RESUMO
CD8+ T cells control tumors but inevitably become dysfunctional in the tumor microenvironment. Here, we show that sodium chloride (NaCl) counteracts T cell dysfunction to promote cancer regression. NaCl supplementation during CD8+ T cell culture induced effector differentiation, IFN-γ production and cytotoxicity while maintaining the gene networks responsible for stem-like plasticity. Accordingly, adoptive transfer of tumor-specific T cells resulted in superior anti-tumor immunity in a humanized mouse model. In mice, a high-salt diet reduced the growth of experimental tumors in a CD8+ T cell-dependent manner by inhibiting terminal differentiation and enhancing the effector potency of CD8+ T cells. Mechanistically, NaCl enhanced glutamine consumption, which was critical for transcriptional, epigenetic and functional reprogramming. In humans, CD8+ T cells undergoing antigen recognition in tumors and predicting favorable responses to checkpoint blockade immunotherapy resembled those induced by NaCl. Thus, NaCl metabolism is a regulator of CD8+ T cell effector function, with potential implications for cancer immunotherapy.
Assuntos
Linfócitos T CD8-Positivos , Imunoterapia , Cloreto de Sódio , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Camundongos , Humanos , Imunoterapia/métodos , Diferenciação Celular , Microambiente Tumoral/imunologia , Neoplasias/imunologia , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Linhagem Celular Tumoral , Interferon gama/metabolismo , Glutamina/metabolismo , Camundongos Endogâmicos C57BL , Imunoterapia Adotiva/métodosRESUMO
The lymphatic vascular system is essential for maintaining a healthy balance between interstitial fluid production and transport. Dysregulation of this balance can lead to the formation of lymphedema, a pathology that is disabling and bothersome in the daily lives of the patients. Lymphofluoroscopy is an invaluable tool that provides static and dynamic images of the superficial lymphatic vessels, with diagnostic and therapeutic implications. This diagnostic tool is beginning to take its place in the field of lymphology, as it is minimally invasive and has virtually no side effects.
Le système lymphatique vasculaire est essentiel pour maintenir un bon équilibre entre la production et le transport du liquide interstitiel. Une dysrégulation de cette balance peut amener à la formation d'un lymphÅdème, pathologie invalidante et gênante dans la vie quotidienne des patients. La lymphofluoroscopie est un instrument précieux qui permet, avec des images statiques et dynamiques, d'observer le système vasculaire lymphatique superficiel, avec des implications diagnostiques et thérapeutiques importantes. Cet instrument diagnostic commence à prendre sa place dans le domaine de la lymphologie, car il est peu invasif et quasiment sans effet secondaire.
Assuntos
Vasos Linfáticos , Linfedema , Humanos , Linfedema/diagnóstico por imagem , Linfedema/etiologia , Vasos Linfáticos/diagnóstico por imagemRESUMO
This document is intended as a supplement to the EANM "Guidelines on current Good Radiopharmacy Practice (cGRPP)" issued by the Radiopharmacy Committee of the EANM (Gillings et al. in EJNMMI Radiopharm Chem. 6:8, 2021). The aim of the EANM Radiopharmacy Committee is to provide a document that describes how to manage risks associated with small-scale "in-house" preparation of radiopharmaceuticals, not intended for commercial purposes or distribution.
Assuntos
Medicina Nuclear , Compostos Radiofarmacêuticos , Humanos , Compostos Radiofarmacêuticos/efeitos adversos , Gestão de RiscosRESUMO
Increasing evidence in the field of bioprospection fosters the necessity of studying poorly investigated poisonous marine invertebrates to expand knowledge on animal venom biology. Among marine annelids, amphinomid fireworms are notorious for their bearded trunk equipped with a powerful stinging capacity. Here, a methodological workflow based on analytical chemistry techniques (compound isolation followed by mass spectrometry and spectroscopy analyses) was applied to gain new insights, leading to the identification and structural elucidation of an array of natural products from Mediterranean specimens of Hermodice carunculata. Eight betaine-derived unprecedented compounds, named "carunculines", were detected, bearing two terminal ammonium groups tri-and disubstituted at the Cα (A, B) and a series of different alkyl chains (I-VIII). The mixture of chemicals was found in all the body parts of H. carunculata, supporting a mechanism of action triggered by their vehiculation inside the dorsal chaetae, and subsequent injection when chaetae break off on contact. Preliminary investigations to understand adaptive features were also performed, showing a trend in carunculine abundance that fits into the evolutionary history of these worms. These findings shed light on the chemical ecology of amphinomids, giving reasons for the success of H. carunculata in benthic environments and providing promising novel metabolites for biotechnological implications.
