MyD88 provides a protective role in long-term radiation-induced lung injury.

Purpose: The role of innate immune regulators is investigated in injury sustained from irradiation as in the clinic for cancer treatment or from a nuclear incident. The protective benefits of flagellin signaling through Toll-like receptors (TLR) in an irradiation setting warrant study of a key intracellular adaptor of TLR signaling, namely Myeloid differentiation primary response factor 88 (MyD88). The role of MyD88 in regulating innate immunity and Nuclear factor kappa-B (NF-κB)-activated responses targets this critical factor for influencing injury and recovery as well as maintaining immune homeostasis.

Therapeutic benefits in thalassemic mice transplanted with long-term-cultured bone marrow cells.

Objective: Autologous bone marrow (BM) cells with a faulty gene corrected by gene targeting could provide a powerful therapeutic option for patients with genetic blood diseases. Achieving this goal is hindered by the low abundance of therapeutically useful BM cells and the difficulty maintaining them in tissue culture long enough to complete gene targeting without differentiating. Our objective was to devise a simple long-term culture system, using unfractioned BM cells, that maintains and expands therapeutically useful cells for ≥4 weeks.

The chemokine, CCL3, and its receptor, CCR1, mediate thoracic radiation-induced pulmonary fibrosis.

Patients receiving thoracic radiation often develop pulmonary injury and fibrosis. Currently, there are no effective measures to prevent or treat these conditions. We tested whether blockade of the chemokine, CC chemokine ligand (CCL) 3, and its receptors, CC chemokine receptor (CCR) 1 and CCR5, can prevent radiation-induced lung inflammation and fibrosis.

Wnt2 coordinates the commitment of mesoderm to hematopoietic, endothelial, and cardiac lineages in embryoid bodies.

Our recent gene expression profiling analyses demonstrated that Wnt2 is highly expressed in Flk1(+) cells, which serve as common progenitors of endothelial cells, blood cells, and mural cells. In this report, we characterize the role of Wnt2 in mesoderm development during embryonic stem (ES) cell differentiation by creating ES cell lines in which Wnt2 was deleted. Wnt2(-/-) embryoid bodies (EBs) generated increased numbers of Flk1(+) cells and blast colony-forming cells compared with wild-type EBs, and had higher Flk1 expression at comparable stages of differentiation.

Antibodies to stem cell marker antigens reduce engraftment of hematopoietic stem cells.

Hematopoietic stem cells (HSCs) have enormous potential for use in transplantation and gene therapy. However, the frequency of repopulating HSCs is often very low; thus, highly effective techniques for cell enrichment and maintenance are required to obtain sufficient cell numbers for therapeutic use and for studies of HSC physiology. Common methods of HSC enrichment use antibodies recognizing HSC surface marker antigens.

Cytoprotection by amifostine during autologous stem cell transplantation for advanced refractory hematologic malignancies.

This study evaluated whether amifostine protects against mucositis and other toxicities in patients with advanced, refractory, or recurrent hematologic malignancies undergoing high-dose chemotherapy and total body irradiation. Thirty-five patients (20 with non-Hodgkin lymphoma, 12 with Hodgkin disease, and 3 with acute myelogenous leukemia) who underwent autologous stem cell transplantation were conditioned with total body irradiation 2 Gy twice daily on days -8 through -6; cyclophosphamide 6 g/m(2), etoposide 1.8 g/m(2), and carboplatin 1 g/m(2) on days -5 through -3; and amifostine 500 mg/m(2) on days -8 through -2.

Differential roles for CCR5 expression on donor T cells during graft-versus-host disease based on pretransplant conditioning.

The coordinated expression of chemokines and receptors may be important in the directed migration of alloreactive T cells during graft-vs-host disease (GVHD). Recent work demonstrated in a murine model that transfer of CCR5-deficient (CCR5(-/-)) donor cells to nonconditioned haploidentical recipients resulted in reduced donor cell infiltration in liver and lymphoid tissues compared with transfer of CCR5(+/+) cells. To investigate the function of CCR5 during GVHD in conditioned transplant recipients, we transferred CCR5(-/-) or wild-type C57BL/6 (B6) T cells to lethally irradiated B6D2 recipients.

Host absence of CCR5 potentiates dendritic cell vaccination.

Previous work has shown that dendritic cells (DCs) express specific chemokine receptors that allow for coordinated movement in vivo. To test the in vivo relevance of this, we used a murine melanoma system and knockout mice to investigate the function of the chemokine receptor CCR5 and its ligands, CCR ligand (CCL)3 and CCL5. We found that the lack of CCR5 in the host mouse resulted in delayed tumor growth, but this effect was overcome at a higher tumor load.