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.

Abstract 1602: Generation of anti-IL-17B antibodies neutralizing IL-17B-mediated alterations of the immune microenvironment, promotion of tumor cell initiating capacity and chemoresistance

Interleukin 17B (IL-17B) is a pro-inflammatory cytokine that belongs to a family encompassing 6 interleukins (IL-17A to F) and binds to the IL-17 receptor B (IL-17RB). Recently, amplified IL-17B/IL-17RB signaling was found critical for breast and pancreatic tumorigenesis and elevated expression of IL-17RB has been associated with the shortest survival rates in patients with breast or pancreatic cancer. Using IL-17B knock-out (IL-17B KO) mice we demonstrate here that melanoma, fibrosarcoma and breast cancer cell tumorigenicity is strongly impaired in immunocompetent IL-17B KO mice compared to WT littermates, including a large number of tumor free mice. Reduced tumor incidence in IL-17B KO mice is associated with alterations of the immune tumor microenvironment especially within innate lymphocyte and myeloid sub-populations. We further demonstrate that IL-17B is a key cytokine shaping the tumor initiating cancer cell niche. Indeed, MDA-MB-468 human breast cancer cells overexpressing IL-17B exhibit 10 times higher frequency of tumor initiating cells when xenografted at a serial limiting dilution in nude mice. Tumor progression is, again, associated with alterations of NK cells within the tumor microenvironment and with increased percentages of CD44hi/CD24lo tumor cells, a phenotype associated with breast cancer stem cells (CSC). This is associated with resistance to conventional chemotherapeutic agents such as taxol, an effect that is totally abrogated by disrupting IL-17B-IL-17RB signaling with a neutralizing antibody. Altogether our results point out the key role of IL-17B in regulating the immune microenvironment as well as cardinal features of CSC, one of the alleged causes of resistance to therapy and tumor relapse. Thereby, IL-17B and its receptor appear as potential therapeutic targets for cancer immunotherapy. Collectively, these data support the ongoing development of IL-17B neutralizing antibodies.

Citation Format: Emilie Laprevotte, Aurélie Docquier, Jeremy Bastid, Cécile Déjou, Marion Lapierre, Gilles Alberici, Armand Bensussan, Jean-François Eliaou, Nathalie Bonnefoy. Generation of anti-IL-17B antibodies neutralizing IL-17B-mediated alterations of the immune microenvironment, promotion of tumor cell initiating capacity and chemoresistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1602. doi:10.1158/1538-7445.AM2017-1602

Abstract 3171: IL-25/IL-17E does not induce breast tumor cell apoptosis and both IL-17A and IL-25/IL-17E contribute to breast cancer survival and proliferation associated with generation of pro-oncogenic low molecular forms of cyclin E

Pro-inflammatory IL-17 cytokines were initially described for their pathogenic role in chronic inflammatory diseases and subsequent accumulating evidence indicated their involvement in carcinogenesis. In the present study we focused our work on IL-17A and IL-17E which are found in the breast tumoral microenvironment. Cell proliferation and cytotoxic assays as well as Quantitative PCR and Western Blot analysis of oncogenic pathways were performed using several breast cancer cell lines and primary tumor cells. We report that IL-17A and IL-17E receptor subunits (IL17RA, RB and RC chains) are up-regulated in breast cancers versus normal samples. Moreover, IL-17E, which is undetectable in most normal breast tissues tested, is expressed at higher levels in tumors. We studied the molecular signaling following the stimulation of cell lines with IL-17A and IL-17E. We found that both cytokines induced cell proliferation and activation of pathways involved in cells survival. Accordingly, IL-17A and IL-17E promoted resistance to Docetaxel but failed to induce apoptosis as previously reported for IL-17E. Interestingly, we also revealed that both cytokines induced the generation of tumorigenic low molecular weight forms of cyclin E (LMW-E), high levels of which correlate strongly with a poor survival in breast cancer patients. These results show for the first time some of the molecular pathways activated by IL-17A and IL-17E that may participate to their pro-oncogenic activity in breast cancers.

