Research
In every single cell in the human body, the six feet of DNA is compacted in the micrometer space of the nucleus by wrapping around spools called nucleosomes in addition to extraordinary three-dimensional folding of DNA inside the nucleus. Tissue-specific decoding of the genetic information from this extreme compression is orchestrated by specialized proteins capable of binding DNA in a sequence-specific manner. Locally, a number of proteins called lineage-determining transcription factors can access their binding sites even if they are partially occluded by nucleosomes, recruiting chromatin-remodeling enzymes and exposing the underlying DNA. Globally, sequence-specific proteins such as CTCF act as structural regulators of spatial genome organization. Considering that every two human genomes contain more than 6 million nucleotide differences and the fact that genetics is a major determinant of susceptibility to common diseases, it is essential to understand how the packaging of DNA inside the nucleus becomes resilient or susceptible to diseases due to large numbers of sequence variation. The overarching goal of the Vahedi laboratory is to understand the molecular mechanisms through which genomic information in our immune cells is interpreted in normal development and further dissect how common genetic variation can lead to misinterpretation of the genetic material in immune mediated diseases, particularly autoimmune disorders.
The multidisciplinary nature of our laboratory allows us to exploit computational and cutting-edge experimental approaches and generate unbiased maps of genome organization in primary immune cells in humans and mice. We further follow our hypothesis-generating yet unbiased efforts with experiments dissecting the mechanisms of our predictions using genome editing in mice or cell lines which provides us with an unparalleled opportunity to rigorously define the link between genetics and chromatin organization.
Research Areas
Deciphering how transcription factors establish T cell fate
Our protection against microorganisms such as viruses, bacteria, and fungi is achieved by the orchestrated interactions among a multitude of distinct and specific cells of the innate and adaptive immune responses. Among many players in this system, the white blood cells called T lymphocytes possess the most powerful ability to recognize and target the pathogenic […]
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Determining how sequence variation associated with type 1 diabetes affects the chromatin organization of T cells
Although the main function of T cells is to protect us from infectious agents, many medically important diseases are associated with abnormal T cell responses directed against proteins produced by our own body’s tissues. This broad category of immune-mediated diseases is referred to as autoimmune disorders and includes diseases such as type 1 diabetes (T1D), […]
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Genome organization at the paralogous transcription factors
The emergence of multicellular life over 500 million years ago was accompanied by profound changes in vertebrate genomes, driven in part by at least two rounds of whole-genome duplication. These duplications generated paralogous transcription factors (TFs) that diversified in function, enabling the rise of specialized cell types and contributing to organismal complexity. While most paralogous […]
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Innovating computational methods to discover grammars of gene regulation in T cells
To achieve our lab’s central goal, which is to better understand the chromatin biology of T cells in health and disease, we also innovate computational techniques to fully understand the complexity of multidimensional epigenomic datasets in T cells. We devised a computational workflow called PRISM to quantify cell-to-cell chromatin accessibility variation at transcription factor binding […]
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