The Google Sheet also has a tab for emergency supply orders we should make now, such as Petri plates, culture media, antibiotics and molecular-biology reagents, so that our research won't be delayed ...when we return. People can indicate which spaces they'll be in - such as to change cell-culture media or do polymerase chain reactions - so that people can stay distanced from each other. ...we shifted the way we operate to accumulate as much raw data as we could in the time left, so that they could be processed and analysed remotely. To avoid contracting or spreading the contagion, we had the lab manager supply hand sanitizer and wipes at the lab entrances, instructed lab members to wash their hands thoroughly every time they came into the lab and, of course, told them to stay at home if they had any symptoms.
Irregular blood flow and endothelial cell anergy, which characterize many solid tumors, hinder tumor infiltration by cytotoxic T lymphocytes (CTL). This confers resistance to cancer immunotherapy ...with monoclonal antibodies directed against regulatory pathways in T lymphocytes (i.e., immune checkpoint blockade, ICB). We investigated whether NGR-TNF, a TNF derivative capable of targeting the tumor vasculature, and improving intratumor infiltration by activated CTLs, could sensitize tumors to ICB with antibodies specific for the PD-1 and CTLA-4 receptors.
Transgenic adenocarcinoma of the mouse prostate (TRAMP) mice with autochthonous prostate cancer and C57BL/6 mice with orthotopic B16 melanoma were treated with NGR-TNF, adoptive T-cell therapy (ACT), and ICB, and monitored for immune surveillance and disease progression.
The combination of ACT, NGR-TNF, and ICB was the most effective in delaying disease progression, and in improving overall survival of mice bearing ICB-resistant prostate cancer or melanoma. Mechanistically, the therapeutic effects were associated with potent tumor infiltration, especially by endogenous but also by adoptively transferred PD-1
, granzyme B
, and interferon-γ
CTLs. The therapeutic effects were also associated with favorable T-effector/regulatory T cell ratios.
Targeting the tumor vasculature with low-dose TNF in association with ACT may represent a novel strategy for enhancing T-cell infiltration in tumors and overcoming resistance to immune checkpoint blockers.
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Epigenetic silencing of promoter and enhancer regions is a common phenomenon in malignant cells. The transcription factor STAT3 is aberrantly activated in several tumors, where its constitutive ...acetylation accounts for the transcriptional repression of a number of tumor suppressor genes (TSG) via molecular mechanisms that remain to be understood. Using nucleophosmin-anaplastic lymphoma kinase-positive (NPM-ALK
) anaplastic large-cell lymphoma (ALCL) as model system, we found in cells and patient-derived tumor xenografts that STAT3 is constitutively acetylated as a result of ALK activity. STAT3 acetylation relied on intact ALK-induced PI3K- and mTORC1-dependent signaling and was sensitive to resveratrol. Resveratrol lowered STAT3 acetylation, rescued TSG expression, and induced ALCL apoptotic cell death. STAT3 constitutively bound the Sin3A transcriptional repressor complex, and both STAT3 and Sin3A bound the promoter region of silenced TSG via a resveratrol-sensitive mechanism. Silencing SIN3A caused reexpression of TSG, induced ALCL apoptotic cell death
, and hindered ALCL tumorigenic potential
. A constitutive STAT3-Sin3A interaction was also found in breast adenocarcinoma cells and proved critical for TSG silencing and cell survival. Collectively, these results suggest that oncogene-driven STAT3 acetylation and its constitutive association with Sin3A represent novel and concomitant events contributing to STAT3 oncogenic potential. SIGNIFICANCE: This study delineates the transcriptional regulatory complex Sin3A as a mediator of STAT3 transcriptional repressor activity and identifies the STAT3/Sin3A axis as a druggable target to antagonize STAT3-addicted tumors. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/12/3076/F1.large.jpg.
