The Role of Transcription Factor TFEB in T cell Memory

T Lymphocytes play a critical role in the function, creation and maintenance of the long-standing memory cells in adaptive immunity. The long-standing memory cells such as memory B cells and T memory cells are important to long-term health of an animal. Memory cell types are determined by many factors including transcription factors. Transcription factors control when the information encoded in a gene is expressed, leading to mRNA synthesis and protein production, and are thus directly involved with the phenotype and functionality of a cell.;In this study we have inactivated the transcription factors TFEB and/or TFE3; TFE3 and TFEB are involved in CD40L expression in T cells. CD40-CD40L is needed to activate B cells' antibody class switching. In addition, TFEB has been shown to activate a cellular recycling system called autophagy that is thought to be important for T cell development, but its role in this process in T cells is not known. This study aims to determine whether TFEB and/or TFE3 expression is necessary for memory T lymphocyte development, which is thought to depend in part on CD40-CD40L interactions and possibly autophagy.;Given that premise, we hypothesize that with the loss of TFEB, there will be a reduction in the number of memory T cells. We used aged unimmunized mice to observe the process of spontaneous malfunction, which might lead to autoimmune or immune deficiency diseases. In contrast to our hypothesis, our findings show that there is no change in numbers of memory T lymphocytes, as measured by flow cytometry. Based on the comparison of body and spleen mass (limited mass changes in either) the animals are in general good health without any indication of immune dysfunction. Therefore, we conclude that TFEB and TFE3 are not necessary for memory T cell development.