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1.
Int J Mol Sci ; 24(11)2023 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-37298237

RESUMEN

Immune checkpoint inhibitors can block inhibitory molecules on the surface of T cells, switching them from an exhausted to an active state. One of these inhibitory immune checkpoints, programmed cell death protein 1 (PD-1) is expressed on T cell subpopulations in acute myeloid leukemia (AML). PD-1 expression has been shown to increase with AML progression following allo-haematopoeitic stem cell transplantation, and therapy with hypomethylating agents. We have previously shown that anti-PD-1 can enhance the response of leukemia-associated antigen (LAA)-specific T cells against AML cells as well as leukemic stem and leukemic progenitor cells (LSC/LPCs) ex vivo. In concurrence, blocking of PD-1 with antibodies such as nivolumab has been shown to enhance response rates post-chemotherapy and stem cell transplant. The immune modulating drug lenalidomide has been shown to promote anti-tumour immunity including anti-inflammatory, anti-proliferative, pro-apoptotic and anti-angiogenicity. The effects of lenalidomide are distinct from chemotherapy, hypomethylating agents or kinase inhibitors, making lenalidomide an attractive agent for use in AML and in combination with existing active agents. To determine whether anti-PD-1 (nivolumab) and lenalidomide alone or in combination could enhance LAA-specific T cell immune responses, we used colony-forming immune and ELISpot assays. Combinations of immunotherapeutic approaches are believed to increase antigen-specific immune responses against leukemic cells including LPC/LSCs. In this study we used a combination of LAA-peptides with the immune checkpoint inhibitor anti-PD-1 and lenalidomide to enhance the killing of LSC/LPCs ex vivo. Our data offer a novel insight into how we could improve AML patient responses to treatment in future clinical studies.


Asunto(s)
Leucemia Mieloide Aguda , Linfocitos T , Humanos , Lenalidomida/farmacología , Lenalidomida/uso terapéutico , Nivolumab/farmacología , Nivolumab/uso terapéutico , Leucemia Mieloide Aguda/patología , Inmunoterapia , Inmunidad
2.
Br J Haematol ; 198(5): 866-874, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35799423

RESUMEN

Nucleophosmin1 (NPM1) is one of the most commonly mutated genes in AML and is often associated with a favourable prognosis. Immune responses play an increasing role in AML treatment decisions; however, the role of immune checkpoint inhibition is still not clear. To address this, we investigated specific immune responses against NPM1, and three other leukaemia-associated antigens (LAA), PRAME, Wilms' tumour 1 and RHAMM in AML patients. We investigated T cell responses against leukaemic progenitor/stem cells (LPC/LSC) using colony-forming immunoassays and flow cytometry. We examined whether immune checkpoint inhibition with the anti-programmed death 1 antibody increases the immune response against stem cell-like cells, comparing cells from NPM1 mutated and NPM1 wild-type AML patients. We found that the anti-PD-1 antibody, nivolumab, increases LAA stimulated cytotoxic T lymphocytes and the cytotoxic effect against LPC/LSC. The effect was strongest against NPM1mut cells when the immunogenic epitope was derived from the mutated region of NPM1 and these effects were enhanced through the addition of anti-PD-1. The data suggest that patients with NPM1 mutated AML could be treated with the immune checkpoint inhibitor anti-PD-1 and that this treatment combined with NPM1-mutation specific directed immunotherapy could be even more effective for this unique group of patients.


Asunto(s)
Inhibidores de Puntos de Control Inmunológico , Leucemia Mieloide Aguda , Nucleofosmina , Linfocitos T Citotóxicos , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Inmunidad , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Mutación , Nivolumab/farmacología , Nucleofosmina/genética , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores
3.
Nature ; 531(7594): 341-3, 2016 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-26934231

RESUMEN

Microquasars are stellar-mass black holes accreting matter from a companion star and ejecting plasma jets at almost the speed of light. They are analogues of quasars that contain supermassive black holes of 10(6) to 10(10) solar masses. Accretion in microquasars varies on much shorter timescales than in quasars and occasionally produces exceptionally bright X-ray flares. How the flares are produced is unclear, as is the mechanism for launching the relativistic jets and their composition. An emission line near 511 kiloelectronvolts has long been sought in the emission spectrum of microquasars as evidence for the expected electron-positron plasma. Transient high-energy spectral features have been reported in two objects, but their positron interpretation remains contentious. Here we report observations of γ-ray emission from the microquasar V404 Cygni during a recent period of strong flaring activity. The emission spectrum around 511 kiloelectronvolts shows clear signatures of variable positron annihilation, which implies a high rate of positron production. This supports the earlier conjecture that microquasars may be the main sources of the electron-positron plasma responsible for the bright diffuse emission of annihilation γ-rays in the bulge region of our Galaxy. Additionally, microquasars could be the origin of the observed megaelectronvolt continuum excess in the inner Galaxy.