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The clinical use of interleukin‐12 (IL12), a cytokine endowed with potent immunotherapeutic anticancer activity, is limited by systemic toxicity. The hypothesis is addressed that gold nanoparticles ...tagged with a tumor‐homing peptide containing isoDGR, an αvβ3‐integrin binding motif, can be exploited for delivering IL12 to tumors and improving its therapeutic index. To this aim, gold nanospheres are functionalized with the head‐to‐tail cyclized‐peptide CGisoDGRG (Iso1) and murine IL12. The resulting nanodrug (Iso1/Au/IL12) is monodispersed, stable, and bifunctional in terms of αvβ3 and IL12‐receptor recognition. Low‐dose Iso1/Au/IL12, equivalent to 18–75 pg of IL12, induces antitumor effects in murine models of fibrosarcomas and mammary adenocarcinomas, with no evidence of toxicity. Equivalent doses of Au/IL12 (a nanodrug lacking Iso1) fail to delay tumor growth, whereas 15 000 pg of free IL12 is necessary to achieve similar effects. Iso1/Au/IL12 significantly increases tumor infiltration by innate immune cells, such as NK and iNKT cells, monocytes, and neutrophils. NK cell depletion completely inhibits its antitumor effects. Low‐dose Iso1/Au/IL12 can also increase the therapeutic efficacy of adoptive T‐cell therapy in mice with autochthonous prostate cancer. These findings indicate that coupling IL12 to isoDGR‐tagged nanogold is a valid strategy for enhancing its therapeutic index and sustaining adoptive T‐cell therapy.
Gold nanospheres can be functionalized with interleukin‐12 (IL12), a potent anticancer and immunostimulatory cytokine, and a cyclic peptide containing the isoDGR motif (Iso1) that, after coupling to albumin (Iso1‐HSA), recognizes the αvβ3 integrin overexpressed in tumor vessels and on different tumor cell types. Bifunctional nanospheres (Iso1/Au/IL12) increase the infiltration of immune cells and inhibit tumor growth in preclinical tumor models.
Summary
The binding of the urokinase plasminogen activator (uPA) to its receptor (uPAR) regulates cell adhesion, surface proteolysis, chemotaxis and cell extravasation in a number of experimental ...systems. Recent evidences have suggested that uPAR can by itself mediate chemotaxis of human monocytes and cause profound changes in cytoskeletal organization indicating that this receptor has the properties of a cell-surface regulated chemokine. Indeed, it is likely that upon binding to uPA, uPAR undergoes a conformational change that uncovers a new epitope located in the linker region between domain 1 and 2 of the receptor and is endowed with a potent chemotactic activity. This conformational change can be mimicked in vitro by enzymatic processing of a recombinant receptor. We have shown that chymotrypsin cleaves uPAR between domain 1 and 2 in an area that can be also cleaved by uPA at high efficiency and generate a receptor that can mediate monocytes migration independently of uPA binding. This mechanism is pertussis-toxin sensitive and involves activation of tyrosine kinases and cytoskeletal reorganization events in vitro. These studies indicate that in addition to its receptor function, upon binding to uPA, uPAR becomes a pleiotropic ligand for other still to be identified surface molecules.
Interleukin (IL)-7 promotes the generation, expansion, and survival of memory T cells. Previous mouse and human studies showed that IL-7 can support immune cell reconstitution in lymphopenic ...conditions, expand tumor-reactive T cells for adoptive immunotherapy, and enhance effector cytokine expression by autoreactive T cells. Whether pathogen-reactive T cells also benefit from IL-7 exposure remains unknown.
In this study, we investigated this issue in cultures of peripheral blood mononuclear cells (PBMCs) derived from patients infected with various endemic pathogens. After short-term exposure to IL-7, we measured PBMC responses to antigens derived from pathogens, such as Mycobacterium tuberculosis, Candida albicans, and cytomegalovirus, and to the superantigen Staphylococcus aureus enterotoxin B.
We found that IL-7 favored the expansion and, in some instances, the uncovering of pathogen-reactive CD4 T cells, by promoting pathogen-specific interferon-γ, IL-2, and tumor necrosis factor recall responses.
Our findings indicate that IL-7 unveils and supports reactivation of pathogen-specific T cells with possible diagnostic, prognostic, and therapeutic significance of clinical value, especially in conditions of pathogen persistence and chronic infection.
The effect of TCR signals on the differentiation of memory T cells is poorly defined. Conventional wisdom suggests that high-avidity interactions are best for the selection of vaccine Ag candidates ...or T cell specificities for adoptive T cell therapy to stimulate robust responses. However, in conditions of Ag persistence, high-avidity clones might exhaust and fail to form long-lived protective memory. We have manipulated the functional avidity of CD4 T cells by reducing expression of Lck, a key kinase involved in TCR triggering. Using a mouse model, we followed tetramer-positive T cells responding to a tumor Ag expressed by an adenocarcinoma. We show that reducing the functional avidity increased effector-effector memory responses and improved the generation of self-renewing, recirculating, tumor Ag-specific memory phenotype CD4 T cells. Moreover, such cells together with wild type CD8 T cells were better able to control tumor growth. Mechanistically, reducing Lck prolonged IL-2 production and cell turnover in the central memory population while reducing expression of exhaustion markers in the face of chronic Ag. Our data indicate that, in situations of persistent Ag challenge, generating T cells with reduced functional avidity may elicit more effective immune responses.
