The signals of chemokines/chemokine receptors guide various leukocytes to respond to inflammatory reactions and infectious agents. Many chemokine receptors play supportive roles in the differentiation, proliferation, angiogenesis, and metastasis of diverse tumor cells. In addition, the signaling functions of a few chemokine receptors are associated with cardiac, pulmonary, and brain disorders. Over the years, numerous promising molecules ranging from small molecules to short peptides and antibodies have been developed to study the role of chemokine receptors in healthy states and diseased states. These drug-like candidates are in turn exploited as radiolabeled probes for the imaging of chemokine receptors using noninvasive in vivo imaging, such as positron emission tomography (PET). Recent advances in the development of radiotracers for various chemokine receptors, particularly of CXCR4, CCR2, and CCR5, shed new light on chemokine-related cancer and cardiovascular research and the subsequent drug development. Here, we present the recent progress in PET radiotracer development for imaging of various chemokine receptors.


2019 ◽  
Vol 12 (576) ◽  
pp. eaav2060 ◽  
Author(s):  
Soichiro Yoshikawa ◽  
Masatsugu Oh-hora ◽  
Ryota Hashimoto ◽  
Toshihisa Nagao ◽  
Louis Peters ◽  
...  

Basophils have nonredundant roles in various immune responses that require Ca2+influx. Here, we examined the role of two Ca2+sensors, stromal interaction molecule 1 and 2 (STIM1 and STIM2), in basophil activation. We found that loss of STIM1, but not STIM2, impaired basophil IL-4 production after stimulation with immunoglobulin E (IgE)–containing immune complexes. In contrast, when basophils were stimulated with IL-3, loss of STIM2, but not STIM1, reduced basophil IL-4 production. This difference in STIM proteins was associated with distinct time courses of Ca2+influx and transcription of theIl4gene that were elicited by each stimulus. Similarly, basophil-specific STIM1 expression was required for IgE-driven chronic allergic inflammation in vivo, whereas STIM2 was required for IL-4 production after combined IL-3 and IL-33 treatment in mice. These data indicate that STIM1 and STIM2 have differential roles in the production of IL-4, which are stimulus dependent. Furthermore, these results illustrate the vital role of STIM2 in basophils, which is often considered to be less important than STIM1.


2019 ◽  
Vol 316 (1) ◽  
pp. L269-L279 ◽  
Author(s):  
Tianwen Lai ◽  
Mindan Wu ◽  
Chao Zhang ◽  
Luanqing Che ◽  
Feng Xu ◽  
...  

Histone deacetylase (HDAC)2 is expressed in airway epithelium and plays a pivotal role in inflammatory cells. However, the role of HDAC2 in allergic airway inflammation remains poorly understood. In the present study, we determined the role of HDAC2 in airway inflammation using in vivo models of house dust mite (HDM)-induced allergic inflammation and in vitro cultures of human bronchial epithelial (HBE) cells exposed to HDM, IL-17A, or both. We observed that HDM-challenged Hdac2+/− mice exhibited substantially enhanced infiltration of inflammatory cells. Higher levels of T helper 2 cytokines and IL-17A expression were found in lung tissues of HDM-challenged Hdac2+/− mice. Interestingly, IL-17A deletion or anti-IL-17A treatment reversed the enhanced airway inflammation induced by HDAC2 impairment. In vitro, HDM and IL-17A synergistically decreased HDAC2 expression in HBE cells. HDAC2 gene silencing further enhanced HDM- and/or IL-17A-induced inflammatory cytokines in HBE cells. HDAC2 overexpresion or blocking IL-17A gene expression restored the enhanced inflammatory cytokines. Collectively, these results support a protective role of HDAC2 in HDM-induced airway inflammation by suppressing IL-17A production and might suggest that activation of HDAC2 and/or inhibition of IL-17A production could prevent the development of allergic airway inflammation.


2003 ◽  
Vol 77 (11) ◽  
pp. 6138-6152 ◽  
Author(s):  
Samantha J. Willey ◽  
Jacqueline D. Reeves ◽  
Richard Hudson ◽  
Koichi Miyake ◽  
Nathalie Dejucq ◽  
...  

ABSTRACT The chemokine receptors CCR5 and CXCR4 are the major coreceptors for human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). At least 12 other chemokine receptors or close relatives support infection by particular HIV and SIV strains on CD4+ transformed indicator cell lines in vitro. However, the role of these alternative coreceptors in vivo is presently thought to be insignificant. Infection of cell lines expressing high levels of recombinant CD4 and coreceptors thus does not provide a true indication of coreceptor use in vivo. We therefore tested primary untransformed cell cultures that lack CCR5 and CXCR4, including astrocytes and brain microvascular endothelial cells (BMVECs), for naturally expressed alternative coreceptors functional for HIV and SIV infection. An adenovirus vector (Ad-CD4) was used to express CD4 in CD4− astrocytes and thus confer efficient infection if a functional coreceptor is present. Using a large panel of viruses with well-defined coreceptor usage, we identified a subset of HIV and SIV strains able to infect two astrocyte cultures derived from adult brain tissue. Astrocyte infection was partially inhibited by several chemokines, indicating a role for the chemokine receptor family in the observed infection. BMVECs were weakly positive for CD4 but negative for CCR5 and CXCR4 and were susceptible to infection by the same subset of isolates that infected astrocytes. BMVEC infection was efficiently inhibited by the chemokine vMIP-I, implicating one of its receptors as an alternative coreceptor for HIV and SIV infection. Furthermore, we tested whether the HIV type 1 and type 2 strains identified were able to infect peripheral blood mononuclear cells (PBMCs) via an alternative coreceptor. Several strains replicated in Δ32/Δ32 CCR5 PBMCs with CXCR4 blocked by AMD3100. This AMD3100-resistant replication was also sensitive to vMIP-I inhibition. The nature and potential role of this alternative coreceptor(s) in HIV infection in vivo is discussed.