4.
Int J Mol Sci ; 23(6)2022 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-35328721

RESUMEN

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. The standard of care in medically and physically fit patients is intensive induction therapy. The majority of these intensively treated patients achieve a complete remission. However, a high number of these patients will experience relapse. In patients older than 60 years, the results are even worse. Therefore, new therapeutic approaches are desperately needed. One promising approach in high-risk leukemia to prevent relapse is the induction of the immune system simultaneously or after reduction of the initial tumor burden. Different immunotherapeutic approaches such as allogenic stem cell transplantation or donor lymphocyte infusions are already standard therapies, but other options for AML treatment are in the pipeline. Moreover, the therapeutic landscape in AML is rapidly changing, and in the last years, a number of immunogenic targets structures eligible for specific therapy, risk assessment or evaluation of disease course were determined. For example, leukemia-associated antigens (LAA) showed to be critical as biomarkers of disease state and survival, as well as markers of minimal residual disease (MRD). Yet many mechanisms and properties are still insufficiently understood, which also represents a great potential for this form of therapy. Therefore, targeted therapy as immunotherapy could turn into an efficient tool to clear residual disease, improve the outcome of AML patients and reduce the relapse risk. In this review, established but also emerging immunotherapeutic approaches for AML patients will be discussed.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Adulto , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Inmunoterapia/métodos , Neoplasia Residual/terapia , Recurrencia , Inducción de Remisión
5.
Nature ; 523(7559): 189-92, 2015 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-26156372

RESUMEN

A new class of ultra-long-duration (more than 10,000 seconds) γ-ray bursts has recently been suggested. They may originate in the explosion of stars with much larger radii than those producing normal long-duration γ-ray bursts or in the tidal disruption of a star. No clear supernova has yet been associated with an ultra-long-duration γ-ray burst. Here we report that a supernova (SN 2011kl) was associated with the ultra-long-duration γ-ray burst GRB 111209A, at a redshift z of 0.677. This supernova is more than three times more luminous than type Ic supernovae associated with long-duration γ-ray bursts, and its spectrum is distinctly different. The slope of the continuum resembles those of super-luminous supernovae, but extends further down into the rest-frame ultraviolet implying a low metal content. The light curve evolves much more rapidly than those of super-luminous supernovae. This combination of high luminosity and low metal-line opacity cannot be reconciled with typical type Ic supernovae, but can be reproduced by a model where extra energy is injected by a strongly magnetized neutron star (a magnetar), which has also been proposed as the explanation for super-luminous supernovae.

6.
Int J Mol Sci ; 22(19)2021 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-34638823

RESUMEN

Despite recent advances in therapies including immunotherapy, patients with acute myeloid leukaemia (AML) still experience relatively poor survival rates. The Inhibition of Apoptosis (IAP) family member, survivin, also known by its gene and protein name, Baculoviral IAP Repeat Containing 5 (BIRC5), remains one of the most frequently expressed antigens across AML subtypes. To better understand its potential to act as a target for immunotherapy and a biomarker for AML survival, we examined the protein and pathways that BIRC5 interacts with using the Kyoto Encyclopedia of Genes and Genomes (KEGG), search tool for recurring instances of neighbouring genes (STRING), WEB-based Gene Set Analysis Toolkit, Bloodspot and performed a comprehensive literature review. We then analysed data from gene expression studies. These included 312 AML samples in the Microarray Innovations In Leukemia (MILE) dataset. We found a trend between above median levels of BIRC5 being associated with improved overall survival (OS) but this did not reach statistical significance (p = 0.077, Log-Rank). There was some evidence of a beneficial effect in adjusted analyses where above median levels of BIRC5 were shown to be associated with improved OS (p = 0.001) including in Core Binding Factor (CBF) patients (p = 0.03). Above median levels of BIRC5 transcript were associated with improved relapse free survival (p < 0.0001). Utilisation of a second large cDNA microarray dataset including 306 AML cases, again showed no correlation between BIRC5 levels and OS, but high expression levels of BIRC5 correlated with worse survival in inv(16) patients (p = 0.077) which was highly significant when datasets A and B were combined (p = 0.001). In addition, decreased BIRC5 expression was associated with better clinical outcome (p = 0.004) in AML patients exhibiting CBF mainly due to patients with inv(16) (p = 0.007). This study has shown that BIRC5 expression plays a role in the survival of AML patients, this association is not apparent when we examine CBF patients as a cohort, but when those with inv(16) independently indicating that those patients with inv(16) would provide interesting candidates for immunotherapies that target BIRC5.