The aim of this study was to characterize the immune response against intrabone marrow (BM-Tx) or intraliver (liver-Tx) transplanted islets in the presence or in the absence of immunosuppression.
...Less (C57BL/6 in Balb/c) and highly (Balb/c in C57BL/6) stringent major histocompatibility complex fully mismatched mouse models were used to evaluate the alloimmune response. Single antigen-mismatched mouse model (C57BL/6 RIP-GP in C57BL/6) was used to evaluate the antigen-specific immune response. Mice received tacrolimus (FK-506, 0.1 mg/kg per day)/mycophenolate mofetil (MMF, 60 mg/kg per day), and anti-CD3 (50 μg/day) either alone or in combination.
Transplant site did not impact the timing nor the kinetics of the alloimmune and single antigen-specific memory T cell responses in the absence of immunosuppression or in the presence of MMF/FK-506 combination. On the other hand, the median time to graft rejection was 28 ± 5.2 days and 16 ± 2.6 days (P = 0.14) in the presence of anti-CD3 treatment, 50 ± 12.5 days and 10 ± 1.3 days (P = 0.003) in the presence of anti-CD3/MMF/FK-506 treatment for liver-Tx and BM-Tx, respectively. Anti-CD3 did not differentially reach BM and liver tissues but was more effective in reducing graft associated T cell responses in liver-Tx than in BM-Tx.
Islets infused in the BM appear less protected from the adaptive immune response in the presence of the anti-CD3 treatment. This result raises some concerns over the potential of the BM as a site for islet allotransplantation.
Transfer of T-cell receptors (TCRs) specific for tumor-associated antigens is a promising approach for cancer immunotherapy. We developed the TCR gene editing technology that is based on the knockout ...of the endogenous TCR α and β genes, followed by the introduction of tumor-specific TCR genes, and that proved safer and more effective than conventional TCR gene transfer. Although successful, complete editing requires extensive cell manipulation and 4 transduction procedures. Here we propose a novel and clinically feasible TCR “single editing” (SE) approach, based on the disruption of the endogenous TCR α chain only, followed by the transfer of genes encoding for a tumor-specific TCR. We validated SE with the clinical grade HLA-A2 restricted NY-ESO-1157-165–specific TCR. SE allowed the rapid production of high numbers of tumor-specific T cells, with optimal TCR expression and preferential stem memory and central memory phenotype. Similarly to unedited T cells redirected by TCR gene transfer (TCR transferred TR), SE T cells efficiently killed NY-ESO-1pos targets; however, although TR cells proved highly alloreactive, SE cells showed a favorable safety profile. Accordingly, when infused in NSG mice previously engrafted with myeloma, SE cells mediated tumor rejection without inducing xenogeneic graft-versus-host disease, thus resulting in significantly higher survival than that observed in mice treated with TR cells. Overall, single TCR gene editing represents a clinically feasible approach that is able to increase the safety and efficacy of cancer adoptive immunotherapy.
•TCR SE is a clinically feasible approach to rapidly produce highly performing and specific tumor reactive T cells.•NY-ESO-1 TCR SE T cells kill multiple myeloma in the absence of off-target reactivity including alloreactivity.
The aim of this work was to assess corneal endothelial morphology in a well-established acute graft-versus-host disease (GVHD) murine model and to quantify the expression of neurokinin-1 receptor ...(NK1R) in the corneal endothelium during ocular GVHD (oGVHD). Pre-conditioning was performed in BALB/c using myeloablative total body irradiation. Subsequently, allogeneic bone marrow transplantation was performed without (BM) or with mature T cells (BM + T). Corneal transparency was monitored with in vivo biomicroscopy. After sacrifice, corneal thickness and endothelial cell number were measured, and the expression of NK1R was investigated in the corneal endothelium through immunofluorescence and quantified by immunohistochemistry. Mice presenting oGVHD showed a significant reduction in endothelial cell number compared to control animals (p < 0.0001). NK1R expression was significantly increased in oGVHD mice endothelium (p < 0.05). Corneal transparency and thickness were unchanged in all groups. Our results suggest that oGVHD affects the corneal endothelium, inducing a reduction of the cell number, and that this is associated with increased expression of the pro-inflammatory marker NK1R.
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