T-Cell Activation: Post-Infection Diagnostic Tool for COVID-19.

COVID-19 is caused by the SARS-CoV-2 virus and has spread globally in 2020. Cellular immunity may serve as an important functional marker of the disease, especially in the asymptomatic cases. Blood samples were collected from 46 convalescent donors with a history of COVID-19 and 38 control donors. Quantification of the T-cell response upon contact with SARS-CoV-2 proteins in vitro was based on IFN-γ. Significantly higher numbers of activated cells were measured in patients who underwent COVID-19. Anti-SARS-CoV-2 T cells were detected weeks after the active virus disappeared from the organism. Repeated sample collection after five months proved that the T-cell activation was weaker in time in 79 % of the patients. In the majority of cases, the CD4+ helper T-cell subpopulation was responsible for the immune reaction. Moreover, different viral proteins triggered activation in CD4+ helper and in CD8+ cytotoxic T cells. Together, these findings suggest that the T-cell activation level identifies the individuals who underwent COVID-19 and may become a diagnostic tool for the disease.

Generation of human induced pluripotent stem cells using genome integrating or non-integrating methods.

Preclinical studies have demonstrated the promising potential of human induced pluripotent stem cells (hiPSCs) for clinical application. To fulfil this goal, efficient and safe methods to generate them must be established. Various reprogramming techniques were presented during seven years of hiPSCs research. Genome non-integrating and completely xeno-free protocols from the first biopsy to stable hiPSC clones are highly preferable in terms of future clinical application. In this short communication, we summarize the reprogramming experiments performed in our laboratories. We successfully generated hiPSCs using STEMCCA lentivirus, Sendai virus or episomal vectors. Human neonatal fibroblasts and CD34(+) blood progenitors were used as cell sources and were maintained either on mouse embryonic feeder cells or in feeder-free conditions. The reprogramming efficiency was comparable for all three methods and both cell types, while the best results were obtained in feeder-free conditions.

Haematopoietic developmental potential of human pluripotent stem cell lines.

The generation of haematopoietic progenitors from human pluripotent stem cells (hPSCs) presents great promise for cell-replacement therapies. However, current protocols for haematopoietic differentiation of hPSCs suffer from low efficiency and functional defects in the derived cells. The technology is also limited by variable ability of hPSC lines to generate blood cells in vitro. To address this issue, methodologies for haematopoietic differentiation in feeder-free conditions were applied to available human embryonic stem cell (hESC) and human induced pluripotent stem cell (hiPSC) lines in this study. It was found that these cell lines did not generate haematopoietic progenitors to such an extent as did H1 and H9 hESC lines that were used for this purpose in the vast majority of relevant studies. These results suggest that for clinical application of blood cells derived from hPSCs, possibly from autologous hiPSCs, it is necessary to overcome the variability in the haematopoietic developmental potential of individual hPSC lines.

New look at nutritional care for obese patient candidates for bariatric surgery.

BACKGROUND: The combination of preoperative deficiencies and the restrictions and malabsorption possibly induced by bariatric surgery could lead patients to experience important nutritional deficits during the late postoperative period. Our objective was to characterize the eating, anthropometric, and biochemical profiles of obese candidates for bariatric surgery at a bariatric surgery center of a university hospital. METHODS: A retrospective study with the analysis of medical records of candidates for bariatric surgery from 2007 to 2008 was performed. A total of 80 adult patients, aged 45 ± 11 years, were included in the present study. RESULTS: The mean patient weight was 145 ± 24 kg, and the mean body mass index was 54 ± 8 kg/m(2). Of the 80 patients, 78% had ≥1 co-morbidities related to obesity. The reported daily energy intake before surgery was 1981 ± 882 kcal, with 48% ± 11% consisting of carbohydrate, 29% ± 8% of lipids, and 23% ± 8% of protein. The mean number of daily meals was 4 ± 1. Patients with a greater body mass index ingested a smaller amount of calories per kilogram of current weight. The occurrence of hyperglycemia, hyperuricemia, and dyslipidemia and of nutritional deficiencies, among them magnesium (19%), vitamin A (15%), vitamin C (16%), iron (9%), ß-carotene (3%), and vitamin B12 (3%), was high. CONCLUSION: The high occurrence of micronutrient deficiency detected by biochemical analysis in morbidly obese candidates for bariatric surgery, representing a disabsorptive process, might involve a poorer prognosis during the late postoperative period. A preoperative evaluation of the nutritional parameters and the food intake pattern is recommended for these patients, together with the necessary interventions.

