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1.
Commun Biol ; 7(1): 590, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755280

RESUMO

Infection of bacteria by phages is a complex multi-step process that includes specific recognition of the host cell, creation of a temporary breach in the host envelope, and ejection of viral DNA into the bacterial cytoplasm. These steps must be perfectly regulated to ensure efficient infection. Here we report the dual function of the tail completion protein gp16.1 of bacteriophage SPP1. First, gp16.1 has an auxiliary role in assembly of the tail interface that binds to the capsid connector. Second, gp16.1 is necessary to ensure correct routing of phage DNA to the bacterial cytoplasm. Viral particles assembled without gp16.1 are indistinguishable from wild-type virions and eject DNA normally in vitro. However, they release their DNA to the extracellular space upon interaction with the host bacterium. The study shows that a highly conserved tail completion protein has distinct functions at two essential steps of the virus life cycle in long-tailed phages.


Assuntos
Proteínas da Cauda Viral , Proteínas da Cauda Viral/metabolismo , Proteínas da Cauda Viral/genética , Bacteriófagos/genética , Bacteriófagos/fisiologia , Bacteriófagos/metabolismo , DNA Viral/metabolismo , DNA Viral/genética , Vírion/metabolismo
2.
Acta Ortop Bras ; 31(spe2): e264305, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37323147

RESUMO

Objective: Present the preliminary results of a case series using the surgical ankle arthrodesis technique with an intramedullary retrograde nail for bone tumors. Methods: We present the preliminary data of 4 patients, 3 males and 1 female, with a mean age of 46,2 (range 32 to 58) years, with histology proven Giant Cell Tumour of bone in 3 and osteosarcoma in 1. The mean resection length of distal tibia was 11,75 (range 9 to 16) cm, and all the patients underwent reconstruction with a tibiotalocalcaneal arthrodesis with an intercalary allograft fixed by a retrograde intramedullary nail. Results: Oncological follow-up evolved without evidence of local recurrence or disease progression in all patients. After a mean time of 69.5 (range 32 to 98 months), patients had a mean MSTS12 functional score of 82.5% (range 75 to 90). All tibial arthrodesis and diaphyseal osteotomy sites were fused within 6 months with a return to activities without complications related to coverage skin or infection. Conclusion: No complications were recorded; all arthrodesis and diaphysial tibial osteotomy sites fused by 6 months, and the mean follow-up of those patients was 69,5 (range 32 to 988) months, with a mean functional MSTS score of 82,5% (range 75-90). Level of Evidence: IV; Retrospective Case Series.


Objetivo: Apresentar os resultados preliminares de uma série de casos utilizando a técnica cirúrgica de artrodese do tornozelo com haste intramedular retrógada para tumores ósseos. Métodos: Apresentamos os dados preliminares de quatro pacientes, três homens e uma mulher, com idade média de 46,2 (variação de 32 a 58) anos, com histologia comprovada de tumor de células gigantes em três e osteossarcoma em um. O comprimento médio de ressecção da tíbia distal foi de 11,75 (variação de 9 a 16) cm, e todos os pacientes foram submetidos à reconstrução com uma artrodese tibiotalocalcaneana com um aloenxerto intercalar fixado por uma haste intramedular retrógrada. Resultados: O acompanhamento oncológico evoluiu sem evidências de recidiva local ou progressão da doença, em todos os pacientes. Após um tempo médio de 69,5 (variação de 32 a 98 meses), os pacientes tiveram uma pontuação média funcional MSTS12 de 82,5% (variação de 75 a 90). Todos os locais de artrodese e osteotomia diafisária tibiais foram fundidos em 6 meses com retorno às atividades de vida diária sem complicações relacionadas à cobertura ou infecção. Conclusão: Não foram registradas complicações; todos os locais de artrodese e osteotomia diafisária da tíbia fundiram-se em 6 meses, e o acompanhamento médio desses pacientes foi de 69,5 (variação de 32 a 988) meses, com uma pontuação média funcional MSTS de 82,5% (variação de 75-90). Nível de Evidência IV; Série de Casos Retrospectivos.

3.
Arch Virol ; 168(7): 187, 2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37351676

RESUMO

The Acinetobacter baumannii bacteriophage Aci01-1, which belongs to the genus Saclayvirus of the order Caudoviricetes, has an icosahedral head and a contractile rigid tail. We report that Aci01-1 has, attached to the tail conical tip, a remarkable 146-nm-long flexible fiber with seven beads and a terminal knot. Its putative gene coding for a 241.36-kDa tail fiber protein is homologous to genes in Aci01-1-related and unrelated phages. Analysis of its 3D structure using AlphaFold provides a structural model for the fiber observed by electron microscopy. We also identified a putative receptor of the phage on the bacterial capsule that is hypothesized to interact with the Aci01-1 long fiber.


