Pathophysiology of cutaneous T-cell lymphomas: Perspective from a French referral centre.

Cutaneous T-cell lymphomas (CTCL) are a diverse group of malignant blood disorders characterized by initial skin infiltration, and sometimes, tumor spreading to lymph nodes, blood, and viscera. Mycosis fungoides is the most common form. Sézary syndrome is a distinctive form of CTCL marked by a significant presence of circulating tumor cells in peripheral blood. These diseases are characterized by the plasticity and heterogeneity of the tumor cells in the different tissue compartments, and a difficulty in identifying these tumor cells for diagnostic purposes and therapeutic monitoring. Progress has been made in the understanding of the pathophysiology of these diseases in recent years, and we provide here a review of these advancements.

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

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.

Cytotoxic activity of peripheral blood mononuclear cells in patients with endometriosis: A cross-sectional study.

Background: Endometriosis is believed to be associated with dysfunction of the lymphocyte population and cytotoxicity of natural killer (NK) cells, induced by the production of interleukin-2 (IL-2). Objective: This study aimed to investigate T lymphocytes and NK cell activity in the peripheral blood mononuclear cells (PBMCs) of women with endometriosis. Materials and Methods: PBMCs were obtained from the peripheral venous blood samples of 14 women with and without endometriosis (n = 7 for each group). Then, the PBMCs were co-cultured for 4 days and were treated with recombinant IL-2 for cytotoxic activity toward target cells (Daudi and K562 cells). The cytotoxicity activity was determined using the 51 chromium release assay before and after stimulation. Flow cytometry measurement was used to examine the expression of T lymphocytes and NK cells before and after being treated with IL-2. Results: The concentration of CD3+CD28+ (co-stimulatory) was significantly lower in the endometriosis group (65.62 ± 5.38) compared to in its counterpart (50.24 ± 4.22) (p = 0.04) before stimulation. However, no significant differences were observed in any other T lymphocytes and NK cells. It was also found that there was a significant increase of CD3-CD28+ after treatment with IL-2 only in the healthy control but not in women with endometriosis. Conclusion: Increased expression of CD160 and decreased CD28 play a role in inhibiting NK cell activation and T cell response in women with endometriosis.

The soluble form of CD160 acts as a tumor mediator of immune escape in melanoma.

Melanoma is responsible for 90% of skin cancer-related deaths. Major therapeutic advances have led to a considerable improvement in the prognosis of patients, with the development of targeted therapies (BRAF or MEK inhibitors) and immunotherapy (anti-CTLA-4 or -PD-1 antibodies). However, the tumor constitutes an immunosuppressive microenvironment that prevents the therapeutic efficacy and/or promotes the development of secondary resistances. CD160 is an activating NK-cell receptor initially described as delineating the NK and CD8+ T-cell cytotoxic populations. Three forms of CD160 have been described: (1) the GPI isoform, constitutively expressed and involved in the initiation of NK-cells' cytotoxic activity, (2) the transmembrane isoform, neo-synthesized upon cell activation, allowing the amplification of NK cells' cytotoxic functions and (3) the soluble form, generated after cleavage of the GPI isoform, which presents an immuno-suppressive activity. By performing immunohistochemistry analyses, we observed a strong expression of CD160 at the primary cutaneous tumor site of melanoma patients. We further demonstrated that melanoma cells express CD160-GPI isoform and constitutively release the soluble form (sCD160) into the tumor environment. sCD160 was shown to inhibit the cytotoxic activity of NK-cells towards their target cells. In addition, it was found in the serum of melanoma patients and associated with increased tumor dissemination. Altogether these results support a role for sCD160 in the mechanisms leading to the inhibition of anti-tumor response and immune surveillance in melanoma.

Extracellular Vesicles Released by Allogeneic Human Cardiac Stem/Progenitor Cells as Part of Their Therapeutic Benefit.

