Lung Regeneration by Transplantation of Allogeneic Lung Progenitors Using a Safer Conditioning Regimen and Clinical-grade Reagents.

Over the last decades, several studies demonstrated the possibility of lung regeneration through transplantation of various lung progenitor populations. Recently, we showed in mice that fetal or adult lung progenitors could potentially provide donor cells for transplantation, provided that the lung stem cell niche in the recipient is vacated of endogenous lung progenitors by adequate conditioning. Accordingly, marked lung regeneration could be attained following i.

Multi-lineage Lung Regeneration by Stem Cell Transplantation across Major Genetic Barriers.

Induction of lung regeneration by transplantation of lung progenitor cells is a critical preclinical challenge. Recently, we demonstrated that robust lung regeneration can be achieved if the endogenous stem cell niches in the recipient's lung are vacated by sub-lethal pre-conditioning. However, overcoming MHC barriers is an additional requirement for clinical application of this attractive approach.

Lung Injury Repair by Transplantation of Adult Lung Cells Following Preconditioning of Recipient Mice.

Repair of injured lungs represents a longstanding therapeutic challenge. We recently demonstrated that human and mouse embryonic lung tissue from the canalicular stage of development are enriched with lung progenitors, and that a single cell suspension of canalicular lungs can be used for transplantation, provided that lung progenitor niches in the recipient mice are vacated by strategies similar to those used in bone marrow transplantation. Considering the ethical limitations associated with the use of fetal cells, we investigated here whether adult lungs could offer an alternative source of lung progenitors for transplantation.

Assessing remyelination - metabolic labeling of myelin in an animal model of multiple sclerosis.

The lack of biomarkers is a major obstacle for investigating myelin repair. We used metabolic incorporation of the choline analog - propargyl-choline (P-Cho) to label and visualize newly synthesized myelin in the CNS of mice induced with experimental autoimmune encephalomyelitis (EAE). We further developed unbiased colocalization analysis to quantify P-Cho incorporation specifically into the myelin.

CD151 Regulates T-Cell Migration in Health and Inflammatory Bowel Disease.

The continuous recirculation of mature lymphocytes and their entry into the peripheral lymph nodes are crucial for the development of an immune response to foreign antigens. Occasionally, the entry and the subsequent response of T lymphocytes in these sites lead to severe inflammation and pathological conditions. Here, we characterized the tetraspanin molecule, CD151, as a regulator of T cell motility in health and in models of inflammatory bowel disease.

Perforin-Positive Dendritic Cells Exhibit an Immuno-regulatory Role in Metabolic Syndrome and Autoimmunity.

Emerging evidence suggests that immunological mechanisms underlie metabolic control of adipose tissue. Here, we have shown the regulatory impact of a rare subpopulation of dendritic cells, rich in perforin-containing granules (perf-DCs). Using bone marrow transplantation to generate animals selectively lacking perf-DCs, we found that these chimeras progressively gained weight and exhibited features of metabolic syndrome.

Preconditioning allows engraftment of mouse and human embryonic lung cells, enabling lung repair in mice.

Repair of injured lungs represents a longstanding therapeutic challenge. We show that human and mouse embryonic lung tissue from the canalicular stage of development (20-22 weeks of gestation for humans, and embryonic day 15-16 (E15-E16) for mouse) are enriched with progenitors residing in distinct niches. On the basis of the marked analogy to progenitor niches in bone marrow (BM), we attempted strategies similar to BM transplantation, employing sublethal radiation to vacate lung progenitor niches and to reduce stem cell competition.

In the hunt for therapeutic targets: mimicking the growth, metastasis, and stromal associations of early-stage lung cancer using a novel orthotopic animal model.

Background: The existing shortage of animal models that properly mimic the progression of early-stage human lung cancer from a solitary confined tumor to an invasive metastatic disease hinders accurate characterization of key interactions between lung cancer cells and their stroma. We herein describe a novel orthotopic animal model that addresses these concerns and consequently serves as an attractive platform to study tumor-stromal cell interactions under conditions that reflect early-stage lung cancer.

Methods: Unlike previous methodologies, we directly injected small numbers of human or murine lung cancer cells into murine's left lung and longitudinally monitored disease progression.

Blood vessels pattern heparan sulfate gradients between their apical and basolateral aspects.