Assuntos
Acinetobacter baumannii , Bacteriófagos , Acinetobacter baumannii/genética , Myoviridae/genética , Bacteriófagos/genética , Microscopia Eletrônica
4.
Psychol Med ; 53(10): 4780-4787, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-35730237

RESUMO

BACKGROUND: The brain functional correlates of delusions have been relatively little studied. However, a virtual reality paradigm simulating travel on the London Underground has been found to evoke referential ideation in both healthy subjects and patients with schizophrenia, making brain activations in response to such experiences potentially identifiable. METHOD: Ninety patients with schizophrenia/schizoaffective disorder and 28 healthy controls underwent functional magnetic resonance imaging while they viewed virtual reality versions of full and empty Barcelona Metro carriages. RESULTS: Compared to the empty condition, viewing the full carriage was associated with activations in the visual cortex, the cuneus and precuneus/posterior cingulate cortex, the inferior parietal cortex, the angular gyrus and parts of the middle and superior temporal cortex including the temporoparietal junction bilaterally. There were no significant differences in activation between groups. Nor were there activations associated with referentiality or presence of delusions generally in the patient group. However, patients with persecutory delusions showed a cluster of reduced activation compared to those without delusions in a region in the right temporal/occipital cortex. CONCLUSIONS: Performance of the metro task is associated with a widespread pattern of activations, which does not distinguish schizophrenic patients and controls, or show an association with referentiality or delusions in general. However, the finding of a cluster of reduced activation close to the right temporoparietal junction in patients with persecutory delusions specifically is of potential interest, as this region is believed to play a role in social cognition.


Assuntos
Transtornos Psicóticos , Esquizofrenia , Humanos , Delusões/diagnóstico , Esquizofrenia/complicações , Imageamento por Ressonância Magnética/métodos , Encéfalo
5.
Acta ortop. bras ; 31(spe2): e264305, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1439153

RESUMO

ABSTRACT Objective Present the preliminary results of a case series using the surgical ankle arthrodesis technique with an intramedullary retrograde nail for bone tumors. Methods We present the preliminary data of 4 patients, 3 males and 1 female, with a mean age of 46,2 (range 32 to 58) years, with histology proven Giant Cell Tumour of bone in 3 and osteosarcoma in 1. The mean resection length of distal tibia was 11,75 (range 9 to 16) cm, and all the patients underwent reconstruction with a tibiotalocalcaneal arthrodesis with an intercalary allograft fixed by a retrograde intramedullary nail. Results Oncological follow-up evolved without evidence of local recurrence or disease progression in all patients. After a mean time of 69.5 (range 32 to 98 months), patients had a mean MSTS12 functional score of 82.5% (range 75 to 90). All tibial arthrodesis and diaphyseal osteotomy sites were fused within 6 months with a return to activities without complications related to coverage skin or infection. Conclusion No complications were recorded; all arthrodesis and diaphysial tibial osteotomy sites fused by 6 months, and the mean follow-up of those patients was 69,5 (range 32 to 988) months, with a mean functional MSTS score of 82,5% (range 75-90). Level of Evidence: IV; Retrospective Case Series.


RESUMO Objetivo Apresentar os resultados preliminares de uma série de casos utilizando a técnica cirúrgica de artrodese do tornozelo com haste intramedular retrógada para tumores ósseos. Métodos Apresentamos os dados preliminares de quatro pacientes, três homens e uma mulher, com idade média de 46,2 (variação de 32 a 58) anos, com histologia comprovada de tumor de células gigantes em três e osteossarcoma em um. O comprimento médio de ressecção da tíbia distal foi de 11,75 (variação de 9 a 16) cm, e todos os pacientes foram submetidos à reconstrução com uma artrodese tibiotalocalcaneana com um aloenxerto intercalar fixado por uma haste intramedular retrógrada. Resultados O acompanhamento oncológico evoluiu sem evidências de recidiva local ou progressão da doença, em todos os pacientes. Após um tempo médio de 69,5 (variação de 32 a 98 meses), os pacientes tiveram uma pontuação média funcional MSTS12 de 82,5% (variação de 75 a 90). Todos os locais de artrodese e osteotomia diafisária tibiais foram fundidos em 6 meses com retorno às atividades de vida diária sem complicações relacionadas à cobertura ou infecção. Conclusão Não foram registradas complicações; todos os locais de artrodese e osteotomia diafisária da tíbia fundiram-se em 6 meses, e o acompanhamento médio desses pacientes foi de 69,5 (variação de 32 a 988) meses, com uma pontuação média funcional MSTS de 82,5% (variação de 75-90). Nível de Evidência IV; Série de Casos Retrospectivos.

