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Multiple myeloma (MM) is a disease which remains incurable. One of the main reasons is a weakened immune system that allows MM cells to survive. Therefore, the current research is focused on the study of immune system imbalance in MM to find the most effective immunotherapy strategies. Aiming to identify the key points of immune failure in MM patients, we analysed peripheral lymphocytes subsets from MM patients (n = 57) at various stages of the disease course and healthy individuals (HI, n = 15) focusing on T, NK, iNKT, B cells and NK-cell cytokines. Our analysis revealed that MM patients exhibited immune alterations in all studied immune subsets. Compared to HI, MM patients had a significantly lower proportion of CD4 + T cells (19.55% vs. 40.85%; p < 0.001) and CD4 + iNKT cells (18.8% vs. 40%; p < 0.001), within B cells an increased proportion of CD21LCD38L subset (4.5% vs. 0.4%; p < 0.01) and decreased level of memory cells (unswitched 6.1% vs. 14.7%; p < 0.001 and switched 7.8% vs. 11.2%; NS), NK cells displaying signs of activation and exhaustion characterised by a more than 2-fold increase in SLAMF7 MFI (p < 0.001), decreased expression of NKG2D (MFI) and NKp46 (%) on CD16 + 56 + and CD16 + 56- subset respectively (p < 0.05), Effective immunotherapy needs to consider these immune defects and monitoring of the immune status of MM patients is essential to define better interventions in the future.
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Acute myeloid leukaemia (AML) is a complex haematological malignancy characterised by diverse genetic alterations leading to abnormal proliferation of myeloid precursor cells. One of the most significant genetic alterations in AML involves mutations in the FLT3 gene, which plays a critical role in haematopoiesis and haematopoietic homeostasis. This review explores the current understanding of FLT3 gene mutations and isoforms and the importance of the FLT3 protein in AML. FLT3 mutations, including internal tandem duplications (FLT3-ITD) and point mutations in the tyrosine kinase domain (FLT3-TKD), occur in 25-30% in AML and are associated with poor prognosis. FLT3-ITD mutations lead to constitutive activation of the FLT3 signalling pathway, promoting cell survival and proliferation. FLT3-TKD mutations affect the tyrosine kinase domain and affect AML prognosis in various ways. Furthermore, FLT3 isoforms, including shorter variants, contribute to the complexity of FLT3 biology. Additionally, nonpathological polymorphisms in FLT3 are being explored for their potential impact on AML prognosis and treatment response. This review also discusses the development of molecular treatments targeting FLT3, including first-generation and next-generation tyrosine kinase inhibitors, highlighting the challenges of resistance that often arise during therapy. The final chapter describes FLT3 protein domain rearrangements and their relevance to AML pathogenesis.
Assuntos
Leucemia Mieloide Aguda , Humanos , Isoformas de Proteínas/genética , Leucemia Mieloide Aguda/genética , Sobrevivência Celular , Mutação/genética , Proteínas Tirosina Quinases , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
We investigated the influence of glycogen (GG), phytoglycogen (PG), mannan (MAN) and cinnamoyl-modified GG (GG-CIN) on amyloid fibril formation. We used hen egg-white lysozyme (HEWL) as a model system and amyloid beta peptide (1-42) (Aß1-42) as an Alzheimer's disease-relevant system. For brief detection of fibrils was used thioflavin T (ThT) fluorescence assay and the results were confirmed by transmission electron microscopy (TEM). We also deal with the interaction of polysaccharides and HEWL with isothermal titration calorimetry (ITC) and dynamic light scattering (DLS). We found that all polysaccharides accelerated the formation of amyloid fibrils from both HEWL and Aß1-42. At high but physiologically relevant concentrations of GG, amyloid fibril formation was extremely accelerated for HEWL. Therefore, on the basis of the herein presented in vitro data, we hypothesize, that dietary d-glucose intake may influence amyloid fibril formation not only by influencing regulatory pathways, but also by direct glycogen-amyloid precursor protein molecular interaction, as glycogen levels in tissues are highly dependent on d-glucose intake.
