Human and Mouse Mast Cells Express and Secrete the GPI-Anchored Isoform of CD160

CD160 is expressed by human and mouse natural killer (NK) cells and other cytotoxic lymphocyte subpopulations. CD160 is mostly expressed as a trimeric 83kDa glycosylphosphatidylinositol (GPI)-anchored activating NK receptor, cleaved upon IL-15 stimulation in a secreted trimeric soluble form (sCD160) that binds to major histocompatibility complex (MHC) class I molecules, while a transmembrane isoform appears. sCD160 exhibits immunoregulatory function as it inhibits CD8+ T-lymphocyte cytotoxic activity. We show that human mast cells (MCs) express CD160. In human and mouse skin, resident MCs expressed CD160, whereas in C57BL/6-KitW-sh/W-sh mice, CD160+ cells were only identified at the site of reconstitution with syngeneic cultured MCs. In the human mast cell line, HMC-1, we only identified the transcripts of the GPI-anchored CD160 isoform. Furthermore, CD160 was identified in HMC-1 and mouse MC supernatants, suggesting that MCs release sCD160. Supporting this hypothesis, HMC-1 express the GPI-specific phospholipase D variant 2 involved in the NK lymphocyte membrane cleavage of CD160, and morphological studies highlighted a relative loss of CD160 expression in inflammatory skin sites, where MC degranulation is expected to occur. We also demonstrated an inhibition of T-cell cytotoxicity by HMC-1 supernatant that was partially reversed by anti-CD160 mAb. In conclusion, sCD160, produced by MCs, may have a role in T-cell–MC interactions in vivo

Identification of a Novel CD160+CD4+ T-Lymphocyte Subset in the Skin: A Possible Role for CD160 in Skin Inflammation

CD160 is a glycosylphosphatidylinositol-anchored cell surface molecule expressed by human circulating cytotoxic lymphocytes that correspond to the majority of natural killer cell (NK) expressing CD56dim, TCRγδ lymphocytes, and to a minor CD8 T-cell subset. CD160 engagement by major histocompatibility complex class I molecules triggers by itself both cytotoxic function and cytokine production in NK lymphocytes, whereas it provides co-activating signals to TCR-induced proliferation in T CD8+ lymphocytes. In this study, we analyzed by immunohistochemistry the phenotype of lymphocytes infiltrating normal skin and inflammatory skin lesions of atopic dermatitis, contact dermatitis, and psoriasis. We identified a minor original subset of CD4+CD160+ T cells infiltrating inflammatory lesions. We found that this lymphocyte subset localization is not restricted to the skin, as we demonstrated that CD160 transcripts could be induced in IL-2 or IL-15-activated CD4+ peripheral blood lymphocytes. Finally, we report that CD160 acts as a co-activator receptor for CD3-induced proliferation of CD4+CD160+ T cells isolated from inflammatory skin lesions. Thus, we hypothesize that the unique CD4+CD160+ lymphocyte subset plays a role in the pathogenesis of skin inflammation

A novel antiangiogenic and vascular normalization therapy targeted against human CD160 receptor

A monoclonal anti-CD160 antibody inhibits the growth of new vessels in pathological ocular and tumor neoangiogenesis but not in healthy tissues

CD160, un récepteur unique des lymphocytes Natural Killer humains

PARIS12-CRETEIL BU Multidisc. (940282102) / SudocSudocFranceF

: CD160-TM, an unique NK cell activating receptor

International audienceCD160 has been initially identified as a GPI-anchored MHC-class I activating receptor mainly expressed on peripheral blood NK cells. Herein, we report the identification of three additional CD160-related mRNAs generated through alternative splicings of the CD160 gene, among which one encoded a putative CD160 transmembrane isoform (CD160-TM). We first establish that CD160-TM surface expression is highly restricted to NK cells and is activation-dependent. Additionally, we provide evidence that CD160-TM represents a novel activating receptor, as assessed by the increased CD107a NK cell surface mobilization observed upon its engagement. Finally, we demonstrate that the CD160-TM cytoplasmic tail is by itself sufficient to mediate the recruitment of Erk1/2 signaling pathway, and that the initiation of this activation process is dependent on the Src-family kinase p56(lck). The identification of CD160-TM therefore provides new possibilities regarding the role of CD160 isoforms in the regulation of NK cell functions

Nouvelle thérapie antiangiogénique indépendante du VEGF qui cible le récepteur CD160

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Chemotherapy treatment induces an increase of autophagy in the luminal breast cancer cell MCF7, but not in the triple-negative MDA-MB231

International audienceAutophagy is one of the chemotherapy resistance mechanisms in breast cancer. The aim of this study was to determine the level of recruitment of the autophagy pathway in the triple-negative breast cancer (TNBC) cell line MDA-MB231 compared with that in the control luminal breast cancer cell line MCF7 before and after treatment with chemotherapy drugs. Furthermore, we investigated the relationship between autophagy and EGFR, MUC1 and IL17-receptors as activators of autophagy. Immunohistochemistry was performed in cell culture blocks using LC3b, MUC1-C, EGFR, IL17A, IL17-RA and IL17-RB antibodies. We found that the basal autophagy level in MDA-MB231 was high, whereas it was low in MCF7. However, in contrast to MDA-MB231, the autophagy level was increased in MCF7 upon treatment with chemotherapy agents. Interestingly, we observed that the expression levels of MUC1-C, EGFR, IL17-RA, and IL17-RB were not modified by the same treatments. Furthermore, the chemotherapy treatments did not increase autophagy in TNBC cells without affecting the expression levels of MUC1-C, EGFR, IL17-RA or IL17-RB

Identification of CD160-TM as a tumor target on triple negative breast cancers: possible therapeutic applications

Abstract Background Despite major therapeutic advances, triple-negative breast cancer (TNBC) still presents a worth prognosis than hormone receptors-positive breast cancers. One major issue relies in the molecular and mutational heterogeneity of TNBC subtypes that is reinforced by the absence of reliable tumor-antigen that could serve as a specific target to further promote efficient tumor cell recognition and depletion. CD160 is a receptor mainly expressed by NK lymphocytes and presenting two isoforms, namely the GPI-anchored form (CD160-GPI) and the transmembrane isoform (CD160-TM). While CD160-GPI is constitutively expressed on resting cells and involved in the generation of NK cells' cytotoxic activity, CD160-TM is neo-synthesized upon activation and promotes the amplification of NK cells' killing ability. Methods CD160 expression was assessed by immunohistochemistry (IHC) and flow cytometry on TNBC patient biopsies or cell lines, respectively. Antibody (Ab)-mediated tumor depletion was tested in vitro by performing antibody-dependent cell cytotoxicity (ADCC) and phagocytosis (ADCP) assays, and in vivo on a TNBC mouse model. Results Preliminary data obtained by IHC on TNBC patients' tumor biopsies revealed an unconventional expression of CD160 by TNBC tumor cells. By using a specific but conformation-dependent anti-CD160-TM Ab, we established that CD160-TM, but not CD160-GPI, was expressed by TNBC tumor cells. A conformation-independent anti-CD160-TM mAb (22B12; muIgG2a isotype) was generated and selected according to pre-defined specificity and functional criterions. In vitro functional assays demonstrated that ADCC and ADCP could be induced in the presence of 22B12, resulting in TNBC cell line apoptosis. The ability of 22B12 to exert an in vivo anti-tumor activity was also demonstrated on a TNBC murine model. Conclusions Our data identify CD160-TM as a tumor marker for TNBC and provide a rational for the use of anti-CD160-TM antibodies as therapeutic tools in this tumor context