Browsing by Author "Serra-Caetano, Ana"
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- Adult B-cell acute lymphoblastic leukemia cells display decreased PTEN activity and constitutive hyperactivation of PI3K/Akt pathway despite high PTEN protein levelsPublication . Gomes, Ana Margarida; Soares, Maria Vieira; Ribeiro, Patrícia; Caldas, Joana; Póvoa, Vanda; Martins, Leila; Melão, Alice; Serra-Caetano, Ana; de Sousa, Aida B.; Lacerda, João; Barata, João T.Adult B-cell acute lymphoblastic leukemia remains a major therapeutic challenge, requiring a better characterization of the molecular determinants underlying disease progression and resistance to treatment. Here, using a phospho-flow cytometry approach we show that adult diagnostic B-cell acute lymphoblastic leukemia specimens display PI3K/Akt pathway hyperactivation, irrespective of their BCR-ABL status and despite paradoxically high basal expression of PTEN, the major negative regulator of the pathway. Protein kinase CK2 is known to phosphorylate PTEN thereby driving PTEN protein stabilization and concomitant PTEN functional inactivation. In agreement, we found that adult B-cell acute lymphoblastic leukemia samples show significantly higher CK2 kinase activity and lower PTEN lipid phosphatase activity than healthy controls. Moreover, the clinical-grade CK2 inhibitor CX-4945 (Silmitasertib) reversed PTEN levels in leukemia cells to those observed in healthy controls, and promoted leukemia cell death without significantly affecting normal bone marrow cells. Our studies indicate that CK2-mediated PTEN posttranslational inactivation, associated with PI3K/Akt pathway hyperactivation, are a common event in adult B-cell acute lymphoblastic leukemia and suggest that CK2 inhibition may constitute a valid, novel therapeutic tool in this malignancy.
- Age-associated distribution of normal B-cell and plasma cell subsets in peripheral bloodPublication . Blanco, Elena; Pérez-Andrés, Martín; Arriba-Méndez, Sonia; Contreras-Sanfeliciano, Teresa; Criado, Ignacio; Pelak, Ondrej; Serra-Caetano, Ana; Romero, Alfonso; Puig, Noemí; Remesal, Ana; Torres Canizales, Juan; López-Granados, Eduardo; Kalina, Tomas; Sousa, Ana E.; van Zelm, Menno; van der Burg, Mirjam; van Dongen, Jacques J. M.; Orfao, AlbertoBackground: Humoral immunocompetence develops stepwise throughout life and contributes to individual susceptibility to infection, immunodeficiency, autoimmunity, and neoplasia. Immunoglobulin heavy chain (IgH) isotype serum levels can partly explain such age-related differences, but their relationship with the IgH isotype distribution within memory B-cell (MBC) and plasma cell (PCs) compartments remains to be investigated. Objective: We studied the age-related distribution of MBCs and PCs expressing different IgH isotypes in addition to the immature/transitional and naive B-cell compartments. Methods: B-cell and PC subsets and plasma IgH isotype levels were studied in cord blood (n = 19) and peripheral blood (n = 215) from healthy donors aged 0 to 90 years by using flow cytometry and nephelometry, respectively. Results: IgH-switched MBCs expressing IgG1, IgG2, IgG3, IgA1, and IgA2 were already detected in cord blood and newborns at very low counts, whereas CD27+IgM++IgD+ MBCs only became detectable at 1 to 5 months and remained stable until 2 to 4 years, and IgD MBCs peaked at 2 to 4 years, with both populations decreasing thereafter. MBCs expressing IgH isotypes of the second immunoglobulin heavy chain constant region (IGHC) gene block (IgG1, IgG3, and IgA1) peaked later during childhood (2-4 years), whereas MBCs expressing third IGHC gene block immunoglobulin isotypes (IgG2, IgG4, and IgA2) reached maximum values during adulthood. PCs were already detected in newborns, increasing in number until 6 to 11 months for IgM, IgG1, IgG2, IgG3, IgA1, and IgA2; until 2 to 4 years for IgD; and until 5 to 9 years for IgG4 and decreasing thereafter. For most IgH isotypes (except IgD and IgG4), maximum plasma levels were reached after PC and MBC counts peaked. Conclusions: PC counts reach maximum values early in life, followed by MBC counts and plasma IgH isotypes. Importantly, IgH isotypes from different IGHC gene blocks show different patterns, probably reflecting consecutive cycles of IgH isotype switch recombination through life.
