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1.
Br J Haematol ; 200(1): 45-53, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36205375

RESUMO

Belantamab mafodotin, an immuno-conjugate targeting B-cell maturation antigen, showed single-agent activity in phase 1 and 2 studies, and was recently approved for heavily pretreated relapsed/refractory multiple myeloma (RRMM) patients. Real-world data and long-term follow-up are scarce. We conducted a multisite retrospective study aimed to assess safety and efficacy of belantamab mafodotin monotherapy administered via the GSK expanded access compassionate care programme. One-hundred and six RRMM patients were treated with belantamab mafodotin between July 2019 and March 2021. The median age was 69.4 years. Patients were heavily pretreated with a median of six (range 2-11) prior therapy lines. Major adverse effects included ocular toxicity (keratopathy 68.4%, grade ≥3: 40.5%; blurred vision 36.8%, grade ≥3: 6.3%), thrombocytopenia (27.4%, grade ≥3: 17.9%) and infections (11.3%, grade ≥3: 7.5%). Median follow-up time was 11.9 [95% confidence interval (CI) 10.0-13.8] months. Overall response rate was 45.5%. Median progression-free survival was 4.7 (95% CI 3.5-5.9) months in the entire cohort and 8.8 (95% CI 6.6-10.9) months among responders. Median overall survival was 14.5 (95% CI 9.5-19.6) months, and not reached for responders. To conclude, in a real-world setting, belantamab mafodotin monotherapy showed efficacy comparable with the prospective clinical trials, with a tolerable toxicity profile.


Assuntos
Mieloma Múltiplo , Humanos , Idoso , Mieloma Múltiplo/tratamento farmacológico , Estudos Retrospectivos , Estudos Prospectivos , Resultado do Tratamento
2.
Pediatr Blood Cancer ; 65(11): e27312, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30070020

RESUMO

INTRODUCTION: Thalassemia major (TM) is an inherited disorder caused by ineffective erythropoiesis. At the present time, allogeneic stem cell transplantation (allo-SCT) is a curative option. Conventional busulfan and cyclophosphamide based myeloablative conditioning regimens are limited by increased toxicity, especially in high-risk patients. Replacement of cyclophosphamide with fludarabine has reduced toxicity and nonrelapse mortality (NRM), thus improving outcomes. We analyzed long-term data of our fludarabine-based myeloablative, reduced toxicity protocol, specifically in high-risk patients. METHODS: We retrospectively analyzed a cohort of 47 consecutive patients with TM undergoing allo-SCT from matched donors, using the fludarabine-based regimen (reduced toxicity regimen). The median age of the cohort was 10 years. Thirty-eight patients (80%) were in the high-risk and nine patients (20%) were in the low-risk category. The primary aim of this analysis was thalassemia-free survival (TFS). RESULTS: The rejection rate was 11% within high-risk patients with NRM of 2%. With a median follow-up period of 7 years (1-15 years), the 10-year TFS in the entire cohort was 87%, and the overall survival (OS) was 97%. The 10-year TFS and OS among the low-risk and high-risk groups were 90% versus 84%, respectively (P = 0.45) and 100% versus 96%, respectively (P = 0.5), and both subsets of patients did equally well. CONCLUSION: In conclusion, replacement of high-dose cyclophosphamide with fludarabine is well tolerated with minimal regimen-related toxicity and acceptable rejection rates, especially in high-risk patients.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Agonistas Mieloablativos/uso terapêutico , Talassemia/cirurgia , Condicionamento Pré-Transplante/métodos , Vidarabina/análogos & derivados , Adolescente , Bussulfano/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Retrospectivos , Transplante Homólogo/métodos , Vidarabina/uso terapêutico
3.
Acta Haematol ; 140(4): 209-214, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30343286

