Biochemistry, Biophysics, and Structural Biology Commons^™

The Role Of Argininosuccinate Synthase Serine 328 Phosphorylation In Nitric Oxide Production, Ricci Haines

USF Tampa Graduate Theses and Dissertations

Until recently, the main mechanism of argininosuccinate synthase (AS) regulation was described to exist mainly at the level of transcription. Transcriptional regulation of AS has been shown to be coordinate with eNOS in response to shear stress, hypoxia, tumor necrosis factor á (TNF-á), and PPAR ã agonist troglitizone. However, it is now understood that one level of NO regulation is cellular control of arginine availability to eNOS via post-translational modifications of AS such as phosphorylation. The purpose of this investigation was to determine under what conditions AS is phosphorylated at S328, identify the pathway that AS phosphorylation at S328 plays …

The Role Of Tumor Suppressors, Ship And Rb, In Immune Suppressive Cells, Michelle Marie Collazo Ruiz

USF Tampa Graduate Theses and Dissertations

Regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSC) have been extensively studied in the past 30-40 years. Their potent suppressive capacity shown in several pathological and clinical settings, such as cancer and transplantation, has made it evident that better understanding their development and function is critical.

Specifically, Tregs play a pivotal role in preventing autoimmunity, graft-versus-host disease (GvHD), and organ graft rejection. We previously demonstrated that germline or induced SH2 domain-containing inositol 5-phosphatase (SHIP) deficiency in the host abrogates GvHD. Here we show that SHIP-deficiency promotes an increase of FoxP3+ cells in both the CD4+CD25+ and the CD4+CD25- T …