6.
Nat Commun ; 13(1): 7283, 2022 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-36435855

RESUMO

Numerous viruses package their dsDNA genome into preformed capsids through a portal gatekeeper that is subsequently closed. We report the structure of the DNA gatekeeper complex of bacteriophage SPP1 (gp612gp1512gp166) in the post-DNA packaging state at 2.7 Å resolution obtained by single particle cryo-electron microscopy. Comparison of the native SPP1 complex with assembly-naïve structures of individual components uncovered the complex program of conformational changes leading to its assembly. After DNA packaging, gp15 binds via its C-terminus to the gp6 oligomer positioning gp15 subunits for oligomerization. Gp15 refolds its inner loops creating an intersubunit ß-barrel that establishes different types of contacts with six gp16 subunits. Gp16 binding and oligomerization is accompanied by folding of helices that close the portal channel to keep the viral genome inside the capsid. This mechanism of assembly has broad functional and evolutionary implications for viruses of the prokaryotic tailed viruses-herpesviruses lineage.


Assuntos
Bacteriófagos , Montagem de Vírus , Microscopia Crioeletrônica , Montagem de Vírus/genética , Proteínas Virais/metabolismo , Bacteriófagos/metabolismo , Genoma Viral
7.
Int J Mol Sci ; 23(17)2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36077209

RESUMO

Solute carrier (SLC) and ATP-binding cassette (ABC) transporters comprise a variety of proteins expressed on cell membranes responsible for intrusion or extrusion of substrates, respectively, including nutrients, xenobiotics, and chemotherapeutic agents. These transporters mediate the cellular disposition of tyrosine kinase inhibitors (TKIs), and their genetic variants could affect its function, potentially predisposing patients to chronic myeloid leukaemia (CML) and modulating treatment response. We explored the impact of genetic variability (single nucleotide variants-SNVs) of drug transporter genes (ABCB1, ABCG2, SLC22A1, and SLC22A5) on CML susceptibility, drug response, and BCR-ABL1 mutation status. We genotyped 10 SNVs by tetra-primers-AMRS-PCR in 198 CML patients and 404 controls, and assessed their role in CML susceptibility and prognosis. We identified five SNVs associated with CML predisposition, with some variants increasing disease risk, including TT genotype ABCB1 (rs1045642), and others showing a protective effect (GG genotype SLC22A5 rs274558). We also observed different haplotypes and genotypic profiles associated with CML predisposition. Relating to drug response impact, we found that CML patients with the CC genotype (rs2231142 ABCG2) had an increased risk of TKI resistance (six-fold). Additionally, CML patients carrying the CG genotype (rs683369 SLC22A1) presented a 4.54-fold higher risk of BCR-ABL1 mutations. Our results suggest that drug transporters' SNVs might be involved in CML susceptibility and TKI response, and predict the risk of BCR-ABL1 mutations, highlighting the impact that SNVs could have in therapeutic selection.


Assuntos
Antineoplásicos , Leucemia Mielogênica Crônica BCR-ABL Positiva , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Genótipo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Proteínas de Membrana Transportadoras/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Membro 5 da Família 22 de Carreadores de Soluto/genética
8.
Biota Neotrop. (Online, Ed. ingl.) ; 22(spe): e20211373, 2022. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1394007

RESUMO

Abstract Natural ecosystems are under severe threat worldwide and environmental policies are essential to minimize present and future impacts on biodiversity, ecosystem services and climate change. The New Forest Act in Brazil is the main policy to protect native vegetation in private lands, which comprise 54% of the remaining Brazilian native vegetation. However, conflicts between environmental and agricultural concerns in its implementation demand for balanced solutions based on scientific evidence. To face the challenge of applying science in environmental policy establishment, we developed a scientific project funded by the São Paulo State Research Foundation (FAPESP) to support the implementation of the New Forest Act in São Paulo State, as part of the Biota/FAPESP Program. The project was conducted differently from a regular research project: the broad objective was to provide scientific support to the State's implementation of the New Forest Act, based on a participatory interaction among stakeholders to build specific objectives, methods, and discussion of results, within an interdisciplinary and intersectoral research team. Here, we present the lessons learned during and after the four years of the research project development to evaluate how scientific knowledge can be produced and adopted in the implementation of a specific environmental policy. We present the main outcomes and the challenges faced in trying to include scientific data in the decision-making process. We also present current and future challenges in the New Forest Act implementation that could be solved with scientific evidence. The lessons learned showed that even designing the project in order to meet the needs to support the implementation of the environmental policy, avoiding difficulties normally pointed out by similar projects, there was a great difficulty for scientific contributions to be adopted in the decision-making process. Most of the scientific information and advice, even after discussion and common understanding among a diverse stakeholder group, were ignored or over-ruled in the final decision-making phases.