Asunto(s)
Bases de Datos de Ácidos Nucleicos , Regulación Leucémica de la Expresión Génica , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/mortalidad , Proteínas de Neoplasias/biosíntesis , Survivin/biosíntesis , Supervivencia sin Enfermedad , Femenino , Perfilación de la Expresión Génica , Humanos , Leucemia Mieloide Aguda/genética , Masculino , Proteínas de Neoplasias/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Tasa de Supervivencia , Survivin/genética
7.
Cancer Immunol Immunother ; 69(4): 629-640, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32020256

RESUMEN

The efficacy of immunotherapies in cancer treatment becomes more and more apparent not only in different solid tumors but also in hematological malignancies. However, in acute myeloid leukemia (AML), mechanisms to increase the efficacy of immunotherapeutic approaches have to be further elucidated. Targeting leukemic progenitor and stem cells (LPC/LSC) by specific CTL, for instance, in an adjuvant setting or in minimal residual disease, might be an option to prevent relapse of AML or to treat MRD. Therefore, we investigated the influence of immune checkpoint inhibitors on LAA-specific immune responses by CTL against leukemic myeloid blasts and colony-forming cells including leukemic progenitor cells (CFC/LPC). In functional immunoassays like CFU/CFI (colony-forming units/immunoassays) and ELISpot analysis, we detected specific LAA-directed immune responses against CFC/LPC that are postulated to be the source population of relapse of the disease. The addition of nivolumab (anti-PD-1) significantly increases LAA-directed immune responses against CFC/LPC, no effect is seen when ipilimumab (anti-CTLA-4) is added. The combination of ipilimumab and nivolumab does not improve the effect compared to nivolumab alone. The anti-PD1-directed immune response correlates to PD-L1 expression on progenitor cells. Our data suggest that immunotherapeutic approaches have the potential to target malignant CFC/LPC and anti-PD-1 antibodies could be an immunotherapeutic approach in AML. Moreover, combination with LAA-directed vaccination strategies might also open interesting application possibilities.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Ipilimumab/uso terapéutico , Leucemia Mieloide/terapia , Células Madre Neoplásicas/efectos de los fármacos , Nivolumab/uso terapéutico , Linfocitos T/inmunología , Enfermedad Aguda , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/inmunología , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/antagonistas & inhibidores , Antígeno CTLA-4/inmunología , Antígeno CTLA-4/metabolismo , Humanos , Inmunoterapia/métodos , Ipilimumab/administración & dosificación , Leucemia Mieloide/inmunología , Leucemia Mieloide/metabolismo , Células Madre Neoplásicas/inmunología , Células Madre Neoplásicas/metabolismo , Nivolumab/administración & dosificación , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Receptor de Muerte Celular Programada 1/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Linfocitos T/metabolismo , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismo , Resultado del Tratamiento
8.
Int J Mol Sci ; 21(15)2020 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-32707816

RESUMEN

Endogenous control mechanisms, including immune checkpoints and immunosuppressive cells, are exploited in the process of tumorigenesis to weaken the anti-tumor immune response. Cancer treatment by chemotherapy or immune checkpoint inhibition can lead to changes of checkpoint expression, which influences therapy success. Peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) were isolated from head and neck squamous cell carcinoma (HNSCC) patients (n = 23) and compared to healthy donors (n = 23). Immune checkpoint expression (programmed cell death ligand 1 (PD-1), tumor necrosis factor receptor (TNFR)-related (GITR), CD137, tumor necrosis factor receptor superfamily member 4 (TNFRSF4) (OX40), t-cell immunoglobulin and mucin-domain containing-3 (TIM3), B- and T-lymphocyte attenuator (BTLA), lymphocyte-activation gene 3 (LAG3)) was determined on immune cells by flow cytometry. PD-L1 expression was detected on tumor tissue by immunohistochemistry. Immune cells were treated with immuno- and chemotherapeutics to investigate treatment-specific change in immune checkpoint expression, in vitro. Specific changes of immune checkpoint expression were identified on PBL and TIL of HNSCC patients compared to healthy donors. Various chemotherapeutics acted differently on the expression of immune checkpoints. Changes of checkpoint expression were significantly less pronounced on regulatory T cells compared to other lymphocyte populations. Nivolumab treatment significantly reduced the receptor PD-1 on all analyzed T cell populations, in vitro. The specific immune checkpoint expression patterns in HNSCC patients and the investigated effects of immunomodulatory agents may improve the development and efficacy of targeted immunotherapy.