RESUMO

The treatment of relapsed/refractory acute lymphoblastic leukemia (RR-ALL) presents a true clinical challenge. In 2012, a protocol combining bortezomib, dexamethasone, asparaginase, doxorubicin, and vincristine administered to children with RR-ALL was published with encouraging results. Over the past 5 years, we have implemented this protocol in the adult RR-ALL population (> 18 years) and addressed its feasibility in terms of remission rate and toxicity. Here, we present the results of our experience in 9 patients, all of whom received multiple previous chemotherapy protocols, two of them relapsing after an allogeneic bone marrow transplantation. All of the five B-ALL patients, and two of the four T-ALL achieved complete remission. Of the seven patients achieving complete remission, two patients were referred for allogeneic bone marrow transplantation, two patients were subsequently given blinatumomab, and one patient subsequently received donor lymphocyte infusion followed by blinatumomab. Thus, five out of nine patients treated (55%) were able to proceed to best available therapy in a complete remission. We observed minimal adverse effects, mainly hematological toxicity. We conclude that the bortezomib-based protocol should be evaluated as an effective and well-tolerated treatment option for adult patients either unfit for or failing standard salvage chemotherapy, as a bridge to immunotherapy or allogeneic bone marrow transplantation.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bortezomib/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Adulto , Idoso , Anticorpos Biespecíficos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Transplante de Medula Óssea , Bortezomib/efeitos adversos , Neutropenia Febril/etiologia , Humanos , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Recidiva , Indução de Remissão , Estudos Retrospectivos
4.
PLoS Genet ; 11(5): e1005265, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26016853

RESUMO

GATA transcription factors play critical roles in cellular differentiation and development. However, their roles in mature tissues are less understood. In C. elegans larvae, the transcription factor ELT-2 regulates terminal differentiation of the intestine. It is also expressed in the adult intestine, where it was suggested to maintain intestinal structure and function, and where it was additionally shown to contribute to infection resistance. To study the function of elt-2 in adults we characterized elt-2-dependent gene expression following its knock-down specifically in adults. Microarray analysis identified two ELT-2-regulated gene subsets: one, enriched for hydrolytic enzymes, pointed at regulation of constitutive digestive functions as a dominant role of adult elt-2; the second was enriched for immune genes that are induced in response to Pseudomonas aeruginosa infection. Focusing on the latter, we used genetic analyses coupled to survival assays and quantitative RT-PCR to interrogate the mechanism(s) through which elt-2 contributes to immunity. We show that elt-2 controls p38-dependent gene induction, cooperating with two p38-activated transcription factors, ATF-7 and SKN-1. This demonstrates a mechanism through which the constitutively nuclear elt-2 can impact induced responses, and play a dominant role in C. elegans immunity.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/imunologia , Fatores de Transcrição GATA/metabolismo , Regulação da Expressão Gênica , Imunidade Inata/genética , Mucosa Intestinal/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Fatores Ativadores da Transcrição/genética , Fatores Ativadores da Transcrição/metabolismo , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição GATA/genética , Técnicas de Silenciamento de Genes , Larva/genética , Larva/metabolismo , Regiões Promotoras Genéticas , Pseudomonas aeruginosa , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética
6.
Hematol Oncol ; 35(4): 797-803, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27338621

RESUMO

The probability of achieving long term remission for patients with refractory acute leukaemia is very low. Allogeneic stem cell transplantation (SCT) is offered to these patients in order to improve their dismal outcome. We retrospectively analyzed 361 acute leukaemia patients, who underwent allogeneic SCT in the Hadassah's bone marrow transplantation department between the years 2005 and 2012 and identified 84 patients with active leukaemia at transplantation. Median age was 34 years. Sixty four patients were diagnosed with acute myeloid leukaemia (AML), 18 patients with acute lymphoblastic leukaemia and two with biphenotypic leukaemia. The majority of patients were diagnosed with de-novo AML and transplanted at relapse. In the surviving patients, median follow up was 15 months. One year OS was 20%. At time of last follow up, 13 patients were alive (15.5%): ten patients with AML and two patients with acute lymphoblastic leukaemia. In the univariate analysis, factors associated with significantly better overall survival were as follows: matched unrelated donor (p = 0.006), matched donor (p = 0.014) and occurrence of acute graft-versus-host disease (aGVHD) (p = 0.019). Karnofsky performance score at SCT and occurrence of cGVHD were found to be borderline significant. Only matched unrelated donor and aGVHD were found to affect overall survival significantly in the multivariate analysis. Other than performance score at SCT, none of the pretransplant patients' characteristics were found to influence survival. In conclusion, as none of the pretransplant characteristics were found to influence the ability to select the patients that will benefit from HSC transplantation, this work supports offering HSCT to all active leukaemia eligible patients with reasonable performance status. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Leucemia Mieloide Aguda/terapia , Condicionamento Pré-Transplante/métodos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
Biochem Biophys Res Commun ; 477(3): 401-5, 2016 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-27329812

