Inducible T-Cell Co-Stimulator Impacts Chronic Graft-Versus-Host Disease by Regulating Both Pathogenic and Regulatory T Cells

The incidence of chronic graft-versus-host disease (cGVHD) is on the rise and still the major cause of morbidity and mortality among patients after allogeneic hematopoietic stem cell transplantation (HCT). Both donor T and B cells contribute to the pathogenesis of cGVHD. Inducible T-cell co-stimulator (ICOS), a potent co-stimulatory receptor, plays a key role in T-cell activation and differentiation. Yet, how ICOS regulates the development of cGVHD is not well understood. Here, we investigated the role of ICOS in cGVHD pathogenesis using mice with germline or regulatory T cell (Treg)-specific ICOS deficiency. The recipients of ICOS−/− donor grafts had reduced cGVHD compared with wild-type controls. In recipients of ICOS−/− donor grafts, we observed significant reductions in donor T follicular helper (Tfh), Th17, germinal center B-cell, and plasma cell differentiation, coupled with lower antibody production. Interestingly, Tregs, including follicular regulatory T (Tfr) cells, were also impaired in the absence of ICOS. Using ICOS conditional knockout specific for Foxp3+ cells, we found that ICOS was indispensable for optimal survival and homeostasis of induced Tregs during cGVHD. Furthermore, administration of anti-ICOS alleviated cGVHD severity via suppressing T effector cells without affecting Treg generation. Taken together, ICOS promotes T- and B-cell activation and differentiation, which can promote cGVHD development; however, ICOS is critical for the survival and homeostasis of iTregs, which can suppress cGVHD. Hence, ICOS balances the development of cGVHD and could offer a potential target after allo-HCT in the clinic

SNL evaluation of Gigabit Passive Optical Networks (GPON).

Gigabit Passive Optical Networks (GPON) is a networking technology which offers the potential to provide significant cost savings to Sandia National Laboratories in the area of network operations. However, a large scale GPON deployment requires a significant investment in equipment and infrastructure. Before a large scale GPON system was acquired and built, a small GPON system manufactured by Motorola was acquired and tested. The testing performed was to determine the suitability of GPON for use at SNL. This report documents that testing. This report presents test results of GPON system consisting of Motorola and Juniper equipment. The GPON system was tested in areas of data throughput, video conferencing, VOIP, security, and operations and management. The GPON system performed well in almost all areas. GPON will not meet the needs of the low percentage of users requiring a true 1-10 Gbps network connection. GPON will also most likely not meet the need of some servers requiring dedicated throughput of 1-10 Gbps. Because of that, there will be some legacy network connections that must remain. If these legacy network connections can not be reduced to a bare minimum and possibly consolidated to a few locations, any cost savings gained by switching to GPON will be negated by maintaining two networks. A contract has been recently awarded for new GPON equipment with larger buffers. This equipment should improve performance and further reduce the need for legacy network connections. Because GPON has fewer components than a typical hierarchical network, it should be easier to manage. For the system tested, the management was performed by using the AXSVison client. Access to the client must be tightly controlled, because if client/server communications are compromised, security will be an issue. As with any network, the reliability of individual components will determine overall system reliability. There were no failures with the routers, OLT, or Sun Workstation Management platform. There were however four ONTs that failed. Because of the small sample size of 64, and the fact that some of the ONTs were used units, no conclusions can be made. However, ONT reliability is an area of concern. Access to the fiber plant that GPON requires must be tightly controlled and all changes documented. The undocumented changes that were performed in the GPON test lab demonstrated the need for tight control and documentation. In summary, GPON should be able to meet the needs of most network users at Sandia National Laboratories. Because it supports voice, video, and data, it positions Sandia National Laboratories to deploy these services to the desktop. For the majority of corporate network users at Sandia National Laboratories GPON should be a suitable replacement for the legacy network

Targeting Transcription Factors XBP-1 and Fli-1 as Novel Translational Strategies to Control Graft-Versus-Host Disease

