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2.
Nat Commun ; 11(1): 4454, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901001

RESUMO

Chronic viral infections are often associated with impaired CD8+ T cell function, referred to as exhaustion. Although the molecular and cellular circuits involved in CD8+ T cell exhaustion are well defined, with sustained presence of antigen being one important parameter, how much T cell receptor (TCR) signaling is actually ongoing in vivo during established chronic infection is unclear. Here, we characterize the in vivo TCR signaling of virus-specific exhausted CD8+ T cells in a mouse model, leveraging TCR signaling reporter mice in combination with transcriptomics. In vivo signaling in exhausted cells is low, in contrast to their in vitro signaling potential, and despite antigen being abundantly present. Both checkpoint blockade and adoptive transfer of naïve target cells increase TCR signaling, demonstrating that engagement of co-inhibitory receptors curtails CD8+ T cell signaling and function in vivo.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transferência Adotiva , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Linfócitos T CD8-Positivos/virologia , Doença Crônica , Citotoxicidade Imunológica , Modelos Animais de Doenças , Regulação para Baixo , Tolerância Imunológica , Imunidade Celular , Técnicas In Vitro , Ativação Linfocitária , Coriomeningite Linfocítica/genética , Vírus da Coriomeningite Linfocítica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/imunologia , Receptor de Morte Celular Programada 1/imunologia , RNA-Seq , Transdução de Sinais/imunologia
3.
Anticancer Res ; 40(10): 5355-5359, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988854

RESUMO

BACKGROUND/AIM: Recent studies indicate that chimeric antigen receptor (CAR)-T-cells seem to be superior to CAR modified NK-92 cells. One, at least partial, explanation to this discrepancy has been addressed herein, by having NK-92 cells as target cells in cytotoxicity reactions using peripheral blood mononuclear cells. MATERIALS AND METHODS: A time-resolved fluorometric assay (TDA-labeled NK-92 or K562 as target cells) was used for measuring the cytotoxic activity of blood mononuclear cells (PBMC). RESULTS: The cytotoxic capacity of the NK-92 cells was initially demonstrated by their ability to efficiently kill K562 cells. Interestingly, having PBMC as effector cells rendered the very same NK-92 cells sensitive to NK-cell mediated cytolysis. A 1:100 target:effector ratio gave 34.1% lysis compared to 72.2% lysis for K562 cells. Incubating PBMC for longer times (24 up to 48 h) potentiated their NK-activity against NK-92 cells even more, reaching a level close to that obtained with K562 cells. CONCLUSION: This study pinpoints a severe problem that has to be considered in future immune-based cancer therapies with NK-92 as well as CAR-transduced NK-92 cells.


Assuntos
Imunoterapia Adotiva , Células Matadoras Naturais/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Neoplasias/terapia , Citotoxicidade Imunológica/efeitos dos fármacos , Humanos , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/imunologia , Interleucina-2/genética , Interleucina-2/imunologia , Células K562 , Neoplasias/imunologia , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia
4.
Anticancer Res ; 40(9): 5015-5024, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878789

RESUMO

BACKGROUND/AIM: Despite being a rare disease, melanoma is considered the most dangerous skin cancer due to its highly invasive and aggressive nature, and still requires for more effective treatments. The aim of this study was to evaluate the in vitro anti-melanoma potential of Ephedranthus pisocarpus R.E.Fr. (Annonaceae), a popular Brazilian plant with medicinal properties. MATERIALS AND METHODS: Initially, the ethanolic extract (EtOH) was obtained from E. pisocarpus leaves and later partitioned using increasing polarity solvents. The anti-melanoma potential of E. pisocarpus was assessed by spectrophotometry and its cytotoxicity determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and confocal microscopy. RESULTS: We demonstrated that the EtOH extract and fractions from E. pisocarpus had a moderate photoprotective action (FPS 3.0-5.0) against UVA radiation. Interestingly, the dichloromethane fraction presented higher anti-melanoma activity against B16-F10 (IC50=46.8 µg/ml) and SK-MEL-28 cells (IC50=40.1 µg/ml) and lesser toxicity on normal cells. Additionally, our study reported that spathulenol, one of the major constituents from E. pisocarpus, acts through an apoptosis-dependent mechanism in SK-MEL-28 cells. CONCLUSION: The present study demonstrated, for the first time, the in vitro anti-melanoma potential of E. pisocarpus against melanoma cells.