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Peptídeos beta-Amiloides , Amiloide , Difusão Dinâmica da Luz , Glicogênio , Microscopia Eletrônica de TransmissãoRESUMO
The formation of amyloid fibrils from certain proteins stays behind a number of pathologies, so-called amyloidoses. Glycosaminoglycans are polysaccharides and are known natural constituents of amyloids in vivo. However, little is known about the effect of other naturally abundant polysaccharides, and even less is known about the effect of chemically modified polysaccharides on the formation of amyloid fibrils. In the case of low-molecular weight compounds, aromatic substances are known to often influence amyloid formation significantly. We investigated the influence of glycogen (GG) and several modifications of GG with cinnamoyl groups, benzoyl groups and phenylacetyl groups. As model systems, hen egg-white lysozyme (HEWL) and amyloid beta peptide (1-42) (Aß1-42), which is an Alzheimer disease-relevant system, were used. The fluorescence of thioflavin-T (ThT) was used for the rapid detection of fibrils, and the fluorescence results were confirmed by transmission electron microscopy (TEM). Other techniques, such as isothermal titration calorimetry (ITC) and dynamic light scattering (DLS), were employed to determine the interactions between HEWL and the modifications. We achieved similar results with both model systems (HEWL and Aß1-42). We showed that π-π interactions played an important role in the process of amyloid fibril formation because fundamental changes were observed in this process even with a very small number of groups containing an aromatic ring. It was found that almost all GG modifications accelerated the formation of amyloid fibrils in both model systems, HEWL and Aß1-42, except for GG-Ph1 (1.6 mol% phenylacetyl groups), which had a retarding effect compared to all other modifications.
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Amiloide , Glicogênio , Peptídeos beta-Amiloides , Difusão Dinâmica da Luz , Microscopia Eletrônica de TransmissãoRESUMO
In some settings, cancer cells responding to treatment undergo an immunogenic form of cell death that is associated with the abundant emission of danger signals in the form of damage-associated molecular patterns. Accumulating preclinical and clinical evidence indicates that danger signals play a crucial role in the (re-)activation of antitumor immune responses in vivo, thus having a major impact on patient prognosis. We have previously demonstrated that the presence of calreticulin on the surface of malignant blasts is a positive prognostic biomarker for patients with acute myeloid leukemia (AML). Calreticulin exposure not only correlated with enhanced T-cell-dependent antitumor immunity in this setting but also affected the number of circulating natural killer (NK) cells upon restoration of normal hematopoiesis. Here, we report that calreticulin exposure on malignant blasts is associated with enhanced NK cell cytotoxic and secretory functions, both in AML patients and in vivo in mice. The ability of calreticulin to stimulate NK-cells relies on CD11c+CD14high cells that, upon exposure to CRT, express higher levels of IL-15Rα, maturation markers (CD86 and HLA-DR) and CCR7. CRT exposure on malignant blasts also correlates with the upregulation of genes coding for type I interferon. This suggests that CD11c+CD14high cells have increased capacity to migrate to secondary lymphoid organs, where can efficiently deliver stimulatory signals (IL-15Rα/IL-15) to NK cells. These findings delineate a multipronged, clinically relevant mechanism whereby surface-exposed calreticulin favors NK-cell activation in AML patients.