Asunto(s)
Neoplasias de Cabeza y Cuello/inmunología , Proteínas de Punto de Control Inmunitario/sangre , Inmunoterapia/métodos , Leucocitos Mononucleares/metabolismo , Linfocitos Infiltrantes de Tumor/inmunología , Ligando OX40/sangre , Receptor de Muerte Celular Programada 1/sangre , Carcinoma de Células Escamosas de Cabeza y Cuello/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Alphapapillomavirus/aislamiento & purificación , Estudios de Cohortes , Femenino , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/virología , Humanos , Proteínas de Punto de Control Inmunitario/metabolismo , Inmunomodulación , Masculino , Persona de Mediana Edad , Nivolumab/uso terapéutico , Ligando OX40/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/virología , Linfocitos T Reguladores/inmunología
9.
Int J Cancer ; 144(5): 1135-1146, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30006990

RESUMEN

T cell responses against malignant cells play a major role in maintaining remission and prolonging overall survival in patients after allogeneic stem cell transplantation and donor lymphocyte infusion (DLI) due to graft-versus-leukemia effect. For better characterization of the T cell responses, we assessed frequency and diversity of leukemia-associated antigen (LAA)-specific cytotoxic T cells using ELISpot and pMHC multimer assays and analyzed the frequency of regulatory T cells (Treg) as well as cytokine profiles before/after DLI. The data were correlated to the clinical course of patients. Significantly more LAA-derived T cell epitopes (p = 0.02) were recognized in clinical responders (R) when compared to nonresponders (NR). In addition, pMHC multimer-based flow cytometry showed a significantly higher frequency of LAA-specific T cells in R versus NR. The frequency of Treg in R decreased significantly (p = 0.008) while keeping stable in NR. No differences in T cell subset analysis before/after DLI were revealed. Clinical responders were correlated to specific immune responses and all clinical responders showed an increase of specific immune responses after DLI. Cytokine assays using enzyme-linked immunosorbent assay showed a significant increase of IL-4 after DLI. Taken together, an increase of specific CTL responses against several LAA after DLI was detected. Moreover, this study suggests that enhanced LAA diversity in T cell responses as well as decreasing numbers of Treg contribute to clinical outcome of patients treated with DLI.


Asunto(s)
Enfermedad Injerto contra Huésped/inmunología , Efecto Injerto vs Leucemia/inmunología , Linfocitos T Reguladores/inmunología , Adulto , Línea Celular , Ensayo de Immunospot Ligado a Enzimas/métodos , Femenino , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Masculino , Persona de Mediana Edad , Subgrupos de Linfocitos T/inmunología , Trasplante Homólogo/métodos
10.
Nature ; 493(7431): 187-90, 2013 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-23235823

RESUMEN

A subset of ultraluminous X-ray sources (those with luminosities of less than 10(40) erg s(-1); ref. 1) are thought to be powered by the accretion of gas onto black holes with masses of ∼5-20M cicled dot, probably by means of an accretion disk. The X-ray and radio emission are coupled in such Galactic sources; the radio emission originates in a relativistic jet thought to be launched from the innermost regions near the black hole, with the most powerful emission occurring when the rate of infalling matter approaches a theoretical maximum (the Eddington limit). Only four such maximal sources are known in the Milky Way, and the absorption of soft X-rays in the interstellar medium hinders the determination of the causal sequence of events that leads to the ejection of the jet. Here we report radio and X-ray observations of a bright new X-ray source in the nearby galaxy M 31, whose peak luminosity exceeded 10(39) erg s(-1). The radio luminosity is extremely high and shows variability on a timescale of tens of minutes, arguing that the source is highly compact and powered by accretion close to the Eddington limit onto a black hole of stellar mass. Continued radio and X-ray monitoring of such sources should reveal the causal relationship between the accretion flow and the powerful jet emission.

