Ana Barbosa

Ms. Ana Barbosa


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 November 2021 in JCI Insight
Verified
Journal Article
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CFCatarina M. Ferreira
Catarina M. Ferreira
ABAna Barbosa
Ana Barbosa
PBPalmira Barreira-Silva
Palmira Barreira-Silva
RSRicardo Silvestre
Ricardo Silvestre
CCCristina Cunha
Cristina Cunha
ETEgídio Torrado
Egídio Torrado
Cytokine-producing CD4 + T cells play a crucial role in the control of Mycobacterium tuberculosis infection; however, there is a delayed appearance of effector T cells in the lungs following aerosol infection. The immunomodulatory cytokine IL-10 antagonizes control of M . tuberculosis infection through mechanisms associated with reduced CD4 + T cell responses. Here, we show that IL-10 overexpression only before the onset of the T cell response impaired control of M . tuberculosis growth; during chronic infection, IL-10 overexpression reduced the CD4 + T cell response without affecting the outcome of infection. IL-10 overexpression early during infection did not, we found, significantly impair the kinetics of CD4 + T cell priming and effector differentiation. However, CD4 + T cells primed and differentiated in an IL-10–enriched environment displayed reduced expression of CXCR3 and, because they did not migrate into the lung parenchyma, their ability to control infection was limited. Importantly, these CD4 + T cells maintained their vasculature phenotype and were unable to control infection, even after adoptive transfer into low IL-10 settings. Together our data support a model wherein, during M . tuberculosis infection, IL-10 acts intrinsically on T cells, impairing their parenchymal migratory capacity and ability to engage with infected phagocytic cells, thereby impeding control of infection.

27 March 2023 in Cancers
Verified
Journal Article
Open access
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PPPaula Roberta Aguiar Pastrez
Paula Roberta Aguiar Pastrez
ABAna Barbosa
Ana Barbosa
VMVânia Sammartino Mariano
Vânia Sammartino Mariano
RCRhafaela Lima Causin
Rhafaela Lima Causin
ACAntónio Gil Castro
António Gil Castro
ALAdhemar Longatto-Filho
Adhemar Longatto-Filho
Esophageal squamous cell carcinoma (ESCC) is a common type of cancer characterized by fast progression and high mortality rates, which generally implies a poor prognosis at time of diagnosis. Intricate interaction networks of cytokines produced by resident and inflammatory cells in the tumor microenvironment play crucial roles in ESCC development and metastasis, thus influencing therapy efficiency. As such, cytokines are the most prominent targets for specific therapies and prognostic parameters to predict tumor progression and aggressiveness. In this work, we examined the association between ESCC progression and the systemic levels of inflammatory cytokines to determine their usefulness as diagnostic biomarkers. We analyzed the levels of IL-1β, IL-6, IL-8, IL-10, TNF-α e IL-12p70 in a group of 70 ESCC patients and 70 healthy individuals using Cytometric Bead Array (CBA) technology. We detected increased levels of IL-1β, IL-6, IL-8, and IL-10 in ESCC patients compared to controls. However, multivariate analysis revealed that only IL8 was an independent prognostic factor for ESCC, as were the well-known risk factors: alcohol consumption, tobacco usage, and exposure to pesticides/insecticides. Importantly, patients with low IL-6, IL-8, TNM I/II, or those who underwent surgery had a significantly higher overall survival rate. We also studied cultured Kyse-30 and Kyse-410 cells in mice. We determined that the ESCC cell line Kyse-30 grew more aggressively than the Kyse-410 cell line. This enhanced growth was associated with the recruitment/accumulation of intratumoral polymorphonuclear leukocytes. In conclusion, our data suggest IL-8 as a valuable prognostic factor with potential as a biomarker for ESCC.

20 August 2021 in Biology
Verified
Journal Article
Open access
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ABAna Barbosa
Ana Barbosa
Olga MartinhoOlga Martinho
Olga Martinho
RNRosete Nogueira
Rosete Nogueira
JCJuliana Campos
Juliana Campos
LLLiliana Lobo
Liliana Lobo
ETEgídio Torrado
Egídio Torrado
Tumor-infiltrating lymphocytes include heterogeneous populations of T lymphocytes that play crucial roles in the tumor immune response; importantly, their presence in the tumor tissue may predict clinical outcomes. Therefore, we herein studied the prognostic significance of the presence and location of CD3+, CD8+, and FoxP3+ T lymphocytes in colorectal cancer samples. In the intratumor analysis, our data did not reveal any association between lymphocyte infiltrations with clinical or pathological data. However, in the tumor margins, we found that the presence of high infiltrations of CD3+, CD8+, or FoxP3+ T lymphocytes were associated with TNM stages I-II (p = 0.021, p = 0.022, and p = 0.012, respectively) and absence of lymph node metastases (p = 0.010, p = 0.003, and p = 0.004, respectively). Despite these associations with good prognostic indicators, we were not able to find any statistically significant alterations in the overall survival of the patients, even though high infiltrations of FoxP3+ T lymphocytes in the tumor margins resulted in an increased overall survival of 14 months. Taken together, these data show that the presence of CD3+, CD8+, or FoxP3+T lymphocyte infiltrates in the tumor margins are associated with the pathogenesis of CRC, but only high Foxp3+ T lymphocyte infiltrations in the tumor invasive margins are inclined to indicate favorable prognosis.

13 November 2021 in Pharmaceutics
Verified
Journal Article
Open access
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FZFernanda Zamboni
Fernanda Zamboni
Ibrahim Fatih CengizIbrahim Fatih Cengiz
Ibrahim Fatih Cengiz
ABAna Barbosa
Ana Barbosa
ACAntónio Gil Castro
António Gil Castro
RRRui M. Reis
Rui M. Reis
Maurice CollinsMaurice Collins
Maurice Collins
Female mice (Black 6 strain) (C57BL/6) aged 6 weeks were subject to low dose streptozotocin (STZ) treatment for five consecutive days to mimic type 1 diabetes mellitus (T1DM) with insulitis. At two weeks after STZ injections, evaluation of the elevated glucose levels was used to confirm diabetes. The diabetic mice were then subject to the transplantation of pancreatic β-cells (MIN-6 line). Four groups of mice were studied. The first group was injected with saline-only acting as the placebo surgery control, also known as SHAM group, the second and third groups were injected with MIN-6 single cells and polyethylene glycol-modified dipalmitoyl-glycerol-phosphatidyl ethanolamine (PEG-DPPE) modified MIN-6 single cells (500 µg per 1.106 cells), respectively, while the fourth group was injected with hyaluronic acid (HA)-coated MIN-6 single cells (5 bilayers). At seven- and fourteen-days following transplantation, the mice were euthanised. The renal and pancreatic tissues were then collected and histologically analysed. The induction of diabetes in female mice, through five-consecutive daily STZ injections resulted in inconsistent glycaemic levels. Interestingly, this shows an incomplete diabetes induction in female mice, of which we attribute to sex dimorphism and hormonal interferences. Transplantation failure of free-floating encapsulated cells was unable to decrease blood glucose hyperglycaemia to physiological ranges. The result is attributed to deprived cell–cell interactions, leading to decreased β-cells functionality. Overall, we highlight the necessity of refining T1DM disease models in female subjects when using multiple low-dose STZ injections together with transplantation protocols. Considerations need to be made regarding the different developmental stages of female mice and oestrogen load interfering with pancreatic β-cells susceptibility to STZ. The use of pseudo islets, cell aggregates and spheroids are sought to improve transplantation outcome in comparison to free-floating single cells.