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1.
Br J Haematol ; 200(1): 45-53, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36205375

RESUMEN

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.


Asunto(s)
Mieloma Múltiple , Humanos , Anciano , Mieloma Múltiple/tratamiento farmacológico , Estudios Retrospectivos , Estudios Prospectivos , Resultado del Tratamiento
2.
Pediatr Blood Cancer ; 65(11): e27312, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30070020

RESUMEN

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.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Agonistas Mieloablativos/uso terapéutico , Talasemia/cirugía , Acondicionamiento Pretrasplante/métodos , Vidarabina/análogos & derivados , Adolescente , Busulfano/uso terapéutico , Niño , Preescolar , Femenino , Humanos , Masculino , Estudios Retrospectivos , Trasplante Homólogo/métodos , Vidarabina/uso terapéutico
3.
Acta Haematol ; 140(4): 209-214, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30343286

RESUMEN

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.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bortezomib/administración & dosificación , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anticuerpos Biespecíficos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Trasplante de Médula Ósea , Bortezomib/efectos adversos , Neutropenia Febril/etiología , Humanos , Persona de Mediana Edad , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Recurrencia , Inducción de Remisión , Estudios Retrospectivos
4.
PLoS Genet ; 11(5): e1005265, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26016853

RESUMEN

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.


Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/inmunología , Factores de Transcripción GATA/metabolismo , Regulación de la Expresión Génica , Inmunidad Innata/genética , Mucosa Intestinal/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Factores de Transcripción Activadores/genética , Factores de Transcripción Activadores/metabolismo , Animales , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Factores de Transcripción GATA/genética , Técnicas de Silenciamiento del Gen , Larva/genética , Larva/metabolismo , Regiones Promotoras Genéticas , Pseudomonas aeruginosa , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/genética
6.
Hematol Oncol ; 35(4): 797-803, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27338621

RESUMEN

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.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Leucemia Mieloide Aguda/terapia , Acondicionamiento Pretrasplante/métodos , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Adulto Joven
7.
Biochem Biophys Res Commun ; 477(3): 401-5, 2016 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-27329812

RESUMEN

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.


Asunto(s)
Adaptación Fisiológica , Caenorhabditis elegans/fisiología , Congelación , Animales
8.
Br J Haematol ; 169(1): 44-56, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25496030

RESUMEN

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.


Asunto(s)
Vacunas contra el Cáncer/administración & dosificación , Epítopos de Linfocito B/administración & dosificación , Epítopos de Linfocito T/administración & dosificación , Mucina-1/administración & dosificación , Mieloma Múltiple/tratamiento farmacológico , Señales de Clasificación de Proteína , Vacunación , Anciano , Antígeno B7-H1/sangre , Antígeno B7-H1/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD4-Positivos/patología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/patología , Vacunas contra el Cáncer/inmunología , Vacunas contra el Cáncer/farmacología , Proliferación Celular/efectos de los fármacos , Epítopos de Linfocito B/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Humanos , Interferón gamma/sangre , Interferón gamma/inmunología , Masculino , Persona de Mediana Edad , Mucina-1/inmunología , Mieloma Múltiple/sangre , Mieloma Múltiple/inmunología
9.
Support Care Cancer ; 23(1): 223-36, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25189149

RESUMEN

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.


Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Atención Odontológica , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Salud Bucal , Higiene Bucal , Médula Ósea , Células de la Médula Ósea/citología , Protocolos Clínicos , Femenino , Neoplasias Hematológicas/terapia , Humanos , Masculino , Manejo del Dolor , Calidad de Vida
10.
Mycoses ; 58(12): 694-8, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26429354

RESUMEN

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.


Asunto(s)
Antifúngicos/administración & dosificación , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Itraconazol/administración & dosificación , Micosis/epidemiología , Infecciones Oportunistas/epidemiología , Administración Oral , Adolescente , Adulto , Anciano , Quimioprevención/métodos , Niño , Preescolar , Protocolos Clínicos , Femenino , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Micosis/diagnóstico , Micosis/prevención & control , Neutropenia/complicaciones , Neutropenia/tratamiento farmacológico , Infecciones Oportunistas/diagnóstico , Infecciones Oportunistas/prevención & control , Soluciones Farmacéuticas/administración & dosificación , Tasa de Supervivencia , Trasplante Homólogo/efectos adversos , Voriconazol/administración & dosificación , Adulto Joven
11.
J Infect Dis ; 209(4): 557-61, 2014 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-23983215

RESUMEN

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.


Asunto(s)
Antivirales/administración & dosificación , Infecciones por Citomegalovirus/prevención & control , Citomegalovirus/aislamiento & purificación , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Adolescente , Adulto , Análisis de Varianza , Distribución de Chi-Cuadrado , Niño , Citomegalovirus/genética , Infecciones por Citomegalovirus/tratamiento farmacológico , Infecciones por Citomegalovirus/virología , Farmacorresistencia Viral , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Estudios Prospectivos
12.
Med Oral Patol Oral Cir Bucal ; 19(3): e212-9, 2014 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-24121920

RESUMEN

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.


Asunto(s)
Terapia por Estimulación Eléctrica/instrumentación , Terapia por Estimulación Eléctrica/métodos , Enfermedad Injerto contra Huésped/complicaciones , Xerostomía/etiología , Xerostomía/terapia , Adulto , Anciano , Método Doble Ciego , Terapia por Estimulación Eléctrica/efectos adversos , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Glándulas Salivales , Resultado del Tratamiento
13.
Aging Biol ; 22024.
Artículo en Inglés | MEDLINE | ID: mdl-38736850

RESUMEN

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.
Artículo en Inglés | MEDLINE | ID: mdl-39026789

RESUMEN

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.
Artículo en Inglés | MEDLINE | ID: mdl-23230286

RESUMEN

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.


Asunto(s)
Infecciones Bacterianas/inmunología , Infecciones Bacterianas/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/inmunología , Caenorhabditis elegans/metabolismo , Microbiología del Suelo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Bacillus megaterium/inmunología , Bacillus megaterium/aislamiento & purificación , Caenorhabditis elegans/enzimología , Caenorhabditis elegans/microbiología , Metagenoma/inmunología , Pseudomonas aeruginosa/inmunología , Pseudomonas aeruginosa/aislamiento & purificación , Pseudomonas mendocina/inmunología , Pseudomonas mendocina/aislamiento & purificación , Virulencia
17.
Nat Genet ; 34(2): 166-76, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12740579

RESUMEN

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.


Asunto(s)
Perfilación de la Expresión Génica/estadística & datos numéricos , Genes Reguladores , Algoritmos , Bases de Datos Genéticas , Regulación Fúngica de la Expresión Génica , Genes Fúngicos , Modelos Genéticos , Modelos Estadísticos , Mutación , Análisis de Secuencia por Matrices de Oligonucleótidos/estadística & datos numéricos , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
18.
bioRxiv ; 2023 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-37646003

RESUMEN

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.
Artículo en Inglés | MEDLINE | ID: mdl-37398063

RESUMEN

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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