Resumo Os ecossistemas naturais estão sob grave ameaça em todo o mundo e as políticas ambientais são essenciais para minimizar os impactos presentes e futuros na biodiversidade, nos serviços ecossistêmicos e nas mudanças climáticas. O Novo Código Florestal no Brasil é a principal política de proteção da vegetação nativa em terras privadas, que compreende 54% da vegetação nativa remanescente brasileira. No entanto, os conflitos entre as preocupações ambientais e agrícolas na sua implementação exigem soluções equilibradas e baseadas em evidências científicas. Para enfrentar o desafio de aplicar a ciência no estabelecimento de políticas ambientais, desenvolvemos um projeto científico financiado pela Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) para apoiar a implementação do Novo Código Florestal no Estado de São Paulo, como parte do Programa Biota/FAPESP. O projeto foi conduzido de forma diferente de um projeto de pesquisa regular: o objetivo amplo foi fornecer suporte científico para a implementação do Novo Código Florestal pelo Estado, a partir de uma interação participativa entre as partes interessadas para construir objetivos específicos, métodos e discussão de resultados, dentro de uma equipe de pesquisa interdisciplinar e intersetorial. Aqui, apresentamos as lições aprendidas durante e após os quatro anos de desenvolvimento do projeto de pesquisa para avaliar como o conhecimento científico pode ser produzido e adotado na implementação de uma política ambiental específica. Apresentamos os principais resultados e os desafios enfrentados na tentativa de incluir dados científicos no processo decisório. Apresentamos também desafios atuais e futuros na implementação do Novo Código Florestal que podem ser resolvidos com evidências científicas. As lições aprendidas mostraram que mesmo concebendo o projeto de forma a atender as necessidades de apoio à implementação da política ambiental, evitando dificuldades normalmente apontadas por projetos semelhantes, houve uma grande dificuldade para que contribuições científicas fossem adotadas no processo decisório. A maioria das informações e conselhos científicos, mesmo após discussão e entendimento comum entre um grupo diversificado de partes interessadas, foi ignorada nas fases finais de tomada de decisão.

9.
Cancers (Basel) ; 13(23)2021 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-34885185

RESUMO

Osteosarcoma (OST) is the most common type of high-grade primary bone tumor, which mainly affects young adults. The current standard of care for OST combines surgical resection with chemotherapy. The clinical outcomes and the current options to treat OST patients are unsatisfactory and novel treatment strategies are needed. The crosstalk between tumor cells and immune cells is essential to the OST microenvironment. Despite the efforts that have been made to address the importance of immune-related factors in OST, there is still a lot to understand. The purpose of the current study was to evaluate the tumor-infiltrating lymphocytes (TIL), the expression of proteins involved in tumor biology, and their impact on the clinical outcome of OST patients. We studied 93 samples of OST patients using immunohistochemistry and histomorphometry. We looked for the infiltration of CD3+, CD4+, CD8+, TIA1+ and CD20+ cells and for the expression of CD44 standard (CD44s) and variant 6 (CD44v6), CD95/Fas, Fas-L, p53 and p-glycoprotein. All the parameters were analyzed for the influence on the occurrence of death and metastasis, plus patient overall survival (OS) and progression-free survival (PFS). The effect of sex, age, tumor location (distal femur or proximal tibia) and the combination with neoadjuvant chemotherapy was also assessed. Our results suggest that the presence of tumor-infiltrating CD4+ cells provides protection to OST patients, and that CD8+ cells have a significant impact on the patient's overall survival (OS) and progression-free survival (PFS), which is more evident in male patients. In addition, a strong association between tumor-infiltrating CD4+ cells and the presence of CD44s expression in tumor samples was observed. Analysis of TIL and tumor markers related to tumor biology could be useful to stratify patients and monitor the response to therapy, as well as to assist with the development of immunotherapy strategies to improve the effects of cytotoxic TIL to eradicate the tumor cells.

