Nkx2-5+Islet1+ Mesenchymal Precursors Generate Distinct Spleen Stromal Cell Subsets and Participate in Restoring Stromal Network Integrity

SummarySecondary lymphoid organ stromal cells comprise different subsets whose origins remain unknown. Herein, we exploit a genetic lineage-tracing approach to show that splenic fibroblastic reticular cells (FRCs), follicular dendritic cells (FDCs), marginal reticular cells (MRCs), and mural cells, but not endothelial cells, originate from embryonic mesenchymal progenitors of the Nkx2-5+Islet1+ lineage. This lineage include embryonic mesenchymal cells with lymphoid tissue organizer (LTo) activity capable also of supporting ectopic lymphoid-like structures and a subset of resident spleen stromal cells that proliferate and regenerate the splenic stromal microenvironment following resolution of a viral infection. These findings identify progenitor cells that generate stromal diversity in spleen development and repair and suggest the existence of multipotent stromal progenitors in the adult spleen with regenerative capacity

The importance of CD4+ follicular helper T cells and tertiary lymphoid structures in the anti-tumor immune response to breast cancer

Breast cancer (BC) is the most common cancer in women. It is a highly heterogeneous disease in terms of histology, therapeutic response and patient outcomes. Early and accurate detection of breast cancer is crucial as the patient prognosis varies greatly depending on the diagnosis of the disease. Patient outcomes have been linked to the presence of tumor infiltrating lymphocytes (TIL) in solid tumors. In human BC, higher TIL infiltration is associated with a better prognosis and also predicts relevant responses to pre-operative chemotherapy. TIL are primarily composed of T cells, albeit around 20% of BC patients (pts) show significant B cell infiltration, and can organize in tertiary lymphoid structures (TLS) located in the peritumoral stroma, which are associated with survival in HER2+ and triple negative BC patients. Further, these studies revealed that CD4+ follicular helper T (Tfh) cells producing CXCL13 were specifically associated with peritumoral TLS. CXCL13 is an important B cell chemoattractant whose function is to recruit B cells to the germinal center (GC) in secondary lymphoid organs and TLS, where they can mature and differentiate into memory or antibody-producing B cells. The principal objective of this thesis project was to investigate the role of CXCL13 and Tfh cells play in the development and/or maintenance of GC-like structures in BC-associated TLS.Further understanding of the factors that promote TLS formation in vivo could provide important insight for treatment decisions in BC. CXCL13 expression was originally identified as an important signal associated with TLS that was predictive for patient outcomes. We investigated factors capable of inducing CXCL13 expression in CD4+ T cells isolated from peripheral blood, using flow cytometry analysis. Treatment with TGFβ1 alone, or together with several cytokines (IL12, IL21, and in particular IL2 blockade), increased CXCL13 expression in activated CD4+ T cells. Similar to our characterization of Tfh TIL in fresh tumor tissues, these CXCL13-producing CD4+ T cells were CXCR5 negative and expressed the Tfh markers PD-1 and ICOS. The positive correlation, in treated cells and fresh TIL, between CXCL13-producing CD4+ T cells and FoxP3-expressing regulatory CD4+ T cells, and the diminished chemokine production upon depletion of the latter population, suggest a possible positive relationship between regulatory CD4+ T cells and CXCL13-producing CD4+ T cells.We then derived a GC-associated B cell gene signature for integration in our previously published Tfh cell gene signature, including CXCL13 gene. The combined GC gene signature was tested for its ability to sensitively detect BC-associated TLS using a qRT-PCR-based assay on two different cohorts, a primary BC set (n=83) and a retrospective series (n=52) of formalin-fixed paraffin-embedded (FFPE) BC tissues. These data revealed a correlation between gene signature expression and the extent of TLS scored by trained pathologists on dual-immunohistochemistry stained (CD3+CD20 for T and B cells, respectively) FFPE tissue sections. In addition, the high GC signature expression predicted better overall and disease-free survival of BC pts in our retrospective BC cohort, as well as in public microarray data.This thesis research has demonstrated that CXCL13-producing CD4+ T cells lacking CXCR5 differentiate and exert their function in IL-2-limited but TGF-β1-rich conditions. Furthermore, we developed a GC-associated gene signature able to detect TLS in BC and predict BC pts better survival.Doctorat en Sciences biomédicales et pharmaceutiques (Médecine)info:eu-repo/semantics/nonPublishe

LAG3: The biological processes that motivate targeting this immune checkpoint molecule in human cancer

The programmed cell death 1 (PD-1) pathway is an important regulator of immune responses in peripheral tissues, including abnormal situations such as the tumor microenvironment. This pathway is currently the principal target for immunotherapeutic compounds designed to block immune checkpoint pathways, with these drugs improving clinical outcomes in a number of solid and hematological tumors. Medical oncology is experiencing an immune revolution that has scientists and clinicians looking at alternative, non-redundant inhibitory pathways also involved in regulating immune responses in cancer. A variety of targets have emerged for combinatorial approaches in immune checkpoint blockade. The main purpose of this narrative review is to summarize the biological role of lymphocyte activation gene 3 (LAG3), an emerging targetable inhibitory immune checkpoint molecule. We briefly discuss its role in infection, autoimmune disease and cancer, with a more detailed analysis of current data on LAG3 expression in breast cancer. Current clinical trials testing soluble LAG3 immunoglobulin and LAG3 antagonists are also presented in this work.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Breast cancer vaccines: Heeding the lessons of the past to guide a path forward