11.
Int J Cancer ; 138(7): 1792-801, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-26519872

RESUMEN

Wilms' tumor gene 1 (WT1) is overexpressed in leukemia and WT1-derived CD8(+) T-cell epitopes for immunotherapies targeting WT1 have been defined. Here, we analyzed expression of WT1 in 226 peripheral blood and bone marrow samples from patients with acute myeloid leukemia or myelodysplastic syndrome (AML/MDS) before and after allogeneic stem cell transplantation (SCT). Transcripts were assessed by quantitative polymerase chain reaction, and WT1-specific CD8+ cytotoxic T cells (CTL) were monitored by tetramer staining and enzyme-linked immunospot (ELISPOT) assays. Reduction of WT1 levels correlated with a longer survival (p < 0.01). Increment of WT1 transcripts eventually resulted in relapse and subsequent death of the patients. In patients with longer survival and continuous complete remission (cCR) after SCT, higher and enduring frequencies of WT1-specific CTL than in patients developing a relapse were detected. These cells were effector T cells secreting interferon gamma and granzyme B. In summary, WT1 is a suitable marker for the detection of minimal residual disease after SCT or chemotherapy. A rising WT1 signal correlated with a dismal prognosis of the patients. WT1-specific CD8(+) T cells might contribute to the maintenance of a cCR. Targeting WT-1 by peptide/protein vaccination as well as adoptive transfer of genetically modified T cells are future options in the individualized therapy for AML/MDS patients.


Asunto(s)
Biomarcadores de Tumor/inmunología , Leucemia Mieloide Aguda/inmunología , Síndromes Mielodisplásicos/inmunología , Proteínas WT1/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/uso terapéutico , Linfocitos T CD8-positivos/inmunología , Ensayo de Immunospot Ligado a Enzimas , Femenino , Citometría de Flujo , Trasplante de Células Madre Hematopoyéticas , Humanos , Leucemia Mieloide Aguda/terapia , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/terapia , Reacción en Cadena en Tiempo Real de la Polimerasa , Linfocitos T Citotóxicos/inmunología , Trasplante Homólogo , Adulto Joven
12.
Int J Cancer ; 136(8): 1751-68, 2015 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-25195787

RESUMEN

Despite high-dose chemotherapy followed by autologs stem-cell transplantation as well as novel therapeutic agents, multiple myeloma (MM) remains incurable. Following the general trend towards personalized therapy, targeted immunotherapy as a new approach in the therapy of MM has emerged. Better progression-free survival and overall survival after tandem autologs/allogeneic stem cell transplantation suggest a graft versus myeloma effect strongly supporting the usefulness of immunological therapies for MM patients. How to induce a powerful antimyeloma effect is the key issue in this field. Pivotal is the definition of appropriate tumor antigen targets and effective methods for expansion of T cells with clinical activity. Besides a comprehensive list of tumor antigens for T cell-based approaches, eight promising antigens, CS1, Dickkopf-1, HM1.24, Human telomerase reverse transcriptase, MAGE-A3, New York Esophageal-1, Receptor of hyaluronic acid mediated motility and Wilms' tumor gene 1, are described in detail to provide a background for potential clinical use. Results from both closed and on-going clinical trials are summarized in this review. On the basis of the preclinical and clinical data, we elaborate on three encouraging therapeutic options, vaccine-enhanced donor lymphocyte infusion, chimeric antigen receptors-transfected T cells as well as vaccines with multiple antigen peptides, to pave the way towards clinically significant immune responses against MM.


Asunto(s)
Mieloma Múltiple/inmunología , Mieloma Múltiple/terapia , Linfocitos T Citotóxicos/inmunología , Animales , Antígenos de Neoplasias/inmunología , Ensayos Clínicos como Asunto , Humanos , Inmunoterapia/métodos
13.
Int J Cancer ; 137(9): 2083-92, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25912930

RESUMEN

Leukemic stem cells (LSC) might be the source for leukemic disease self-renewal and account for disease relapse after treatment, which makes them a critical target for further therapeutic options. We investigated the role of cytotoxic T-lymphocytes (CTL) counteracting and recognizing LSC. Leukemia-associated antigens (LAA) represent immunogenic structures to target LSC. We enriched the LSC-containing fraction of 20 AML patients and hematopoietic stem cells (HSC) of healthy volunteers. Using microarray analysis and qRT-PCR we detected high expression of several LAA in AML cells but also in LSC. PRAME (p = 0.0085), RHAMM (p = 0.03), WT1 (p = 0.04) and Proteinase 3 (p = 0.04) showed significant differential expression in LSC compared with HSC. PRAME, RHAMM and WT1 are furthermore also lower expressed on leukemic bulk. In contrast, Proteinase 3 indicates a higher expression on leukemic bulk than on LSC. In colony forming unit (CFU) immunoassays, T cells stimulated against various LAA indicated a significant inhibition of CFUs in AML patient samples. The LAA PRAME, RHAMM and WT1 showed highest immunogenic responses with a range up to 58-83%. In a proof of principle xenotransplant mouse model, PRAME-stimulated CTL targeted AML stem cells, reflected by a delayed engraftment of leukemia (p = 0.0159). Taken together, we demonstrated the expression of several LAA in LSC. LAA-specific T cells are able to hamper LSC in immunoassays and in a mouse model, which suggests that immunotherapeutic approaches have the potential to target malignant stem cells.


