Molecular Biology Commons^™

The Expression Of Connexin-43 By Cd11c+ Dendritic Cells Is Required To Maintain Cd4+ Foxp3+ Regulatory T Cell Population In Peripheral Lymphoid Organs, Caroline Titus Miller

Biological Sciences Theses & Dissertations

Foxp3⁺ regulatory T cells (T_R) are an immunosuppressive subset of CD4⁺ T cells that maintain homeostasis of the immune system. They are sustained by the interaction between the Major Histocompatibility Complex (MHC) molecules present on antigen presenting dendritic cells and the T Cell Receptor (TCR) expressed on T_R cells that is specific for the MHC loaded with an antigenic peptide. Here, we show that in addition to MHC/TCR interaction, Connexin-43 (Cx43) expression by dendritic cells is required to maintain the TR cell population. CD11c⁺ dendritic cells represent a major subset of antigen presenting cells. …

Dna Repair Deficiency In Huntington's Disease Fibroblasts And Induced Pluripotent Stem Cells, Peter Anthony Mollica

Biological Sciences Theses & Dissertations

Mutant huntingtin protein (mhtt)– the protein responsible for cellular dysfunction in Huntington’s disease (HD) –is a product of an expanded trinucleotide repeat (TNR) cytosine-adenine-guanine (CAG) sequence in exon 1 of the huntingtin (HTT) gene. The pathology of HD has been extensively researched; however, the mechanism by which the disease-causing TNR expansions occur in somatic cells remains elusive. Interestingly, HD has often been referred to a ‘DNA repair disease’, even though DNA repair dysfunction in situ has not been identified. We hypothesized that presence of the mhtt protein affects the expression of DNA repair genes used to address DNA repair, ultimately …

Effects Of Chemical Aneuploidogens On Taxol Purified Drosophila And Mouse Brain Microtubules Polymerization And Depolymerization In Vitro, Anil Sehgal

Biological Sciences Theses & Dissertations

The effects of aneuploidogens (aneuploidy causing agents) on taxol-purified microtubules from Drosophila and mouse brain in vitro were studied by using a spectrophotometric assay and electron microscopy. Colchicine, acetonitrile, propionitrile, acrylonitrile, dimethyl sulfoxide (DMSO), griseofulvin and cadmium chloride inhibited microtubule polymerization whereas methoxyethyl acetate (MEA) and methyl mercuric chloride (MMC) did not. All aneuploidogens tested (at 50mM) resulted in reduced rate of elongation of mouse brain microtubules. MMC, cadmium chloride and DMSO resulted in increased rates of Drosophila microtubule elongation whereas the rest of the drugs resulted in decreases. The in vitro results from Drosophila correlate well with the previously …

Solid Phase Extraction Of Mammalian Cell Mitochondrial Dna And Its Electrophoretic Separation In Agarose Gels, Theresa Brick-Miller

Biological Sciences Theses & Dissertations

An improved and efficient electrophoretic procedure for the isolation of mitochondrial DNA (mtDNA) is described. The solid phase extraction procedure for the isolation of mtDNA involves embedding as few as 200,000 Ehrlich ascites tumor cells into a block of agarose, digestion of cellular membranes by detergent action and subsequent electrophoretic separation of nucleic acids in agarose gels. Genomic DNA remains in the original block of agarose while the mtDNA migrates in the separation gel to a position equivalent to that obtained for mtDNA isolated by traditional procedures.

The efficacy of a large number of detergents, agarose concentrations, embedding conditions, embedding …