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1.
Front Mol Neurosci ; 17: 1334862, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38318533

RESUMO

Aging-related memory impairment and pathological memory disorders such as Alzheimer's disease differ between males and females, and yet little is known about how aging-related changes in the transcriptome and chromatin environment differ between sexes in the hippocampus. To investigate this question, we compared the chromatin accessibility landscape and gene expression/alternative splicing pattern of young adult and aged mouse hippocampus in both males and females using ATAC-seq and RNA-seq. We detected significant aging-dependent changes in the expression of genes involved in immune response and synaptic function and aging-dependent changes in the alternative splicing of myelin sheath genes. We found significant sex-bias in the expression and alternative splicing of hundreds of genes, including aging-dependent female-biased expression of myelin sheath genes and aging-dependent male-biased expression of genes involved in synaptic function. Aging was associated with increased chromatin accessibility in both male and female hippocampus, especially in repetitive elements, and with an increase in LINE-1 transcription. We detected significant sex-bias in chromatin accessibility in both autosomes and the X chromosome, with male-biased accessibility enriched at promoters and CpG-rich regions. Sex differences in gene expression and chromatin accessibility were amplified with aging, findings that may shed light on sex differences in aging-related and pathological memory loss.

2.
Intern Med ; 63(4): 547-551, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-37380452

RESUMO

Intrathecal chemotherapy is often administered for prophylaxis and treatment of central nervous system involvement in hematological malignancies. However, it may rarely cause neurotoxicity as a side effect. We herein report a 74-year-old woman with diffuse large B-cell lymphoma including a spinal lesion. She received systemic and intrathecal chemotherapy. After five doses of intrathecal chemotherapy, she developed intrathecal chemotherapy-induced myelopathy. Intrathecal treatment was discontinued, and she was administered vitamin B12 and folic acid, along with steroid pulses. However, her symptoms did not improve. Intrathecal chemotherapy-induced myelopathy is rare, but may be irreversible; therefore, clinicians should be aware of this potential complication.


Assuntos
Antineoplásicos , Doenças da Medula Óssea , Linfoma Difuso de Grandes Células B , Doenças da Medula Espinal , Feminino , Humanos , Idoso , Doenças da Medula Espinal/induzido quimicamente , Doenças da Medula Espinal/diagnóstico por imagem , Doenças da Medula Espinal/tratamento farmacológico , Linfoma Difuso de Grandes Células B/complicações , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Doenças da Medula Óssea/tratamento farmacológico , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Metotrexato/uso terapêutico
3.
J Clin Exp Hematop ; 63(4): 240-245, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-37899239

RESUMO

Mature B-cell acute lymphoblastic leukemia (ALL) is defined by the expression of light chain-restricted surface immunoglobulin (sIg) and usually has features of the leukemic phase of Burkitt lymphoma including FAB-L3 morphology and MYC rearrangement. Recently, another distinct entity in childhood mature B-cell ALL has been characterized as non-L3 morphology and KMT2A rearrangement. Here we report an unusual case of mature B-cell ALL that presented with RUNX1 rearrangement. A 65-year-old male was admitted to our department for thorough examination of leukocytosis and thrombocytopenia. The patient's bone marrow was hypercellular and infiltrated with 97.8% myeloperoxidase-negative, medium-to-large-sized blasts without cytoplasmic vacuoles. Immunophenotypes were characterized by the presence of light chain-restricted sIg and the lack of immature markers, indicating a diagnosis of mature B-cell ALL with L2 morphology: sIg-κ+, CD19+, CD20+, CD22+, CD79a+, TdT-, and CD34-. G-banding combined with spectral karyotyping showed the following complex karyotype: 45,X,der(Y;10)(p10;q10),del(13)(q?),inv(21)(p13q22.1). Fluorescence in situ hybridization revealed separated signals of RUNX1 at 21q22.1, whereas rearrangements of MYC and KMT2A were not found. To our knowledge, inv(21)(p13q22.1) involving RUNX1 is a novel cytogenetic aberration and this is the first case of mature B-cell ALL that presented with RUNX1 rearrangement. Thus, RUNX1 may be implicated in the pathogenesis of mature B-cell ALL showing non-L3 morphology without MYC rearrangement.