Assuntos
Annonaceae/química , Antineoplásicos Fitogênicos/farmacologia , Extratos Vegetais/farmacologia , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Brasil , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citotoxicidade Imunológica , Relação Dose-Resposta a Droga , Hemólise , Humanos , Melanoma Experimental , Camundongos , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação
5.
Nat Commun ; 11(1): 3858, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737343

RESUMO

Checkpoint blockade therapy has provided noteworthy benefits in multiple cancers in recent years; however, its clinical benefits remain confined to 10-40% of patients with extremely high costs. Here, we design an ultrafast, low-temperature, and universal self-assembly route to integrate immunology-associated large molecules into metal-organic-framework (MOF)-gated mesoporous silica (MS) as cancer vaccines. Core MS nanoparticles, acting as an intrinsic immunopotentiator, provide the niche, void, and space to accommodate antigens, soluble immunopotentiators, and so on, whereas the MOF gatekeeper protects the interiors from robust and off-target release. A combination of MOF-gated MS cancer vaccines with systemic programmed cell death 1 (PD-1) blockade therapy generates synergistic effects that potentiate antitumour immunity and reduce the effective dose of an anti-PD-1 antibody to as low as 1/10 of that for PD-1 blockade monotherapy in E.G7-OVA tumour-bearing mice, with eliciting the robust adaptive OVA-specific CD8+ T-cell responses, reversing the immunosuppressive pathway and inducing durable tumour suppression.


Assuntos
Anticorpos Neutralizantes/farmacologia , Vacinas Anticâncer/farmacologia , Linfoma/terapia , Estruturas Metalorgânicas/farmacologia , Nanopartículas/administração & dosagem , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Animais , Antígenos de Neoplasias/administração & dosagem , Antígenos de Neoplasias/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/química , Citotoxicidade Imunológica , Composição de Medicamentos , Feminino , Humanos , Imunidade Inata/efeitos dos fármacos , Imunoterapia/métodos , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Linfoma/imunologia , Linfoma/mortalidade , Linfoma/patologia , Estruturas Metalorgânicas/síntese química , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Ovalbumina/administração & dosagem , Ovalbumina/imunologia , Receptor de Morte Celular Programada 1/imunologia , Dióxido de Silício/química , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Nat Commun ; 11(1): 4166, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820173

RESUMO

T cells engineered to express chimeric antigen receptors (CAR-T cells) have shown impressive clinical efficacy in the treatment of B cell malignancies. However, the development of CAR-T cell therapies for solid tumors is hampered by the lack of truly tumor-specific antigens and poor control over T cell activity. Here we present an avidity-controlled CAR (AvidCAR) platform with inducible and logic control functions. The key is the combination of (i) an improved CAR design which enables controlled CAR dimerization and (ii) a significant reduction of antigen-binding affinities to introduce dependence on bivalent interaction, i.e. avidity. The potential and versatility of the AvidCAR platform is exemplified by designing ON-switch CARs, which can be regulated with a clinically applied drug, and AND-gate CARs specifically recognizing combinations of two antigens. Thus, we expect that AvidCARs will be a highly valuable platform for the development of controllable CAR therapies with improved tumor specificity.