- Blood biomarkers associated with inflammation predict poor prognosis in cerebral venous thrombosis : a multicenter prospective observational studyPublication . de Sousa, Diana Aguiar; Pereira Santos, M. C.; Serra-Caetano, Ana; Lucas Neto, Lia; Sousa, A. L.; Gabriel, D.; Correia, M.; Gil-Gouveia, Raquel; Oliveira, Renato; Penas, Sara; Carvalho Dias, Mariana; Correia, M. A.; Carvalho, M.; Sousa, Ana E.; Canhão, Patrícia; Ferro, JoséBackground and purpose: Experimental studies suggest inflammation can contribute to blood barrier disruption and brain injury in cerebral venous thrombosis (CVT). We aimed to determine whether blood biomarkers of inflammation were associated with the evolution of brain lesions, persistent venous occlusion or functional outcome in patients with CVT. Methods: Pathophysiology of Venous Infarction-Prediction of Infarction and Recanalization in CVT (PRIORITy-CVT) was a multicenter prospective cohort study of patients with newly diagnosed CVT. Evaluation of neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) concentrations in peripheral blood samples was performed at admission in 62 patients. Additional quantification of interleukin (IL)-6 was performed at day 1, 3 and 8 in 35 patients and 22 healthy controls. Standardized magnetic resonance imaging was performed at day 1, 8 and 90. Primary outcomes were early evolution of brain lesion, early recanalization and functional outcome at 90 days. Results: Interleukin-6 levels were increased in patients with CVT with a peak at baseline. IL-6, NLR and CRP levels were not related with brain lesion outcomes or early recanalization but had a significant association with unfavourable functional outcome at 90 days (IL-6: OR = 1.28, 95% CI: 1.05-1.56, P = 0.046; NLR: OR = 1.39, 95% CI: 1.4-1.87, P = 0.014; CRP: OR = 1.756, 95% CI: 1.010-3.051, P = 0.029). Baseline IL-6 had the best discriminative capacity, with an area under the receiver operating characteristic curve to predict unfavourable functional outcome of 0.74 (P = 0.031). Conclusions: Increased baseline levels of NLR, CRP and IL-6 may serve as new predictive markers of worse functional prognosis at 90 days in patients with CVT. No association was found between inflammatory markers and early evolution of brain lesion or venous recanalization.
- Foxp3 induction in human and murine thymus precedes the CD4+ CD8+ stage but requires early T-cell receptor expressionPublication . Nunes-Cabaço, H.; C Ribot, Julie; Caramalho, Íris; Serra-Caetano, Ana; Silva-Santos, Bruno; E Sousa, AnaThe thymus generates a T-cell lineage dedicated to immune regulation, 'naturally occurring' regulatory T cells, best specified by the forkhead family transcription factor Foxp3. Here, we have conducted a parallel study in humans and mice where we have dissected the earliest stages of Foxp3 induction during thymocyte development. By analyzing a large collection of 21 human thymuses we show that Foxp3 can be consistently detected in CD4 immature single positive thymocytes that precede the CD4(+)CD8(+) (double positive, DP) stage. The reduced levels of CD3 expression found at this stage of human thymocyte development raise the question of TCR (T-cell receptor) requirement for Foxp3 induction. We further show that, in mice, Foxp3 expression was also detected in pre-DP thymocytes of TCRalpha-sufficient but not in TCRalpha-deficient animals, genetically showing the TCR dependence of Foxp3 expression at pre-DP stages of T-cell development.