RESUMO

This study is the first experimental evidence showing that a living multicellular organism, the nematode Caenorhabditis elegans, can survive subfreezing temperatures in an isochoric (constant volume) thermodynamic system, while immersed in a simple isotonic solution, without the addition of cryoprotectants. Some of the test conditions were more extreme than those found at the ice/water interface of the Antarctic subglacial Vostok lake. On earth, life takes place in an isobaric (constant pressure) environment. In isobaric systems, subfreezing temperature survival of organisms in nature and subfreezing temperature preservation of living material for biotechnology and medicine, is made possible by use of cryoprotective chemicals additives. Our theoretical thermodynamic studies suggested that in an isochoric system, living biological material could survive subfreezing temperatures, without any cryoprotective chemicals. By confirming the theoretical predictions, this paper suggests a new technology for subfreezing preservation of cells, organs and organisms of possible value for biotechnology and medicine as well as new possible mechanisms of living organism survival in nature.


Assuntos
Adaptação Fisiológica , Caenorhabditis elegans/fisiologia , Congelamento , Animais
8.
Br J Haematol ; 169(1): 44-56, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25496030

RESUMO

ImMucin, a 21-mer cancer vaccine encoding the signal peptide domain of the MUC1 tumour-associated antigen, possesses a high density of T- and B-cell epitopes but preserves MUC1 specificity. This phase I/II study assessed the safety, immunity and clinical response to 6 or 12 bi-weekly intradermal ImMucin vaccines, co-administered with human granulocyte-macrophage colony-stimulating factor to 15 MUC1-positive multiple myeloma (MM) patients, with residual or biochemically progressive disease following autologous stem cell transplantation. Vaccination was well tolerated; all adverse events were temporal grade 1 2 and spontaneously resolved. ImMucin vaccination induced a robust increase in γ-interferon (IFN-γ-producing CD4+ and CD8+ T-cells (≤80-fold), a pronounced population of ImMucin multimer CD8+ T-cells (>2%), a 9·4-fold increase in peripheral blood mononuclear cells proliferation and 6·8-fold increase in anti-ImMucin antibodies, accompanied with T-cell and antibody-dependent cell-mediated cytotoxicity. A significant decrease in soluble MUC1 levels was observed in 9/10 patients. Stable disease or improvement, persisting for 17·5-41·3 months (ongoing) was achieved in 11/15 patients and appeared to be associated with low-intermediate PDL1 (CD274) bone marrow levels pre- and post-vaccination. In summary, ImMucin, a highly tolerable cancerous vaccine, induces robust, diversified T- and B-cell ImMucin-specific immunity in MM patients, across major histocompatibility complex-barrier, resulting in at least disease stabilization in most patients.


Assuntos
Vacinas Anticâncer/administração & dosagem , Epitopos de Linfócito B/administração & dosagem , Epitopos de Linfócito T/administração & dosagem , Mucina-1/administração & dosagem , Mieloma Múltiplo/tratamento farmacológico , Sinais Direcionadores de Proteínas , Vacinação , Idoso , Antígeno B7-H1/sangue , Antígeno B7-H1/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/farmacologia , Proliferação de Células/efeitos dos fármacos , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Feminino , Humanos , Interferon gama/sangue , Interferon gama/imunologia , Masculino , Pessoa de Meia-Idade , Mucina-1/imunologia , Mieloma Múltiplo/sangue , Mieloma Múltiplo/imunologia
9.
Support Care Cancer ; 23(1): 223-36, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25189149

RESUMO

PURPOSE: Hematology-oncology patients undergoing chemotherapy and hematopoietic stem cell transplantation (HSCT) recipients are at risk for oral complications which may cause significant morbidity and a potential risk of mortality. This emphasizes the importance of basic oral care prior to, during and following chemotherapy/HSCT. While scientific evidence is available to support some of the clinical practices used to manage the oral complications, expert opinion is needed to shape the current optimal protocols. METHODS: This position paper was developed by members of the Oral Care Study Group, Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and the European Society for Blood and Marrow Transplantation (EBMT) in attempt to provide guidance to the health care providers managing these patient populations. RESULTS: The protocol on basic oral care outlined in this position paper is presented based on the following principles: prevention of infections, pain control, maintaining oral function, the interplay with managing oral complications of cancer treatment and improving quality of life. CONCLUSION: Using these fundamental elements, we developed a protocol to assist the health care provider and present a practical approach for basic oral care. Research is warranted to provide robust scientific evidence and to enhance this clinical protocol.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Assistência Odontológica , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Saúde Bucal , Higiene Bucal , Medula Óssea , Células da Medula Óssea/citologia , Protocolos Clínicos , Feminino , Neoplasias Hematológicas/terapia , Humanos , Masculino , Manejo da Dor , Qualidade de Vida
10.
Mycoses ; 58(12): 694-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26429354