Assuntos
Imunoterapia Adotiva/métodos , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Animais , Antígenos de Neoplasias/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Citotoxicidade Imunológica/imunologia , Humanos , Ativação Linfocitária/imunologia , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Linfócitos T/metabolismo
7.
Proc Natl Acad Sci U S A ; 117(32): 19388-19398, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32727906

RESUMO

CD8+ T cells play pivotal roles in eradicating pathogens and tumor cells. T cell receptor (TCR) signaling is vital for the optimal activation of CD8+ T cells. Upon TCR engagement, the transmembrane adapter protein LAT (linker for activation of T cells) recruits other key signaling molecules and forms the "LAT signalosome" for downstream signal transduction. However, little is known about which functional partners could restrain the formation of the LAT signalosome and inhibit CD8+ cytotoxic T lymphocyte (CTL)-mediated cytotoxicity. Here we have demonstrated that LRCH1 (leucine-rich repeats and calponin homology domain containing 1) directly binds LAT, reduces LAT phosphorylation and interaction with GRB2, and also promotes the endocytosis of LAT. Lrch1 -/- mice display better protection against influenza virus and Listeria infection, with enhanced CD8+ T cell proliferation and cytotoxicity. Adoptive transfer of Lrch1 -/- CD8+ CTLs leads to increased B16-MO5 tumor clearance in vivo. Furthermore, knockout of LRCH1 in human chimeric antigen receptor (CAR) T cells that recognize the liver tumor-associated antigen glypican-3 could improve CAR T cell migration and proliferation in vitro. These findings suggest LRCH1 as a potential translational target to improve T cell immunotherapy against infection and tumors.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linfócitos T CD8-Positivos/imunologia , Proteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/deficiência , Transdução de Sinais , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/transplante , Movimento Celular , Células Cultivadas , Citotoxicidade Imunológica , Endocitose , Proteína Adaptadora GRB2/metabolismo , Humanos , Imunoterapia Adotiva , Infecções/imunologia , Infecções/microbiologia , Infecções/virologia , Interferon gama/metabolismo , Neoplasias Pulmonares/terapia , Ativação Linfocitária , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fosforilação , Ligação Proteica , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/metabolismo
8.
PLoS Comput Biol ; 16(7): e1007972, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32658891

RESUMO

Although quantitative insights into the killing behaviour of Cytotoxic T Lymphocytes (CTLs) are necessary for the rational design of immune-based therapies, CTL killing function remains insufficiently characterised. One established model of CTL killing treats CTL cytotoxicity as a Poisson process, based on the assumption that CTLs serially kill antigen-presenting target cells via delivery of lethal hits, each lethal hit corresponding to a single injection of cytotoxic proteins into the target cell cytoplasm. Contradicting this model, a recent in vitro study of individual CTLs killing targets over a 12-hour period found significantly greater heterogeneity in CTL killing performance than predicted by Poisson-based killing. The observed killing process was dynamic and varied between CTLs, with the best performing CTLs exhibiting a marked increase in killing during the final hours of the experiments, along with a "burst killing" kinetic. Despite a search for potential differences between CTLs, no mechanistic explanation for the heterogeneous killing kinetics was found. Here we have used stochastic simulations to assess whether target cells might require multiple hits from CTLs before undergoing apoptosis, in order to verify whether multiple-hitting could explain the late onset, burst killing dynamics observed in vitro. We found that multiple-hitting from CTLs was entirely consistent with the observed killing kinetics. Moreover, the number of available targets and the spatiotemporal kinetics of CTL:target interactions influenced the realised CTL killing rate. We subsequently used realistic, spatial simulations to assess methods for estimating the hitting rate and the number of hits required for target death, to be applied to microscopy data of individual CTLs killing targets. We found that measuring the cumulative duration of individual contacts that targets have with CTLs would substantially improve accuracy when estimating the killing kinetics of CTLs.