Assuntos
Linfoma de Burkitt , Linfoma de Células B , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Masculino , Humanos , Idoso , Linfoma de Burkitt/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Hibridização in Situ Fluorescente , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Linfoma de Células B/diagnóstico , Linfoma de Células B/genética
4.
Blood Cell Ther ; 6(2): 54-60, 2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37342353

RESUMO

Hyperglycemia in the early days following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a well-known risk factor for acute graft-versus-host disease (GVHD) and non-relapse mortality. The FreeStyle Libre Pro, a factory calibrated continuous glucose monitoring (CGM) device, has been used for the retrospective analysis of glucose testing in patients with diabetes. We assessed the safety and accuracy of the device in patients undergoing allo-HSCT. We recruited eight patients who underwent allo-HSCT between August 2017 and March 2020. They wore the FreeStyle Libre Pro on the day before or on the day of transplantation until 28 days after transplantation. Adverse events, especially bleeding and infection, were monitored to assess safety, and blood glucose levels were measured and compared with the device values. None of the eight participants experienced bleeding that was difficult to stop from the sensor site or local infection that required antimicrobial administration. The device value was well correlated with blood glucose (correlation coefficient r=0.795, P<0.01); however, the overall mean absolute relative difference was 32.1%±16.0%. Our study demonstrated the safety of FreeStyle Libre Pro in allo-HSCT patients. However, the sensor results tended to be lower than the blood glucose levels.

5.
Br J Haematol ; 202(3): 504-516, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37349876

RESUMO

The use of anti-SARS-CoV-2 antibody products like tixagevimab/cilgavimab represents an important strategy to protect immunocompromised patients with haematological malignancies from COVID-19. Although patients who receive these agents should still be vaccinated, the use of tixagevimab/cilgavimab can mask the production of anti-spike antibody after vaccination, making it hard to assess vaccine response. We have newly established a quantification method to assess the response to SARS-CoV-2 vaccination at the mRNA level using B-cell receptor (BCR) repertoire assay and the Coronavirus Antibody Database (CoV-AbDab). Repeated blood samples before and after vaccination were analysed for the BCR repertoire, and BCR sequences were searched in the database. We analysed the number and percentage frequency of matched sequences. We found that the number of matched sequences increased 2 weeks after the first vaccination and quickly decreased. Meanwhile, the number of matched sequences more rapidly increased after the second vaccination. These results show that the postvaccine immune response can be assessed at the mRNA level by analysing the fluctuation in matching sequences. Finally, BCR repertoire analysis with CoV-AbDab clearly demonstrated the response to mRNA SARS-CoV-2 vaccination even after tixagevimab/cilgavimab administration in haematological malignancy patients who underwent allogeneic haematopoietic stem cell transplantation.


Assuntos
COVID-19 , Neoplasias Hematológicas , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , SARS-CoV-2 , Vacinação , Anticorpos Antivirais , Neoplasias Hematológicas/tratamento farmacológico , RNA Mensageiro , Receptores de Antígenos de Linfócitos B/genética
6.
Intern Med ; 62(20): 2949-2958, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36792187

RESUMO

Objective High-dose chemotherapy with autologous hematopoietic stem cell transplantation (auto-HSCT) is an effective treatment option for relapsed and refractory aggressive malignant lymphoma. However, patients frequently experience treatment-induced gastrointestinal symptoms. Synbiotics, including live microorganisms and nondigestible food ingredients, reportedly ameliorate chemotherapy-induced mucosal damage. In this study, we assessed the efficacy and safety of synbiotics in patients undergoing auto-HSCT. Methods This randomized, double-blinded study included patients with malignant lymphoma eligible for auto-HSCT. The patients were randomly assigned to either a synbiotic group receiving Bifidobacterium longum (BB536) and guar gum or a placebo group receiving a placebo containing dextrin. The supplements were administered twice daily from the start of conditioning chemotherapy up to 28 days after auto-HSCT. The primary endpoint was the duration of total parenteral nutrition (TPN). Results In total, 12 patients were included and randomized. The median duration of TPN was 15 (range, 12-33) days in the synbiotic group and 17.5 (range, 0-32) days in the placebo group. The median duration of grade ≥3 diarrhea was shorter in the synbiotic group than in then placebo group (2.5 vs. 6.5 days), as was the duration of hospital stay (31.5 vs. 43 days). The oral intake and quality of life regarding diarrhea and anorexia improved in the synbiotic group after engraftment. Synbiotic infections, including bacteremia, were not observed. Conclusion Synbiotics may reduce gastrointestinal toxicity, thereby reducing nutritional problems and improving the quality of life of patients undergoing auto-HSCT, without severe adverse events.


