Effect of ageing on CMV-specific CD8 T cells from CMV seropositive healthy donors

<p>Abstract</p> <p>Background</p> <p>Ageing is associated with changes in the immune system with substantial alterations in T-lymphocyte subsets. Cytomegalovirus (CMV) is one of the factors that affect functionality of T cells and the differentiation and large expansions of CMV pp65-specific T cells have been associated with impaired responses to other immune challenges. Moreover, the presence of clonal expansions of CMV-specific T cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious diseases in the elderly. In this study, we analyse the effect of ageing on the phenotype and frequency of CMV pp65-specific CD8 T cell subsets according to the expression of CCR7, CD45RA, CD27, CD28, CD244 and CD85j.</p> <p>Results</p> <p>Peripheral blood from HLA-A2 healthy young, middle-aged and elderly donors was analysed by multiparametric flow cytometry using the HLA-A*0201/CMV pp65_495–504(NLVPMVATV) pentamer and mAbs specific for the molecules analysed. The frequency of CMV pp65-specific CD8 T cells was increased in the elderly compared with young and middle-aged donors. The proportion of naïve cells was reduced in the elderly, whereas an age-associated increase of the CCR7^nulleffector-memory subset, in particular those with a CD45RA^dimphenotype, was observed, both in the pentamer-positive and pentamer-negative CD8 T cells. The results also showed that most CMV pp65-specific CD8 T cells in elderly individuals were CD27/CD28 negative and expressed CD85j and CD244.</p> <p>Conclusion</p> <p>The finding that the phenotype of CMV pp65-specific CD8 T cells in elderly individuals is similar to the predominant phenotype of CD8 T cells as a whole, suggests that CMV persistent infections contributes to the age-related changes observed in the CD8 T cell compartment, and that chronic stimulation by other persistent antigens also play a role in T cell immunosenescence. Differences in subset distribution in elderly individuals showing a decrease in naive and an increase in effector-memory CD8 T cells may be relevant in the age-associated defective immune response.</p

Age-Dependent Association between Low Frequency of CD27/CD28 Expression on pp65 CD8+ T Cells and Cytomegalovirus Replication after Transplantation

In this cross-sectional study of 42 solid organ transplant recipients, the association of human cytomegalovirus (HCMV) replication and age with the phenotype of the HCMV-specific CD8+ T cells was analyzed by using the CMV pp65 HLA-A*0201 pentamer. A correlation between the proportion of CD28− HCMV-specific CD8+ T cells and age was observed in patients without HCMV replication (r = 0.50; P = 0.02) but not in patients with HCMV replication (r = −0.05; P = 0.83), a finding which differs from that observed for total CD8+ T cells. Within the group of patients younger than 50 years of age, patients with HCVM replication after transplantation had higher percentages of CD28− HCMV-specific CD8+ T cells (85.6 compared with 58.7% for patients without HCMV replication; P = 0.004) and CD27− HCMV-specific CD8+ T cells (90.7 compared with 68.8% for patients without HCMV replication; P = 0.03). However, in patients older than age 50 years, a high frequency of these two subpopulations was observed in patients both with and without previous HCMV replication (for CD28− HCMV-specific CD8+ T cells, 84.4 and 80.9%, respectively [P = 0.39]; for CD27− HCMV-specific CD8+ T cells 86.6 and 81.5%, respectively [P = 0.16]). In conclusion, the present study shows that in the group of recipients younger than age 50 years, HCMV replication after transplantation is associated with a high percentage of CD27− and CD28− HCMV-specific CD8+ T cells. These results suggest that the increased percentage of CD27− or CD28− HCMV-specific subsets can be considered a biomarker of HCMV replication in solid organ transplant recipients younger than age 50 years but not in older patients. Further studies are necessary to define the significance of these changes in HCMV-associated clinical complications posttransplantation

Redox activities and ROS, NO and phenylpropanoids production by axenically cultured intact olive seedling roots after interaction with a mycorrhizal or a pathogenic fungus