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Calreticulina , Leucemia Mieloide Aguda , Animais , Calreticulina/genética , Calreticulina/metabolismo , Citotoxicidade Imunológica , Humanos , Interleucina-15 , Células Matadoras Naturais , Leucemia Mieloide Aguda/terapia , Ativação Linfocitária , CamundongosRESUMO
Relapsed acute myeloid leukemia (AML) is a significant post-transplant complication lacking standard treatment and associated with a poor prognosis. Cellular therapy, which is already widely used as a treatment for several hematological malignancies, could be a potential treatment alternative. Natural killer (NK) cells play an important role in relapse control but can be inhibited by the leukemia cells highly positive for HLA class I. In order to restore NK cell activity after their ex vivo activation, NK cells can be combined with conditioning target cells. In this study, we tested NK cell activity against KG1a (AML cell line) with and without two types of pretreatment-Ara-C treatment that induced NKG2D ligands (increased activating signal) and/or blocking of HLA-KIR (killer-immunoglobulin-like receptors) interaction (decreased inhibitory signal). Both treatments improved NK cell killing activity. Compared with target cell killing of NK cells alone (38%), co-culture with Ara-C treated KG1a target cells increased the killing to 80%. Anti-HLA blocking antibody treatment increased the proportion of dead KG1a cells to 53%. Interestingly, the use of the combination treatment improved the killing potential to led to the death of 85% of KG1a cells. The combination of Ara-C and ex vivo activation of NK cells has the potential to be a feasible approach to treat relapsed AML after hematopoietic stem cell transplantation.
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Imunoterapia/métodos , Células Matadoras Naturais/imunologia , Leucemia Mieloide Aguda/terapia , Linhagem Celular Tumoral , Células Cultivadas , Ensaios Clínicos como Assunto , Citarabina/farmacologia , Humanos , Imunossupressores/farmacologia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/transplante , Leucemia Mieloide Aguda/imunologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , Receptores KIR/imunologia , Transdução de SinaisRESUMO
Cell therapy products represent a new trend of treatment in the field of immunotherapy and regenerative medicine. Their biological nature and multistep preparation procedure require the application of complex release criteria and quality control. Microbial contamination of cell therapy products is a potential source of morbidity in recipients. The automated blood culture systems are widely used for the detection of microorganisms in cell therapy products. However the standard 2-week cultivation period is too long for some cell-based treatments and alternative methods have to be devised. We tried to verify whether a shortened cultivation of the supernatant from the mesenchymal stem cell (MSC) culture obtained 2 days before the cell harvest could sufficiently detect microbial growth and allow the release of MSC for clinical application. We compared the standard Ph. Eur. cultivation method and the automated blood culture system BACTEC (Becton Dickinson). The time to detection (TTD) and the detection limit were analyzed for three bacterial and two fungal strains. The Staphylococcus aureus and Pseudomonas aeruginosa were recognized within 24 h with both methods (detection limit ~10 CFU). The time required for the detection of Bacillus subtilis was shorter with the automated method (TTD 10.3 vs. 60 h for 10-100 CFU). The BACTEC system reached significantly shorter times to the detection of Candida albicans and Aspergillus brasiliensis growth compared to the classical method (15.5 vs. 48 and 31.5 vs. 48 h, respectively; 10-100 CFU). The positivity was demonstrated within 48 h in all bottles, regardless of the size of the inoculum. This study validated the automated cultivation system as a method able to detect all tested microorganisms within a 48-h period with a detection limit of ~10 CFU. Only in case of B. subtilis, the lowest inoculum (~10 CFU) was not recognized. The 2-day cultivation technique is then capable of confirming the microbiological safety of MSC and allows their timely release for clinical application.
Assuntos
Automação , Técnicas de Cultura de Células/métodos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Esterilização/métodos , Bactérias/crescimento & desenvolvimento , Contagem de Células , Ensaio de Unidades Formadoras de Colônias , Fungos/crescimento & desenvolvimento , Humanos , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
Mesenchymal stromal cells (MSC) are fibroblast-like cells present in different types of tissues. Their immunomodulatory potential represents a promising method for post-transplant immunotherapy in the treatment of GVHD (graft-versus-host disease) with suboptimal response to standard immunosuppression. In this study we tested influence of 1-8 month-long cryopreservation on ability of MSC to suppress activation of non-specifically stimulated lymphocytes. We did not observe any changes in proliferation capacity of MSC after thawing. Lymphocytes metabolic activity was inhibited by 30% and number of dividing cells was three times smaller in the presence of MSC. Two activation markers were studied (CD25 and CD69) to confirm preservation of functional cell integrity. Expression of CD25 antigen on CD3(+)CD4(+) and CD3(+)CD4(-) cells was decreased in all co-cultivated samples. Level of CD69 expression on CD3(+)CD4(+) cells was lower in samples with added MSC (10-15% on day +2) but without reaching statistical significance. The lower expression (approximately 5%) was observed also on CD4-cells. The study confirms the preservation of immunomodulatory properties of cryopreserved and re-expanded MSC. Aliquots with cryopreserved cells can represent an optimal source for a quick preparation of MSC cell product with the possibility to apply the same cells repeatedly.