10.
Infectio ; 25(3): 197-199, jul.-set. 2021. graf
Artigo em Inglês | LILACS, COLNAL | ID: biblio-1250093

RESUMO

Abstract Mycetoma is a chronic and slow-developing granulomatous disease characterized by the triad of large painless tumour-like subcutaneous swellings, the formation of sinuses, and discharge that usually contains grains. Phellinus spp. are saprophytic wood-decaying filamentous basidiomycetes. They are an under-recognised cause of invasive fungal infections and are rarely reported worldwide. We report a 59-year-old male patient with mycetoma caused by Phellinus spp. The diagnosis was confirmed with clinical examination, magnetic resonance imaging (MRI) study, soft tissue and bone biopsy culture, and polymerase chain reaction. To the best of our knowledge, this is the first reported case of mycetoma due to Phellinus spp. without chronic granulomatous disease (CGD).


Resumen El micetoma es una enfermedad granulomatosa crónica y de lento desarrollo caracterizada por la tríada de grandes inflamaciones subcutáneas similares a tumores indoloras, la formación de los senos nasales y secreción que generalmente contiene granos. Phellinus spp. son basidiomicetos filamentosos saprofitos que descomponen la madera. Son un poco reconocido causa de infecciones fúngicas invasivas y rara vez se informan en todo el mundo. Presentamos un paciente masculino de 59 años con micetoma causado por Phellinus spp. El diagnostico se confirmó con examen clínico, estudio de resonancia magnética (RM), cultivo de biopsia de tejido blando y óseo y reacción en cadena de la polimerasa. A lo mejor que sepamos, este es el primer caso reportado de micetoma debido a Phellinus spp. sin enfermedad granulomatosa crónica (EGC).


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Basidiomycota , Phellinus , Micetoma , Brasil , Reação em Cadeia da Polimerase , Infecções Fúngicas Invasivas , Micoses
11.
Brain Sci ; 11(7)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34356166

RESUMO

Anti-GAD ataxia is one of the most common forms of immune-mediated cerebellar ataxias. Many neurological syndromes have been reported in association with anti-GAD. Ophthalmoparesis has been described in stiff person syndrome. We report a case of anti-GAD ataxia presenting initially with isolated ophthalmoplegia and showing complete resolution after immunotherapy. A 26-year-old male patient presented with ophthalmoparesis characterized by tonic upwards deviation of the right eye. In the following month, he developed progressive ataxia with anti-GAD titers of 1972 UI/mL. After treatment with methylprednisolone and immunoglobulin, there was complete resolution of symptoms and anti-GAD titers decreased. This is the first report of isolated ophthalmoparesis due to tonic eye deviation associated with anti-GAD antibodies without stiff-person syndrome. Tonic eye deviation has been reported in SPS, possibly secondary to continuous discharge in gaze holding neurons in the brainstem (similar to what occurs in spinal motor neurons). With growing evidence for ocular abnormalitites in SPS, anti-GAD associated neurological syndromes should be included in the differential diagnosis of isolated ophthalmoplegia.

12.
Cancers (Basel) ; 13(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34359767

RESUMO

Soft-tissue sarcomas (STS) represent about 80% of sarcomas, and are a heterogeneous group of rare and malignant tumors. STS arise from mesenchymal tissues and can grow into structures such as adipose tissue, muscles, nervous tissue and blood vessels. Morphological evaluation has been the standard model for the diagnosis of sarcomas, and even in samples with similar characteristics, they present a diversity in cytogenetic and genetic sequence alterations, which further increases the diversity of sarcomas. This variety is one of the main challenges for the classification and understanding of STS patterns, as well as for their respective treatments, which further decreases patient survival (<5 years). Despite some studies, little is known about the immunological profile of STS. As for the immunological profile of STS in relation to NK cells, there is also a shortage of studies. Observations made in solid tumors show that the infiltration of NK cells in tumors is associated with a good prognosis of the disease. Notwithstanding the scarcity of studies to characterize NK cells, their receptors, and ligands in STS, it is noteworthy that the progression of these malignancies is associated with altered NK phenotypes. Despite the scarcity of information on the function of NK cells, their phenotypes and their regulatory pathways in STS, the findings of this study support the additional need to explore NK cell-based immunotherapy in STS further. Some clinical trials, very tentatively, are already underway. STS clinical trials are still the basis for adoptive NK-cell and cytokine-based therapy.