The positive effects of therapeutic human allogeneic cardiac stem/progenitor cells (hCPC) in terms of cardiac repair/regeneration are very likely mediated by paracrine effects. Our previous studies revealed the advantageous immune interactions of allogeneic hCPC and proposed them as part of the positive paracrine effects occurring upon their application postmyocardial infarction (MI). Currently, extracellular vesicles/exosomes (EV/Exs) released by stem/progenitor cells are also proposed as major mediators of paracrine effects of therapeutic cells. Along this line, we evaluated contribution of EV/Exs released by therapeutic hCPC to the benefit of their successful allogeneic clinical application. Through tailored allogeneic in vitro human assay models mimicking the clinical setting, we demonstrate that hCPC-released EV/Exs were rapidly and efficiently up-taken by chief cellular actors of cardiac repair/regeneration. This promoted MAPK/Erk1/2 activation, migration, and proliferation of human leukocyte antigens (HLA)-mismatched hCPC, mimicking endogenous progenitor cells and cardiomyocytes, and enhanced endothelial cell migration, growth, and organization into tube-like structures through activation of several signaling pathways. EV/Exs also acted as pro-survival stimuli for HLA-mismatched monocytes tuning their phenotype toward an intermediate anti-inflammatory pro-angiogenic phenotype. Thus, while positively impacting the intrinsic regenerative and angiogenic programs, EV/Exs released by therapeutic allogeneic hCPC can also actively contribute to shaping MI-inflammatory environment, which could strengthen the benefits of hCPC allogeneic interactions. Collectively, our data might forecast the application of allogeneic hCPC followed by their cell-free EV/Exs as a strategy that will not only elicit the cell-contact mediated reparative/regenerative immune response but also have the desired long-lasting effects through the EV/Exs. Stem Cells Translational Medicine 2019;8:911&924.

CD160 Expression in Retinal Vessels Is Associated With Retinal Neovascular Diseases.

Purpose: Anti-angiogenic agents stand first in the treatment of neovascular diseases of the retina. CD160 appeared in several experimental studies as a marker of activated endothelial cells, suggesting it could represent a promising target for novel anti-angiogenic therapies. The aim of the present study was to assess the distribution of CD160 in the human eye, and to search for a possible correlation with retinal neovascular diseases. Methods: The physiological distribution of CD160 in the normal eye was assessed with immunolabeling in 10 human donor eyes. Then, in a retrospective cohort of 75 surgical retinal specimens, the density of CD160+ microvessels was evaluated, along with immunolabeling on serial sections against ERG (pan-endothelial cell marker), CD105 (activated endothelial cell marker), and α-SMA (pericyte cell marker). The cohort was divided into two groups: 29 patients with neovascular disease (NV+) and 46 control patients (NV-). Results: CD160 was physiologically expressed by several cell types: endothelial cells of retinal blood vessels, ganglion cells, macrophages, epithelial cells of the conjunctiva, ciliary body, and retinal pigment epithelium. In the patient cohort, the percentage of CD160+ vessels in the retina was significantly and independently higher in patients suffering from neovascular diseases (P = 0.04). On the contrary, the expression of CD105 was correlated neither with retinal neovascular diseases, nor with CD160 expression. Conclusions: CD160 was expressed in some retinal vessels in both normal and pathologic eyes. CD160 expression by endothelial cells of retinal vessels was correlated with ocular neovascular diseases. CD160 could therefore represent an interesting target for novel anti-angiogenic therapies.

Anti-CD160, Alone or in Combination With Bevacizumab, Is a Potent Inhibitor of Ocular Neovascularization in Rabbit and Monkey Models.

Purpose: To assess the efficacy of the murine first-in-class CL1-R2 monoclonal antibody (mAb) targeting human CD160 (alone or in combination with bevacizumab) by using the rabbit corneal neovascularization (CNV) model, and determine the safety and efficacy of ELB01101, a novel CL1-R2-derived humanized IgG4 mAb, in a monkey model of choroidal neovascularization (ChNV). Methods: Comparison of effect of CL1-R2, bevacizumab, or aflibercept or IgG1 (control) injections in early and late treatment schemes on evolution of VEGF- or FGF2-induced rabbit CNV was performed. In the combination setting, bevacizumab was coinjected with different doses of CL1-R2. ELB01101 or vehicle was administered intravitreally in monkeys after laser-induced ChNV. Individual laser-induced lesions were semiquantitatively graduated by using fluorescein angiography to determine leakage. Results: In the rabbit model, early and late treatments with CL1-R2 significantly decreased both area and length of CNV neovessels. The effect was as potent as produced with anti-VEGF comparators. When combined with bevacizumab, an additive effect of CL1-R2 was measured at all doses tested. In the ChNV model, on day 29, eyes treated with ELB01101 showed a statistically significant reduction in clinically relevant lesions compared to vehicle-treated eyes (∼50%; χ2 test, P = 0.032001). Conclusions: The additive effects of anti-CD160 and bevacizumab in the CNV model suggest that these compounds could act via different pathways, opening new therapeutic pathways for cotargeted or combination therapies. In the ChNV model, ELB01101 was well tolerated and prevented approximately 50% of clinically relevant lesions, validating CD160 targeting as a safe approach for treatment of retinal diseases in the most relevant animal model of wet AMD.