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Criopreservação , Doença Enxerto-Hospedeiro/terapia , Células-Tronco Mesenquimais/citologia , Proliferação de Células , Humanos , Imunofenotipagem , Ativação LinfocitáriaRESUMO
MOTIVATION: Amyloidoses are diseases caused by the accumulation of normally soluble proteins in the form of insoluble amyloids, leading to the gradual dysfunction and failure of various organs and tissues. Inhibiting amyloid formation is therefore an important therapeutic target. HYPOTHESIS: We hypothesized that mono- and di-gradient amphiphilic copolymers of hydrophilic 2-(m)ethyl-2-oxazoline and hydrophobic 2-aryl-2-oxazolines may inhibit amyloid fibril formation. EXPERIMENTS: In the model system with hen egg white lysozyme (HEWL) as amyloidogenic protein we determined the effect of these polymers on the amyloid formation by making use of the thioflavin T fluorescence, transmission electron microscopy, isothermal titration calorimetry, and dynamic light scattering. FINDINGS: We found that some gradient copolymers possess very potent concentration-dependent inhibitory effects on HEWL amyloid formation. Structure-activity relationship revealed that copolymers with higher ratios of aromatic monomeric units had stronger amyloid suppression effects, most plausibly due to the combination of hydrophobic and π-π interactions. The measurements also revealed that the polymers that inhibit amyloid formation most plausibly do so in the form of micelles that interact with the growing amyloid fibril ends, not with isolated HEWL molecules in solution. These findings suggest the potential use of these gradient copolymers as therapeutic agents for amyloidoses.
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Amiloide , Amiloidose , Humanos , Proteínas Amiloidogênicas , Calorimetria , PolímerosRESUMO
While type I interferon (IFN) is best known for its key role against viral infection, accumulating preclinical and clinical data indicate that robust type I IFN production in the tumor microenvironment promotes cancer immunosurveillance and contributes to the efficacy of various antineoplastic agents, notably immunogenic cell death inducers. Here, we report that malignant blasts from patients with acute myeloid leukemia (AML) release type I IFN via a Toll-like receptor 3 (TLR3)-dependent mechanism that is not driven by treatment. While in these patients the ability of type I IFN to stimulate anticancer immune responses was abolished by immunosuppressive mechanisms elicited by malignant blasts, type I IFN turned out to exert direct cytostatic, cytotoxic and chemosensitizing activity in primary AML blasts, leukemic stem cells from AML patients and AML xenograft models. Finally, a genetic signature of type I IFN signaling was found to have independent prognostic value on relapse-free survival and overall survival in a cohort of 132 AML patients. These findings delineate a clinically relevant, therapeutically actionable and prognostically informative mechanism through which type I IFN mediates beneficial effects in patients with AML.
