Biology subjects

Brandacher, G.

Publications and source records attributed to Brandacher, G..

3 recordsLinked to original sources

bioRxiv2020

A short course of Tofacitinib sustains the immunoregulatory effect of CTLA4-Ig in presence of inflammatory cytokines and promotes long-term survival of murine cardiac allografts

Costimulation blockade-based regimens are a promising strategy for management of transplant recipients. However, maintenance immunosuppression via CTLA4-Ig monotherapy is characterized by high frequency of rejection episodes. Recent evidence suggests that inflammatory cytokines contribute to alloreactive T cell activation in a CD28-independent manner, a reasonable contributor to the limited efficacy of CTLA4-Ig. In this study, we investigated the possible synergism of a combined short-term inhibition of cytokine signaling and CD28 engagement on the modulation of rejection. Our results demonstrate that the JAK/STAT inhibitor Tofacitinib restored the immunomodulatory effect of CTLA4-Ig on mouse alloreactive T cells in presence of inflammatory cytokines. Tofacitinib exposure conferred dendritic cells with a tolerogenic phenotype reducing their cytokine secretion and costimulatory molecules expression. JAK inhibition also directly affected T cell activation. In vivo, the combination of CTLA4-Ig and Tofacitinib induced long-term survival of heart allografts and, importantly, it was equally effective when using grafts subjected to prolonged ischemia. Transplant survival correlated with a reduction in effector T cells and intragraft accumulation of regulatory T cells. Collectively, our studies demonstrate a powerful synergism between CTLA4-Ig and Tofacitinib and suggest their combined use is a promising strategy for improved management of transplanted patients.

immunology↗

bioRxiv2020

IDENTIFICATION AND CHARACTERIZATION OF A LARGE SOURCE OF PRIMARY MESENCHYMAL STEM CELLS TIGHTLY ADHERED TO BONE SURFACES OF HUMAN VERTEBRAL BODY MARROW CAVITIES

Therapeutic allogeneic mesenchymal stem/stromal cells (MSC) are currently in clinical trials for evaluating their effectiveness in treating many different disease indications. Eventual commercialization for broad distribution will require further improvements in manufacturing processes to economically manufacture MSC at sufficient scales required to satisfy projected demands. A key contributor to the present high cost of goods (COG) for MSC manufacturing is the need to create master cell banks (MCBs) from multiple donors, which leads to variability in large-scale manufacturing runs. Therefore, the availability of large single donor depots of primary MSC would greatly benefit the cell therapy market by reducing costs associated with manufacturing. We have discovered that an abundant population of cells possessing all the hallmarks of MSC is tightly associated with the vertebral body (VB) bone matrix and are only liberated by proteolytic digestion. Here we demonstrate that these vertebral bone-adherent (vBA) MSC possess all the International Society of Cell and Gene Therapy (ISCT)-defined characteristics (e.g., plastic adherence, surface marker expression, and trilineage differentiation) of MSC and, therefore, have termed them vBA-MSC, to distinguish this population from loosely associated MSC recovered through aspiration or rinsing of the bone marrow (BM) compartment. Pilot banking and expansion was performed with vBA-MSC obtained from 3 deceased donors and it was demonstrated that bank sizes averaging 2.9x108 {+/-} 1.35x108 vBA-MSC at passage one were obtainable from only 5 g of digested VB bone fragments. Each bank of cells demonstrated robust proliferation through a total of 9 passages without significant reduction in population doubling times. The theoretical total cell yield from the entire amount of bone fragments (approximately 300g) from each donor with limited expansion through 4 passages is 100 trillion (1x1014) vBA-MSC, equating to over 105 doses at 10x106 cells/kg for an average 70 kg recipient. Thus, we have established a novel and plentiful source of MSC which will benefit the cell therapy market by overcoming manufacturing and regulatory inefficiencies due to donor-to-donor variability.

bioengineering↗

bioRxiv2018

Type-I interferons inhibit interleukin-10 signaling and favor type 1 diabetes development in NOD mice

Destruction of insulin-producing {beta}-cells by autoreactive T lymphocytes leads to the development of type 1 diabetes. Type I interferons (TI-IFN) and interleukin-10 (IL-10) have been connected with the pathophysiology of this disease; however, their interplay in the modulation of diabetogenic T cells remains unknown. We have discovered that TI-IFN cause a selective inhibition of IL-10 signaling in effector and regulatory T cells, altering their responses. This correlates with diabetes development in NOD mice, where the inhibition is also spatially localized to T cells of pancreatic and mesenteric lymph nodes. IL-10 signaling inhibition is reversible and can be restored via blockade of TI-IFN/IFN-R interaction, paralleling with the resulting delay in diabetes onset and reduced severity. Overall, we propose a novel molecular link between TI-IFN and IL-10 signaling that helps better understand the complex dynamics of autoimmune diabetes development and reveals new strategies of intervention.\n\nAbbreviations

immunology↗