Assuntos
Compostos de Amônio , Anelídeos , Produtos Biológicos , Poliquetos , Animais , Betaína , Produtos Biológicos/farmacologiaRESUMO
Genetic variation in the serotonin transporter gene (SLC6A4) is associated with vulnerability to affective disorders and pharmacotherapy efficacy. We recently identified sequence polymorphisms in the common marmoset SLC6A4 repeat region (AC/C/G and CT/T/C) associated with individual differences in anxiety-like trait, gene expression, and response to antidepressants. The mechanisms underlying the effects of these polymorphisms are unknown, but a key mediator of serotonin action is the serotonin 2A receptor (5HT2A). Thus, we correlated 5HT2A binding potential (BP) and RNA gene expression in 16 SLC6A4 genotyped marmosets with responsivity to 5HT2A antagonism during the human intruder test of anxiety. Voxel-based analysis and RNA measurements showed a reduction in 5HT2A BP and gene expression specifically in the right posterior insula of individuals homozygous for the anxiety-related variant AC/C/G. These same marmosets displayed an anxiogenic, dose-dependent response to the human intruder after 5HT2A pharmacological antagonism, while CT/T/C individuals showed no effect. A voxel-based correlation analysis, independent of SLC6A4 genotype, revealed that 5HT2A BP in the adjacent right anterior insula and insula proisocortex was negatively correlated with trait anxiety scores. Moreover, 5HT2A BP in both regions was a good predictor of the size and direction of the acute emotional response to the human intruder threat after 5HT2A antagonism. Our findings suggest that genetic variation in the SLC6A4 repeat region may contribute to the trait anxious phenotype via neurochemical changes in brain areas implicated in interoceptive and emotional processing, with a critical role for the right insula 5HT2A in the regulation of affective responses to threat.
Assuntos
Ansiedade/genética , Comportamento Animal/fisiologia , Callithrix/fisiologia , Córtex Cerebral/patologia , Receptor 5-HT2A de Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Animais , Ansiedade/patologia , Ansiedade/psicologia , Comportamento Animal/efeitos dos fármacos , Feminino , Fluorbenzenos/administração & dosagem , Genótipo , Humanos , Injeções Intramusculares , Masculino , Modelos Animais , Piperidinas/administração & dosagem , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , RNA/metabolismo , Antagonistas do Receptor 5-HT2 de Serotonina/administração & dosagem , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Estresse Psicológico/genética , Estresse Psicológico/psicologiaRESUMO
BACKGROUND: Myelodysplastic syndromes (MDS) represent the most common type of acquired bone marrow failure in adults and is characterized by ineffective maturation of myeloid precursor cells and peripheral cytopenias associated with higher rates of infection, bleeding and transfusion dependence. In higher-risk patients with MDS who relapse or do not respond after standard hypomethylating agent (HMA) therapy, the 2-year survival rate is 15%. METHODS: Here the authors report the feasibility and safety of a novel experimental T-cell therapy called personalized adoptive cell therapy, which selects, immunizes and expands T cells against MDS-specific mutations and is targeted to patient-specific tumor cell neoantigens. Somatic mutations serve as the pathogenic drivers of cancer, including MDS, as these transformative genetic mutations may generate novel immunogenic proteins (i.e., neopeptides and possible neoantigens) that may be targeted therapeutically. RESULTS: The authors demonstrate that the adaptive immune system can be trained ex vivo to recognize neopeptides as neoantigens and that the infusion of culture-expanded, neoantigen-immunized autologous T cells has been feasible and safe in the three patients treated to date. DISCUSSION: The authors report on early results from their first-in-human phase 1 clinical trial that aims to assess the safety and tolerability of this novel form of adoptive T-cell immunotherapy for HMA-refractory patients with higher-risk MDS.