Citation Format: Jérôme Giustiniani, Hervé Curé, Christian Garbar, Yacine Merrouche, Nathalie Bonnefoy, Jérémy Bastid, Gilles Alberici, Jean-François Eliaou, Armand Bensussan. IL-25/IL-17E does not induce breast tumor cell apoptosis and both IL-17A and IL-25/IL-17E contribute to breast cancer survival and proliferation associated with generation of pro-oncogenic low molecular forms of cyclin E. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3171. doi:10.1158/1538-7445.AM2015-3171

CD39: A complementary target to immune checkpoints to counteract tumor-mediated immunosuppression

We report that CD39-expressing-melanoma cells inhibited both T-cell proliferation and the generation of cytotoxic effectors in an adenosine-dependent manner, and that treatment with a CD39-blocking antibody alleviated tumor-mediated immunosuppression. Thus, blocking CD39 ectonucleotidase may represent a novel immunotherapeutic strategy to restore antitumor immunity.

Inhibition of CD39 enzymatic function at the surface of tumor cells alleviates their immunosuppressive activity

The ectonucleotidases CD39 and CD73 hydrolyze extracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP) to generate adenosine, which binds to adenosine receptors and inhibits T-cell and natural killer (NK)-cell responses, thereby suppressing the immune system. The generation of adenosine via the CD39/CD73 pathway is recognized as a major mechanism of regulatory T cell (Treg) immunosuppressive function. The number of CD39⁺ Tregs is increased in some human cancers, and the importance of CD39⁺ Tregs in promoting tumor growth and metastasis has been demonstrated using several in vivo models. Here, we addressed whether CD39 is expressed by tumor cells and whether CD39⁺ tumor cells mediate immunosuppression via the adenosine pathway. Immunohistochemical staining of normal and tumor tissues revealed that CD39 expression is significantly higher in several types of human cancer than in normal tissues. In cancer specimens, CD39 is expressed by infiltrating lymphocytes, the tumor stroma, and tumor cells. Furthermore, the expression of CD39 at the cell surface of tumor cells was directly demonstrated via flow cytometry of human cancer cell lines. CD39 in cancer cells displays ATPase activity and, together with CD73, generates adenosine. CD39⁺CD73⁺ cancer cells inhibited the proliferation of CD4 and CD8 T cells and the generation of cytotoxic effector CD8 T cells (CTL) in a CD39- and adenosine-dependent manner. Treatment with a CD39 inhibitor or blocking antibody alleviated the tumor-induced inhibition of CD4 and CD8 T-cell proliferation and increased CTL- and NK cell-mediated cytotoxicity. In conclusion, interfering with the CD39-adenosine pathway may represent a novel immunotherapeutic strategy for inhibiting tumor cell-mediated immunosuppression.

Abstract 5036: Blockade of the CD39 immunoregulatory pathway by monoclonal antibodies

The CD39/ CD73/ adenosine pathway is an important regulator of effector immune cell response. We previously demonstrated that, in human cancer specimen, CD39 is expressed by infiltrating regulatory T cells, tumor cells and the tumor associated stroma. CD39 enzymatic activity decreases peritumoral ATP, a potent tumor cell toxicity and immunogenic inducer, and generates immunosuppressive adenosine that binds adenosine receptors and inhibits CD4, CD8 T cell and NK cell responses. We and other demonstrated that CD39-mediated decrease of extracellular ATP and increase of adenosine promote tumor progression and immune escape as well as resistance to chemotherapy-induced immune response. We therefore generated several CD39 blocking monoclonal antibodies and present here the latest developments of these antibodies. We provide evidence that CD39 blocking antibodies restore the proliferation of CD4 and CD8 T cells inhibited by melanoma cells expressing CD39 and increase the generation of CD8 cytotoxic T cells against CD39+ melanoma cells. We also demonstrated that CD39+ lymphoma cells are less sensitive to NK cell cytotoxic activity than CD39- lymphoma cells, and that CD39-blocking monoclonal antibodies increase NK-mediated lysis of CD39+ lymphoma cells but not CD39- lymphoma cells. In conclusion, CD39 blocking antibodies may represent a novel immunotherapy strategy for inhibiting regulatory T cells and tumor cell-mediated immunosuppression. The results presented here support the ongoing development of CD39 blocking monoclonal antibodies as potential anticancer drugs to restore antitumor immune response.