- Human naïve regulatory T-cells feature high steady-state turnover and are maintained by IL-7Publication . Silva, Susana L.; Albuquerque, Adriana S.; Serra-Caetano, Ana; Foxall, Russell B.; Pires, Ana R.; Matoso, Paula; Fernandes, Susana M.; Ferreira, João; Cheynier, Rémi; Victorino, Rui M. M.; Caramalho, Iris; Barata, João T.; Sousa, Ana E.Naïve FoxP3-expressing regulatory T-cells (Tregs) are essential to control immune responses via continuous replenishment of the activated-Treg pool with thymus-committed suppressor cells. The mechanisms underlying naïve-Treg maintenance throughout life in face of the age-associated thymic involution remain unclear. We found that in adults thymectomized early in infancy the naïve-Treg pool is remarkably well preserved, in contrast to conventional naïve CD4 T-cells. Naïve-Tregs featured high levels of cycling and pro-survival markers, even in healthy individuals, and contrasted with other circulating naïve/memory CD4 T-cell subsets in terms of their strong γc-cytokine-dependent signaling, particularly in response to IL-7. Accordingly, ex-vivo stimulation of naïve-Tregs with IL-7 induced robust cytokine-dependent signaling, Bcl-2 expression, and phosphatidylinositol 3-kinase (PI3K)-dependent proliferation, whilst preserving naïve phenotype and suppressive capacity. Altogether, our data strongly implicate IL-7 in the thymus-independent long-term survival of functional naïve-Tregs, and highlight the potential of targeting the IL-7 pathway to modulate Tregs in different clinical settings.
- Matrix Metalloproteinase-9 levels are associated with brain lesion and persistent venous occlusion in patients with cerebral venous thrombosisPublication . de Sousa, Diana Aguiar; Pereira Santos, Maria Conceição; Serra-Caetano, Ana; Lucas Neto, Lia; Sousa, Ana Luísa; Gabriel, Denis; Correia, Manuel; Gil-Gouveia, Raquel; Oliveira, Renato; Penas, Sara; Carvalho Dias, Mariana; Correia, Manuel A.; Carvalho, Marta; Sousa, Ana E.; Canhão, Patrícia; Ferro, JoséBackground: Elucidating mechanisms of brain damage in cerebral venous thrombosis (CVT) would be instrumental to develop targeted therapies and improve prognosis prediction. Matrix metalloproteinase-9 (MMP-9), a gelatinase that degrades major components of the basal lamina, has been associated to blood-brain barrier disruption. We aimed to assess, in patients with CVT, the temporal change in serum concentrations of MMP-9 and its association with key imaging and clinical outcomes. Methods: Pathophysiology of Venous Infarction-PRediction of InfarctiOn and RecanalIzaTion in CVT (PRIORITy-CVT) was a multicenter prospective cohort study of patients with newly diagnosed CVT. Serial collection of peripheral blood samples performed on day 1, 3, and 8, and standardized magnetic resonance imaging on day 1, 8, and 90. MMP-9 was quantified using enzyme-linked immunosorbent assay in 59 patients and 22 healthy controls. Primary outcomes were parenchymal brain lesion, early evolution of brain lesion, early recanalization, and functional outcome on day 90. Results: CVT patients with parenchymal brain lesion had higher baseline concentrations of MMP-9 compared with controls (adjusted p = 0.001). The area under receiver operating characteristic curve value for MMP-9 for predicting brain lesion was 0.71 (95% confidence interval [CI]: 0.57-0.85, p = 0.009). Patients with venous recanalization showed early decline of circulating MMP-9 and significantly lower levels on day 8 (p = 0.021). Higher MMP-9 on day 8 was associated with persistent venous occlusion (odds ratio: 1.20 [per 20 ng/mL], 95% CI: 1.02-1.43, p = 0.030). Conclusion: We report a novel relationship among MMP-9, parenchymal brain damage, and early venous recanalization, suggesting that circulating MMP-9 is a dynamic marker of brain tissue damage in patients with CVT.