Assuntos
Citoplasma/metabolismo , Processos Estocásticos , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/imunologia , Actinas/química , Algoritmos , Células Apresentadoras de Antígenos , Apoptose , Movimento Celular , Simulação por Computador , Citotoxicidade Imunológica , Humanos , Cinética , Funções Verossimilhança , Método de Monte Carlo , Distribuição de Poisson
9.
Scand J Immunol ; 92(4): e12938, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32697853

RESUMO

Cancer is a major cause of death in the industrialized world. New therapies are constantly being developed in order to reduce morbidity and mortality. NK cell-based cellular therapies have shown effect against haematological malignancies, but it has been difficult to target solid tumours due to low NK cell infiltration of the tumour and efficient tumour evasion strategies. NK cells release extracellular vesicles that naturally contain cytolytic proteins and tumour-targeting molecules. These vesicles can directly interact with and kill malignant cells, and their small size could allow more efficient extravasation into the tumour tissue. Extracellular vesicles are also less sensitive to the hostile tumour microenvironment compared to cells. Based on their features, NK cell-derived extracellular vesicles represent promising novel tools in oncology. In this review, we summarize the current available literature on NK cell-derived extracellular vesicles and discuss how they may be utilized in therapy for solid tumours.


Assuntos
Citotoxicidade Imunológica/imunologia , Vesículas Extracelulares , Células Matadoras Naturais/imunologia , Neoplasias , Transferência Adotiva/métodos , Animais , Vesículas Extracelulares/imunologia , Vesículas Extracelulares/transplante , Humanos , Neoplasias/imunologia , Neoplasias/terapia
10.
PLoS Biol ; 18(6): e3000644, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32511236

RESUMO

Mucosa-associated invariant T (MAIT) cells are abundant antimicrobial T cells in humans and recognize antigens derived from the microbial riboflavin biosynthetic pathway presented by the MHC-Ib-related protein (MR1). However, the mechanisms responsible for MAIT cell antimicrobial activity are not fully understood, and the efficacy of these mechanisms against antibiotic resistant bacteria has not been explored. Here, we show that MAIT cells mediate MR1-restricted antimicrobial activity against Escherichia coli clinical strains in a manner dependent on the activity of cytolytic proteins but independent of production of pro-inflammatory cytokines or induction of apoptosis in infected cells. The combined action of the pore-forming antimicrobial protein granulysin and the serine protease granzyme B released in response to T cell receptor (TCR)-mediated recognition of MR1-presented antigen is essential to mediate control against both cell-associated and free-living, extracellular forms of E. coli. Furthermore, MAIT cell-mediated bacterial control extends to multidrug-resistant E. coli primary clinical isolates additionally resistant to carbapenems, a class of last resort antibiotics. Notably, high levels of granulysin and granzyme B in the MAIT cell secretomes directly damage bacterial cells by increasing their permeability, rendering initially resistant E. coli susceptible to the bactericidal activity of carbapenems. These findings define the role of cytolytic effector proteins in MAIT cell-mediated antimicrobial activity and indicate that granulysin and granzyme B synergize to restore carbapenem bactericidal activity and overcome carbapenem resistance in E. coli.


Assuntos
Antígenos de Diferenciação de Linfócitos T/metabolismo , Carbapenêmicos/farmacologia , Citotoxicidade Imunológica , Farmacorresistência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Granzimas/metabolismo , Células T Invariáveis Associadas à Mucosa/imunologia , Anti-Infecciosos/farmacologia , Carga Bacteriana/efeitos dos fármacos , Citotoxicidade Imunológica/efeitos dos fármacos , Células HeLa , Humanos , Cinética
11.
Mol Immunol ; 124: 153-160, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32580073

RESUMO

Patients with Huntington's diseases display reduced tumor incidence mediated by unclear mechanisms. Besides, the effects of characteristic overexpression of 97 polyglutamine protein (polyQ protein) on tumor surveillance by the host immune system have not been investigated. NK cells are cytotoxic innate lymphocytes that sense and kill stressed and transformed cells through recognition of abnormal molecular patterns. Here, we found that polyQ protein induced the accumulation of misfolded proteins in tumor cells and sensitized these tumor cells to NK cell cytolysis in vitro. Transcriptome analysis showed that polyQ protein overexpression caused an abnormal transcriptome changes in tumor cells, which might predispose these tumor cells to death upon NK cell cytolysis. However, on the other hand, polyQ protein in NK cells compromised NK cell cytolytic activity through forcing the accumulation of misfolded proteins. Furthermore, polyQ overexpression enriched oxidative phosphorylation related gene set in NK cells, which might lead to an exhaustion-like status of NK cells with reduced cytolytic activity. Therefore, our study shows that polyQ protein overexpression in tumors alone, but not in both tumor cells and NK cells, might result in increased tumor rejection by NK cells, revealing a dual role of polyQ protein on tumor surveillance by the immune system.