Asunto(s)
Antígenos de Neoplasias/inmunología , Leucemia Mieloide Aguda/inmunología , Células Madre Neoplásicas/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Supervivencia Celular/inmunología , Humanos , Leucemia Mieloide Aguda/patología , Ratones Endogámicos NOD , Ratones SCID , Trasplante de Neoplasias , Células Tumorales Cultivadas
14.
Blood ; 120(6): 1282-9, 2012 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-22592607

RESUMEN

Mutations in the nucleophosmin gene (NPM1(mut)) are one of the most frequent molecular alterations in acute myeloid leukemia (AML), and immune responses may contribute to the favorable prognosis of AML patients with NPM1(mut). In the present study, we were able to demonstrate both CD4(+) and CD8(+) T-cell responses against NPM1(mut). Ten peptides derived from wild-type NPM1 and NPM1(mut) were subjected to ELISPOT analysis in 33 healthy volunteers and 27 AML patients. Tetramer assays against the most interesting epitopes were performed and Cr(51)-release assays were used to show the cytotoxicity of peptide-specific T cells. Moreover, HLA-DR-binding epitopes were used to test the role of CD4(+) T cells in NPM1 immunogenicity. Two epitopes (epitopes #1 and #3) derived from NPM1(mut) induced CD8(+) T-cell responses. A total of 33% of the NPM1(mut) AML patients showed immune responses against epitope #1 and 44% against epitope #3. Specific lysis of leukemic blasts was detected. To obtain robust immune responses against tumor cells, the activation of CD4(+) T cells is crucial. Therefore, overlapping (OL) peptides were analyzed in ELISPOT assays and OL8 was able to activate both CD8(+) and CD4(+) T cells. The results of the present study show that NPM1(mut) induces specific T-cell responses of CD4(+) and CD8(+) T cells and therefore is a promising target for specific immunotherapies in AML.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Leucemia Mieloide Aguda/inmunología , Proteínas Nucleares/genética , Proteínas Nucleares/inmunología , Secuencia de Aminoácidos , Células Cultivadas , Citotoxicidad Inmunológica/genética , Antígeno HLA-A2/metabolismo , Humanos , Inmunidad Celular/genética , Leucemia Mieloide Aguda/genética , Activación de Linfocitos/genética , Proteínas Mutantes/genética , Proteínas Mutantes/inmunología , Proteínas Mutantes/fisiología , Proteínas Nucleares/química , Proteínas Nucleares/fisiología , Nucleofosmina , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/metabolismo , Unión Proteica , Estructura Terciaria de Proteína/genética
15.
Leukemia ; 38(6): 1307-1314, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38678093

RESUMEN

The therapy of relapsed or refractory (r/r) mantle cell lymphoma (MCL) patients remains a major clinical challenge to date. We conducted a randomized, open-label, parallel-group phase-III trial hypothesizing superior efficacy of rituximab, high-dose cytarabine and dexamethasone with bortezomib (R-HAD + B) versus without (R-HAD) in r/r MCL ineligible for or relapsed after autologous stem cell transplant (ASCT). Primary endpoint was time to treatment failure (TTF), secondary endpoints included response rates, progression free survival, overall survival, and safety. In total, 128 of 175 planned patients were randomized to R-HAD + B (n = 64) or R-HAD (n = 64). Median TTF was 12 vs. 2.6 months (p = 0.045, MIPI-adjusted HR 0.69; 95%CI 0.47-1.02). Overall and complete response rates were 63 vs. 45% (p = 0.049) and 42 vs. 19% (p = 0.0062). A significant treatment effect was seen in the subgroup of patients >65 years (aHR 0.48, 0.29-0.79) and without previous ASCT (aHR 0.52, 0.28-0.96). Toxicity was mostly hematological and attributable to the chemotherapeutic backbone. Grade ≥3 leukocytopenia and lymphocytopenia were more common in R-HAD + B without differences in severe infections between both arms. Bortezomib in combination with chemotherapy can be effective in r/r MCL and should be evaluated further as a therapeutic option, especially if therapy with BTK inhibitors is not an option. Trial registration: NCT01449344.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Bortezomib , Citarabina , Dexametasona , Linfoma de Células del Manto , Recurrencia Local de Neoplasia , Rituximab , Humanos , Bortezomib/administración & dosificación , Bortezomib/uso terapéutico , Linfoma de Células del Manto/tratamiento farmacológico , Linfoma de Células del Manto/patología , Linfoma de Células del Manto/mortalidad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Femenino , Masculino , Dexametasona/administración & dosificación , Dexametasona/uso terapéutico , Dexametasona/efectos adversos , Anciano , Persona de Mediana Edad , Citarabina/administración & dosificación , Citarabina/uso terapéutico , Rituximab/administración & dosificación , Rituximab/uso terapéutico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/patología , Adulto , Resistencia a Antineoplásicos , Tasa de Supervivencia , Anciano de 80 o más Años , Estudios de Seguimiento
16.
J Immunol ; 187(5): 2172-80, 2011 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-21810614