Assuntos
Síndromes Mielodisplásicas , Recidiva Local de Neoplasia , Idoso , Terapia Baseada em Transplante de Células e Tecidos , Humanos , Imunoterapia Adotiva , Síndromes Mielodisplásicas/terapia , Linfócitos TRESUMO
Therapies that utilize immune checkpoint inhibition work by leveraging mutation-derived neoantigens and have shown greater clinical efficacy in tumors with higher mutational burden. Whether tumors with a low mutational burden are susceptible to neoantigen-targeted therapy has not been fully addressed. To examine the feasibility of neoantigen-specific adoptive T-cell therapy, the authors studied the T-cell response against somatic variants in five patients with myelodysplastic syndrome (MDS), a malignancy with a very low tumor mutational burden. DNA and RNA from tumor (CD34+) and normal (CD3+) cells isolated from the patients' blood were sequenced to predict patient-specific MDS neopeptides. Neopeptides representing the somatic variants were used to induce and expand autologous T cells ex vivo, and these were systematically tested in killing assays to determine the proportion of neopeptides yielding neoantigen-specific T cells. The authors identified a total of 32 somatic variants (four to eight per patient) and found that 21 (66%) induced a peptide-specific T-cell response and 19 (59%) induced a T-cell response capable of killing autologous tumor cells. Of the 32 somatic variants, 11 (34%) induced a CD4+ response and 11 (34%) induced a CD8+ response that killed the tumor. These results indicate that in vitro induction of neoantigen-specific T cells is feasible for tumors with very low mutational burden and that this approach warrants investigation as a therapeutic option for such patients.
Assuntos
Síndromes Mielodisplásicas , Neoplasias , Antígenos de Neoplasias/genética , Humanos , Mutação , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/terapia , Linfócitos TRESUMO
We have previously shown that impulsivity in rats is linked to decreased dopamine D2/3 receptor availability in the ventral striatum. In the present study, we investigated, using longitudinal positron emission tomography (PET), the effects of orally administered methylphenidate (MPH), a first-line treatment for attention deficit hyperactivity disorder, on D2/3 receptor availability in the dorsal and ventral striatum and related these changes to impulsivity. Rats were screened for impulsive behavior on a five-choice serial reaction time task. After a baseline PET scan with the D2/3 ligand [(18)F]fallypride, rats received 6 mg/kg MPH, orally, twice each day for 28 d. Rats were then reassessed for impulsivity and underwent a second [(18)F]fallypride PET scan. Before MPH treatment, we found that D2/3 receptor availability was significantly decreased in the left but not the right ventral striatum of high-impulse (HI) rats compared with low-impulse (LI) rats. MPH treatment increased impulsivity in LI rats, and modulated impulsivity and D2/3 receptor availability in the dorsal and ventral striatum of HI rats through inverse relationships with baseline levels of impulsivity and D2/3 receptor availability, respectively. However, we found no relationship between the effects of MPH on impulsivity and D2/3 receptor availability in any of the striatal subregions investigated. These findings indicate that trait-like impulsivity is associated with decreased D2/3 receptor availability in the left ventral striatum, and that stimulant drugs modulate impulsivity and striatal D2/3 receptor availability through independent mechanisms.
Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Corpo Estriado/metabolismo , Inibidores da Captação de Dopamina/farmacologia , Comportamento Impulsivo/efeitos dos fármacos , Metilfenidato/farmacologia , Receptores de Dopamina D2/efeitos dos fármacos , Receptores de Dopamina D3/efeitos dos fármacos , Animais , Corpo Estriado/efeitos dos fármacos , Masculino , Metilfenidato/análogos & derivados , Tomografia por Emissão de Pósitrons , RatosRESUMO
The preparation of an Investigational Medicinal Product Dossier (IMPD) for a radiopharmaceutical to be used in a clinical trial is a challenging proposition for radiopharmaceutical scientists working in small-scale radiopharmacies. In addition to the vast quantity of information to be assembled, the structure of a standard IMPD is not well suited to the special characteristics of radiopharmaceuticals. This guideline aims to take radiopharmaceutical scientists through the practicalities of preparing an IMPD, in particular giving advice where the standard format is not suitable. Examples of generic IMPDs for three classes of radiopharmaceuticals are given: a small molecule, a kit-based diagnostic test and a therapeutic radiopharmaceutical.
Assuntos
Medicina Nuclear , Compostos Radiofarmacêuticos/uso terapêutico , Sociedades Científicas , Ensaios Clínicos como Assunto , Estabilidade de Medicamentos , Regulamentação Governamental , Medicina Nuclear/legislação & jurisprudência , Medicina Nuclear/normas , Controle de Qualidade , Padrões de Referência , Terminologia como AssuntoRESUMO
Addicted patients show impaired social functioning. Chronic drug consumption may lead to impairments in decoding empathic cues. The aim of the study is to explore empathy abilities in addicted patients and the hypothesis of a differential impairment between affective and cognitive empathy. 62 addicted patients and 40 healthy volunteers were evaluated using the empathy quotient (EQ) and its subscales cognitive empathy (factor 1), emotional empathy (factor 2), social skills (factor 3). Patients scored statistically significantly lower than controls in EQ total score, in particular in factor 2. No difference was found in factor 1 and in factor 3. Consistent with previous findings, our study suggests specific impairment in emotional empathy combined with preserved cognitive empathy. These findings show important clinical implication in the development of specific rehabilitative programmes for the empowerment of empathy abilities and interpersonal skills that constitute important components in the prevention of relapse.