RESUMO

Invasive fungal infections are an important cause of morbidity and mortality after allogeneic haematopoietic stem cell transplantation. We evaluated, in our allogeneic stem cell transplant patients, the effect on the incidence of invasive fungal infection during neutropenia of a strategy combining a diagnostic-driven approach with chemoprophylaxis during higher risk periods of graft vs. host disease and prolonged neutropenia, using itraconazole oral solution with parenteral voriconazole bridging. One hundred and thirty patients admitted for allogeneic stem cell transplantation within two predefined 20 month periods were included in the study. Data for all patients were collected prospectively. Implementation of the protocol resulted in the administration of more prophylactic antifungals to more patients. Following implementation, there was a non-significant decrease in the overall number of invasive fungal infections (IFI) [11 of 65 patients (17.2%) vs. 4 of 65 patients (6.2%, P = 0.051)], as well as in the occurrence of invasive mould infections [8 of 65 patients (12.5%) vs. 2 of 65 patients (3.1%, P = 0.054)]. Survival rates at three and 6 months were not significantly affected. A combined diagnostic-driven approach and antifungal prophylaxis with oral itraconazole and an intravenous voriconazole bridging protocol, was associated with a reduced, albeit non-statistically significant, number of IFI in our medical centre.


Assuntos
Antifúngicos/administração & dosagem , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Itraconazol/administração & dosagem , Micoses/epidemiologia , Infecções Oportunistas/epidemiologia , Administração Oral , Adolescente , Adulto , Idoso , Quimioprevenção/métodos , Criança , Pré-Escolar , Protocolos Clínicos , Feminino , Doença Enxerto-Hospedeiro/prevenção & controle , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Micoses/diagnóstico , Micoses/prevenção & controle , Neutropenia/complicações , Neutropenia/tratamento farmacológico , Infecções Oportunistas/diagnóstico , Infecções Oportunistas/prevenção & controle , Soluções Farmacêuticas/administração & dosagem , Taxa de Sobrevida , Transplante Homólogo/efeitos adversos , Voriconazol/administração & dosagem , Adulto Jovem
11.
J Infect Dis ; 209(4): 557-61, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23983215

RESUMO

We examined the rate, clinical impact, and risk factors of cytomegalovirus (CMV) drug resistance in 561 patients who underwent 616 hematopoietic stem cell transplantations (HSCTs) over 5 years. Drug resistance was exclusively identified in haploidentical (haplo)-HSCT recipients receiving preemptive therapy, among whom the rate was 14.5%. Resistance appeared after prolonged treatment (median, 70 days), was associated with higher preceding viral load (P < .001), and was the strongest predictor for disease by multivariate analysis. The high rate of drug resistance as interlinked with severe disease in haplo-HSCT recipients suggests the potential advantage of prophylactic over preemptive treatment in high-risk patients and highlights the need for better-tolerable anti-CMV drugs.


Assuntos
Antivirais/administração & dosagem , Infecções por Citomegalovirus/prevenção & controle , Citomegalovirus/isolamento & purificação , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Adolescente , Adulto , Análise de Variância , Distribuição de Qui-Quadrado , Criança , Citomegalovirus/genética , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/virologia , Farmacorresistência Viral , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Estudos Prospectivos
12.
Med Oral Patol Oral Cir Bucal ; 19(3): e212-9, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24121920

RESUMO

OBJECTIVES: Patients with chronic graft-versus-host disease (cGVHD) often suffer from dry mouth and oral mucosal lesions. The primary objective of this study was to investigate the safety of an intra-oral electrostimulator (GenNarino) in symptomatic cGVHD patients. The secondary objective was to study the impact on the salivary gland involvement of cGVHD patients. STUDY DESIGN: This paper presents a case series. The study included patients treated for 4 weeks, randomly assigned to the active device and then crossed-over to a sham-device or vice versa. The patients and clinicians were blind to the treatment delivered. Data regarding oral mucosal and salivary gland involvement were collected. RESULTS: Six patients were included in this series. Most of the intraoral areas with manifestations of cGVHD were not in contact with the GenNarino device. Two patients developed mild mucosal lesions in areas in contact with the GenNarino during the study. However, only one of them had a change in the National Institutes of Health (NIH) score for oral cGVHD. The unstimulated and stimulated salivary flow rate increased in 4 out of the 5 patients included in this analysis. Symptoms of dry mouth and general oral comfort improved. CONCLUSION: This study suggests that GenNarino is safe in cGVHD patients with respect to oral tissues. Furthermore the use of GenNarino resulted in subjective and objective improvements in dry mouth symptoms. A large scale study is needed to confirm the impact and safety of GenNarino on systemic cGVHD.


