2B4 (CD244) Is Expressed and Functional on Human Eosinophils

Department of Pharmacology, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel.
The Journal of Immunology (Impact Factor: 4.92). 02/2005; 174(1):110-8. DOI: 10.4049/jimmunol.174.1.110
Source: PubMed


Eosinophils are present in parasitic, allergic, various immunological, and malignant disorders as well as in a variety of idiopathic hypereosinophilic syndromes. However, their exact role in some of these conditions remains elusive. They can be activated both in vivo and in vitro by various agonists, such as Igs, lipid mediators, and cytokines. By phenotyping the surface of the eosinophils, it may be possible to better define their function(s) in different pathophysiological settings. In the present work we screened eosinophils with a panel of Abs recognizing CD2 subfamily receptors usually present on a number of hemopoietic cells. We have demonstrated that human peripheral blood eosinophils, but not basophils or neutrophils, express NTB-A. In addition eosinophils express 2B4, CD84, CD58, and CD48, but not signaling lymphocytic activation molecule or CD2, on their surface (FACS). Cross-linking of 2B4 on eosinophils elicited a significant release of eosinophil peroxidase (30 min), IFN-gamma, and IL-4 (18 h). Moreover, activation of eosinophils via 2B4 induced eosinophil-mediated cytotoxicity toward two malignant cell lines, i.e., mouse mastocytoma P815 and EBV-infected 721.221 B cell lines. Cross-linking of 2B4 on the surface of eosinophils or pervenadate treatment elicited ERK and tyrosine phosphorylation, respectively. Furthermore, we showed that eosinophils express slam-associated protein. The demonstration that human eosinophils express a functional 2B4 receptor indicates a broader role for these cells in health and disease.

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Available from: Ariel Munitz, Oct 07, 2015
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    • "Costimulatory molecules including ICAM-1 and LFA-3 [39] have been shown to assist in antigen presentation by eosinophils lacking conventional costimulatory molecules [31]. There are two reports supporting LFA-3 expression by human basophils [40]-[41], but the results from our peptide assay suggest that this costimulatory molecule expression (if present) together with MHC Class II is not sufficient to induce T cell activation/proliferation to peptide. "
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    ABSTRACT: The antigen-presenting abilities of basophils and their role in initiating a Th2 phenotype is a topic of current controversy. We aimed to determine whether human basophils can be induced to express MHC Class II and act as antigen presenting cells for T cell stimulation. Isolated human basophils were exposed to a panel of cytokines and TLR-ligands and assessed for MHC Class II expression. MHC Class II was expressed in up to 17% of isolated basophils following incubation with a combination of IL-3, IFN-γ and GM-CSF for 72 hours. Costimulatory molecules (CD80 and CD86) were expressed at very low levels after stimulation. Gene expression analysis of MHC Class II-positive basophils confirmed up-regulation of HLA-DR, HLA-DM, CD74 and Cathepsin S. However, MHC Class II expressing basophils were incapable of inducing antigen-specific T cell activation or proliferation. This is the first report of significant cytokine-induced MHC Class II up-regulation, at both RNA and protein level, in isolated human basophils. By testing stimulation with relevant T cell epitope peptide as well as whole antigen, the failure of MHC Class II expressing basophils to induce T cell response was shown not to be solely due to inefficient antigen uptake and/or processing.
    PLoS ONE 12/2013; 8(12):e81777. DOI:10.1371/journal.pone.0081777 · 3.23 Impact Factor
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    • "To understand how Fyn binding might promote 2B4 function, we analyzed tyrosine phosphorylation of Vav-1 and SHIP-1, the two most prominent tyrosine phosphorylation substrates triggered by 2B4 (Figures 2D and 2E; Chen et al., 2004; Mesecke et al., 2011; Munitz et al., 2005). Vav-1 is an exchange factor promoting multiple functions in immune cells, including "
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    ABSTRACT: The adaptor SAP, mutated in X-linked lymphoproliferative disease, has critical roles in multiple immune cell types. Among these, SAP is essential for the ability of natural killer (NK) cells to eliminate abnormal hematopoietic cells. Herein, we elucidated the molecular and cellular bases of this activity. SAP enhanced NK cell responsiveness by a dual molecular mechanism. It coupled SLAM family receptors to the kinase Fyn, which triggered the exchange factor Vav-1 and augmented NK cell activation. SAP also prevented the inhibitory function of SLAM family receptors. This effect was Fyn independent and correlated with uncoupling of SLAM family receptors from the lipid phosphatase SHIP-1. Both mechanisms cooperated to enable conjugate formation with target cells and to stimulate cytotoxicity and cytokine secretion by NK cells. These data showed that SAP secures NK cell activation by a dichotomous molecular mechanism, which is required for conjugate formation. These findings may have implications for the role of SAP in other immune cell types.
    Immunity 06/2012; 36(6):974-85. DOI:10.1016/j.immuni.2012.03.023 · 21.56 Impact Factor
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    • "Eosinophils have been associated with many tumors in vivo. Furthermore, both γδ T cells [41] and eosinophils [19] exert potent cytotoxic activity towards many tumor cells. Therefore, we investigated γδTCR-mediated eosinophil cytotoxicity towards Colo-205 carcinoma cell line. "
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    ABSTRACT: Eosinophils are effector cells during parasitic infections and allergic responses. However, their contribution to innate immunity has been only recently unravelled. Here we show that human eosinophils express CD3 and gammadelta T Cell Receptor (TCR) but not alphabeta TCR. Surface expression of gammadeltaTCR/CD3 is heterogeneous between eosinophil donors and inducible by mycobacterial ligands. Surface immunoprecipitation revealed expression of the full gammadeltaTCR/CD3 complex. Real-time PCR amplification for CD3, gamma and delta TCR constant regions transcripts showed a significantly lower expression in eosinophils than in gammadeltaT cells. Limited TCR rearrangements occur in eosinophils as shown by spectratyping analysis of CDR3 length profiles and in situ hybridization. Release by eosinophils of Reactive Oxygen Species, granule proteins, Eosinophil Peroxidase and Eosinophil-Derived Neurotoxin and cytokines (IFN-gamma and TNF-alpha) was observed following activation by gammadeltaTCR-specific agonists or by mycobacteria. These effects were inhibited by anti-gammadeltaTCR blocking antibodies and antagonists. Moreover, gammadeltaTCR/CD3 was involved in eosinophil cytotoxicity against tumor cells. Our results provide evidence that human eosinophils express a functional gammadeltaTCR/CD3 with similar, but not identical, characteristics to gammadeltaTCR from gammadeltaT cells. We propose that this receptor contributes to eosinophil innate responses against mycobacteria and tumors and may represent an additional link between lymphoid and myeloid lineages.
    PLoS ONE 02/2009; 4(6):e5926. DOI:10.1371/journal.pone.0005926 · 3.23 Impact Factor
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