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Biology subjects

Lecis, D.

Publications and source records attributed to Lecis, D..

4 recordsLinked to original sources

ENPP3 expressed by HER2-positive breast cancer cells is associated with good prognosis by restraining epithelial-to-mesenchymal phenotype

Background Ectonucleotide pyrophosphatase/phosphodiesterase 3 (ENPP3/CD203c) is largely studied as a marker of mast cells and basophils. By depleting extracellular ATP, it prevents excessive activation of mast cells and basophils, hence reducing inflammation and allergic reactions. Recent findings have also shown that Enpp3 can deplete cGAMP, another molecule involved in STING activation and IFN-mediated pro-inflammation. Little is still known regarding the role of Enpp3 in non-immune cells although a few reports have described its expression in healthy tissues and tumors. Methods In silico analysis were performed to investigate the expression levels and the prognostic value of Enpp3 in breast cancer, together with ovarian, prostate and colon carcinoma. ENPP3 expression was evaluated in formalin-fixed, paraffin-embedded tumor samples of breast cancer patients by immunohistochemistry, and in mouse mammary cancer cell lines by western blots. Cells were treated with EGFR ligands to stimulate the EGFR/HER2 axis. A mouse-derived mammary cancer cell line was engineered by CRISPR/Cas9 to introduce a GFP sequence under the control of the Enpp3 promoter. GFP-positive and -negative cells were sorted and analyzed by gene expression profiling to identify genes and pathways associated with Enpp3 expression. Finally, wild type and Enpp3 knockout cells were injected in the fat pad of Wsh mice, which do not have mast cells, to evaluate the growth of the tumors which were further analyzed by immunohistochemistry. Results We provide evidence that HER2-positive cells express higher levels of ENPP3 in samples of breast cancer patients. Moreover, in vitro models confirmed that HER2 expression and EGFR stimulation result in up-regulation of Enpp3. We identified pathways that can concur to Enpp3 expression and showed that in vivo the absence of Enpp3 promotes tumor growth and development of tumors with a marked epithelial-to-mesenchymal phenotype. Finally, in a small cohort of HER2-positive breast cancer patients, we found that ENPP3 expression correlates with increased relapse-free survival. Conclusions Despite its potential immunosuppressive role, our findings support the notion that ENPP3 expression is promoted by HER2 in breast cancer, and that it is endowed with a positive prognostic value.

cancer biology↗

ANTIGEN-SPECIFIC CD8+ T-CELLS ARE INVOLVED IN HUMAN CAROTID ATHEROSCLEROTIC PLAQUES DESTABILIZATION

Immunization of ApoE-/- mice expressing human HLA-A 02:01 with p210, an apoB100-derived peptide, reduces atherosclerotic plaque development by inducing a p210-specific CD8+ T cell population. Studying Class-I MHC/CD8+ T cell signaling offers a promising approach to understanding the mechanism behind the athero-protective effects of p210 immunization. We aimed to identify a p210-specific CD8+ T cell population in human carotid atherosclerotic plaques from blood-positive HLA-A 02:01 patients undergoing surgical carotid endarterectomy (CEA). The study included 22 consecutive patients who were HLA-A 02:01 (+) out of 49 enrolled (reflecting an estimated prevalence of about 30% HLA-A02:01(+) in the Caucasian population). Immunohistochemistry staining used a PE-marked A 02:01-KTTKQSFDL Pentamer on fixed endarterectomy plaques. Both HLA-A 02:01 (+) and (-) patient plaques were used, with the latter serving as an internal negative control. Presence of pentamer (+) CD8 T cells indicated a p210-specific CD8+ T cell population. Patients positive for HLA-A 02:01 showed an average of 3.40 {+/-} 2.17 x 10^3 HPF p210-specific CD8+ T cells (61.80%, 3% of total CD3+) in the shoulders of atherosclerotic plaques post-CEA, significantly higher than in controls (p < 0.0001). The proportion of p210-specific CD8+ T cells was lower in plaques displaying morphological features of instability. This study, for the first time, identifies a p210-specific CD8+ T cell population in human carotid atherosclerotic plaques from HLA-A02:01(+) patients, suggesting a role for autoimmunity in atherosclerosis development and supporting the potential efficacy of p210 immunization in HLA-A02:01 (+) individuals to reduce atherosclerosis. The variation in this specific T cell population within human plaques correlates with plaque vulnerability, highlighting p210-specific CD8+ T cells as a potential target for future therapies.

immunology↗

ZEB1 shapes AML immunological niches suppressing CD8 T-cell activity while fostering Th17 cell expansion.

Acute myeloid leukemia (AML) development and progression is favored by immune suppression directly triggered by leukemia cells. ZEB1 is a key transcription factor in epithelial-to-mesenchymal transition which, we show here, is capable immune regulation in AML. Leukemic cells which had ZEB1 knocked down have reduced engraftment and extramedullary disease when transplanted into immune competent mice due to concomitant activation of CD8 T lymphocytes and reduced expansion of Th17 cells. Differently, in ZEB1 competent AML, IL-17 sustains the development of a pro-invasive and self-maintaining loop inducing MMPs and SOCS2. In humans, AML patients show, in situ on bone marrow biopsies, a direct correlation between ZEB1 and Th17 and, in gene expression profile when divided according to the median value of ZEB1 expression, a different overall survival and relapse along with the expression of MMPs, SOCS2 and Th17 cells enrichment. Overall, our data shed new light into the role of ZEB1 in AML that entwines both pro-tumoral and immune regulatory capacity in AML blasts.

immunology↗

SPARC regulation of PMN clearance protects from pristane induced lupus and rheumatoid arthritis

One step along the pathogenesis of Systemic lupus erythematosus (SLE) is associated with polymorphonuclear leukocyte (PMN) death and their ineffective removal by M2-macrophages. The secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein with unexpected immunosuppressive function in M2-macrophages and myeloid cells. To investigate the role of SPARC in autoimmunity, we adopted a pristane-induced model of lupus in mice, which recapitulates clinical manifestations of human SLE. Sparc-/- mice developed earlier and more severe renal disease, lung and liver parenchymal damage than the WT counterpart. Most prominently, Sparc-/- mice had anticipated and severe occurrence of arthritis. An intermediate phenotype was obtained in Sparc+/- hemizygous mice, a result that suggests Sparc gene-dosage as relevant in autoimmune-related events. Mechanistically, a defective Sparc expression in PMN blocks their clearance by macrophages, through a defective delivery of eat-me and dont eat-me signals. Sparc-/- PMN that escape macrophage scavenging becomes a source of autoantigens for dendritic cell (DC) presentation and a direct stimulus for IL-17 expression in {gamma}{delta}-T-cells. Gene profile analysis of synovial biopsies of knees affected by SLE-associated arthritis showed an inverse correlation between SPARC and key autoimmune genes. These results point to SPARC down-regulation as a key event characterizing SLE and associated rheumatoid arthritis pathogenesis.

immunology↗