2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Wai Y. Sun ◽  
Claudine S. Bonder

Allergic inflammation is an immune response to foreign antigens, which begins within minutes of exposure to the allergen followed by a late phase leading to chronic inflammation. Prolonged allergic inflammation manifests in diseases such as urticaria and rhino-conjunctivitis, as well as chronic asthma and life-threatening anaphylaxis. The prevalence of allergic diseases is profound with 25% of the worldwide population affected and a rising trend across all ages, gender, and racial groups. The identification and avoidance of allergens can manage this disease, but this is not always possible with triggers being common foods, prevalent air-borne particles and only extremely low levels of allergen exposure required for sensitization. Patients who are sensitive to multiple allergens require prophylactic and symptomatic treatments. Current treatments are often suboptimal and associated with adverse effects, such as the interruption of cognition, sleep cycles, and endocrine homeostasis, all of which affect quality of life and are a financial burden to society. Clearly, a better therapeutic approach for allergic diseases is required. Herein, we review the current knowledge of allergic inflammation and discuss the role of sphingolipids as potential targets to regulate inflammatory development in vivo and in humans. We also discuss the benefits and risks of using sphingolipid inhibitors.


Blood ◽  
1999 ◽  
Vol 93 (2) ◽  
pp. 694-702
Author(s):  
Holger Petering ◽  
Otto Götze ◽  
Daniela Kimmig ◽  
Regina Smolarski ◽  
Alexander Kapp ◽  
...  

Chemokines play an important role in attracting granulocytes into sites of inflammation. Two chemokine subfamilies differ in their biologic activity for different granulocyte subsets. Whereas CXC chemokines such as interleukin-8 (IL-8) activate predominantly neutrophils, CC chemokines such as RANTES and eotaxin activate predominantly eosinophils. However, controversial results have been published in the past regarding the biologic role of IL-8 in eosinophil activation, particularly in allergic diseases. In this study, we investigated the functional evidence and expression of both IL-8 receptors, CXCR1 and CXCR2, on highly purified human eosinophils. In the first set of experiments, a chemotaxis assay was performed showing that IL-8 did not induce chemotaxis of eosinophils. In addition, and in contrast to neutrophils and lymphocytes, IL-8 did not induce a rapid and transient release of cytosolic free Ca2+([Ca2+]i) in eosinophils, even after preincubation with TH1- and TH2-like cytokines. To investigate whether neutrophil contamination might be responsible for the reported IL-8 effects on eosinophils, neutrophils were added to highly purified eosinophils from the same donor in different concentrations. Interestingly, as little as 5% of neutrophil contamination was sufficient to induce an increase of [Ca2+]iafter stimulation with IL-8. Flow cytometry experiments with monoclonal antibodies against both IL-8 receptors demonstrated no expression of CXCR1 and CXCR2 on eosinophils before or after cytokine activation. Reverse transcriptase-polymerase chain reaction experiments showed that eosinophils, in contrast to neutrophils and lymphocytes, did not express mRNA for CXCR1 and CXCR2. In summary, this study clearly demonstrates that CXCR1 and CXCR2 are not expressed on human eosinophils, even after priming with different bioactive cytokines. Because the CXC chemokine IL-8 did not induce in vitro effects on human eosinophils, IL-8 may also not contribute in vivo to the influx of eosinophil granulocytes into sites of allergic inflammation. Our results suggest that CC chemokines such as eotaxin, eotaxin-2, and MCP-4 are predominant for the activation of eosinophils.


2006 ◽  
Vol 176 (3) ◽  
pp. 1326-1330 ◽  
Author(s):  
Fabio P. Mesquita-Santos ◽  
Adriana Vieira-de-Abreu ◽  
Andrea S. Calheiros ◽  
Isabela H. Figueiredo ◽  
Hugo C. Castro-Faria-Neto ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Peng Gao ◽  
Zhenzhong Su ◽  
Xuejiao Lv ◽  
Jie Zhang

Interleukin- (IL-) 35 is a member of the IL-12 cytokine family and a heterodimeric protein formed by Epstein-Barr-induced gene 3 (EBI3) and IL-12p35. Emerging evidence shows that IL-35 is a key player in the regulation of cellular communication, differentiation, and inflammation. Altered IL-35 expression has been found in disease conditions such as cancer, rheumatoid arthritis, and, more recently, asthma. In cancer, IL-35 is involved in the regulation of tumorigenesis, cancer progression, and metastasis. In rheumatoid arthritis, IL-35 acts as a negative regulator of inflammation. Similarly, IL-35 also appears to suppress allergic inflammation in asthma. In an in vivo murine model of asthma, transfer of adenovirus-mediated IL-35 markedly reduced the degree of airway hyperresponsiveness (AHR) and inflammatory cell infiltration. Many studies have shown the involvement of IL-35 in a number of aspects of allergic inflammation, such as eosinophil and neutrophil recruitment as well as inhibition of inflammatory mediators of the Th2 subtype. However, the exact molecular mechanisms underlying the role of IL-35 in human asthma have yet to be fully elucidated. This review describes the current evidence regarding the role of IL-35 in the pathophysiology of asthma and evaluates the potential of IL-35 as a biomarker for airway inflammation and a therapeutic target for the treatment of asthma.


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