Citation Format: Jeremy Bastid, Cécile Dejou, Jérôme Giustiniani, Stéphanie Cochaud, Gilles Alberici, Armand Bensussan, Jean-François Eliaou, Nathalie Bonnefoy. Blockade of the CD39 immunoregulatory pathway by monoclonal antibodies. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5036. doi:10.1158/1538-7445.AM2014-5036

Abstract B3: CD39+ cancer cells mediate immunosuppression reverted by CD39-blocking antibodies

The CD39 and CD73 ectonucleotidases hydrolyze extracellular ATP and ADP into immunosuppressive adenosine that binds adenosine receptor and inhibits T cell and NK cell responses. It has been demonstrated that CD39+ Tregs are increased in some human cancers and participate to immunosuppression. The importance of CD39+ Tregs in promoting tumor growth and metastasis has been evidenced in several models in vivo (for a review, see Bastid J et al., Oncogene, 2012). Here, we addressed whether CD39 is expressed by tumor cells and whether CD39+ tumor cells mediate suppression through the CD39-adenosine pathway. Immunohistochemical staining of normal and tumor tissues revealed that CD39 is upregulated in several types of human cancer. In cancer specimens, CD39 is expressed by infiltrating lymphocytes, tumor stroma and tumor cells, whereas its expression in normal samples is absent or weak and mostly limited to vascular endothelia. The expression of CD39 at the cell surface of tumor cells was further directly demonstrated by flow cytometry in human cancer cell lines. We evidenced that CD39+ tumor cells express functional CD39 and inhibit CD4 and CD8 T cell function in a CD39-dependant manner. Treatment with CD39-blocking antibodies was able to alleviate CD39+ tumor cell-mediated inhibition of CD4 and CD8 T cells in co-culture experiments. In conclusion, interfering with the CD39-adenosine pathway could represent a novel immunotherapy strategy for inhibiting Treg and tumor cell-mediated immunosuppression. Furthermore, these results support the ongoing development of CD39-blocking monoclonal antibodies as potential anticancer drugs.

Citation Format: Anne Regairaz, Caroline Laheurte, Nathalie Bonnefoy, Jean-Francois Eliaou, Gilles Alberici, Armand Bensussan, Jeremy Bastid. CD39+ cancer cells mediate immunosuppression reverted by CD39-blocking antibodies. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr B3.

Pharmacokinetics, foreign protein immune response, cytokine release, and lymphocyte subsets in patients receiving thymoglobuline and immunosuppression

The pharmacokinetics and immune response to the rabbit IgG of rabbit antihuman thymocyte globulin, Thymoglobuline has been characterized. A cytokine release pattern of TNF alpha and IL-6 but not IL-1 beta and IFN chi has been demonstrated with the first and not subsequent doses. An effect on lymphocyte depletion of peripheral blood with major subset suppression has been shown to last more than the 3-month observation period in patients on a regimen of quadruple sequential immunosuppression.

A dose-searching trial of an anti-LFA1 monoclonal antibody in first kidney transplant recipients

25.3, a mouse IgG1 monoclonal antibody (MoAb), directed at the alpha chain of the LFA1 molecule (CD11a) has been used in prophylaxis of rejection in recipients of cadaveric kidney graft. Promising clinical results have been obtained for both tolerance and efficacy [1]. The aim of this trial was to determine the optimal dosage, base on a pharmacokinetic-pharmacodynamic analysis of the data obtained from the 15 patients included in this dose-searching study. Biological parameters, such as circulating levels and functional inhibition (as detected in an adhesion assay of patient lymphocytes), were measured during and after treatment. A Hill relation was calculated between the effect and the concentration measured and led us to select a 15 mg/day dose for further clinical trials, with a loading dose of 30 mg. An additional group receiving this protocol was submitted to the same calculation, and the results from this last group were in agreement with this previous analysis.

Evaluation of a new preservation solution: Celsior in the isolated rat lung. Paris-Sud University Lung Transplatation Group

BACKGROUND

We compared Celsior solution, a new and original extracellular preservation solution, with blood-based Wallwork's solution.