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Antineoplásicos , Interferon Tipo I , Leucemia Mieloide Aguda , Humanos , Leucemia Mieloide Aguda/patologia , Antineoplásicos/uso terapêutico , Resultado do Tratamento , Transdução de Sinais , Microambiente TumoralRESUMO
Natural killer cells possess key regulatory function in various malignant diseases, including acute myeloid leukemia. NK cell activity is driven by signals received through ligands binding activating or inhibitory receptors. Their activity towards elimination of transformed or virally infected cells can be mediated through MICA, MICB and ULBP ligands binding the activating receptor NKG2D. Given the efficiency of NK cells, potential target cells developed multiple protecting mechanisms to overcome NK cells killing on various levels of biogenesis of NKG2D ligands. Targeted cells can degrade ligand transcripts via microRNAs or modify them at protein level to prevent their presence at cell surface via shedding, with added benefit of shed ligands to desensitize NKG2D receptor and avert the threat of destruction via NK cells. NK cells and their activity are also indispensable during hematopoietic stem cell transplantation, crucial treatment option for patients with malignant disease, including acute myeloid leukemia. Function of both NKG2D and its ligands is strongly affected by polymorphisms and particular allelic variants, as different alleles can play variable roles in ligand-receptor interaction, influencing NK cell function and HSCT outcome differently. For example, role of amino acid exchange at position 129 in MICA or at position 98 in MICB, as well as the role of other polymorphisms leading to different shedding of ligands, was described. Finally, match or mismatch between patient and donor in NKG2D ligands affect HSCT outcome. Having the information beyond standard HLA typing prior HSCT could be instrumental to find the best donor for the patient and to optimize effects of treatment by more precise patient-donor match. Here, we review recent research on the NKG2D/NKG2D ligand biology, their regulation, description of their polymorphisms across the populations of patients with AML and the influence of particular polymorphisms on HSCT outcome.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Células Matadoras Naturais/imunologia , Leucemia Mieloide Aguda/terapia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , Recidiva Local de Neoplasia/epidemiologia , Intervalo Livre de Doença , Seleção do Doador/métodos , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Células Matadoras Naturais/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/mortalidade , Ligantes , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Recidiva Local de Neoplasia/genética , Polimorfismo de Nucleotídeo Único , Medicina de Precisão/métodos , Resultado do TratamentoRESUMO
Cryopreserved haematopoietic progenitor cells are used to restore autologous haematopoiesis after high dose chemotherapy. Although the cells are routinely stored for a long period, concerns remain about the maximum storage time and the possible negative effect of storage on their potency. We evaluated the effect of cryopreservation on the quality of peripheral stem cell grafts stored for a short (3 months) and a long (10 years) period and we compared it to native products.The viability of CD34+ cells remained unaffected during storage, the apoptotic cells were represented up to 10% and did not differ between groups. The clonogenic activity measured by ATP production has decreased with the length of storage (ATP/cell 1.28 nM in native vs. 0.63 in long term stored products, P < 0.05). Only borderline changes without statistical significance were detected when examining mitochondrial and aldehyde dehydrogenase metabolic activity and intracellular pH, showing their good preservation during cell storage. Our experience demonstrates that cryostorage has no major negative effect on stem cell quality and potency, and therefore autologous stem cells can be stored safely for an extended period of at least 10 years. On the other hand, long term storage for 10 years and longer may lead to mild reduction of clonogenic capacity. When a sufficient dose of stem cells is infused, these changes will not have a clinical impact. However, in products stored beyond 10 years, especially when a low number of CD34+ cells is available, the quality of stem cell graft should be verified before infusion using the appropriate potency assays.
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Criopreservação/métodos , Células-Tronco Hematopoéticas/metabolismo , Transplante de Células-Tronco de Sangue Periférico/métodos , Células-Tronco de Sangue Periférico/metabolismo , HumanosRESUMO
NKG2D and its ligands, MICA and MICB, are known as the key regulators of NK cells. NK cells are the first reconstituted cells after the allogeneic hematopoietic stem cell transplantation (HSCT); therefore, it is crucial to understand their role in HSCT outcome. In the presented study, we investigated the single amino acid changes across the exons 2-4 of MICA and MICB genes, and point mutations within the NKG2D gene, which defines the type of NKG2D haploblock (HNK/LNK) in the donors (n = 124), as well as in patients with acute myeloid leukemia (n = 78). In our cohort, we found that graft from a donor with at least one MICA allele containing glycine at position 14 (MICA-14Gly) is significantly associated with deterioration of a patient's overall survival (OS) (p < 0.05). We also observed a negative effect of MICB-58 (Lys â Glu) polymorphism on relapse-free survival (RFS), although it was not statistically significant in multivariate analysis (p = 0.069). To our knowledge, this is the first work describing the role of MICA-14 and MICB-58 polymorphisms on HSCT outcome.