Hematopoietic stem-cell transplantation (HCT) is a curative procedure for hematological malignancies, but chronic graft-versus-host disease (GVHD) remains a major complication after allogeneic HCT. Because donor B cells are essential for chronic GVHD (cGVHD) development and B cells are sensitive to endoplasmic reticulum stress, we hypothesized that the IRE-1α/XBP-1 pathway is required for B-cell activation and function in cGVHD. Here, we used mice deficient of XBP-1 specifically in B cells, and recipients transplanted with grafts containing XBP-1–deficient B cells displayed reduced cGVHD compared with controls that was associated with reduced B-cell activation and production of alloreactive antibodies. Prophylactic administration of B-I09 (an IRE-1α/XBP-1 inhibitor) also reduced cGVHD without compromising GVL effect against chronic myelogenous leukemia. Although B cells play an important role in chronic GVHD development, effector T cells are still primary drivers of the disease. We investigated the T-cell specific role of a second transcription factor, Fli-1, in GVHD pathogenesis. Ablation of two critical exons of the fli-1 gene in donor-derived T cells was associated with significant reduction of disease development in allo-HCT models of cGVHD and aGVHD. This reduction was associated with increased regulatory T cells (Tregs) and decreased IFN-γ+, IL-17A+, and TFH T cells in lymphoid organs. We also demonstrated that low-dose camptothecin exhibits action as a potent Fli-1 inhibitor, both in vitro and in vivo against mouse and human Fli-1. Utilization of drugs that targeted Fli-1 was able to prevent cGVHD development and reverse already established cGVHD. Camptothecin also prevented aGVHD while preserving the GVL effect against P815 mastocytoma. Further, camptothecin reduced human T-cell proliferation both in vitro and in vivo, while also reducing GVHD in a human xenograft model. These findings in combination suggest that XBP-1 is a critical factor regulating the B-cell component of chronic GVHD development while Fli-1 is a critical factor involved in the T-cell component. Many transcription factors are also notoriously difficult to inhibit, however, we identified that both XBP-1 and Fli-1 could be targeted using pharmaceuticals, making these factors promising translational strategies for reducing GVHD in the clinical setting, while also preserving the GVL effect of the donor graft

Fig4D

This data file is associated with Fig4D of the accompanied publication. Mice treated with BM alone, vehicle, or 10mg/kg Ibrutinib were injected with 5 x 10^6 whole splenocytes. Skin lesions from each recipient were excised after euthanasia and subjected to H&E staining for scoring by a professional pathologist. Skin sections were scored based on several criteria as described in the accompanied manuscript. Columns and row titles are self-explanatory. Any other relevant information including experimental conditions and setup are included in the accompanied publication

Fig6B

This data file is associated with Fig6B of the accompanied publication. Column A indicates time-point at which the clinical score was measured. Additional column and row titles are self-explanatory. Any relevant information for this figure, including experimental conditions and setup are included in the methods, results, or discussion section of the accompanied publication

Fig4A

This data file is associated with Fig4A of the accompanied publication. Mice treated with BM alone, vehicle, or 10mg/kg Ibrutinib were injected with 5 x 10^6 whole splenocytes. Clinical scores representing 6 visible factors were recorded and tabulated once per week following Day 14 post-transplant. Column A represents the day post-transplant the scoring was conducted on. Additional column and row titles are self-explanatory. Any other relevant information including experimental conditions and setup are included in the accompanied publication

Fig3B

This data file is associated with Fig3B of the accompanied publication. Mice treated with no injection, vehicle, or 10mg/kg Ibrutinib were injected with 80-100 x 10^6 whole splenocytes. Peripheral blood was collected from each recipient and serum was taken for ELISA measurement of total IgG and IgG2a autoantibodies. Each value represents the reported optical density (OD) output of an ELISA plate-reader. Column A indicates the number of weeks post-transplant serum samples was taken. Additional Column and row labels are self-explanatory. Any other relevant information including experimental conditions and setup are included in the accompanied publication

Fig1D

This data file is associated with Fig1D of the accompanied publication. Urine protein measurement data of bone marrow only, vehicle treated, and Ibrutinib treated recipients. Column A is an arbitrary identification number given to each mouse. Column B indicates the time-point at which a non-proteinuria event (marked as "0') or a proteinuria event (marked as "1") occurred. Proteinuria event "1" is defined as a mouse showing a >2,000mg/dL score using Albustix urine test strips.Column C indicates the BM only group, Column D indicates mice treated with vehicle. Column E indicates mice treated with Ibrutinib 10mg/kg beginning 7 days post-transplant, Column F indicates mice treated with 10mg/kg Ibrutinib beginning 14 days post-transplant. Any other relevant information, including experimental conditions and setup is detailed in the accompanied publication

Fig1C

This data file is associated with Fig1C of the accompanied publication. Survival data of bone marrow only, vehicle treated, and Ibrutinib treated recipients. Column A is an arbitrary identification number given to each mouse. Column B indicates the time-point at which a survival (marked as "0') or non-survival event (marked as "1") occurred. Column C indicates the bone marrow alone group. Column D indicates mice treated with vehicle. Column E indicates mice treated with Ibrutinib 10mg/kg. Column F indicates mice treated with 10mg/kg Ibrutinib beginning 14 days post transplantation. Any other relevant information, including experimental conditions and setup is detailed in the accompanied publication