Assuntos
Emoções , Empatia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adulto , Afeto , Cognição , Feminino , Humanos , MasculinoRESUMO
In recent years, climate change has led to higher grape must sugar content and, consequently, increased alcohol by volume. Evaporative or pertraction is a common method for post-fermentation ethanol removal from wines, but it selectively removes some less polar volatile compounds along with ethanol. To mitigate volatile substance loss, this study investigates blending of the red wine (Marzemino-Cabernet blend) with obtained dealcoholized samples from it by industrial evaporative pertraction system, while maintaining the final product within a two-percentage-point reduction in ethanol. Thus MIX 1 and MIX 2 blends were prepared, reducing the ABV of the initial wine (12.5% alcohol by volume) to 10.5% and 9.5%. Chemical analyses highlighted that most alcohols, acetates, and ethyl esters of fatty acids decreased with alcohol by volume reduction. However, compounds with polar groups (acetoin and acetovanillone), C13-norisoprenoids, and certain lactones showed increasing trends. Sensory analysis indicated high scores for sweetness and smoothness in the blended wines, with a decrease in acidic taste. Floral scents notably increased, particularly in MIX 2, closely resembling the initial wine's sensory profile. The blending of initial wine with appropriately dealcoholized wine samples has proven to be an effective strategy for preserving bouquet and color of dealcoholized wines. This approach broadens the consumer base by catering to people who prefer low-alcohol options, have dietary restrictions, or are health-conscious, but who still wish to savor wines with aromatic quality rather than a flat taste. This strategy is crucial in the wine industry as it successfully addresses technical challenges and ensures economic viability.
RESUMO
The intratumoral microbiota has been recently identified as important in cancer evasion strategies. It can induce DNA damage, favor the epithelial-mesenchymal transition, inactivate drugs, polarize the immune system toward a protumorigenic profile, induce vascular reshaping and favor metastasis formation, and protect tumor cells from fluid shear stress during cell migration. However, recently also some positive effects of the intratumoral microbiota have been highlighted such as the activation of bacterial antigen-specific responses that could be harnessed to broaden not only the immune response to tumor antigens, but also the polarization of antitumorigenic responses. As in the gut, it is likely that the ratio between symbionts and pathobionts affects the outcome. More research is needed in this field to better understand this dual role.
Assuntos
Microbiota , Neoplasias , Humanos , Imunoterapia , Antígenos de NeoplasiasRESUMO
Recent data have shown that gut microbiota has a major impact on the clinical response to immune checkpoint inhibitors (ICIs) in the context of solid tumors. ICI-based therapy acts by unlocking cognate cytotoxic T lymphocyte (CTL) effector responses, and increased sensitivity to ICIs is due to an enhancement of patients' tumor antigen (TA)-specific CTL responses. Cancer clearance by TA-specific CTL requires expression of relevant TAs on cancer cells' HLA class I molecules, and reduced HLA class I expression is a common mechanism used by cancer cells to evade the immune system. Here, we show that metabolites released by bacteria, in particular, phytosphingosine, can upregulate HLA class I expression on cancer cells, sensitizing them to TA-specific CTL lysis in vitro and in vivo, in combination with immunotherapy. This effect is mediated by postbiotic-induced upregulation of NLRC5 in response to upstream MYD88-NF-κB activation, thus significantly controlling tumor growth.
RESUMO
Malignant pleural mesothelioma (MPM) is an aggressive tumor with a poor prognosis. As the available therapeutic options show a lack of efficacy, novel therapeutic strategies are urgently needed. Given its T-cell infiltration, we hypothesized that MPM is a suitable target for therapeutic cancer vaccination. To date, research on mesothelioma has focused on the identification of molecular signatures to better classify and characterize the disease, and little is known about therapeutic targets that engage cytotoxic (CD8+) T cells. In this study we investigate the immunopeptidomic antigen-presented landscape of MPM in both murine (AB12 cell line) and human cell lines (H28, MSTO-211H, H2452, and JL1), as well as in patients' primary tumors. Applying state-of-the-art immuno-affinity purification methodologies, we identify MHC I-restricted peptides presented on the surface of malignant cells. We characterize in vitro the immunogenicity profile of the eluted peptides using T cells from human healthy donors and cancer patients. Furthermore, we use the most promising peptides to formulate an oncolytic virus-based precision immunotherapy (PeptiCRAd) and test its efficacy in a mouse model of mesothelioma in female mice. Overall, we demonstrate that the use of immunopeptidomic analysis in combination with oncolytic immunotherapy represents a feasible and effective strategy to tackle untreatable tumors.