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Accumulating evidence indicates that immune checkpoint inhibitors (ICIs) can restore CD8+ cytotoxic T lymphocyte (CTL) functions in preclinical models of acute myeloid leukemia (AML). However, ICIs targeting programmed cell death 1 (PDCD1, best known as PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4) have limited clinical efficacy in patients with AML. Natural killer (NK) cells are central players in AML-targeting immune responses. However, little is known on the relationship between co-inhibitory receptors expressed by NK cells and the ability of the latter to control AML. Here, we show that hepatitis A virus cellular receptor 2 (HAVCR2, best known as TIM-3) is highly expressed by NK cells from AML patients, correlating with improved functional licensing and superior effector functions. Altogether, our data indicate that NK cell frequency as well as TIM-3 expression levels constitute prognostically relevant biomarkers of active immunity against AML.
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Receptor Celular 2 do Vírus da Hepatite A , Células Matadoras Naturais , Leucemia Mieloide Aguda , Linfócitos T CD8-Positivos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Linfócitos T CitotóxicosRESUMO
Killer-immunoglobulin-like receptors (KIRs) are critical natural killer (NK) cell regulators. The expression of KIRs is a dynamic process influenced by many factors. Their ligands-HLA(Human Leukocyte Antigen) class I molecules-are expressed on all nucleated cells that keep NK cells under control. In hematopoietic stem cell transplantation (HSCT), NK cells play an essential role in relapse protection. In the presented pilot study, we characterized the dynamic expression of inhibitory KIRS (iKIRs), which protect cells against untoward lysis, in donors and patients during the first three months after HSCT using flow cytometry. The expression of all iKIRs was highly variable and sometimes correlated with patients' clinical presentation and therapy regiment. Cyclophosphamide (Cy) in the graft-versus-host disease (GvHD) prevention protocol downregulated KIR2DL1 to just 25% of the original donor value, and the FEAM (Fludarabine + Etoposid + Ara-C + Melphalan) conditioning protocol reduced KIR2DL3. In lymphoid neoplasms, there was a slightly increased KIR2DL3 expression compared to myeloid malignancies. Additionally, we showed that the ex vivo activation of NK cells did not alter the level of iKIRs. Our study shows the influence of pre- and post-transplantation protocols on iKIR expression on the surface of NK cells and the importance of monitoring their cell surface.
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Genetic and transcriptional heterogeneity of Chronic lymphocytic leukaemia (CLL) limits prevention of disease progression. Longitudinal single-cell transcriptomics represents the state-of-the-art method to profile the disease heterogeneity at diagnosis and to inform about disease evolution. Here, we apply single-cell RNA-seq to a CLL case, sampled at diagnosis and relapse, that was treated with FCR (Fludarabine, Cyclophosphamide, Rituximab) and underwent a dramatic decrease in CD19 expression during disease progression. Computational analyses revealed a major switch in clones' dominance during treatment. The clone that expanded at relapse showed 17p and 3p chromosomal deletions, and up-regulation of pathways related to motility, cytokine signaling and antigen presentation. Single-cell RNA-seq uniquely revealed that this clone was already present at low frequency at diagnosis, and it displays feature of plasma cell differentiation, consistent with a more aggressive phenotype. This study shows the benefit of single-cell profiling of CLL heterogeneity at diagnosis, to identify clones that might otherwise not be recognized and to determine the best treatment options.
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Natural killer (NK) cells constitute the predominant innate lymphocyte subset that mediates the anti-viral and anti-tumor immune responses. NK cells use an array of innate receptors to sense their environment and to respond to infections, cellular stress and transformation. The resulting NK cell activation, including cytotoxicity and cytokine production, is a fundamental component of the early immune response. The most recent discoveries in NK cell biology have stimulated the translational research that has led to remarkable results for the treatment of human malignancies. Therefore, the rapid isolation of NK cells from the peripheral blood or tumor microenvironment and the subsequent assessment of cytolytic function are crucial to the study of their potency and NK cell-mediated immunosurveillance. Here, we provide protocols for NK cell isolation and the assessment of NK cell cytotoxicity using flow cytometry.