A hallmark of immune cell trafficking is directional guidance via gradients of soluble or surface bound chemokines. Vascular endothelial cells produce, transport and deposit either their own chemokines or chemokines produced by the underlying stroma. Endothelial heparan sulfate (HS) was suggested to be a critical scaffold for these chemokine pools, but it is unclear how steep chemokine gradients are sustained between the lumenal and ablumenal aspects of blood vessels.

A novel role for factor VIII and thrombin/PAR1 in regulating hematopoiesis and its interplay with the bone structure.

Analysis of hematopoietic stem cells (HSCs) in factor VIII knockout (FVIIIKO) mice revealed a novel regulatory role for the coagulation cascade in hematopoiesis. Thus, HSCs in FVIIIKO mice had reduced proportions of CD34(low) cells within Lin(-)Sca(+)Kit(+) progenitors, and exhibited reduced long-term repopulating capacity as well as hyper granulocyte-colony-stimulating factor (G-CSF)-induced mobilization. This disregulation of HSCs is likely caused by reduced levels of thrombin, and is associated with altered protease-activated receptor 1 (PAR1) signaling, as PAR1 KO mice also exhibited enhanced G-CSF-induced mobilization.

Two initiation sites of early detection of colon cancer revealed by localization of pERK1/2 in the nuclei or in aggregates at the perinuclear region of the tumor cells.

We have used human specimens and antibodies to pERK1/2 to detect early development of colon cancer using indirect immunocytochemistry. Two distinct sites were stained; one at the tip of the colon crypts and the other in the stromal tissue associated with the colonic tissue. These foci represent early stages of colon cancer initiation sites as established by enhanced Kirsten Rat Sarcoma Virus (KRAS) and the lack of p53 staining.

Murine anti-third-party central-memory CD8(+) T cells promote hematopoietic chimerism under mild conditioning: lymph-node sequestration and deletion of anti-donor T cells.

Transplantation of T cell-depleted BM (TDBM) under mild conditioning, associated with minimal toxicity and reduced risk of GVHD, offers an attractive therapeutic option for patients with nonmalignant hematologic disorders and can mediate immune tolerance to subsequent organ transplantation. However, overcoming TDBM rejection after reduced conditioning remains a challenge. Here, we address this barrier using donorderived central memory CD8(+) T cells (Tcms), directed against third-party antigens.

Monocytes-macrophages that express α-smooth muscle actin preserve primitive hematopoietic cells in the bone marrow.

Hematopoietic stem and progenitor cells (HSPCs) are regulated by various bone marrow stromal cell types. Here we identified rare activated bone marrow monocytes and macrophages with high expression of α-smooth muscle actin (α-SMA) and the cyclooxygenase COX-2 that were adjacent to primitive HSPCs. These myeloid cells resisted radiation-induced cell death and further upregulated COX-2 expression under stress conditions.

Deletion of cognate CD8 T cells by immature dendritic cells: a novel role for perforin, granzyme A, TREM-1, and TLR7.

Immature dendritic cells (imDCs) can have a tolerizing effect under normal conditions or after transplantation. However, because of the significant heterogeneity of this cell population, it is extremely difficult to study the mechanisms that mediate the tolerance induced or to harness the application of imDCs for clinical use. In the present study, we describe the generation of a highly defined population of imDCs from hematopoietic progenitors and the direct visualization of the fate of TCR-transgenic alloreactive CD4(+) and CD8(+) T cells after encountering cognate or noncognate imDCs.

FGF-2 expands murine hematopoietic stem and progenitor cells via proliferation of stromal cells, c-Kit activation, and CXCL12 down-regulation.

Cytokine-induced expansion of hematopoietic stem and progenitor cells (HSPCs) is not fully understood. In the present study, we show that whereas steady-state hematopoiesis is normal in basic fibroblast growth factor (FGF-2)-knockout mice, parathyroid hormone stimulation and myeloablative treatments failed to induce normal HSPC proliferation and recovery. In vivo FGF-2 treatment expanded stromal cells, including perivascular Nestin(+) supportive stromal cells, which may facilitate HSPC expansion by increasing SCF and reducing CXCL12 via mir-31 up-regulation.

Differential staining of γ synuclein in poorly differentiated compared to highly differentiated colon cancer cells.