Assuntos
Citotoxicidade Imunológica/imunologia , Vigilância Imunológica/imunologia , Células Matadoras Naturais/imunologia , Neoplasias/imunologia , Peptídeos/metabolismo , Linhagem Celular Tumoral , Humanos , Dobramento de Proteína
12.
Mol Immunol ; 124: 125-141, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32563081

RESUMO

Both mouse and human harbour memory phenotype CD8+ T cells specific for antigens in hosts that have not been previously exposed to these antigens. The origin and the nature of the stimuli responsible for generation of CD44hi CD8+ T cells in specific pathogen-free (SPF) mice remain controversial. It is known that microbiota plays a crucial role in the prevention and resolution of systemic infections by influencing myelopoiesis, regulating dendritic cells, inflammasome activation and promoting the production of type I and II interferons. By contrast, here we suggest that microbiota has a direct effect on generation of memory phenotype CD44hiGP33+CD8+ T cells. In SPF mice, it generates a novel GP33+CD44hiCD8+ T cell sub-population associating the properties of innate and genuine memory cells. These cells are highly enriched in the bone marrow, proliferate rapidly and express immediate effector functions. They dominate the response to LCMV and express particular TCRß chains. The sequence of these selected TCRß chains overlaps with that of GP33+CD8+ T cells directly selected by microbiota in the gut epithelium of SPF mice, demonstrating a common selection mechanism in gut and peripheral CD8+ T cell pool. Therefore microbiota has a direct role in priming T cell immunity in SPF mice and in the selection of TCRß repertoires during systemic infection. We identify a mechanism that primes T cell immunity in SPF mice and may have a major role in colonization resistance and protection from infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Microbiota/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Citotoxicidade Imunológica/imunologia , Memória Imunológica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Organismos Livres de Patógenos Específicos , Subpopulações de Linfócitos T/imunologia
13.
Science ; 368(6493): 897-901, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32381591

RESUMO

Cytotoxic T lymphocytes (CTLs) kill infected and cancerous cells. We detected transfer of cytotoxic multiprotein complexes, called supramolecular attack particles (SMAPs), from CTLs to target cells. SMAPs were rapidly released from CTLs and were autonomously cytotoxic. Mass spectrometry, immunochemical analysis, and CRISPR editing identified a carboxyl-terminal fragment of thrombospondin-1 as an unexpected SMAP component that contributed to target killing. Direct stochastic optical reconstruction microscopy resolved a cytotoxic core surrounded by a thrombospondin-1 shell of ~120 nanometer diameter. Cryo-soft x-ray tomography analysis revealed that SMAPs had a carbon-dense shell and were stored in multicore granules. We propose that SMAPs are autonomous extracellular killing entities that deliver cytotoxic cargo targeted by the specificity of shell components.


Assuntos
Citotoxicidade Imunológica , Granzimas/metabolismo , Complexos Multiproteicos/metabolismo , Perforina/metabolismo , Linfócitos T Citotóxicos/metabolismo , Trombospondina 1/metabolismo , Sistemas CRISPR-Cas , Exocitose , Edição de Genes , Humanos , Células K562 , Trombospondina 1/genética , Tomografia por Raios X
14.
Transl Res ; 223: 61-75, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32438074

RESUMO

Despite the success of anti-retroviral therapy (ART) in transforming HIV into a manageable disease, it has become evident that long-term ART will not eliminate the HIV reservoir and cure the infection. Alternative strategies to eradicate HIV infection, or at least induce a state of viral control and drug-free remission are therefore needed. Therapeutic vaccination aims to induce or enhance immunity to alter the course of a disease. In this review we provide an overview of the current state of therapeutic HIV vaccine research and summarize the obstacles that the field faces while highlighting potential ways forward for a strategy to cure HIV infection.