13.
Cancers (Basel) ; 13(15)2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34359785

RESUMO

Soft Tissue Sarcomas (STS) are a heterogeneous and rare group of tumors. Immune cells, soluble factors, and immune checkpoints are key elements of the complex tumor microenvironment. Monitoring these elements could be used to predict the outcome of the disease, the response to therapy, and lead to the development of new immunotherapeutic approaches. Tumor-infiltrating B cells, Natural Killer (NK) cells, tumor-associated neutrophils (TANs), and dendritic cells (DCs) were associated with a better outcome. On the contrary, tumor-associated macrophages (TAMs) were correlated with a poor outcome. The evaluation of peripheral blood immunological status in STS could also be important and is still underexplored. The increased lymphocyte-to-monocyte ratio (LMR) and neutrophil-to-lymphocyte ratio (NLR), higher levels of monocytic myeloid-derived suppressor cells (M-MDSCs), and Tim-3 positive CD8 T cells appear to be negative prognostic markers. Meanwhile, NKG2D-positive CD8 T cells were correlated with a better outcome. Some soluble factors, such as cytokines, chemokines, growth factors, and immune checkpoints were associated with the prognosis. Similarly, the expression of immune-related genes in STS was also reviewed. Despite these efforts, only very little is known, and much research is still needed to clarify the role of the immune system in STS.

14.
Proc Natl Acad Sci U S A ; 118(28)2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34244425

RESUMO

Virus infection causes major rearrangements in the subcellular architecture of eukaryotes, but its impact in prokaryotic cells was much less characterized. Here, we show that infection of the bacterium Bacillus subtilis by bacteriophage SPP1 leads to a hijacking of host replication proteins to assemble hybrid viral-bacterial replisomes for SPP1 genome replication. Their biosynthetic activity doubles the cell total DNA content within 15 min. Replisomes operate at several independent locations within a single viral DNA focus positioned asymmetrically in the cell. This large nucleoprotein complex is a self-contained compartment whose boundaries are delimited neither by a membrane nor by a protein cage. Later during infection, SPP1 procapsids localize at the periphery of the viral DNA compartment for genome packaging. The resulting DNA-filled capsids do not remain associated to the DNA transactions compartment. They bind to phage tails to build infectious particles that are stored in warehouse compartments spatially independent from the viral DNA. Free SPP1 structural proteins are recruited to the dynamic phage-induced compartments following an order that recapitulates the viral particle assembly pathway. These findings show that bacteriophages restructure the crowded host cytoplasm to confine at different cellular locations the sequential processes that are essential for their multiplication.


Assuntos
Bacillus subtilis/virologia , Compartimento Celular , Viroses/patologia , Bacillus subtilis/ultraestrutura , Bacteriófagos/fisiologia , Bacteriófagos/ultraestrutura , Capsídeo/metabolismo , Replicação do DNA , DNA Viral/biossíntese , DNA Polimerase Dirigida por DNA , Interações Hospedeiro-Patógeno , Complexos Multienzimáticos , Fatores de Tempo , Vírion/metabolismo
15.
J Mol Biol ; 433(18): 167112, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34153288

RESUMO

Siphoviruses are main killers of bacteria. They use a long non-contractile tail to recognize the host cell and to deliver the genome from the viral capsid to the bacterial cytoplasm. Here, we define the molecular organization of the Bacillus subtilis bacteriophage SPP1 ~ 6.8 MDa tail and uncover its biogenesis mechanisms. A complex between gp21 and the tail distal protein (Dit) gp19.1 is assembled first to build the tail cap (gp19.1-gp21Nter) connected by a flexible hinge to the tail fiber (gp21Cter). The tip of the gp21Cter fiber is loosely associated to gp22. The cap provides a platform where tail tube proteins (TTPs) initiate polymerization around the tape measure protein gp18 (TMP), a reaction dependent on the non-structural tail assembly chaperones gp17.5 and gp17.5* (TACs). Gp17.5 is essential for stability of gp18 in the cell. Helical polymerization stops at a precise tube length followed by binding of proteins gp16.1 (TCP) and gp17 (THJP) to build the tail interface for attachment to the capsid portal system. This finding uncovers the function of the extensively conserved gp16.1-homologs in assembly of long tails. All SPP1 tail components, apart from gp22, share homology to conserved proteins whose coding genes' synteny is broadly maintained in siphoviruses. They conceivably represent the minimal essential protein set necessary to build functional long tails. Proteins homologous to SPP1 tail building blocks feature a variety of add-on modules that diversify extensively the tail core structure, expanding its capability to bind host cells and to deliver the viral genome to the bacterial cytoplasm.