Corrigendum: Minimizing the risk of allo-sensitization to optimize the benefit of allogeneic cardiac-derived stem/progenitor cells.

This corrects the article DOI: 10.1038/srep41125.

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

Autophagy 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.

Minimizing the risk of allo-sensitization to optimize the benefit of allogeneic cardiac-derived stem/progenitor cells.

Allogeneic human cardiac-derived stem/progenitor cells (hCPC) are currently under clinical investigation for cardiac repair. While cellular immune response against allogeneic hCPC could be part of their beneficial-paracrine effects, their humoral immune response remains largely unexplored. Donor-specific HLA antibodies (DSA-HLA-I/DSA-HLA-II), primary elements of antibody-mediated allograft injury, might present an unidentified risk to allogeneic hCPC therapy. Here we established that the binding strength of anti-HLA monoclonal antibodies delineates hCPC proneness to antibody-mediated injury. In vitro modeling of clinical setting demonstrated that specific DSA-HLA-I of high/intermediate binding strength are harmful for hCPC whereas DSA-HLA-II are benign. Furthermore, the Luminex-based solid-phase assays are suitable to predict the DSA-HLA risk to therapeutic hCPC. Our data indicate that screening patient sera for the presence of HLA antibodies is important to provide an immune-educated choice of allogeneic therapeutic cells, minimize the risk of precipitous elimination and promote the allogeneic reparative effects.

The IL-17B-IL-17 receptor B pathway promotes resistance to paclitaxel in breast tumors through activation of the ERK1/2 pathway.

Interleukin 17B (IL-17B) is a pro-inflammatory cytokine that belongs to the IL-17 cytokines family and binds to IL-17 receptor B (IL-17RB). Here we found that high expression of IL-17B and IL-17RB is associated with poor prognosis in patients with breast cancer and that IL-17B expression upregulation is specifically associated with poorer survival in patients with basal-like breast cancer. We thus focused on IL-17B role in breast cancer by using luminal and triple negative (TN)/basal-like tumor cell lines. We found that IL-17B induces resistance to conventional chemotherapeutic agents. In vivo, IL-17B induced resistance to paclitaxel and treatment with an anti-IL-17RB neutralizing antibody completely restored breast tumor chemosensitivity, leading to tumor shrinkage. We next focused on the signaling pathways activated in human breast cancer cell lines upon incubation with IL-17B. We observed that IL-17B induces ERK1/2 pathway activation, leading to upregulation of anti-apoptotic proteins of the BCL-2 family. IL-17B-induced chemoresistance was completely abolished by incubation with PD98059, an inhibitor of the MAPK/ERK pathway, indicating that the ERK pathway plays a crucial role. Altogether our results emphasize the role of the IL-17B/IL-17RB signaling pathway in breast tumors and identify IL-17B and its receptor as attractive therapeutic targets for potentiating breast cancer chemotherapy.

Targeting the Tumor Microenvironment: The Protumor Effects of IL-17 Related to Cancer Type.

The inflammatory process contributes to immune tolerance as well as to tumor progression and metastasis. By releasing extracellular signals, cancerous cells constantly shape their surrounding microenvironment through their interactions with infiltrating immune cells, stromal cells and components of extracellular matrix. Recently, the pro-inflammatory interleukin 17 (IL-17)-producing T helper lymphocytes, the Th17 cells, and the IL-17/IL-17 receptor (IL-17R) axis gained special attention. The IL-17 family comprises at least six members, IL-17A, IL-17B, IL-17C, IL-17D, IL-17E (also called IL-25), and IL-17F. Secreted as disulfide-linked homo- or heterodimers, the IL-17 bind to the IL-17R, a type I cell surface receptor, of which there are five variants, IL-17RA to IL-17RE. This review focuses on the current advances identifying the promoting role of IL-17 in carcinogenesis, tumor metastasis and resistance to chemotherapy of diverse solid cancers. While underscoring the IL-17/IL-17R axis as promising immunotherapeutic target in the context of cancer managing, this knowledge calls upon further in vitro and in vivo studies that would allow the development and implementation of novel strategies to combat tumors.

IL-17E synergizes with EGF and confers in vitro resistance to EGFR-targeted therapies in TNBC cells.