Synuclein α, β and γ are proteins usually found in neurodegenerative diseases. However, interestingly synucleins are expressed in cancer cells of several organs including ovary, mammary gland and colon. By immunocytochemistry using specific antibodies to γ synuclein (SNCG), we examined the distribution of this protein in poorly differentiated, compared to highly differentiated colon cancer cells.

Two initiation sites of early detection of colon cancer, revealed by localization of pERK1/2 in the nuclei or in aggregates at the perinuclear region of tumor cells.

We have used human specimens and antibodies to pERK1/2 to detect early development of colon cancer, using indirect immunocytochemistry. Two distinct sites were stained; one at the tip of the colon villi and the other in the stromal tissue, associated with the colon tissue. These foci represent early stages of colon cancer initiation, as established by enhanced KRAS, and lack of p53 staining.

In vivo structure/function and expression analysis of the CX3C chemokine fractalkine.

The CX3C chemokine family is composed of only one member, CX3CL1, also known as fractalkine, which in mice is the sole ligand of the G protein-coupled, 7-transmembrane receptor CX3CR1. Unlike classic small peptide chemokines, CX3CL1 is synthesized as a membrane-anchored protein that can promote integrin-independent adhesion. Subsequent cleavage by metalloproteases, either constitutive or induced, can generate shed CX3CL1 entities that potentially have chemoattractive activity.

Epiregulin as a marker for the initial steps of ovarian cancer development.

Epiregulin (Ep) was found to be produced in non-cancer ovarian cells in response to gonadotropin stimulation as well in ovarian cancer cells in an autonomous manner. However, there were no systematic follow-up studies of Ep expression in the development of different stages of ovarian cancer. Using specific antibodies to Ep and the indirect immunocytochemistry methods, we found that in normal ovary the staining for Ep was mainly confined to the epithelial cells, while the stromal cells were only occasionally and moderately stained.

Nuclear localization of phosphorylated ERK1 and ERK2 as markers for the progression of ovarian cancer.

We examined the possibility that the localization of phosphorylated ERK1 and ERK2 (pERK1/2) can serve as a marker for the development of benign and borderline tumors as well as carcinoma of the ovary by an immunohistochemical method on ovarian paraffin sections, obtained from women aged 41-83 years. In normal tissue, 28.3% of nuclei were labeled, mainly confined to the epithelial cells at the surface of the ovary.

Embryonic pig pancreatic tissue for the treatment of diabetes: potential role of immune suppression with "off-the-shelf" third-party regulatory T cells.

Background: Xenogeneic embryonic pancreatic tissue can provide an attractive alternative for organ replacement therapy. However, immunological rejection represents a major obstacle. This study examines the potential of regulatory T cells (Tregs) in the prevention of E42 pancreas rejection.

CTLs respond with activation and granule secretion when serving as targets for T-cell recognition.

Cytotoxic T lymphocytes (CTLs) suppress T cell responses directed against their antigens regardless of their own T cell receptor (TCR) specificity. This makes the use of CTLs promising for tolerance induction in autoimmunity and transplantation. It has been established that binding of the CTL CD8 molecule to the major histocompatibility complex (MHC) class I α3 domain of the recognizing T cell must be permitted for death of the latter cell to ensue.

Enhanced c-Met activity promotes G-CSF-induced mobilization of hematopoietic progenitor cells via ROS signaling.

Mechanisms governing stress-induced hematopoietic progenitor cell mobilization are not fully deciphered. We report that during granulocyte colony-stimulating factor-induced mobilization c-Met expression and signaling are up-regulated on immature bone marrow progenitors. Interestingly, stromal cell-derived factor 1/CXC chemokine receptor-4 signaling induced hepatocyte growth factor production and c-Met activation.

Glatiramer acetate reduces Th-17 inflammation and induces regulatory T-cells in the CNS of mice with relapsing-remitting or chronic EAE.

The aim of this study was to identify cell populations relevant to pathogenesis and repair within the injured CNS in mice that recovered from experimental autoimmune encephalomyelitis (EAE). We demonstrate that in two EAE models, with either relapsing-remitting or chronic course, T-cells and resident activated microglia manifested extensive IL-17 expression, with apparent localization within regions of myelin loss. In mice treated with glatiramer acetate (GA, Copaxone), even when treatment started after disease exacerbation, CNS inflammation and Th-17 occurrence were drastically reduced, with parallel elevation in T-regulatory cells, indicating the immunomodulatory therapeutic consequences of GA treatment in situ.