Assuntos
Bacillus subtilis/virologia , Capsídeo/metabolismo , Genoma Viral , Siphoviridae/fisiologia , Proteínas da Cauda Viral/metabolismo , Vírion/fisiologia , Montagem de Vírus , Chaperonas Moleculares , Siphoviridae/química , Siphoviridae/genética , Proteínas da Cauda Viral/genética
16.
Case Rep Oncol ; 13(1): 113-119, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32231532

RESUMO

Leiomyosarcomas of the lower extremity are extremely rare disorders and account for 10-15% of limb soft tissue sarcomas. These tumours have poor prognosis and even in early stages, patients persist at high risk for local and distant relapse; consequently, the treatment of advanced leiomyosarcoma of the lower extremity embodies a substantial defy. We present the case of a 73-year-old man diagnosed with metastatic lower extremity leiomyosarcoma of the hallux soft tissue, and with bone, lung and lymph node metastasis. After core needle biopsy confirmation of high-grade fusocellular sarcoma, the patient underwent surgery of the primary tumour and received anthracycline-based chemotherapy. However, after a 7-month progression-free survival period, a CT revealed lung disease progression. Sequentially, the patient was treated with trabectedin (Yondelis®) at a dose of 1.5 mg/m2 resulting in complete remission of the lung metastasis and stable disease of the remaining lesions after 26 months of treatment. Afterwards, the patient started on maintenance therapy with trabectedin, resulting in long-lasting stable disease, as he was able to receive 94 cycles with very acceptable quality of life. Finally, in March 2019, the patient died of community-acquired pneumonia without objective progression disease. This clinical case reports the first patient ever treated with 94 cycles of trabectedin. Our results additionally confirm that trabectedin wields relevant oncostatic benefits with a manageable safety profile and without cumulative toxicities. Trabectedin properties enable a maintenance long-term therapy (until disease progression or unbearable toxicity), with a high impact on survival and with a preserved quality of life.

17.
J Transl Med ; 18(1): 2, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900171

RESUMO

BACKGROUND: Tumor cells have evolved complex strategies to escape immune surveillance, a process which involves NK cells and T lymphocytes, and various immunological factors. Indeed, tumor cells recruit immunosuppressive cells [including regulatory T-cells (Treg), myeloid-derived suppressor cells (MDSC)] and express factors such as PD-L1. Molecularly targeted therapies, such as imatinib, have off-target effects that may influence immune function. Imatinib has been shown to modulate multiple cell types involved in anti-cancer immune surveillance, with potentially detrimental or favorable outcomes. Imatinib and other tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) have dramatically changed disease course. Our study aimed to characterize the different populations of the immune system in patients with CML affected by their treatment. METHODS: Forty-one patients with CML [33 treated with TKIs and 8 with TKIs plus interferon (IFN)-α] and 20 controls were enrolled in the present study. Peripheral blood populations of the immune system [referred to as the overview of immune system (OVIS) panel, Treg cells and MDSCs] and PD-1 expression were evaluated by flow cytometry. The immunological profile was assessed using the mRNA Pan-Cancer Immune Profiling Panel and a NanoString nCounter FLEX platform. RESULTS: Patients receiving combination therapy (TKIs + IFN-α) had lower numbers of lymphocytes, particularly T cells [838/µL (95% CI 594-1182)] compared with healthy controls [1500/µL (95% CI 1207 - 1865), p = 0.017]. These patients also had a higher percentage of Treg (9.1%) and CD4+PD-1+ cells (1.65%) compared with controls [Treg (6.1%) and CD4+/PD-1+(0.8%); p ≤ 0.05]. Moreover, patients treated with TKIs had more Mo-MDSCs (12.7%) whereas those treated with TKIs + IFN-α had more Gr-MDSC (21.3%) compared to controls [Mo-MDSC (11.4%) and Gr-MDSC (8.48%); p ≤ 0.05]. CD56bright NK cells, a cell subset endowed with immune-regulatory properties, were increased in patients receiving TKIs plus IFN-α compared with those treated with TKIs alone. Interestingly, serum IL-21 was significantly lower in the TKIs plus IFN-α cohort. Within the group of patients treated with TKI monotherapy, we observed that individuals receiving 2nd generation TKIs had lower percentages of CD4+ Treg (3.63%) and Gr-MDSC (4.2%) compared to patients under imatinib treatment (CD4+ Treg 6.18% and Gr-MDSC 8.2%), but higher levels of PD-1-co-expressing CD4+ cells (1.92%). CONCLUSIONS: Our results suggest that TKIs in combination with IFN-α may promote an enhanced immune suppressive state.