Assuntos
Vacinas contra a AIDS/uso terapêutico , Infecções por HIV/tratamento farmacológico , Citotoxicidade Imunológica , Reservatórios de Doenças/virologia , Infecções por HIV/imunologia , Humanos , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/imunologia
15.
J Clin Invest ; 130(9): 4694-4703, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32463803

RESUMO

BACKGROUNDCoronavirus disease 19 (COVID-19) is an emerging infectious disease caused by SARS-CoV-2. Antiviral immune response is crucial to achieve pathogen clearance; however, in some patients an excessive and aberrant host immune response can lead to an acute respiratory distress syndrome. The comprehension of the mechanisms that regulate pathogen elimination, immunity, and pathology is essential to better characterize disease progression and widen the spectrum of therapeutic options.METHODSWe performed a flow cytometric characterization of immune cell subsets from 30 patients with COVID-19 and correlated these data with clinical outcomes.RESULTSPatients with COVID-19 showed decreased numbers of circulating T, B, and NK cells and exhibited a skewing of CD8+ T cells toward a terminally differentiated/senescent phenotype. In agreement, CD4+ T and CD8+ T, but also NK cells, displayed reduced antiviral cytokine production capability. Moreover, a reduced cytotoxic potential was identified in patients with COVID-19, particularly in those who required intensive care. The latter group of patients also showed increased serum IL-6 levels that inversely correlated to the frequency of granzyme A-expressing NK cells. Off-label treatment with tocilizumab restored the cytotoxic potential of NK cells.CONCLUSIONThe association between IL-6 serum levels and the impairment of cytotoxic activity suggests the possibility that targeting this cytokine may restore antiviral mechanisms.FUNDINGThis study was supported by funds from the Department of Experimental and Clinical Medicine of University of Florence (the ex-60% fund and the "Excellence Departments 2018-2022 Project") derived from Ministero dell'Istruzione, dell'Università e della Ricerca (Italy).


Assuntos
Betacoronavirus , Infecções por Coronavirus/imunologia , Citotoxicidade Imunológica , Interleucina-6/imunologia , Pneumonia Viral/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Coronavirus/sangue , Infecções por Coronavirus/epidemiologia , Cuidados Críticos , Citocinas/sangue , Citocinas/imunologia , Feminino , Granzimas/sangue , Granzimas/imunologia , Humanos , Interleucina-6/sangue , Células Matadoras Naturais/imunologia , Masculino , Pessoa de Meia-Idade , Modelos Imunológicos , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/epidemiologia
16.
Nat Commun ; 11(1): 2283, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385241

RESUMO

Chimeric antigen receptor (CAR)-T cell therapy has shown remarkable clinical efficacy against B-cell malignancies, yet marked vulnerability to antigen escape and tumor relapse exists. Here we report the rational design and optimization of bispecific CAR-T cells with robust activity against heterogeneous multiple myeloma (MM) that is resistant to conventional CAR-T cell therapy targeting B-cell maturation antigen (BCMA). We demonstrate that BCMA/CS1 bispecific CAR-T cells exhibit superior CAR expression and function compared to T cells that co-express individual BCMA and CS1 CARs. Combination therapy with anti-PD-1 antibody further accelerates the rate of initial tumor clearance in vivo, while CAR-T cell treatment alone achieves durable tumor-free survival even upon tumor re-challenge. Taken together, the BCMA/CS1 bispecific CAR presents a promising treatment approach to prevent antigen escape in CAR-T cell therapy against MM, and the vertically integrated optimization process can be used to develop robust cell-based therapy against novel disease targets.