METHODS

In two groups of isolated rat lungs submitted to 4 hours of cold ischemia, pulmonary arterial and venous resistances, coefficient of filtration, and wet-to-dry lung weight ratio were determined at baseline and after 90 minutes of reperfusion.

RESULTS

After ischemia-reperfusion, percentage of increases above the respective baseline coefficient of filtration values were 93% +/- 7% in the Wallwork group and 7% +/- 3% in the Celsior group (p < 0.001 versus Wallwork's solution).

CONCLUSIONS

These results show that Celsior consistently prevented the ischemia-reperfusion-induced increase in pulmonary microvascular permeability as compared with Wallwork's solution.

Experimental evaluation of Celsior, a new heart preservation solution

An original heart preservation solution (Celsior) has been developed, the formulation of which has been designed to fulfil two major objectives: (1) to combine the general principles of hypothermic organ preservation with those specific for the myocardium, and (2) to offer the possibility of being used not only as a storage medium but also as a perfusion fluid during initial donor heart arrest, poststorage graft reimplantation and early reperfusion. The major principles addressed by the Celsior formulation include (1) prevention of cell swelling (by mannitol and lactobionate), (2) prevention of by the Celsior formulation include (1) prevention of cell swelling (by mannitol and lactobionate), (2) prevention of oxygen-derived free radical injury (by reduced glutathione, histidine and mannitol), and (3) prevention of contracture by enhancement of energy production (glutamate) and limitation of calcium overload (high magnesium content, slight degree of acidosis). Two experimental preparations were used: The isolated isovolumic buffer-perfused rat heart model and the heterotopic rabbit heart transplantation model. In isolated heart experiments, hearts were arrested with and stored in Celsior for 5 h at 4 degrees C and subsequently reperfused for 1 h. A similar protocol was used in the transplantation experiments except that the total ischemic time was approximately 1 1/2 h longer (corresponding to 6 h of storage followed by the 25 additional minutes of cold ischemia required for graft implantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal antibodies distinguish synthetic peptides that differ in one chemical group

By using human calcitonin (hCT), human calcitonin-gene-related peptide (hCGRP), and a synthetic peptide with a sequence analogous to the 34 C-terminal amino acids of human preprocalcitonin (designated as PQN-34) as haptens in the generation of monoclonal antibodies, we assessed the role of amido and amino groups in paratope-epitope binding. By using peptide inhibition experiments and solid-phase immunoassays, monoclonal anti-hCT antibody CT07 and monoclonal anti-hCGRP antibody CGR01 were found to bind to an antigenic determinant located in the C-terminal segment of the hormones. These epitopes comprise the seven C-terminal amino acids of the hormones, and the presence of the hormone-ending carboxamide group was found to be essential for antibody binding. The corresponding heptapeptides, either bearing a carboxyl group or else linked to a glycine residue at their C-terminal part, failed to react with the antibodies. Moreover, these monoclonal antibodies did not bind to synthetic peptides analogous to the C-terminal region of the hormone precursor molecules that comprised the epitope site flanked by a peptide sequence. In an attempt to assess whether amido groups when present on the side-chain of amino acids may also modulate antibody binding, a monoclonal antibody referred to as QPO1 was produced and was found to recognize an antigenic determinant localized in the N-terminal region of the PQN-34 peptide bearing a glutamine residue as the N-terminal amino acid. The epitope was found to correspond to a topographic assembled site, and binding of QPO1 was found to be substantially dependent on the presence of the free amino and the side-chain amido groups borne by the N-terminal glutamine residue of this peptide PQN-34. In contrast to these findings, an antigenic determinant located in the internal sequence of calcitonin and recognized by monoclonal anti-hCT antibody CT08 was found to be expressed on the mature form of the hormone, as well as on synthetic peptides with sequence mimicking that of preprocalcitonin. These data should guide the choice of synthetic peptide haptens for the production of anti-protein antibodies.

