LSUHSC COBRE:PROJ 3: ALTERNATIONS IN T CELL SIGNAL TRANSDUCTION

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Alterations in T cell signal transduction caused by chronic inflammation in SRNS: A. Specific Aims Steroid-resistant idiopathic nephrotic syndrome (SRINS) is a primary cause for end stage renal disease in children. There is strong evidence supporting the role of T cells in the pathogenesis of SRINS and steroid sensitive idiopathic nephrotic syndrome (SSINS). The applicant preliminary studies have shown that T cells from SRINS patients have an increased expression of IL-2 and a selective decrease in NF-kB p65. This is relevant since decreased expression of NF-kB p65 can decrease T cell apoptosis an increase IL-2 production, which activates STAT5. In turn, STAT 5 can bind the glucocorticoid receptor (GCR) preventing its nuclear translocation and resulting in steroid resistance. Our preliminary data support the hypothesis that patients with SRINS have specific alterations in signal transduction mechanism that impair nuclear tranlocation of GCR and lead to steroid resistance. Patient samples and in vitro models will be used to accomplish the proposed work. To test the hypothesis, we propose the following specific aims 1. Determine the frequency of alterations in T cells from patients with SRINS vs. SSINS. This specific aim will expand initial observations and determine association with SRINS. 2. To test the hypothesis that the absence of NF-kB p65 is associated with impaired nuclear transfer of of the GCR in T cells from SRINS a. Demonstrate this phenomenom in T cells from patients. b. Develop an in vitro model to test molecular mechanism. 3. Test the hypothesis that increased IL-2 activity in SRINS is associated with increased STAT 5 production and increased formation of GCR-STAT 5 complexes. B. Studies and Results These will be discussed based on the specific aims 1. Determine the frequency of alterations in T cells from patients with SRINS vs. SSINS. The applicant has obtained IRB approval and started collecting patient samples. Six additional centers are in the process of obtaining IRB approval. Methodologies for real time PCR have been validated for the proposed primers to be used and the limited amount of cells available for the proposed exeriments. The samples collected so far have been saved on liquid nitrogen for future analysis. T cells will be isolated using negative selection columns.