Las raíces de las plántulas de olivo, en cultivo axénico, fueron colocadas alternativamente en contacto con Rhizophagus irregulares (micorrícicos) o con hongos Verticillim dahliae (patógenos). También se incluyeron tratamientos MeJA. Las raíces intactas (generación de anión superóxido, superóxido dismutasa y actividades de peroxidasa) se midieron en las actividades in vivo del apoplasto. Todos nuestros resultados mostraron que las actividades redox apoplásticas de raíces de las plántulas intactas en contacto con el hongo micorriza compatible fueron claramente atenuados en comparación con el hongo patógeno o tratado con MeJA, incluso en las primeras etapas usadas en el tratamiento. Los fenoles totales, flavonoides y glucósidos fenilpropanoides, también fueron cuantificados. Las raíces en contacto con el hongo micorriza no mejoraron la biosíntesis de compuestos fenólicos con respecto a los controles, mientras que los de contacto con el patógeno mejoraron de forma significativa la biosíntesis de todas las fracciones fenólicas medidas. Las especies reactivas del oxígeno y la acumulación de óxido nítrico en las raíces fueron examinadas por microscopía de fluorescencia. Todos ellas presentaron una acumulación mucho mayor en las raíces en contacto con el patógeno que con el hongo micorriza. En total, estos resultados indican que las raíces de las plántulas intactas de olivo, claramente diferenciadas entre micorrizas y hongos patógenos, atenuan las reacciones de defensa contra la primera para facilitar su creación, mientras que induce una reacción de defensa fuerte y sostenida contra el segundo. Ambas especies reactivas de oxígeno y nitrógeno parecían estar involucrados en estas respuestas desde los primeros momentos de contacto. Sin embargo, se necesitan más investigaciones para aclarar la diafonía propuesta entre ellos y sus respectivas funciones en estas respuestas ya que las imágenes de fluorescencia de las raíces revelaron que las especies reactivas del oxígeno se acumulan principalmente en el apoplasto (congruente con las actividades redox medidas en este compartimento), mientras el óxido nítrico se almacena principalmente en el citosol.Roots of intact olive seedlings, axenically cultured, were alternatively placed in contact with Rhizophagus irregularis (mycorrhizal) or Verticillim dahliae (pathogenic) fungi. MeJA treatments were also included. In vivo redox activities in the apoplast of the intact roots (anion superoxide generation, superoxide dismutase and peroxidase activities) were measured. All our results showed that apoplastic redox activities of intact seedling roots in contact with the compatible mycorrhizal fungus were clearly attenuated in comparison with the pathogenic fungus or treated with MeJA, even at the early stages of treatment used. Total phenolics, flavonoids and phenylpropanoid glycosides were also quantified. Roots in contact with the mycorrhizal fungus did not enhance the biosynthesis of phenolic compounds with respect to controls, while those in contact with the pathogenic one significantly enhanced the biosynthesis of all phenolic fractions measured. Reactive oxygen species and nitric oxid accumulation in roots were examined by fluorescence microscopy. All of them presented much higher accumulation in roots in contact with the pathogenic than with the mycorrhizal fungus. Altogether these results indicate that intact olive seedling roots clearly differentiated between mycorrhizal and pathogenic fungi, attenuating defense reactions against the first to facilitate its establishment, while inducing a strong and sustained defense reaction against the second. Both reactive oxygen and nitrogen species seemed to be involved in these responses from the first moments of contact. However, further investigations are required to clarify the proposed crosstalk between them and their respective roles in these responses since fluorescence images of roots revealed that reactive oxygen species were mainly accumulated in the apoplast (congruently with the measured redox activities in this compartment) while nitric oxid was mainly stored in the cytosol.-- Ministerio de Ciencia e Innovación. Proyecto CGL2009-12406 -- Junta de Extremadura. Proyecto PRI09A023peerReviewe

Bienvenida institucional a las jornadas

Bienvenida institucional a las Jornada de RIs en Ciencias Biomédicas “El papel de las RIs en medicina personalizada” por parte de Pilar Gayoso (Subdirectora General de Terapia Celular y Medicina Regenerativa del ISCIII), Ángeles Gómez (Vicepresidenta Relaciones Internacionales CSIC) e Inmaculada Figueroa (Subdirectora General de Internacionalización de la Ciencia y la Innovación. MCIN)N

Clinical Factors Influencing Phenotype of HCMV-Specific CD8+ T Cells and HCMV-Induced Interferon-Gamma Production after Allogeneic Stem Cells Transplantation