Assuntos
Gastroenteropatias , Transplante de Células-Tronco Hematopoéticas , Linfoma , Simbióticos , Humanos , Qualidade de Vida , Projetos Piloto , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Linfoma/etiologia , Transplante Autólogo , Gastroenteropatias/etiologia , Diarreia/etiologia
7.
Cancer Genet ; 272-273: 41-46, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36774707

RESUMO

As an uncommon but nonrandom translocation in acute myeloid leukemia (AML) t(5;11)(q31;q23) results in fusion between KMT2A at 11q23 and ARHGAP26 at 5q31. The 5q31 region has another KMT2A partner, AFF4, which was identified in acute lymphoblastic leukemia harboring ins(5;11)(q31;q13q23). We report here a 65-year-old woman with AML M5b. G-banding and spectral karyotyping demonstrated 46,XX,t(5;11)(q31;q23.3). Fluorescence in situ hybridization revealed not only separated 5' and 3' KMT2A signals but a faint 5' KMT2A signal. Reverse transcription polymerase chain reaction (RT-PCR), using a KMT2A sense primer and ARHGAP26 antisense primer, detected no band whereas RT-PCR with a AFF4 antisense primer revealed an amplified band. However, sequence analysis unexpectedly disclosed that KMT2A exon 6 was connected with MLLT10 exons 15 to 18. This may be due to cross-hybridization between MLLT10 exon 18 and AFF4 antisense primer derived from AFF4 exon 10 since both exons had eight identical bases (AAGCAGCT). The MLLT10 gene is located at 10p12.31; a faint 5' KMT2A signal was probably present at this locus. These findings indicate that in AML the 5' KMT2A fragment containing exons 1 to 6 may be cryptically inserted into MLLT10 intron 14 when a reciprocal translocation t(5;11)(q31;q23.3) involving KMT2A occurred.


Assuntos
Leucemia Mieloide Aguda , Fatores de Transcrição , Feminino , Humanos , Idoso , Hibridização in Situ Fluorescente , Fatores de Transcrição/genética , Proteína de Leucina Linfoide-Mieloide/genética , Leucemia Mieloide Aguda/genética , Translocação Genética , Éxons , Fatores de Elongação da Transcrição/genética
8.
EJHaem ; 4(1): 192-198, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36819160

RESUMO

Global longitudinal strain (GLS), a new cardiac parameter measured by the speckle-tracking method, is reportedly more sensitive than ejection fraction (EF) in detecting slight cardiac dysfunction in heart failure patients. We validated the utility of GLS in allogeneic hematopoietic stem cell transplantation (HSCT) patients during a long-term follow-up. Medical records of patients who underwent allogeneic HSCT between 2013 and 2020 were reviewed retrospectively. We evaluated the last echocardiography performed before transplantation and those performed annually during the 5 years after transplantation. We also investigated newly diagnosed cardiac events, which developed after HSCT. Among 85 patients, 22 used cardioprotective drugs. The median follow-up duration in surviving patients was 54.1 months (range, 2.9-92.6 months). GLS significantly decreased year by year, and patients taking cardioprotective agents tended to have a better GLS at 5 years than at 3 years, while EF did not change. Fifteen patients developed newly diagnosed cardiac events. Multivariate analysis revealed that low GLS and high serum ferritin levels at baseline were independently associated with the development of cardiac events. Therefore, we need a continuous follow-up of cardiac function by GLS and prescription of cardioprotective drugs might be considered for HSCT patients with low GLS. Further research is warranted.

