CD52/FLAG and CD52/HA Fusion Proteins as Novel Magnetic Cell Selection Markers.

At present, the magnetic selection of genetically modified cells is mainly performed with surface markers naturally expressed by cells such as CD4, LNGFR (low affinity nerve growth factor receptor), and MHC class I molecule H-2Kk. The disadvantage of such markers is the possibility of their undesired and poorly predictable expression by unmodified cells before or after cell manipulation, which makes it essential to develop new surface markers that would not have such a drawback. Earlier, modified CD52 surface protein variants with embedded HA and FLAG epitope tags (CD52/FLAG and CD52/HA) were developed by the group of Dr.

Large Subunit of the Human Herpes Simplex Virus Terminase as a Promising Target in Design of Anti-Herpesvirus Agents.

Herpes simplex virus type 1 (HSV-1) is an extremely widespread pathogen characterized by recurrent infections. HSV-1 most commonly causes painful blisters or sores around the mouth or on the genitals, but it can also cause keratitis or, rarely, encephalitis. First-line and second-line antiviral drugs used to treat HSV infections, acyclovir and related compounds, as well as foscarnet and cidofovir, selectively inhibit herpesvirus DNA polymerase (DNA-pol).

L-Lysine-modified FeO nanoparticles for magnetic cell labeling.

The efficiency of magnetic labeling with L-Lys-modified FeO magnetic nanoparticles (MNPs) and the stability of magnetization of rat adipose-derived mesenchymal stem cells, lineage-negative (Lin(-)) hematopoietic progenitor cells from mouse bone marrow and human leukemia K562 cells were studied. For this purpose, covalent modification of MNPs with 3-aminopropylsilane and N-di-Fmoc-L-lysine followed by removal of N-protecting groups was carried out. Since the degree of hydroxylation of the surface of the starting nanoparticles plays a crucial role in the silanization reaction and the possibility of obtaining stable colloidal solutions.

Persistence of plasmid-mediated expression of transgenes in human mesenchymal stem cells depends primarily on CpG levels of both vector and transgene.

Background: Gene therapy and cell modification for clinical applications using plasmid vectors are considered to be a safe and promising strategy. One of the major problems with plasmid vector-based constructs is a rapid decline of transgene expression in cells in vitro and in vivo. An important role of CpG motifs or bacterial vector backbone in expression silencing has been suggested.

Isolation and Expansion of Mesenchymal Stem Cells from Murine Adipose Tissue.

Mesenchymal stem cells (MSCs) are currently intensively studied due to significant promise which they represent for successful implementations of future cell therapy clinical protocols. This in turn emphasizes importance of careful preclinical studies of MSC effects in various murine disease models. The appropriate cell preparations with reproducible biological properties are important to minimize variability of results of experimental cell therapies.

Formaldehyde Fixation of Extracellular Matrix Protein Layers for Enhanced Primary Cell Growth.

Coating tissue culture vessels with the components of the extracellular matrix such as fibronectin and collagens provides a more natural environment for primary cells and stimulates their proliferation. However, the effects of such protein layers are usually rather modest, which might be explained by the loss immobilized proteins due to their weak non-covalent association with the tissue culture plastic. Here we describe a simple protocol for a controlled fixation of fibronectin, vitronectin and collagen IV layers by formaldehyde, which substantially enhances the stimulation of primary cell proliferation by these extracellular proteins.

Combined treatment, based on lysomustine administration with mesenchymal stem cells expressing cytosine deaminase therapy, leads to pronounced murine Lewis lung carcinoma growth inhibition.

Background: The combination of stem cell-based gene therapy with chemotherapy comprises an advantageous strategy that results in a reduction of system toxicity effects and an improvement in the general efficacy of treatment. In the present study, we estimated the efficacy of adipose tissue-derived mesenchymal stem cells (AT-MSCs) expressing cytosine deaminase (CDA) combined with lysomustine chemotherapy in mice bearing late stage Lewis lung carcinoma (LLC).

Methods: Adipose tissue-derived mesenchymal stem cells were transfected with non-insert plasmid construct transiently expressing fused cytosine deaminase-uracil phosphoribosyltransferase protein (CDA/UPRT) or the same construct fused with Herpes Simplex Virus Type1 tegument protein VP22 (CDA/UPRT/VP22).

Magnetic stromal layers for enhanced and unbiased recovery of co-cultured hematopoietic cells.

Cell co-culture systems have a long history of application in hematology and hold promise for successful hematopoietic stem and progenitor cell expansion. Here we report that various types of stromal cells used in such co-cultures can be rapidly and efficiently labeled with l-lysine-modified Fe3O4 magnetic nanoparticles. Hematopoiesis-supporting activity does not seem to be compromised after magnetic labeling of stromal cells, and the loss of the label by stromal layers during extended culturing is negligible.

TSC-22 contributes to hematopoietic precursor cell proliferation and repopulation and is epigenetically silenced in large granular lymphocyte leukemia.

Aberrant methylation of tumor suppressor genes can lead to their silencing in many cancers. TSC-22 is a gene silenced in several solid tumors, but its function and the mechanism(s) responsible for its silencing are largely unknown. Here we demonstrate that the TSC-22 promoter is methylated in primary mouse T or natural killer (NK) large granular lymphocyte (LGL) leukemia and this is associated with down-regulation or silencing of TSC-22 expression.

The protein encoded by the germ plasm RNA Germes associates with dynein light chains and functions in Xenopus germline development.

Germ plasm plays a prominent role in germline formation in a large number of animal taxons. We previously identified a novel maternal RNA named Germes associated with Xenopus germ plasm. In the present work, we addressed possible involvement of Germes protein in germ plasm function.

Jedi--a novel transmembrane protein expressed in early hematopoietic cells.

Self-renewal and differentiation of hematopoietic stem and progenitor cells are defined by the ensembles of genes expressed by these cells. Here we report identification of a novel gene named Jedi, which is expressed predominantly in short- and long-term repopulating stem cells when compared to more mature bone marrow progenitors. Jedi mRNA encodes a transmembrane protein that contains multiple EGF-like repeats.

Xenopus Germes encodes a novel germ plasm-associated transcript.

A cDNA tag specific for the vegetal pole of early Xenopus embryo was used to isolate a novel cDNA using RACE technique. The corresponding mRNA demonstrated a localization pattern typical for the germ plasm-associated messages, and was, therefore, named Germes. The open reading frame of Germes encodes a predicted 68 kDa protein with two leucine zipper motifs and a putative EF-hand domain, but otherwise no substantial homology to known proteins.

Identification of differentially expressed genes in sorted cell populations by two-dimensional gene-expression fingerprinting.

Differential activity of genes is one of the major mechanisms underlying a vast array of biological phenomena. Classical genetic approaches (from phenotypes to genes) have proven their exquisite potential for dissection of complex signaling pathways regulating the development of organisms and the functioning of individual cells. In recent years, with the advent of a number of techniques for studying gene function, the reverse genetics approach (from genes to phenotypes) has received broad acceptance.