Human cytomegalovirus (HCMV) infection causes significant morbidity and mortality after hematopoietic stem cell transplantation (HSCT). In this work, we characterized the phenotype and interferon-gamma (INF-γ) production of HCMV-specific T cells using QuantiFERON-HCMV assay in 26 patients 6 months after HSCT. We analysed whether these two parameters were associated with clinical variables. Our results showed that the patients receiving stem cells from donors ≥40 years old were 12 times more likely to have HCMV-specific CD8+ T cells with “differentiated phenotype” (CD45RA+CCR7+ ≤6.7% and CD28+ ≤30%) than patients grafted from donors <40 years old (OR=12; P=0.014). In addition, a detectable IFN-γ production in response to HCMV peptides (cutoff 0.2 IU/mL IFN-γ; “reactive” QuantiFERON-HCMV test) was statistically associated with HCMV replication after transplantation (OR=11; P=0.026), recipients ≥40 versus <40 years old (OR=11; P=0.026), and the use of peripheral blood versus bone marrow as stem cell source (OR=17.5; P=0.024). In conclusion, donor age is the only factor significantly associated with the presence of the “differentiated phenotype” in HCMV-specific CD8+ T cells, whereas HCMV replication after transplantation, recipient age, and stem cell source are the factors associated with the production of IFN-γ in response to HCMV epitopes

Phase II Study of Yttrium-90-Ibritumomab Tiuxetan as Part of Reduced-Intensity Conditioning (with Melphalan, Fludarabine ± Thiotepa) for Allogeneic Transplantation in Relapsed or Refractory Aggressive B Cell Lymphoma : A GELTAMO Trial

We designed a phase II clinical trial including Y-90 ibritumomab-tiuxetan as part of a reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (AlloSCT) in high-risk non-Hodgkin lymphoma (Clinical Trials Identifier: NCT00644371). Eligible patients had high-risk relapsed/refractory aggressive lymphoma. The conditioning regimen consisted of rituximab 250 mg (days −21 and −14), Y-90 ibritumomab IV (.4 m Ci/kg, day −14), fludarabine 30 mg/m i.v. (days −3 and −2) plus melphalan 70 mg/m i.v. (days −3 and −2) or 1 dose of melphalan and thiotepa 5 mg/kg (day −8). Donors were related. Eighteen patients were evaluable. At the time of transplantation, responses were complete remission (CR) (n = 7, 39%), partial remission (n = 6, 33%) or refractory disease (n = 4, 28%). Y-90-ibritumomab infusions were well tolerated, with no adverse reactions. Nonrelapse mortality at 1 year was 28%. Median follow-up was 46 (range, 39 to 55) months. Estimated 1-year progression-free survival (PFS) was 50%, and 4-year overall survival (OS) and PFS were both 44.4%. CR at the moment of AlloSCT had significant impact on PFS (71% versus 27%, P = .046) and OS (71% versus 27%, P = .047). Our results show that Y-90-ibritumomab-tiuxetan as a component of RIC for AlloSCT is feasible in patients with high-risk B cell lymphoma. Development of phase III clinical trials is needed to clarify the contribution of radioimmunotherapy to RIC AlloSCT

COVID-19 in transplant recipients: The Spanish experience.

We report the nationwide experience with solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients diagnosed with coronavirus disease 2019 (COVID-19) in Spain until 13 July 2020. We compiled information for 778 (423 kidney, 113 HSCT, 110 liver, 69 heart, 54 lung, 8 pancreas, 1 multivisceral) recipients. Median age at diagnosis was 61 years (interquartile range [IQR]: 52-70), and 66% were male. The incidence of COVID-19 in SOT recipients was two-fold higher compared to the Spanish general population. The median interval from transplantation was 59 months (IQR: 18-131). Infection was hospital-acquired in 13% of cases. No donor-derived COVID-19 was suspected. Most patients (89%) were admitted to the hospital. Therapies included hydroxychloroquine (84%), azithromycin (53%), protease inhibitors (37%), and interferon-β (5%), whereas immunomodulation was based on corticosteroids (41%) and tocilizumab (21%). Adjustment of immunosuppression was performed in 85% of patients. At the time of analysis, complete follow-up was available from 652 patients. Acute respiratory distress syndrome occurred in 35% of patients. Ultimately, 174 (27%) patients died. In univariate analysis, risk factors for death were lung transplantation (odds ratio [OR]: 2.5; 95% CI: 1.4-4.6), age >60 years (OR: 3.7; 95% CI: 2.5-5.5), and hospital-acquired COVID-19 (OR: 3.0; 95% CI: 1.9-4.9)