Assuntos
Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Neoplasias Pleurais , Humanos , Feminino , Animais , Camundongos , Neoplasias Pleurais/tratamento farmacológico , Mesotelioma/tratamento farmacológico , Imunoterapia , Peptídeos/uso terapêutico , Linhagem Celular Tumoral , Neoplasias Pulmonares/patologiaRESUMO
N-(4-fluorobut-2-yn-1-yl)-2ß-carbomethoxy-3ß-(4'-tolyl)nortropane (PR04.MZ, 1) is a PET radioligand for the non-invasive exploration of the function of the cerebral dopamine transporter (DAT). A reliable automated process for routine production of the carbon-11 labelled analogue [(11)C]PR04.MZ ([(11)C]-1) has been developed using GMP compliant equipment. An adult female Papio anubis baboon was studied using a test-retest protocol with [(11)C]-1 in order to assess test-retest reliability, metabolism and CNS distribution profile of the tracer in non-human primates. Blood sampling was performed throughout the studies for determination of the free fraction in plasma (f(P)), plasma input functions and metabolic degradation of the radiotracer [(11)C]-1. Time-activity curves were derived for the putamen, the caudate nucleus, the ventral striatum, the midbrain and the cerebellum. Distribution volumes (V(T)) and non-displaceable binding potentials (BP(ND)) for various brain regions and the blood were obtained from kinetic modelling. [(11)C]-1 shows promising results as a selective marker of the presynaptic dopamine transporter. With the reliable visualisation of the extra-striatal dopaminergic neurons and no indication on labelled metabolites, the tracer provides excellent potential for translation into man.
Assuntos
Mapeamento Encefálico/métodos , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacologia , Tropanos/farmacologia , Animais , Sítios de Ligação , Encéfalo/patologia , Isótopos de Carbono/química , Desenho de Fármacos , Feminino , Concentração Inibidora 50 , Cinética , Modelos Químicos , Papio anubis , Ligação Proteica , Prótons , Compostos Radiofarmacêuticos/síntese química , Ratos , Fatores de Tempo , Tropanos/síntese químicaRESUMO
A rapid and efficient protocol to afford the title compound 2-[(18)F]-fluoro-2,2-difluoroethyl tosylate ([(18)F]7b) is described. Starting from [(18)F]fluoride ion, labelling reagent 7b was obtained in good yields and a high specific radioactivity. Compound ([(18)F]7b) was then used to synthesise a prospective radiotracer for PET-imaging in dementia.
Assuntos
Compostos de Tosil/química , Compostos de Tosil/síntese química , Radioisótopos de Flúor , Marcação por Isótopo , Tomografia por Emissão de Pósitrons , RadioquímicaRESUMO
PURPOSE: To evaluate and address the safety of vertebroplasty (VP) and kyphoplasty (KP) in terms of rate and type of cement leakage in the treatment of Multiple Myeloma (MM) vertebral fractures. METHODS: A total number of 37 treated vertebrae were evaluated post-operatively by using standard X-rays and CT scan looking for a cement leakage. VP was done using a monoportal approach in all cases (18 treated levels, group A), while KP was done using a monopedicular approach in 9 levels (group B1) and using a bipedicular approach in the remaining 10 levels (group B2). A computed tomography was used to establish the presence of any cement leakage and to determine its localization. RESULTS: Vertebral augmentation through VP and KP provides immediate pain relief and an improvement of the quality of life of patients affected by MM but it is gravated by high risk of cement leakage. Cement extravasation occurred in 27.7% of total VP procedures and in 21.05% of total KP procedures, but considering the whole number of treated levels, it was more common in multi-level VP and in bipedicular KP, in which a higher quantity of cement was employed. CONCLUSIONS: KP procedure in these patients is slightly less risky but we suggest doing it with a monopedicular approach. It's mandatory to use an high viscosity cement and we suggest not to use an amount of PMMA over 2 cc and a previous treatment with bone marrow transplant is related to a lower risk of cement leakage.