Assuntos
Imunoterapia Adotiva , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/terapia , Receptores de Antígenos Quiméricos/metabolismo , Antígenos de Neoplasias/imunologia , Antígeno de Maturação de Linfócitos B/metabolismo , Citotoxicidade Imunológica , Edição de Genes , Humanos , Memória Imunológica , Células K562 , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T/imunologia
17.
Nat Commun ; 11(1): 2330, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393818

RESUMO

Recombinant T cell receptors (TCRs) can be used to redirect naïve T cells to eliminate virally infected or cancerous cells; however, they are plagued by low stability and uneven expression. Here, we use molecular modeling to identify mutations in the TCR constant domains (Cα/Cß) that increase the unfolding temperature of Cα/Cß by 20 °C, improve the expression of four separate α/ß TCRs by 3- to 10-fold, and improve the assembly and stability of TCRs with poor intrinsic stability. The stabilizing mutations rescue the expression of TCRs destabilized through variable domain mutation. The improved stability and folding of the TCRs reduces glycosylation, perhaps through conformational stabilization that restricts access to N-linked glycosylation enzymes. The Cα/Cß mutations enables antibody-like expression and assembly of well-behaved bispecific molecules that combine an anti-CD3 antibody with the stabilized TCR. These TCR/CD3 bispecifics can redirect T cells to kill tumor cells with target HLA/peptide on their surfaces in vitro.


Assuntos
Anticorpos Biespecíficos/imunologia , Biologia Computacional/métodos , Receptores de Antígenos de Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Biespecíficos/química , Varredura Diferencial de Calorimetria , Citotoxicidade Imunológica , Imunoglobulina G/metabolismo , Camundongos , Mutação/genética , Polissacarídeos/metabolismo , Desnaturação Proteica , Estabilidade Proteica , Subunidades Proteicas/metabolismo , Receptores de Antígenos de Linfócitos T/química , Proteínas Recombinantes/metabolismo , Solubilidade , Temperatura
18.
Cancer Immunol Immunother ; 69(10): 2147-2155, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32468232

RESUMO

A major factor impeding the success of numerous therapeutic approaches in cancer is the immunosuppressive nature of the tumor microenvironment (TME). Hence, methods capable of reverting tumor immunosuppression through depletion or reprogramming of myeloid-derived suppressive cells (MDSCs) and regulatory T cells (Tregs) are of great clinical need. Here, we explore NKG2D-Fc as a modality to modulate antitumor immunity through the depletion of immunosuppressive MDSCs and Tregs in the TME. We have generated the NKG2D-Fc fusion protein and characterized its potential to mediate tumor control and overall survival in LL2 and MC38 murine models. Upon treatment of LL2 or MC38 tumor-bearing mice with NKG2D-Fc, we observe significant tumor control and enhanced survival compared to Fc control. When characterizing MDCSs and Tregs from tumor-bearing mice, we observe clear expression of NKG2D-ligand RAE1γ and subsequent binding of NKG2D-Fc fusion protein to both MDSCs and Tregs. Examining the immune profile of mice treated with NKG2D-Fc reveals significant depletion of MDSCs and Tregs in the TME, as well as an increase in NK cells likely due to the reversed suppressive TME. In conclusion, NKG2D-Fc induces antitumor immunity and tumor control through the depletion of MDSCs and Tregs, subsequently providing a niche for the infiltration and expansion of proinflammatory cells, such as NK cells. Strategies capable of modulating the immunosuppressive state in cancer are in high clinical demand. NKG2D-Fc is a simple, single tool capable of depleting both MDSCs and Tregs and should be further investigated as a therapeutic agent for the treatment of cancer.


Assuntos
Neoplasias do Colo/imunologia , Fragmentos Fc das Imunoglobulinas/imunologia , Neoplasias Pulmonares/imunologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , Proteínas Recombinantes de Fusão/imunologia , Linfócitos T Reguladores/imunologia , Microambiente Tumoral/imunologia , Animais , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Citotoxicidade Imunológica/imunologia , Feminino , Imunossupressão , Células Matadoras Naturais/imunologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos C57BL , Células Supressoras Mieloides/imunologia , Células Tumorais Cultivadas
19.
Cancer Sci ; 111(6): 1910-1920, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32232903