Assuntos
Terapia por Estimulação Elétrica/instrumentação , Terapia por Estimulação Elétrica/métodos , Doença Enxerto-Hospedeiro/complicações , Xerostomia/etiologia , Xerostomia/terapia , Adulto , Idoso , Método Duplo-Cego , Terapia por Estimulação Elétrica/efeitos adversos , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Glândulas Salivares , Resultado do Tratamento
13.
Aging Biol ; 22024.
Artigo em Inglês | MEDLINE | ID: mdl-38736850

RESUMO

The gut microbiome plays important roles in host function and health. Core microbiomes have been described for different species, and imbalances in their composition, known as dysbiosis, are associated with pathology. Changes in the gut microbiome and dysbiosis are common in aging, possibly due to multi-tissue deterioration, which includes metabolic shifts, dysregulated immunity, and disrupted epithelial barriers. However, the characteristics of these changes, as reported in different studies, are varied and sometimes conflicting. Using clonal populations of Caenorhabditis elegans to highlight trends shared among individuals, we employed 16s rRNA gene sequencing, CFU counts and fluorescent imaging, identifying an Enterobacteriaceae bloom as a common denominator in aging animals. Experiments using Enterobacter hormaechei, a representative commensal, suggested that the Enterobacteriaceae bloom was facilitated by a decline in Sma/BMP immune signaling in aging animals and demonstrated its potential for exacerbating infection susceptibility. However, such detrimental effects were context-dependent, mitigated by competition with commensal communities, highlighting the latter as determinants of healthy versus unhealthy aging, depending on their ability to restrain opportunistic pathobionts.

14.
bioRxiv ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-39026789

RESUMO

One of the most exceptional adaptations to extreme drought is found in the sister group to tetrapods, the lungfishes (Dipnoi), which can aestivate inside a mucus cocoon for multiple years at reduced metabolic rates with complete cessation of ingestion and excretion. However, the function of the cocoon tissue is not fully understood. Here we developed a new more natural laboratory protocol for inducing aestivation in the West African lungfish, Protopterus annectens, and investigated the structure and function of the cocoon. We used electron microscopy and imaging of live tissue-stains to confirm that the inner and outer layers of the paper-thin cocoon are composed primarily of living cells. However, we also repeatedly observed extensive bacterial and fungal growth covering the cocoon and found no evidence of anti-microbial activity in vitro against E. coli for the cocoon tissue in this species. This classroom discovery-based research, performed during a course-based undergraduate research experience course (CURE), provides a robust laboratory protocol for investigating aestivation and calls into the question the function of this bizarre vertebrate adaptation.

15.
Infect Immun ; 81(2): 514-20, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23230286

RESUMO

The importance of our inner microbial communities for proper immune responses against invading pathogens is now well accepted, but the mechanisms underlying this protection are largely unknown. In this study, we used Caenorhabditis elegans to investigate such mechanisms. Since very little is known about the microbes interacting with C. elegans in its natural environment, we began by taking the first steps to characterize the C. elegans microbiota. We established a natural-like environment in which initially germfree, wild-type larvae were grown on enriched soil. Bacterial members of the adult C. elegans microbiota were isolated by culture and identified using 16S rRNA gene sequencing. Using pure cultures of bacterial isolates as food, we identified two, Bacillus megaterium and Pseudomonas mendocina, that enhanced resistance to a subsequent infection with the Gram-negative pathogen Pseudomonas aeruginosa. Whereas protection by B. megaterium was linked to impaired egg laying, corresponding to a known trade-off between fecundity and resistance, the mechanism underlying protection conferred by P. mendocina depended on weak induction of immune genes regulated by the p38 MAPK pathway. Disruption of the p38 ortholog, pmk-1, abolished protection. P. mendocina enhanced resistance to P. aeruginosa but not to the Gram-positive pathogen Enterococcus faecalis. Furthermore, protection from P. aeruginosa was similarly induced by a P. aeruginosa gacA mutant with attenuated virulence but not by a different C. elegans-associated Pseudomonas sp. isolate. Our results support a pivotal role for the conserved p38 pathway in microbiota-initiated immune protection and suggest that similarity between microbiota members and pathogens may play a role in such protection.