The MEK inhibitor PD184352 enhances BMS-214662-induced apoptosis in CD34+ CML stem/progenitor cells.

The cytotoxic farnesyl transferase inhibitor BMS-214662 has been shown to potently induce mitochondrial apoptosis in primitive CD34+ chronic myeloid leukaemia (CML) stem/progenitor cells. Here, to enhance the BMS-214662 apoptotic effect, we further targeted the extracellular signal-regulated kinase (ERK) pathway, downstream of BCR-ABL, by treating CD34+ CML stem/progenitor cells with a highly selective adenosine triphosphate (ATP) non-competitive MEK inhibitor, PD184352. PD184352 increased the apoptotic effect of BMS-214662 in a CML blast crisis cell line, K562, and in primary chronic phase CD34+ CML cells. Compared with BMS-214662, after combination treatment we observed inhibition of ERK phosphorylation, increased Annexin-V levels, caspase-3, -8 and -9 activation and potentiated mitochondrial damage, associated with decreased levels of anti-apoptotic BCL-2 family protein MCL-1. Inhibition of K-RAS function by a dominant-negative mutant resulted in CML cell death and this process was further enhanced by the addition of BMS-214662 and PD184352. Together, these findings suggest that the addition of a MEK inhibitor improves the ability of BMS-214662 to selectively target CML stem/progenitor cells, notoriously insensitive to tyrosine kinase inhibitor treatment and presumed to be responsible for the persistence and relapse of the disease.

Change in predicted 10-year cardiovascular risk following Roux-en-Y gastric bypass surgery: who benefits?

BACKGROUND: The risk of developing cardiovascular disease is higher in obese than in non-obese individuals. Surgery for obesity is effective in reducing weight and resolution of diabetes, hypertension, and dyslipidemia. Our aim was to assess the estimated 10-year cardiovascular risk of obese patients before and after treatment of obesity with a gastric bypass. METHODS: Weight, body mass index systolic and diastolic blood pressure, lipid profile, glycemia, and history of cardiovascular disease were obtained for obese patients before and 2 years after Roux-en-Y gastric bypass surgery. Ten-year cardiovascular risk was calculated using the Framingham score. RESULTS: Forty-two patients were included in the study. We observed a significant reduction (p < 0.05) of 10-year cardiovascular risk mainly associated with weight reduction and improvement of comorbidities associated with obesity. The benefits were greater among patients who already presented known risk factors such as diabetes and hypertension. Superobese patients benefited as early as 2 years after surgery, when weight loss was greater. CONCLUSIONS: Weight loss secondary to surgery was sustained after 2 years and promoted improvement of comorbidities, with an important reduction of 10-year cardiovascular risk especially among patients with previous risk factors.

Combination of mRNA and protein microarray analysis in complex cell profiling.

UNLABELLED: This study combines mRNA and protein analysis using cDNA and antibody microarray techniques, respectively. These create a novel, integrated perspective into cellular molecular profiles. The aims of this study were to establish a reliable way of integrating these two approaches in order to obtain complex molecular profiles of the cell and to find suitable methods to normalize the data obtained using these approaches.

Antibody microarray and cDNA microarray techniques were used to study expression alterations in HL-60 cells that were differentiated into granulocytes using all-trans retinoic acid (ATRA). We selected this model to evaluate this combined profiling technique because the expression levels of most of the mRNA and protein species in these cells are not altered; therefore it is easier to track and define those species that are changed. The proteins whose levels were altered included c-myc, c-jun, Pyk2, FAK, PKC, TRF1, NF-kappaB and certain caspase types. These proteins are involved in apoptosis and hematopoietic differentiation pathways, and some have also been reported to have oncogenic potential. We compared the results obtained using the two methods, verified them by immunoblotting analysis, and devised normalization approaches.

This is one of the first demonstrations that a combination of antibody microarray and cDNA microarray techniques is required for complex molecular profiling of cells based on multiple parameters. This approach allows a more detailed molecular phenotype of the given sample to be obtained. The results obtained using a combination of the two profiling methods are consistent with those from previous studies that used more traditional methods.