Assuntos
Interferon-alfa , Leucemia Mielogênica Crônica BCR-ABL Positiva , Citometria de Fluxo , Humanos , Interferon-alfa/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Transcriptoma
18.
Br J Neurosurg ; 34(5): 552-558, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31213096

RESUMO

Background: Although reinnervation of the suprascapular nerve is frequently obtained through brachial plexus surgery, reestablishment of infraspinatus muscle function is rarely achieved.Methods: The viability of transfer of the radial nerve to the nerve branch to the infraspinatus muscle was determined anatomically, including histomorphometrical analysis on 30 adult cadavers. Eleven adult patients were then treated using the proposed nerve transfer.Results: The branch to the medial head was more suitable for the nerve transfer. In one cadaver, nerve transfer was impossible because there was no donor of sufficient length. According to axon counts, the branches to the lateral and medial heads had sufficient numbers of axons (means = 994.2 ± 447.6 and 1030.8 ± 258.5, respectively) for reinnervation of the branch to the infraspinatus (means = 830.2 ± 241.2 axons). In the surgical series, one patient was lost in the follow-up and only two patients achieved a good result from the transfer. Recovery of external shoulder rotation started 14 months after surgery in one patient and 8 months in the other. The first patient reached 90° of external rotation 6 months later and the second, achieved 120°of shoulder external rotation 6 months after surgery . Four other patients recovered small amounts of movement: 20, 35, 40 and 45°.Conclusions: Although anatomically feasible, the proposed nerve transfer resulted in a small number of good clinical outcomes.


Assuntos
Ombro/cirurgia , Neuropatias do Plexo Braquial/cirurgia , Humanos , Transferência de Nervo , Nervo Radial/cirurgia , Rotação , Manguito Rotador/cirurgia
19.
Front Immunol ; 10: 2493, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695700

RESUMO

Therapy with Tyrosine Kinase Inhibitors (TKI) aiming stable deep molecular response is the gold standard to treat Chronic Myeloid Leukemia (CML). NKT-like cells (CD3+CD56+) combine characteristics of T and NK cells. The physiopathological role of these cells remains unknown although the literature refers their association with inflammation, autoimmune diseases, and cancer. Since the information regarding the role of NKT-like cells in CML is rare, we aimed at the characterization of these cells in CML patients treated with TKIs. Peripheral blood NKT-like cells from 48 CML patients and 40 healthy donors were analyzed by multiparametric flow cytometry. Functional tests consisting of co-culture with leukemic target cells (K562 cell line) were used to measure degranulation and cytokine production. Our results revealed that NKT-like cells are decreased in treated CML patients, although they present increased expression of activation markers (CD69 and HLA-DR), increased degranulation (CD107a) and impaired IFN-γ production. Significantly alterations on the expression of tumor recognition (NCRs and NKp80), and immune regulation receptors (LAG-3, TIM-3, and CD137) by NKT-like cells were observed in CML patients. Second generation TKIs increased cell activation (CD69) and decreased expression of NKp44 and NKp80 by NKT-like cells from CML patients when compared to Imatinib. CML patients that achieved deep molecular response (MR4.5) presented downregulation of NKp44 and LAG-3. Further studies are needed to clarify the role of these cells as biomarkers of therapy response and also to evaluate their value for discrimination of better candidates for sustained treatment-free remission after TKI discontinuation.


Assuntos
Antígenos de Diferenciação/imunologia , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Células T Matadoras Naturais/imunologia , Proteínas de Neoplasias/imunologia , Inibidores de Proteínas Quinases/administração & dosagem , Feminino , Regulação Leucêmica da Expressão Gênica/imunologia , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Células T Matadoras Naturais/patologia
20.
Nat Commun ; 10(1): 4840, 2019 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-31649265

RESUMO

Assembly of tailed bacteriophages and herpesviruses starts with formation of procapsids (virion precursors without DNA). Scaffolding proteins (SP) drive assembly by chaperoning the major capsid protein (MCP) to build an icosahedral lattice. Here we report near-atomic resolution cryo-EM structures of the bacteriophage SPP1 procapsid, the intermediate expanded procapsid with partially released SPs, and the mature capsid with DNA. In the intermediate state, SPs are bound only to MCP pentons and to adjacent subunits from hexons. SP departure results in the expanded state associated with unfolding of the MCP N-terminus and straightening of E-loops. The newly formed extensive inter-capsomere bonding appears to compensate for release of SPs that clasp MCP capsomeres together. Subsequent DNA packaging instigates bending of MCP A domain loops outwards, closing the hexons central opening and creating the capsid auxiliary protein binding interface. These findings provide a molecular basis for the sequential structural rearrangements during viral capsid maturation.


Assuntos
Bacteriófagos/ultraestrutura , Proteínas do Capsídeo/ultraestrutura , Capsídeo/ultraestrutura , Montagem de Vírus , Bacteriófagos/metabolismo , Capsídeo/metabolismo , Proteínas do Capsídeo/metabolismo , Microscopia Crioeletrônica , Cristalografia por Raios X , Proteínas Estruturais Virais/metabolismo , Proteínas Estruturais Virais/ultraestrutura
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