RESUMEN

Immunodominance hierarchies operating in immune responses to viral Ags limit the diversity of the elicited CD8 T cell responses. We evaluated in I-A(b+)/A2-HHD-II and HLA-DR1(+)/A2-DR1 mice the HLA-A*0201-restricted, multispecific CD8 T cell responses to the human CMV tegument phosphoprotein pp65 (pp65) Ag. Vaccination of mice with pp65-encoding DNA elicited high IFN-γ(+) CD8 T cell frequencies to the pp65(495-503)/(e6) epitope and low responses to the pp65(320-328)/(e3) and pp65(522-530)/(e8) epitopes. Abrogation of the e6-specific immunity efficiently enhanced e3- and e8-specific T cell responses by a pp65(Δ501-503) DNA vaccine. The immunodominant e6-specific (but not the e3- and e8-specific) CD8 T cell response critically depends on CD4 T cell help. Injection of monospecific DNA- or peptide-based vaccines encoding the e3 or e8 (but not the e6) epitope into mice elicited CD8 T cells. Codelivering the antigenic peptides with different heterologous CD4 T cell helper epitopes enhanced e6-specific (but not e3- or e8-specific) CD8 T cell responses. Similarly, homologous CD4 T cell help, located within an overlapping (nested) pp65(487-503) domain, facilitated induction of e6-specific CD8 T cell responses by peptide-based vaccination. The position of the e6 epitope within this nested domain is not critical to induce the immunodominant, e6-specific CD8 T cell response to the pp65 Ag. Distant CD4 T cell epitope(s) can thus provide efficient help for establishing pp65-e6 immunodominance in vaccinated mice. These results have practical implications for the design of new T cell-stimulating vaccines.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Epítopos de Linfocito T/inmunología , Antígenos HLA-A/inmunología , Epítopos Inmunodominantes/inmunología , Fosfoproteínas/inmunología , Proteínas de la Matriz Viral/inmunología , Animales , Células HEK293 , Antígenos HLA-A/genética , Antígeno HLA-A2 , Humanos , Activación de Linfocitos/inmunología , Ratones , Ratones Transgénicos , Transfección , Vacunación
17.
Mycoses ; 56(3): 304-10, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23170837

RESUMEN

Invasive aspergillosis is an important cause of morbidity and mortality in haematological patients. Current guidelines recommend voriconazole as first-line therapy. A change in class of antifungal agent is generally recommended for salvage therapy. The focus of this analysis was to assess if posaconazole is suitable for salvage therapy following voriconazole treatment. This was a retrospective investigation on patients with sequential antifungal therapy of posaconazole after voriconazole identified at four German hospitals. Response rates at 30 and 60 days following start of posaconazole application and toxicity of azoles by comparing liver enzymes and cholestasis parameters were evaluated. Data were analysed by descriptive statistics. Overall, the success rate was 72.2% [15 of 36 patients showed complete response (41.7%), 11 patients partial response (30.6%) at any time point], eight patients failed treatment and two were not evaluable. Mean laboratory values increased during voriconazole and decreased during posaconazole treatment: aspartate aminotransferase (increase: 31.9 U l(-1) vs. decrease: 19.6 U l(-1) ), alanine aminotransferase (32.4 U l(-1) vs. 19.8 U l(-1) ), gamma-glutamyl transferase (124.2 U l(-1) vs. 152.3 U l(-1) ) and alkaline phosphatase (71.5 U l(-1) vs. 40.3 U l(-1) ) respectively. No patient discontinued posaconazole therapy due to an adverse event. In this analysis posaconazole was a safe and effective antifungal salvage therapy in patients with prior administration of another triazole.