Estrogen receptor-, progesterone receptor- and HER2-negative breast cancers, also known as triple-negative breast cancers (TNBCs), have poor prognoses and are refractory to current therapeutic agents, including epidermal growth factor receptor (EGFR) inhibitors. Resistance to anti-EGFR therapeutic agents is often associated with sustained kinase phosphorylation, which promotes EGFR activation and translocation to the nucleus and prevents these agents from acting on their targets. The mechanisms underlying this resistance have not been fully elucidated. In addition, the IL-17E receptor is overexpressed in TNBC tumors and is associated with a poor prognosis. We have previously reported that IL-17E promotes TNBC resistance to anti-mitotic therapies. Here, we investigated whether IL-17E promotes TNBC resistance to anti-EGFR therapeutic agents by exploring the link between the IL-17E/IL-17E receptor axis and EGF signaling. We found that IL-17E, similarly to EGF, activates the EGFR in TNBC cells that are resistant to EGFR inhibitors. It also activates the PYK-2, Src and STAT3 kinases, which are essential for EGFR activation and nuclear translocation. IL-17E binds its specific receptor, IL-17RA/IL17RB, on these TNBC cells and synergizes with the EGF signaling pathway, thereby inducing Src-dependent EGFR transactivation and pSTAT3 and pEGFR translocation to the nucleus. Collectively, our data indicate that the IL-17E/IL-17E receptor axis may underlie TNBC resistance to EGFR inhibitors and suggest that inhibiting IL-17E or its receptor in combination with EGFR inhibitor administration may improve TNBC management.

Integrating longitudinal serum IL-17 and IL-23 follow-up, along with autoantibodies variation, contributes to predict bullous pemphigoid outcome.

Bullous pemphigoid (BP) is an inflammatory autoimmune bullous disease involving cytokines and proteases in the process of blister formation. Recently, IL-17 and IL-23 were evidenced in lesional skin and serum of BP patients at time of diagnosis, but their involvement in disease outcome has still not been investigated yet. We then analysed IL-17 and IL-23 serum levels during the first months of follow-up upon treatment. Compared with age- and sex- matched controls, high levels of IL-23 were observed at baseline in BP patients serum (P < 0.01), while IL-17 levels was not. However, some BP patients expressed high IL-17 serum level, independently of disease severity. In these patients, those with ongoing remission reduced IL-17 concentration upon treatment (P < 0.001), whereas IL-17 level remained elevated in patients who relapsed. Meanwhile, IL-23 serum levels increased during the first month of treatment in BP patients who later relapsed (P < 0.01) and MMP-9 serum level was not controlled. Accordingly, we found that both IL-17 and IL-23 increased MMP-9 secretion from leukocytes in-vitro. Then, we showed that elevated IL-17/IL-23 serum concentrations helped to discriminate BP patients who later relapsed. Such uncontrolled inflammatory response raises the question whether these molecules could become biological target for BP patients resistant to steroid treatment.

Autophagy is decreased in triple-negative breast carcinoma involving likely the MUC1-EGFR-NEU1 signalling pathway.

Triple-negative breast carcinoma (TN) is a heterogeneous cancer type expressing EGFR in 75% of cases. MUC1 is a large type I sialylated glycoprotein comprising two subunits (α and ß chains, also called respectively MUC1-VNTR and MUC1-CT), which was found to regulate EGFR activity through endocytic internalisation. Endocytosis and autophagy use the lysosome pathway involving NEU1. Recently, a molecular EGFR-MUC1-NEU1 complex was suggested to play a role in EGFR pathway. In the aim to understand the relationship between EGFR-MUC1-NEU1 complex and autophagy in breast carcinoma, we compared triple negative (TN) showing a high-EGFR expression with luminal (LUM) presenting low-EGFR level. We studied the expression of MUC1-VNTR, MUC1-CT and NEU1 in comparison with those of two molecular actors of autophagy, PI3K (p110ß) and Beclin1. A total of 87 breast cancers were split in two groups following the immunohistochemical classification of breast carcinoma: 48 TN and 39 LUM. Our results showed that TN presented a high expression of EGFR and a low expression of MUC1-VNTR, MUC1-CT, NEU1, Beclin-1 and PI3Kp110ß. Moreover, in TN, a positive statistical correlation was observed between Beclin-1 or PI3Kp110ß and MUC1-VNTR or NEU1, but not with EGFR. In conclusion, our data suggest that autophagy is reduced in TN leading likely to the deregulation of EGFR-MUC1-NEU1 complex and its associated cellular pathways.