- Monozygotic twins concordant for common variable immunodeficiency : strikingly similar clinical and immune profile associated with a polygenic burdenPublication . Silva, Susana L.; Fonseca, Mariana; Pereira, Marcelo L. M.; Silva, Sara P.; Barbosa, Rita R.; Serra-Caetano, Ana; Blanco, Elena; Rosmaninho, Pedro; Pérez-Andrés, Martin; Sousa, Ana Berta; Raposo, Alexandre; Gama-Carvalho, Margarida; Victorino, Rui; Hammarstrom, Lennart; Sousa, Ana E.Monozygotic twins provide a unique opportunity to better understand complex genetic diseases and the relative contribution of heritable factors in shaping the immune system throughout life. Common Variable Immunodeficiency Disorders (CVID) are primary antibody defects displaying wide phenotypic and genetic heterogeneity, with monogenic transmission accounting for only a minority of the cases. Here, we report a pair of monozygotic twins concordant for CVID without a family history of primary immunodeficiency. They featured a remarkably similar profile of clinical manifestations and immunological alterations at diagnosis (established at age 37) and along the subsequent 15 years of follow-up. Interestingly, whole-exome sequencing failed to identify a monogenic cause for CVID, but unraveled a combination of heterozygous variants, with a predicted deleterious impact. These variants were found in genes involved in relevant immunological pathways, such as JUN, PTPRC, TLR1, ICAM1, and JAK3. The potential for combinatorial effects translating into the observed disease phenotype is inferred from their roles in immune pathways, namely in T and B cell activation. The combination of these genetic variants is also likely to impose a significant constraint on environmental influences, resulting in a similar immunological phenotype in both twins, despite exposure to different living conditions. Overall, these cases stress the importance of integrating NGS data with clinical and immunological phenotypes at the single-cell level, as provided by multi-dimensional flow-cytometry, in order to understand the complex genetic landscape underlying the vast majority of patients with CVID, as well as those with other immunodeficiencies.
- Vacinas vivas em crianças com síndrome de DiGeorge/Deleção 22q11.2Publication . Miranda, Mariana; Martins, Andreia Teixeira; Carvalho, Sara; Serra-Caetano, Ana; Esteves, Isabel; Marques, José GonçaloChildren with DiGeorge syndrome/chromosome 22q11.2 deletion syndrome might have a variable degree of immunodeficiency, which may limit the use of live vaccines. The aim of this study was to review the adverse effects of live vaccines and possible relation with immune status in patients with DiGeorge Syndrome/partial 22q11.2 deletion syndrome.Material e Métodos: Foi realizado um estudo retrospetivo por revisão dos processos clínicos das crianças com deleção do cromossoma 22q11.2 e fenótipo de síndrome de DiGeorge, seguidos num centro de referência de imunodeficiências primárias. Foi realizada colheita de dados, incluindo: características demográficas; história médica; historial de vacinação com vacinas vivas; contagem de linfócitos T-CD4+ e respostas proliferativas linfocitárias a antigénios e mitogénios; reações adversas; falências vacinais. Resultados: Foram incluídas 23 crianças com síndrome de DiGeorge/deleção 22q11.2, 65,2% do sexo masculino e idade média de diagnóstico de 11,3 meses. Destas, 18 crianças (78%) receberam a vacina bacillus Calmette-Guérin: todas com evidência de atividade tímica; três apresentaram linfopénia T-CD4+ moderada e respostas proliferativas linfocitárias anormais; uma com respostas proliferativas linfocitárias anormais para mitogénios, quatro para derivado de proteína purificada e uma para toxóide tetânico. A vacina tríplice contra o sarampo, parotidite e rubéola foi administrada a 15 crianças, três com imunossupressão moderada e respostas proliferativas linfocitárias anormais. A vacina viva atenuada contra poliomielite foi administrada a quatro crianças sem imunossupressão e a vacina contra o rotavírus a três crianças, uma com imunossupressão moderada. Não foram reportadas reações adversas. Discussão: Estes dados estão de acordo com as conclusões de outros estudos internacionais. Conclusão: Na nossa amostra, as vacinas vivas atenuadas foram bem toleradas, incluindo em crianças com linfopénia T-CD4+ moderada e com respostas proliferativas linfocitárias a antigénios/mitogénios anormais.