Asunto(s)
Aspergilosis/tratamiento farmacológico , Pirimidinas/farmacología , Triazoles/farmacología , Adolescente , Adulto , Anciano , Alanina Transaminasa/análisis , Antifúngicos/administración & dosificación , Antifúngicos/farmacología , Aspartato Aminotransferasas/análisis , Evaluación de Medicamentos , Femenino , Humanos , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Persona de Mediana Edad , Pirimidinas/administración & dosificación , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento , Triazoles/administración & dosificación , Voriconazol , Adulto Joven , gamma-Glutamiltransferasa/análisis
19.
Clin Dev Immunol ; 2012: 820394, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22611422

RESUMEN

Multiple myeloma remains an incurable disease although the prognosis has been improved by novel therapeutics and agents recently. Relapse occurs in the majority of patients and becomes fatal finally. Immunotherapy might be a powerful intervention to maintain a long-lasting control of minimal residual disease or to even eradicate disseminated tumor cells. Several tumor-associated antigens have been identified in patients with multiple myeloma. These antigens are expressed in a tumor-specific or tumor-restricted pattern, are able to elicit immune response, and thus could serve as targets for immunotherapy. This review discusses immunogenic antigens with therapeutic potential for multiple myeloma.


Asunto(s)
Antígenos de Neoplasias/inmunología , Antígenos de Neoplasias/uso terapéutico , Inmunoterapia Activa/métodos , Mieloma Múltiple/terapia , Animales , Vacunas contra el Cáncer/uso terapéutico , Humanos , Inmunidad , Terapia Molecular Dirigida
20.
Eur J Med Res ; 27(1): 63, 2022 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-35505368

RESUMEN

BACKGROUND: Immune thrombocytopenia (ITP) is a rare autoimmune disorder characterized by low platelet counts and increased bleeding risk. The disease may be induced by other disorders, including malignancies, autoimmune diseases, infectious agents or drugs. However, ITP has also been described following vaccinations, such as the measles-mumps-rubella vaccination. In rare cases, ITP may occur in children who received a DTaP-IP (diphtheria, tetanus, acellular pertussis vaccine and inactivated poliovirus) vaccine. Hereinafter, we report the first well-documented cases of ITP in an adult patient in the temporal context of a DTaP-IP vaccination. CASE PRESENTATION: This case report attempts to capture the life-threatening picture of a 36-year-old otherwise healthy Caucasian woman with newly diagnosed severe immune thrombocytopenia in the temporal context of a DTaP-IP vaccination. Four days after receiving the vaccine, the women presented to her primary care physician with malaise, fever and recurrent epistaxis. Clinical examination revealed oral petechiae, ecchymoses, and non-palpable petechiae on both legs. The patient was immediately referred to a local hematology unit where she developed hematuria and an intestinal bleeding (WHO Bleeding Grade III) requiring multiple transfusions. After receiving oral corticosteroids and intravenous immunoglobulins, her platelets gradually recovered. Common causes of secondary ITP were ruled out by laboratory investigations, bone marrow and peripheral blood examinations. This raises the possibility of a (secondary) vaccination-associated thrombocytopenia. To the best of our knowledge, this is the first well-documented case of a DTaP-IP vaccination-related ITP in an adult patient in the English literature. CONCLUSION: Although a causal connection between both entities may not be established, we would like to raise awareness in clinicians that ITP following DTaP-IP vaccinations is potentially not limited to children, but may also occur in adults. Users of DTaP-IP booster vaccines should be alert of the possibility of such adverse reactions.


Asunto(s)
Vacunas contra Difteria, Tétanos y Tos Ferina Acelular , Difteria , Poliomielitis , Púrpura Trombocitopénica Idiopática , Tétanos , Trombocitopenia , Tos Ferina , Adulto , Anticuerpos Antibacterianos , Niño , Difteria/etiología , Difteria/prevención & control , Vacunas contra Difteria, Tétanos y Tos Ferina Acelular/efectos adversos , Femenino , Humanos , Inmunización Secundaria/efectos adversos , Poliomielitis/inducido químicamente , Poliomielitis/prevención & control , Vacuna Antipolio de Virus Inactivados/efectos adversos , Púrpura Trombocitopénica Idiopática/inducido químicamente , Tétanos/etiología , Tétanos/prevención & control , Vacunación/efectos adversos , Tos Ferina/etiología , Tos Ferina/prevención & control
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