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Jacobsen, J. T.

Publications and source records attributed to Jacobsen, J. T..

3 recordsLinked to original sources

One-step generation of TCR knock-in mice targeted to the TCRβ locus results in functional mature T lymphocytes

Transgenic mouse models expressing predefined T cell receptors (TCRs) have been instrumental in advancing our understanding of T cell biology. However, these traditional models rely on random genomic insertion of large constructs, require labor-intensive embryo manipulation, and frequently result in aberrant TCR expression and phenotypes. These limitations render TCR transgenic models insufficient to meet the mounting demands for rapid and precise model systems to evaluate TCR specificities. To address these challenges, we developed a streamlined method that combines Adeno-Associated Virus (AAV), coupled with CRISPR/Cas9 genome editing to precisely integrate pre-rearranged TCR/{beta} sequences into the mouse Trb locus, enabling the rapid generation of first-of-its-kind TCR knock-in mice with physiological TCR expression and functional T cell differentiation. This approach bypasses the need for technically advanced embryo manipulation and enables rapid generation of models through a universally optimized AAV vector system, significantly enhancing the versatility and utility of monoclonal TCR mice in basic immunology and preclinical research such as cancer immunotherapy and vaccine development, providing a transformative resource to accelerate discovery and translation across disciplines.

immunology↗

Universal recording of cell-cell contacts in vivo for interaction-based transcriptomics

Cellular interactions are essential for tissue organization and functionality. In particular, immune cells rely on direct and usually transient interactions with other immune and non-immune populations to specify and regulate their function. To study these "kiss-and-run" interactions directly in vivo, we previously developed LIPSTIC (Labeling Immune Partnerships by SorTagging Intercellular Contacts), an approach that uses enzymatic transfer of a labeled substrate between the molecular partners CD40L and CD40 to label interacting cells. Reliance on this pathway limited the use of LIPSTIC to measuring interactions between CD4+ helper T cells and antigen presenting cells, however. Here, we report the development of a universal version of LIPSTIC (uLIPSTIC), which can record physical interactions both among immune cells and between immune and non-immune populations irrespective of the receptors and ligands involved. We show that uLIPSTIC can be used, among other things, to monitor the priming of CD8+ T cells by dendritic cells, reveal the cellular partners of regulatory T cells in steady state, and identify germinal center (GC)-resident T follicular helper (Tfh) cells based on their ability to interact cognately with GC B cells. By coupling uLIPSTIC with single-cell transcriptomics, we build a catalog of the immune populations that physically interact with intestinal epithelial cells (IECs) and find evidence of stepwise acquisition of the ability to interact with IECs as CD4+ T cells adapt to residence in the intestinal tissue. Thus, uLIPSTIC provides a broadly useful technology for measuring and understanding cell-cell interactions across multiple biological systems.

immunology↗

One-step generation of monoclonal B cell receptor mice capable of class switch recombination and somatic hypermutation

We developed a method for rapid generation of B cell receptor (BCR) monoclonal mice expressing pre-rearranged Igh and Igk chains monoallelically from the Igh locus by CRISPR/Cas9 injection into fertilized oocytes. B cells from these mice undergo somatic hypermutation (SHM), class switch recombination (CSR), and affinity-based selection in germinal centers. This method combines the practicality of BCR transgenes with the ability to study Ig SHM, CSR and affinity maturation.

immunology↗