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PurposeTo determine whether intravenous ferumoxytol can be used to effectively label mesenchymal stem cells (MSCs) in vivo and can be used for tracking of stem cell transplants.Materials and methodsThis study was approved by the institutional animal care and use committee. Sprague-Dawley rats (6-8 weeks old) were injected with ferumoxytol 48 hours prior to extraction of MSCs from bone marrow. Ferumoxytol uptake by these MSCs was evaluated with fluorescence, confocal, and electron microscopy and compared with results of traditional ex vivo-labeling procedures. The in vivo-labeled cells were subsequently transplanted in osteochondral defects of 14 knees of seven athymic rats and were evaluated with magnetic resonance (MR) imaging up to 4 weeks after transplantation. T2 relaxation times of in vivo-labeled MSC transplants and unlabeled control transplants were compared by using t tests. MR data were correlated with histopathologic results.ResultsIn vivo-labeled MSCs demonstrated significantly higher ferumoxytol uptake compared with ex vivo-labeled cells. With electron microscopy, iron oxide nanoparticles were localized in secondary lysosomes. In vivo-labeled cells demonstrated significant T2 shortening effects in vitro and in vivo when they were compared with unlabeled control cells (T2 in vivo, 15.4 vs 24.4 msec; P < .05) and could be tracked in osteochondral defects for 4 weeks. Histologic examination confirmed the presence of iron in labeled transplants and defect remodeling.ConclusionIntravenous ferumoxytol can be used to effectively label MSCs in vivo and can be used for tracking of stem cell transplants with MR imaging. This method eliminates risks of contamination and biologic alteration of MSCs associated with ex vivo-labeling procedures.

In this &apos;double-blind&apos;, randomized, placebo-controlled phase II trial, we compared an altered peptide ligand of myelin basic protein with placebo, evaluating their safety and influence on magnetic resonance imaging in relapsing-remitting multiple sclerosis. A safety board suspended the trial because of hypersensitivity reactions in 9% of the patients. There were no increases in either clinical relapses or in new enhancing lesions in any patient, even those with hypersensitivity reactions. Secondary analysis of those patients completing the study showed that the volume and number of enhancing lesions were reduced at a dose of 5 mg. There was also a regulatory type 2 T helper-cell response to altered peptide ligand that cross-reacted with the native peptide., Author(s): Ludwig Kappos [1]; Giancarlo Comi [2]; Hillel Panitch [3]; Joel Oger [4]; Jack Antel [5]; Paul Conlon [6]; Lawrence Steinman (corresponding author) [7]; Giancarlo Comi [8, 24]; Ludwig Kappos [...]

Various types of T cells with heterogeneous receptors are found in the inflammatory infiltrate in the central nervous system after experimental encephalomyelitis is induced with a T-cell clone L10C1. This clone responds to the myelin basic protein epitope p87-99. It is shown that in vivo tolerization of L10C1 with an analogue of p87-99 reverses established paralysis, reduces inflammatory infiltrates and eliminates the heterogeneous T-cell infiltrate from the brain..

Experimental autoimmune encephalomylelitis is a model that can adequately explain the role of infection in causing various autoimmune diseases. The amino-terminal epitope Ac1-11 of myelin basic protein in some species of mice is engaged by the T lymphocytes that express the V beta 8 T-cell receptors. The V beta 8 expressing expressing T cells are activated by the bacterial superantigen staphylococcal enteroxin B (SEB). The mechanism causing the SEB induced exacerbation of disease is critically induced by the tumor neurosis factor.

The impact of COVID-19 disease on health and economy has been global, and the magnitude of devastation is unparalleled in modern history. Any potential course of action to manage this complex disease requires the systematic and efficient analysis of data that can delineate the underlying pathogenesis. We have developed a mathematical model of disease progression to predict the clinical outcome, utilizing a set of causal factors known to contribute to COVID-19 pathology such as age, comorbidities, and certain viral and immunological parameters. Viral load and selected indicators of a dysfunctional immune response, such as cytokines IL-6 and IFNα, which contribute to the cytokine storm and fever, parameters of inflammation d-dimer and ferritin, aberrations in lymphocyte number, lymphopenia, and neutralizing antibodies were included for the analysis. The model provides a framework to unravel the multi-factorial complexities of the immune response manifested in SARS-CoV-2 infected individuals. Further, this model can be valuable to predict clinical outcome at an individual level, and to develop strategies for allocating appropriate resources to mitigate severe cases at a population level., Competing Interests: Conflict of Interest Statement. Narendra Chirmule and Ravindra Khare are employed by SymphonyTech Biologics Inc, and own stock in the company; the opinions of Pradip Nair do not represent those of Biocon; Bela Desai, Vivek Nerurkar and Amitabh Gaur do not have any conflict of interest.

BD FACS™ CAP (CAP = combinatorial antibody profile) is a screening tool for rapid characterization of human cell surface protein expression profiles using semi-automated high-throughput flow cytometry. The current configuration consists of 229 directly conjugated antibodies arrayed in a 96-well plate as three-color cocktails, which enables the characterization of each of the 229 individual surface markers. Each individual cell type of interest is analyzed on the 96-well screening plates and the data are acquired on a flow cytometer equipped with a high-throughput sampler. The expression level of each marker for each cell type is then calculated using semiautomated custom flow cytometry software. The process of characterizing these surface markers in a highly efficient manner using BD FACS™ CAP is enabled by automated liquid handling for staining, automated flow cytometry for data acquisition, and standardized algorithms for automated data analysis.