The ability of cancer immunotherapy to generate lasting responses in a broad spectrum of tumors has generated great enthusiasm in medical oncology. A number of new immune-based compounds have now been approved based on the recent success of immune checkpoint blockade, either administered as monotherapy or in combination with other agents. Because clinical activity is limited only to subsets of patients, two major goals of cancer immunotherapy are (1) to reliably identify responders to these current treatments, and (2) to increase the number of patients who can respond to immunotherapy by developing new strategies. These goals are critically important since the hallmark of immune-based therapies is the induction of durable immunologic and clinical responses that result in overall survival benefit. Innovative combination strategies have great potential for bringing the benefit of immunotherapy to more patients. The use of cancer vaccines to actively induce immune effectors together with other drugs, which may include immune checkpoint blockade, chemotherapy, and/or molecularly targeted agents, is a particularly attractive strategy. Cancer vaccines have been tested both to prevent or intercept the development of cancer, and to decrease established tumor burdens. No vaccine has yet been approved for either breast cancer treatment or prevention. Here, we review the history of breast cancer vaccine development, and highlight near-term opportunities for moving forward.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Numerical and Experimental Study of Gas Phase Nanoparticle Synthesis Using NanoDOME

Nowadays, with the rocketing of computational power, advanced numerical tools, and parallel computing, multi-scale simulations are becoming applied more and more to complex multi-physics industrial processes. One of the several challenging processes to be numerically modelled is gas phase nanoparticle synthesis. In an applied industrial scenario, the possibility to correctly estimate the geometric properties of the mesoscopic entities population (e.g., their size distribution) and to more precisely control the results is a crucial step to improve the quality and efficiency of the production. The “NanoDOME” project (2015–2018) aims to be an efficient and functional computational service to be applied in such processes. NanoDOME has also been refactored and upscaled during the H2020 Project “SimDOME”. To prove its reliability, we present here an integrated study between experimental data and NanoDOME’s predictions. The main goal is to finely investigate the effect of a reactor’s thermodynamic conditions on the thermophysical history of mesoscopic entities along the computational domain. To achieve this goal, the production of silver nanoparticles has been assessed for five cases with different experimental operative conditions of the reactor. The time evolution and final size distribution of nanoparticles have been simulated with NanoDOME by exploiting the method of moments and population balance model. The validation is performed by comparing NanoDOME’s calculations with the experimental data

Targeting CTLA-4 in cancer: Is it the ideal companion for PD-1 blockade immunotherapy combinations?

Immunotherapy approaches boosting spontaneous and durable antitumor immune responses through immune checkpoint blockade are revolutionizing treatment and patient outcomes in solid tumors and hematological malignancies. Among the various inhibitory molecules employed by the immune system to regulate the adaptive immune responses, cytotoxic T lymphocyte antigen-4 (CTLA-4) is the first successfully targeted immune checkpoint molecule in the clinic, giving rise to significant but selective benefit either when targeted alone or in combination with anti-programmed cell death protein-1 (PD-1) antibodies (Abs). However, the use of anti-CTLA-4 Abs was associated with the incidence of autoimmune-like adverse events (AEs), which were particularly frequent and severe with the use of combinational strategies. Nevertheless, the higher incidence of AEs is associated with an improved clinical benefit indicating treatment response. A prompt recognition of AEs followed by early and adequate treatment with immunosuppressive agents allows the management of these potentially serious AEs. This narrative review aims to summarize CTLA-4 biology, the rationale for the use as a companion for anti-PD-1 Abs in humans with results from the most relevant Phase III clinical trials including anti-CTLA-4 Abs in combination with anti-PD-1 Abs in solid tumors.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Thromboembolism and Immune Checkpoint Blockade in Cancer Patients: An Old Foe for New Research

: Patients with cancer are at an increased risk of venous (VTE) and arterial thromboembolism (ATE), and thromboembolic events (TEs) represent the second-leading cause of death in cancer patients. The risk of cancer-associated thromboembolism is multifactorial. In addition to patient risk factors, anticancer treatments have been found to increase the risk of both VTE and ATE. Immune checkpoint blockade (ICB) has become a mainstay of treatment in various types of cancers. Their use is associated with the occurrence of a new spectrum of side effects called immune-related adverse events. Meta-analyses-including data from prospective and retrospective studies-and case reports both reported VTE and ATE as adverse events associated with ICB, with a cumulative incidence equaling around 3% and 1%, respectively. The exact mechanism underlying a TE after ICB use is currently unclear, as well as its associated risk factors. Considering their potential life-threatening impact, it is important for clinicians to be aware of the potential thrombotic complications, to educate patients and recognize early signs and symptoms of VTE and ATE, in order to allow prompt treatment (if needed) and avoid complications

Targeting PD-1 in cancer: Biological insights with a focus on breast cancer

Programmed cell death-1 (PD-1) receptor and its ligands physiologically regulate the activity of the adaptive immune system to limit excessive inflammatory processes, thus preventing normal tissue damage. Tumor cells escape from the host immune surveillance using this pathway, rendering it relevant therapeutic target. Despite the relevant clinical efficacy observed in patients with solid and hematological malignancies, the clinical benefit of these novel treatments is limited to a relatively restricted number of patients. A wide amount of genomic and immune related features is currently under investigation as potential predictive biomarkers for treatment selection. The results obtained so far are encouraging but still imperfect. Combination strategies using different immunotherapeutic agents or with other treatments (such as chemotherapy) are being investigated, showing promising but still not completely satisfactory results. This review aims to shed light on the main principles of targeting PD-1 in breast cancer, from biology through its functional and clinical implications.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Characteristics of B cells present in organized tumor-associated tertiary lymphoid structures in human breast cancer

Poster non publiéinfo:eu-repo/semantics/nonPublishe