Assuntos
Infecções Bacterianas/imunologia , Infecções Bacterianas/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/imunologia , Caenorhabditis elegans/metabolismo , Microbiologia do Solo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Bacillus megaterium/imunologia , Bacillus megaterium/isolamento & purificação , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/microbiologia , Metagenoma/imunologia , Pseudomonas aeruginosa/imunologia , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas mendocina/imunologia , Pseudomonas mendocina/isolamento & purificação , Virulência
17.
Nat Genet ; 34(2): 166-76, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12740579

RESUMO

Much of a cell's activity is organized as a network of interacting modules: sets of genes coregulated to respond to different conditions. We present a probabilistic method for identifying regulatory modules from gene expression data. Our procedure identifies modules of coregulated genes, their regulators and the conditions under which regulation occurs, generating testable hypotheses in the form 'regulator X regulates module Y under conditions W'. We applied the method to a Saccharomyces cerevisiae expression data set, showing its ability to identify functionally coherent modules and their correct regulators. We present microarray experiments supporting three novel predictions, suggesting regulatory roles for previously uncharacterized proteins.


Assuntos
Perfilação da Expressão Gênica/estatística & dados numéricos , Genes Reguladores , Algoritmos , Bases de Dados Genéticas , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Modelos Genéticos , Modelos Estatísticos , Mutação , Análise de Sequência com Séries de Oligonucleotídeos/estatística & dados numéricos , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
18.
bioRxiv ; 2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37646003

RESUMO

Human activity is altering the environment in a rapid pace, challenging the adaptive capacities of genetic variation within animal populations. Animals also harbor extensive gut microbiomes, which play diverse roles in host health and fitness and may help expanding host capabilities. The unprecedented scale of human usage of xenobiotics and contamination with environmental toxins describes one challenge against which bacteria with their immense biochemical diversity would be useful, by increasing detoxification capacities. To explore the potential of bacteria-assisted rapid adaptation, we used Caenorhabditis elegans worms harboring a defined microbiome, and neomycin as a model toxin, harmful for the worm host and neutralized to different extents by some microbiome members. Worms raised in the presence of neomycin showed delayed development and decreased survival but were protected when colonized by neomycin-resistant members of the microbiome. Two distinct mechanisms facilitated this protection: gut enrichment driven by altered bacterial competition for the strain best capable of modifying neomycin; and host avoidance behavior, which depended on the conserved JNK homolog KGB-1, enabling preference and acquisition of neomycin-protective bacteria. We further tested the consequences of adaptation, considering that enrichment for protective strains may represent dysbiosis. We found that neomycin-adapted gut microbiomes caused increased susceptibility to infection as well as an increase in gut lipid storage, suggesting metabolic remodeling. Our proof-of-concept experiments support the feasibility of bacteria-assisted host adaptation and suggest that it may be prevalent. The results also highlight trade-offs between toxin adaptation and other traits of fitness.

19.
bioRxiv ; 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37398063

RESUMO

The gut microbiome plays important roles in host function and health. Core microbiomes have been described for different species, and imbalances in their composition, known as dysbiosis, are associated with pathology. Changes in the gut microbiome and dysbiosis are common in aging, possibly due to multi-tissue deterioration, which includes metabolic shifts, dysregulated immunity, and disrupted epithelial barriers. However, the characteristics of these changes, as reported in different studies, are varied and sometimes conflicting. Using clonal populations of C. elegans to highlight trends shared among individuals, and employing NextGen sequencing, CFU counts and fluorescent imaging to characterize age-dependent changes in worms raised in different microbial environments, we identified an Enterobacteriaceae bloom as a common denominator in aging animals. Experiments using Enterobacter hormachei, a representative commensal, suggested that the Enterobacteriaceae bloom was facilitated by a decline in Sma/BMP immune signaling in aging animals and demonstrated its detrimental potential for increasing susceptibility to infection. However, such detrimental effects were context-dependent, mitigated by competition with commensal communities, highlighting the latter as determinants of healthy versus unhealthy aging, depending on their ability to restrain opportunistic pathobionts.

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