Quantifying Ocular Surface Inflammation and Correlating It With Inflammatory Cell Infiltration In Vivo: A Novel Method.

PURPOSE The purpose of this study was to develop a novel, objective, and semiautomated method to quantify conjunctival redness by correlating measured redness with standard clinical redness and symptom scales and inflammatory cell infiltration. METHODS Eleven outpatients presenting with mild to severe conjunctival hyperemia were included in the study. Clinical examination included patient history; visual analogue score (VAS) for ocular symptoms; 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ 25) for quality of life/vision; photographs of the anterior segment graded for conjunctival hyperemia, using Efron, relative redness of image (RRI), and edge feature (EF) scales; and conjunctival impression cytology analyzed by flow cytometry. Differences between affected and unaffected eyes were evaluated, and correlations among questionnaire scores, ocular hyperemia grading scores, and assessment of biological markers were performed. RESULTS Visual analogue score (P < 0.0001), Efron scale (P = 0.0003), RRI scores (P = 0.0004), and EF scores (P < 0.0001) and the percentage of granulocytes (defined as cluster of differentiation [CD] 45dim; P = 0.0080) were significantly higher in affected eyes. Conversely, the percentage of CD45bright leukocytes was reduced in affected eyes (P = 0.0054). Both the RRIs and EFs were positively correlated with VAS, Efron scale, percentages of conjunctival granulocytes, and CD45brightCD3neg cells, whereas they were negatively correlated with the percentage of CD45brightCD3pos cells. Edge feature and RRI were correlated (Spearman r = 0.78, P < 0.0001). CONCLUSIONS Ocular redness is a cardinal sign driving clinical judgment in highly prevalent ocular disorders; hence, we suggest that our semiautomated and reproducible method may represent a helpful tool in the follow-up of these patients. Italian Abstract

The Impact of Amino Acid Variability on Alloreactivity Defines a Functional Distance Predictive of Permissive HLA-DPB1 Mismatches in Hematopoietic Stem Cell Transplantation

AbstractA major challenge in unrelated hematopoietic stem cell transplantation (HSCT) is the prediction of permissive HLA mismatches, ie, those associated with lower clinical risks compared to their nonpermissive counterparts. For HLA-DPB1, a clinically prognostic model has been shown to be matching for T cell epitope (TCE) groups assigned by cross reactivity of T cells alloreactive to HLA-DPB1∗09:01; however, the molecular basis of this observation is not fully understood. Here, we have mutated amino acids (aa) in 10 positions of HLA-DPB1∗09:01 to other naturally occurring variants, expressed them by lentiviral vectors in B cell lines, and quantitatively measured allorecognition by 17 CD4+ T cell effectors from 6 unrelated individuals. A significant impact on the median alloresponse was observed for peptide contact positions 9, 11, 35, 55, 69, 76, and 84, but not for positions 8, 56, and 57 pointing away from the groove. A score for the “functional distance” (FD) from HLA-DPB1∗09:01 was defined as the sum of the median impact of polymorphic aa in a given HLA-DPB1 allele on T cell alloreactivity. Established TCE group assignment of 23 alleles correlated with FD scores of ≤0.5, 0.6 to 1.9 and ≥2 for TCE groups 1, 2, and 3, respectively. Based on this, prediction of TCE group assignment will be possible for any given HLA-DPB1 allele, including currently 367 alleles encoding distinct proteins for which T cell cross reactivity patterns are unknown. Experimental confirmation of the in silico TCE group classification was successfully performed for 7 of 7 of these alleles. Our findings have practical implications for the applicability of TCE group matching in unrelated HSCT and provide new insights into the molecular mechanisms underlying this model. The innovative concept of FD opens new potential avenues for risk prediction in unrelated HSCT

Evaluation of Lymphocyte Response to the Induced Oxidative Stress in a Cohort of Ageing Subjects, including Semisupercentenarians and Their Offspring

The production of reactive oxygen species (ROS) may promote immunosenescence if not counterbalanced by the antioxidant systems. Cell membranes, proteins, and nucleic acids become the target of ROS and progressively lose their structure and functions. This process could lead to an impairment of the immune response. However, little is known about the capability of the immune cells of elderly individuals to dynamically counteract the oxidative stress. Here, the response of the main lymphocyte subsets to the induced oxidative stress in semisupercentenarians (CENT), their offspring (OFF), elderly controls (CTRL), and young individuals (YO) was analyzed using flow cytometry. The results showed that the ratio of the ROS levels between the induced and noninduced (I/NI) oxidative stress conditions was higher in CTRL and OFF than in CENT and YO, in almost all T, B, and NK subsets. Moreover, the ratio of reduced glutathione levels between I/NI conditions was higher in OFF and CENT compared to the other groups in almost all the subsets. Finally, we observed significant correlations between the response to the induced oxidative stress and the degree of methylation in specific genes on the oxidative stress pathway. Globally, these data suggest that the capability to buffer dynamic changes in the oxidative environment could be a hallmark of longevity in humans

The NAD-Booster Nicotinamide Riboside Potently Stimulates Hematopoiesis through Increased Mitochondrial Clearance

It has been recently shown that increased oxidative phosphorylation, as reflected by increased mitochondrial activity, together with impairment of the mitochondrial stress response, can severely compromise hematopoietic stem cell (HSC) regeneration. Here we show that the NAD(+)-boosting agent nicotinamide riboside (NR) reduces mitochondrial activity within HSCs through increased mitochondrial clearance, leading to increased asymmetric HSC divisions. NR dietary supplementation results in a significantly enlarged pool of progenitors, without concurrent HSC exhaustion, improves survival by 80%, and accelerates blood recovery after murine lethal irradiation and limiting-HSC transplantation. In immune-deficient mice, NR increased the production of human leucocytes from hCD34+ progenitors. Our work demonstrates for the first time a positive effect of NAD(+)-boosting strategies on the most primitive blood stem cells, establishing a link between HSC mitochondrial stress, mitophagy, and stem-cell fate decision, and unveiling the potential of NR to improve recovery of patients suffering from hematological failure including post chemo- and radiotherapy.Peer reviewe

Microbiological Follow-Up of Bioreactor-Assisted Must Alcoholic Fermentation by Flow Cytometry

The monitoring of must fermentation in a bioreactor, in which the main physico-chemical parameters are tightly controlled, can provide useful analytical information transferable to winemaking on a larger scale. In this experiment, we followed the growth of Saccharomyces cerevisiae during the bioreactor-assisted alcoholic fermentation of a Chasselas must by means of flow cytometry. We used fluorescent dyes and volumetric counting to monitor cell viability and concentration for two weeks. Our study suggests that the use of flow cytometry during bioreactor-assisted alcoholic fermentation provides various types of information&mdash;viz., cell viability, number and function&mdash;in a timely manner, and that the process can therefore be used effectively to inform experimentation at this scale