9.
Intern Med ; 62(2): 285-292, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35705274

RESUMO

A 68-year-old man was admitted because of a left shoulder mass and swollen right testis. Pathological examinations indicated a diagnosis of diffuse large B-cell lymphoma (DLBCL) with the CD20+BCL6+MUM1+BCL2+CD10-MYC- phenotype in both lesions. G-banding of soft tissue showed 47,XY,+18, whereas testicular cells showed 47,X,+X,-Y,der (4) t (4;18) (p15;?),del (5) (q?),+13. Fluorescence in situ hybridization detected additional MALT1 and BCL2 signals in both lesions. Southern blot demonstrated different IGH rearrangements between the soft tissue and testis. The patient was diagnosed with biclonal DLBCL with different karyotypes but similar immunophenotypes. Partial trisomy 18q involving MALT1 and BCL2 may be commonly involved in the pathogenesis of this biclonal DLBCL.


Assuntos
Linfoma Difuso de Grandes Células B , Trissomia , Masculino , Humanos , Trissomia/genética , Translocação Genética , Hibridização in Situ Fluorescente , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/genética
10.
Vaccines (Basel) ; 10(11)2022 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-36366338

RESUMO

We previously reported that a second dose of BNT162b2 was safe and effective for allogeneic hematopoietic stem cell transplantation (HSCT) patients. Here, we investigated the safety and efficacy of a third dose of COVID-19 mRNA vaccine in allogeneic HSCT patients. Antibody titers against the S1 spike protein were measured using the QuaResearch COVID-19 Human IgM IgG ELISA kit. The previous study included 25 allogeneic HSCT patients who received two doses of BNT162b2. Following the exclusion of three patients because of the development of COVID-19 (n = 2) and loss to follow-up (n = 1), the study evaluated 22 allogeneic HSCT patients who received a third dose of COVID-19 mRNA vaccine (BNT162b2 [n = 15] and mRNA-1273 [n = 7]). Median age at the time of the first vaccination was 56 (range, 23-71) years. Five patients were receiving immunosuppressants at the third vaccination, namely calcineurin inhibitors (CI) alone (n = 1), steroids alone (n = 2), or CI combined with steroids (n = 2). Twenty-one patients (95%) seroconverted after the third dose. None of our patients had serious adverse events, new-onset graft-versus-host disease (GVHD), or GVHD exacerbation after vaccination. A third dose of the BNT162b2 and mRNA-1273 COVID-19 vaccines was safe and effective for allogeneic HSCT patients.

11.
Vaccines (Basel) ; 10(6)2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35746573

RESUMO

Anti-CD20 antibodies react with CD20 expressed not only on malignant B cells, but also on normal B cells. It has been reported that patients treated with anti-CD20 antibodies had an insufficient response to two-dose mRNA SARS-CoV-2 vaccination. To investigate the efficacy of a third dose in these patients, we investigated serum IgG antibody titers for the S1 protein after a third vaccination in 22 patients treated with the anti-CD20 antibody who failed two-dose vaccination. Results showed that overall, 50% of patients seroconverted. Although no patient who received the third dose within 1 year of the last anti-CD20 antibody administration showed an increase in S1 antibody titer, 69% of patients who received the third dose more than 1 year after the last anti-CD20 antibody administration seroconverted. Our data show that a third dose of vaccination is effective in improving the seroconversion rate in patients treated with the anti-CD20 antibody who failed standard two-dose vaccination.