Assuntos
Testes Imunológicos de Citotoxicidade/métodos , Citotoxicidade Imunológica , Citometria de Fluxo/métodos , Células Matadoras Naturais/imunologia , Separação Celular/métodos , Humanos , Ativação LinfocitáriaRESUMO
Cardiac damage is one of major cause of worldwide morbidity and mortality. Despite the development in pharmacotherapy, cardiosurgery and interventional cardiology, many patients remain at increased risk of developing adverse cardiac remodeling. An alternative treatment approach is the application of stem cells. Mesenchymal stem cells are among the most promising cell types usable for cardiac regeneration. Their homing to the damaged area, differentiation into cardiomyocytes, paracrine and/or immunomodulatory effect on cardiac tissue was investigated extensively. Despite promising preclinical reports, clinical trials on human patients are not convincing. Meta-analyses of these trials open many questions and show that routine clinical application of mesenchymal stem cells as a cardiac treatment may be not as helpful as expected. This review summarizes contemporary knowledge about mesenchymal stem cells role in cardiac tissue repair and discusses the problems and perspectives of this experimental therapeutical approach.
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Doenças Cardiovasculares/terapia , Células-Tronco Mesenquimais/citologia , Miócitos Cardíacos/fisiologia , Regeneração/fisiologia , Medicina Regenerativa , Doenças Cardiovasculares/patologia , Humanos , Transplante de Células-Tronco Mesenquimais/métodos , MiocárdioRESUMO
Severe influenza infection has no effective treatment available. One of the key barriers to developing host-directed therapy is a lack of reliable prognostic factors needed to guide such therapy. Here, we use a network analysis approach to identify host factors associated with severe influenza and fatal outcome. In influenza patients with moderate-to-severe diseases, we uncover a complex landscape of immunological pathways, with the main changes occurring in pathways related to circulating neutrophils. Patients with severe disease display excessive neutrophil extracellular traps formation, neutrophil-inflammation and delayed apoptosis, all of which have been associated with fatal outcome in animal models. Excessive neutrophil activation correlates with worsening oxygenation impairment and predicted fatal outcome (AUROC 0.817-0.898). These findings provide new evidence that neutrophil-dominated host response is associated with poor outcomes. Measuring neutrophil-related changes may improve risk stratification and patient selection, a critical first step in developing host-directed immune therapy.
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Armadilhas Extracelulares/imunologia , Influenza Humana/imunologia , Influenza Humana/patologia , Ativação de Neutrófilo/imunologia , Neutrófilos/imunologia , Ciclo Celular/imunologia , Feminino , Expressão Gênica/genética , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/imunologia , Vírus da Influenza B/isolamento & purificação , Influenza Humana/mortalidade , Pulmão/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Respiração Artificial , Insuficiência Respiratória/mortalidade , Insuficiência Respiratória/patologia , Insuficiência Respiratória/virologiaRESUMO
Chimeric antigen receptor anti-CD19 (CAR19)-T cell immunotherapy-induced clinical remissions in CD19+ B cell lymphomas are often short lived. We tested whether CAR19-engineering of the CD1d-restricted invariant natural killer T (iNKT) cells would result in enhanced anti-lymphoma activity. CAR19-iNKT cells co-operatively activated by CD1d- and CAR19-CD19-dependent interactions are more effective than CAR19-T cells against CD1d-expressing lymphomas in vitro and in vivo. The swifter in vivo anti-lymphoma activity of CAR19-iNKT cells and their enhanced ability to eradicate brain lymphomas underpinned an improved tumor-free and overall survival. CD1D transcriptional de-repression by all-trans retinoic acid results in further enhanced cytotoxicity of CAR19-iNKT cells against CD19+ chronic lymphocytic leukemia cells. Thus, iNKT cells are a highly efficient platform for CAR-based immunotherapy of lymphomas and possibly other CD1d-expressing cancers.