Monoclonal antibodies distinguish synthetic peptides that differ in one chemical group

By using human calcitonin (hCT), human calcitonin-gene-related peptide (hCGRP), and a synthetic peptide with a sequence analogous to the 34 C-terminal amino acids of human preprocalcitonin (designated as PQN-34) as haptens in the generation of monoclonal antibodies, we assessed the role of amido and amino groups in paratope-epitope binding. By using peptide inhibition experiments and solid-phase immunoassays, monoclonal anti-hCT antibody CT07 and monoclonal anti-hCGRP antibody CGR01 were found to bind to an antigenic determinant located in the C-terminal segment of the hormones. These epitopes comprise the seven C-terminal amino acids of the hormones, and the presence of the hormone-ending carboxamide group was found to be essential for antibody binding. The corresponding heptapeptides, either bearing a carboxyl group or else linked to a glycine residue at their C-terminal part, failed to react with the antibodies. Moreover, these monoclonal antibodies did not bind to synthetic peptides analogous to the C-terminal region of the hormone precursor molecules that comprised the epitope site flanked by a peptide sequence. In an attempt to assess whether amido groups when present on the side-chain of amino acids may also modulate antibody binding, a monoclonal antibody referred to as QPO1 was produced and was found to recognize an antigenic determinant localized in the N-terminal region of the PQN-34 peptide bearing a glutamine residue as the N-terminal amino acid. The epitope was found to correspond to a topographic assembled site, and binding of QPO1 was found to be substantially dependent on the presence of the free amino and the side-chain amido groups borne by the N-terminal glutamine residue of this peptide PQN-34. In contrast to these findings, an antigenic determinant located in the internal sequence of calcitonin and recognized by monoclonal anti-hCT antibody CT08 was found to be expressed on the mature form of the hormone, as well as on synthetic peptides with sequence mimicking that of preprocalcitonin. These data should guide the choice of synthetic peptide haptens for the production of anti-protein antibodies.

Utilization of synthetic peptides for the study of calcitonin and biosynthetic precursors for calcitonin

By using synthetic peptides and a library of monoclonal anti-peptide antibodies, we have developed a panel of techniques that allow the dissection of circulating immunoreactive calcitonin in the serum. C Cells of the thyroid were found to release both mature calcitonin and biosynthetic intermediates in the circulation. Finally, these products were found to circulate as heterogenous molecular species. A methodology for the standardization of the measurement of calcitonin is proposed in the form of a two-site immunoradiometric assay specific for mature calcitonin.

A radioimmunoassay for the antimalarial drug chloroquine

We describe a 3H-based RIA for the antimalarial drug chloroquine (CLQ), the most commonly used antimalarial drug. In the assay a monoclonal antibody is used that is directed against 4-amino-7-chloroquinoline conjugated to keyhole limpet hemocyanin by the glutaraldehyde method. Besides CLQ, this antibody also recognizes with good affinity the 4-aminoquinoline homologs, hydroxychloroquine and amodiaquine. No extraction step or sample preparation is required, and the method can detect as little as 10 micrograms/L, the lower concentration in plasma of humans who are taking CLQ as a preventive measure. The between-assay CV is less than or equal to 10%, the within-assay CV less than or equal to 3%. Results correlate with those by liquid chromatography (r2 = 0.96). The speed and simplicity of the RIA method make it useful in evaluating the CLQ concentrations in acutely toxic patients.

A radioimmunoassay for the antimalarial drug chloroquine

We describe a 3H-based RIA for the antimalarial drug chloroquine (CLQ), the most commonly used antimalarial drug. In the assay a monoclonal antibody is used that is directed against 4-amino-7-chloroquinoline conjugated to keyhole limpet hemocyanin by the glutaraldehyde method. Besides CLQ, this antibody also recognizes with good affinity the 4-aminoquinoline homologs, hydroxychloroquine and amodiaquine. No extraction step or sample preparation is required, and the method can detect as little as 10 micrograms/L, the lower concentration in plasma of humans who are taking CLQ as a preventive measure. The between-assay CV is less than or equal to 10%, the within-assay CV less than or equal to 3%. Results correlate with those by liquid chromatography (r2 = 0.96). The speed and simplicity of the RIA method make it useful in evaluating the CLQ concentrations in acutely toxic patients.