12.
Vaccines (Basel) ; 10(2)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35214617

RESUMO

Patients who have undergone hematopoietic stem cell transplantation (HSCT) for hematological disease experience high mortality when infected by coronavirus disease 2019 (COVID-19). However, the safety and efficacy of the COVID-19 vaccine in HSCT patients remain to be investigated. We prospectively evaluated the safety and immunogenicity of the BNT162b2 mRNA COVID-19 vaccine (Pfizer BioNTech) in 25 Japanese allogeneic HSCT patients in comparison with 19 healthy volunteers. While anti-S1 antibody titers in almost all healthy volunteers after the second dose were higher than the cut-off value reported previously, levels in HSCT patients after the second dose were diverse. Nineteen patients (76%) had seroconversion of anti-S1 IgG. The median optical density of antibody levels in HSCT patients with low IgG levels (<600 mg/dL), steroid treatment, or low lymphocytes (<1000/µL) was significantly lower than that in the other HSCT patients. There were no serious adverse events (>Grade 3) and no new development or exacerbation of graft-versus-host disease after vaccination. We concluded that the BNT162b2 mRNA vaccine is safe and effective in Japanese allogeneic HSCT patients.

13.
Int J Hematol ; 115(1): 7-10, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34981433

RESUMO

We investigated the efficacy of BNT162b2 mRNA COVID-19 vaccine in patients with B-cell malignancies treated with anti-CD20 antibody. Although T-cell-mediated immune responses were detected even in patients receiving R-CHOP treatment, the S1 antibody titer following BNT162b2 vaccination remained only marginally increased for more than 3 years after the final dose of anti-CD20 antibody. We found no relationship between the percent of B-cells and S1 antibody titer. The duration of this suppression was much longer than we anticipated. Further protection and treatment strategies against COVID-19 for these patients are warranted.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Vacina BNT162/uso terapêutico , COVID-19/prevenção & controle , Linfoma de Células B/complicações , Linfoma de Células B/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Formação de Anticorpos , Antígenos CD20/imunologia , COVID-19/imunologia , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Humanos , Linfoma de Células B/imunologia , Masculino , Pessoa de Meia-Idade , Prednisona/uso terapêutico , Rituximab/uso terapêutico , Vincristina/uso terapêutico
14.
Cancer Genet ; 254-255: 92-97, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33647817

RESUMO

The t(1;11)(p32;q23) translocation is a rare but recurrent cytogenetic aberration in acute myeloid leukemia (AML) and B-cell acute lymphoblastic leukemia (B-ALL). This translocation was initially shown to form a fusion gene between KMT2A exon 8 at 11q23 and EPS15 exon 2 at 1p32 in AML. Activating mutations of FLT3 are frequently found in AML but are very rare in ALL. Here, we describe a 75-year-old woman who was diagnosed with B-ALL since her bone marrow was made up of 98.2% lymphoblasts. These blasts were positive for CD19, CD22, CD79a, CD13, and CD33 but negative for CD10 and myeloperoxidase. The karyotype by G-banding and spectral karyotyping was 46,XX,t(1;11)(p32;q23). Expression of KMT2A/EPS15 and reciprocal EPS15/KMT2A fusion transcripts were shown: KMT2A exon 8 was in-frame fused to EPS15 exon 12, indicating that this fusion transcript was a novel type. Considering three reported B-ALL cases, EPS15 breakpoints were markedly different between AML (exon 2) and B-ALL (exons 10-12). Furthermore, an uncommon type of FLT3 mutation in the juxtamembrane domain was detected: in-frame 4-bp deletion and 10-bp insertion. Accordingly, our results indicate that the novel type of KMT2A/EPS15 fusion transcript and FLT3 mutation may cooperate in the pathogenesis of adult B-ALL as class II and class I mutations, respectively.


Assuntos
Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 1/genética , Mutação/genética , Proteínas de Fusão Oncogênica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Translocação Genética , Tirosina Quinase 3 Semelhante a fms/genética , Idoso , Sequência de Aminoácidos , Sequência de Bases , Células da Medula Óssea/patologia , Forma Celular , Evolução Fatal , Feminino , Humanos , Proteínas de Fusão Oncogênica/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tirosina Quinase 3 Semelhante a fms/química
15.
Case Rep Hematol ; 2019: 2084325, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31885951

RESUMO

A 71-year-old male smoker was referred to our hospital because of increased hemoglobin and hematocrit. At initial consultation, his hemoglobin and hematocrit levels were 21.8 g/dl and 64.8%, respectively. Other laboratory data and his cardiopulmonary functions were almost normal, and JAK2 V617F mutation was negative. He had smoked about 25 cigarettes per day for 50 years until the age of 70, when he switched from conventional smoking to electronic cigarettes (e-cigarettes). We requested that he quit e-cigarette use. Thereafter, his hemoglobin and hematocrit gradually decreased and normalized. Here, we report the first case of e-cigarette-induced polycythemia.