RESUMO

Pemetrexed (PEM) is a useful drug that can be combined with immune checkpoint blockade therapy for treatment of patients with advanced non-small-cell lung cancer (NSCLC). However, its effects on anti-cancer immunity, especially the sensitivity of NSCLC cells to cytotoxic immune cells, have not been fully investigated. In this study, we examined the effects of PEM on the sensitivity of human NSCLC cells to two different types of cytotoxic immune cells. Pre-treatment with PEM increased the sensitivity of two NSCLC cell lines, PC9 and A549, to activated T cells and natural killer (NK) cells, and decreased the expression of anti-apoptotic proteins, including XIAP and Mcl-1. In addition, PEM treatment increased the cell surface expression of programmed death-ligand 1 (PD-L1) on PC9 cells. PEM-induced upregulation of PD-L1 on PC9 cells was at least partially ascribed to activation of ERK and the NFκB pathway. In contrast, PEM treatment increased the expression of UL16-binding proteins (ULBP), ligands for the NKG2D NK receptor, on PC9 and A549 cells, as well as the induction of senescence. Although the addition of anti-programmed cell death 1 antibody showed no effect on the sensitivity of PEM-treated PC9 and A549 cells to activated T cells, that of anti-NKG2D antibody decreased the enhanced sensitivity of PEM-treated A549 cells to NK cells. These results indicate that PEM can effectively sensitize human NSCLC cells to cytotoxic immune cells while modulating the expression of immune-regulatory molecules.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Citotoxicidade Imunológica/efeitos dos fármacos , Neoplasias Pulmonares/imunologia , Pemetrexede/farmacologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica/imunologia , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Neoplasias Pulmonares/patologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
20.
Cancer Sci ; 111(7): 2223-2233, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32324315

RESUMO

Invariant natural killer T (iNKT) cells are innate-like CD1d-restricted T cells that express the invariant T cell receptor (TCR) composed of Vα24 and Vß11 in humans. iNKT cells specifically recognize glycolipid antigens such as α-galactosylceramide (αGalCer) presented by CD1d. iNKT cells show direct cytotoxicity toward CD1d-positive tumor cells, especially when CD1d presents glycolipid antigens. However, iNKT cell recognition of CD1d-negative tumor cells is unknown, and direct cytotoxicity of iNKT cells toward CD1d-negative tumor cells remains controversial. Here, we demonstrate that activated iNKT cells recognize leukemia cells in a CD1d-independent manner, however still in a TCR-mediated way. iNKT cells degranulated and released Th1 cytokines toward CD1d-negative leukemia cells (K562, HL-60, REH) as well as αGalCer-loaded CD1d-positive Jurkat cells. The CD1d-independent cytotoxicity was enhanced by natural killer cell-activating receptors such as NKG2D, 2B4, DNAM-1, LFA-1 and CD2, but iNKT cells did not depend on these receptors for the recognition of CD1d-negative leukemia cells. In contrast, TCR was essential for CD1d-independent recognition and cytotoxicity. iNKT cells degranulated toward patient-derived leukemia cells independently of CD1d expression. iNKT cells targeted myeloid malignancies more than acute lymphoblastic leukemia. These findings reveal a novel anti-tumor mechanism of iNKT cells in targeting CD1d-negative tumor cells and indicate the potential of iNKT cells for clinical application to treat leukemia independently of CD1d.


Assuntos
Antígenos CD1d/metabolismo , Leucemia/imunologia , Leucemia/metabolismo , Ativação Linfocitária/imunologia , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Animais , Antígenos CD1d/genética , Biomarcadores , Degranulação Celular , Linhagem Celular Tumoral , Receptores Coestimuladores e Inibidores de Linfócitos T/metabolismo , Citocinas/metabolismo , Citotoxicidade Imunológica , Modelos Animais de Doenças , Feminino , Edição de Genes , Xenoenxertos , Humanos , Imunofenotipagem , Leucemia/genética , Leucemia/patologia , Ativação Linfocitária/genética , Camundongos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores Desencadeadores da Citotoxicidade Natural/metabolismo
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