Assuntos
Cimentos Ósseos , Extravasamento de Materiais Terapêuticos e Diagnósticos/epidemiologia , Cifoplastia/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Mieloma Múltiplo/cirurgia , Vertebroplastia/métodos , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Incidência , Cifoplastia/efeitos adversos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/lesões , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Mieloma Múltiplo/complicações , Mieloma Múltiplo/diagnóstico por imagem , Estudos Retrospectivos , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/etiologia , Fraturas da Coluna Vertebral/cirurgia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/lesões , Vértebras Torácicas/cirurgia , Tomografia Computadorizada por Raios X , Vertebroplastia/efeitos adversosRESUMO
3'-Deoxyadenosine (3'-dA, Cordycepin, 1) is a nucleoside analogue with anticancer properties, but its clinical development has been hampered due to its deactivation by adenosine deaminase (ADA) and poor cellular uptake due to low expression of the human equilibrative transporter (hENT1). Here, we describe the synthesis and characterization of NUC-7738 (7a), a 5'-aryloxy phosphoramidate prodrug of 3'-dA. We show in vitro evidence that 7a is an effective anticancer drug in a panel of solid and hematological cancer cell lines, showing its preferential cytotoxic effects on leukemic stem cells. We found that unlike 3'-dA, the activity of 7a was independent of hENT1 and kinase activity. Furthermore, it was resistant to ADA metabolic deactivation. Consistent with these findings, 7a showed increased levels of intracellular 3'-deoxyadenosine triphosphate (3'-dATP), the active metabolite. Mechanistically, levels of intracellular 3'-dATP were strongly associated with in vitro potency. NUC-7738 is now in Phase II, dose-escalation study in patients with advanced solid tumors.
Assuntos
Antineoplásicos , Humanos , Antineoplásicos/farmacologiaRESUMO
The PD-1:PD-L1 axis is a binary interaction that delivers inhibitory signals to T cells, impeding both immune surveillance and response to immunotherapy. Here we analyzed a phenomenon whereby tumor-specific T cells induce PD-L1 upregulation in autologous MDS cells in short-term culture, through a mechanism that is cell-contact-independent and partially IFNγ-dependent. After investigating a panel of small-molecule inhibitors, we determined that PD-L1 upregulation was attributed to the PKR-like ER kinase (PERK) branch of the unfolded protein response. Interestingly, we found that the cytotoxic capacity of tumor-specific T cells was not impaired by the expression of PD-L1 on MDS target cells. These results highlight a little appreciated aspect of PD-1:PD-L1 regulation in hematologic cancers and indicate that this phenomenon, while likely to hinder autochthonous immune surveillance, may not be an obstacle to immunotherapies such as personalized adoptive T-cell therapy.
RESUMO
Despite efforts to develop novel treatment strategies, human and canine osteosarcomas continue to have poor prognosis and limited overall survival. The aim of this clinical trial was to test the antitumor effect and safety of multiple dermal administrations of a peptide-based anticancer vaccine in dogs with non-metastatic appendicular osteosarcoma undergoing standard of care (SOC), consisting of limb amputation and adjuvant chemotherapy. Salmonella-infected canine osteosarcoma cells were induced to release immunogenic peptides in the extracellular space via Cx43 hemichannels opening; the secretome was collected and constituted the vaccine. Dogs with non-metastatic appendicular osteosarcoma were eligible for recruitment. Following limb amputation and adjuvant carboplatin, dogs were vaccinated on a monthly basis for six times and followed up with serial thoracic radiographs. A population of dogs undergoing SOC treatment (amputation and adjuvant carboplatin) before the vaccine was available served as controls. Primary endpoints were time to metastasis (TTM) and tumor-specific survival (TSS). Secondary endpoints were feasibility, toxicity, T-cell and humoral immune responses. A total of 20 dogs were vaccinated along with SOC and 34 received SOC only. Vaccine-specific humoral and T-cell responses were observed; their amplitude correlated with TSS. Vaccine-associated toxicity was not recorded. TTM and TSS were significantly longer in vaccinated versus unvaccinated dogs (TTM: 308 vs. 240 days, respectively; p = 0.010; TSS: 621 vs. 278 days, respectively; p = 0.002). In dogs with non-metastatic osteosarcoma undergoing SOC, the addition of a bacteria-based vaccination strategy increased TTM, thereby prolonging survival, while maintaining a safe profile. Additionally, vaccinated dogs developed a long-term tumor-specific response, as documented by the immunomonitoring of these patients over time. These results hold promise for future management of canine osteosarcoma.