17.
J Virol ; 87(9): 5053-64, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23427157

RESUMO

The folding and pentamer assembly of the simian virus 40 (SV40) major capsid protein Vp1, which take place in the infected cytoplasm, have been shown to progress through disulfide-bonded Vp1 folding intermediates. In this report, we further demonstrate the existence of another category of Vp1 folding or assembly intermediates: the nonreducible, covalently modified mdVp1s. These species were present in COS-7 cells that expressed a recombinant SV40 Vp1, Vp1ΔC, through plasmid transfection. The mdVp1s persisted under cell and lysate treatment and SDS-PAGE conditions that are expected to have suppressed the formation of artifactual disulfide cross-links. As shown through a pulse-chase analysis, the mdVp1s were derived from the newly synthesized Vp1ΔC in the same time frame as Vp1's folding and oligomerization. The apparent covalent modifications occurred in the cytoplasm within the core region of Vp1 and depended on the coexpression of the SV40 large T antigen (LT) in the cells. Analogous covalently modified species were found with the expression of recombinant polyomavirus Vp1s and human papillomavirus L1s in COS-7 cells. Furthermore, the mdVp1s formed multiprotein complexes with LT, Hsp70, and Hsp40, and a fraction of the largest mdVp1, md4, was disulfide linked to the unmodified Vp1ΔC. Both mdVp1 formation and most of the multiprotein complex formation were blocked by a Vp1 folding mutation, C87A-C254A. Our observations are consistent with a role for LT in facilitating the folding process of SV40 Vp1 by stimulating certain covalent modifications of Vp1 or by recruiting certain cellular proteins.


Assuntos
Antígenos Virais de Tumores/metabolismo , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Infecções por Polyomavirus/virologia , Vírus 40 dos Símios/metabolismo , Animais , Antígenos Virais de Tumores/genética , Células COS , Proteínas do Capsídeo/metabolismo , Linhagem Celular , Chlorocebus aethiops , Humanos , Dobramento de Proteína , Vírus 40 dos Símios/química , Vírus 40 dos Símios/genética
18.
J Virol ; 83(1): 37-46, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18945763

RESUMO

Proper folding of newly synthesized viral proteins in the cytoplasm is a prerequisite for the formation of infectious virions. The major capsid protein Vp1 of simian virus 40 forms a series of disulfide-linked intermediates during folding and capsid formation. In addition, we report here that Vp1 is associated with cellular chaperones (HSP70) and a cochaperone (Hsp40) which can be coimmunoprecipitated with Vp1. Studies in vitro demonstrated the ATP-dependent interaction of Vp1 and cellular chaperones. Interestingly, viral cochaperones LT and ST were essential for stable interaction of HSP70 with the core Vp1 pentamer Vp1 (22-303). LT and ST also coimmunoprecipitated with Vp1 in vivo. In addition to these identified (co)chaperones, stable, covalently modified forms of Vp1 were identified for a folding-defective double mutant, C49A-C87A, and may represent a "trapped" assembly intermediate. By a truncation of the carboxyl arm of Vp1 to prevent the Vp1 folding from proceeding beyond pentamers, we detected several apparently modified Vp1 species, some of which were absent in cells transfected with the folding-defective mutant DNA. These results suggest that transient covalent interactions with known or unknown cellular and viral proteins are important in the assembly process.


Assuntos
Antígenos Virais de Tumores/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Vírus 40 dos Símios/fisiologia , Proteínas Estruturais Virais/metabolismo , Montagem de Vírus , Animais , Linhagem Celular , Chlorocebus aethiops , Proteínas de Choque Térmico HSP40/metabolismo , Imunoprecipitação , Mutação Puntual , Ligação Proteica , Deleção de Sequência , Proteínas não Estruturais Virais/metabolismo
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