Faries, C. | Search bioRxiv

bioRxiv2023

Cell Surface β-Lactamase Recruitment: A Facile Selection to Identify Protein-Protein Interactions

Protein-protein interactions are central to many cellular processes, and the identification of novel protein-protein interactions is a critical step in the discovery of protein therapeutics. Simple methods to identify naturally existing or laboratory evolved protein-protein interactions are therefore valuable research tools. We have developed a facile selection that links protein-protein interaction-dependent {beta}-lactamase recruitment on the surface of E. coli with resistance to ampicillin. Bacteria displaying a protein which form a complex with a specific protein-{beta}-lactamase fusion are protected from ampicillin-dependent cell death. In contrast, bacteria that do not recruit {beta}-lactamase to the cell surface are killed by ampicillin. Given its simplicity and tunability, we anticipate this selection will be a valuable addition to the palette of methods for illuminating and interrogating protein-protein interactions.

biochemistry↗

bioRxiv2019

Immune Profiling of Atherosclerotic Plaques Identifies Innate and Adaptive Dysregulations Associated with Ischemic Cerebrovascular Events

Atherosclerosis is driven by multifaceted contributions of the immune system within the circulation and at vascular focal sites. Yet the specific immune dysregulations within the atherosclerotic lesions that lead to clinical cerebro- and cardiovascular complications (i.e. ischemic stroke and myocardial infarction) are poorly understood. Here, using single-cell mass cytometry with Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) we found that atherosclerotic plaques were enriched in activated, differentiated, and exhausted subsets of T cells vs. blood. Next, using single-cell proteomic, transcriptomic, and cell-to-cell interaction analyses we found unique functional dysregulations of both T cells and macrophages in plaques of patients with clinically symptomatic (SYM; recent stroke of TIA) or asymptomatic (ASYM, no recent stroke) carotid artery disease. SYM plaques were enriched with a distinct CD4+ T cell subset, and T cells were activated, differentiated and presented subset specific exhaustion. SYM macrophages presented alternatively activated phenotypes including subsets associated with plaque vulnerability. In ASYM plaques, T cells and macrophages were activated and displayed a strong IL-1{beta} signaling across cell types, that was absent in SYM plaques. The identification of plaque-specific innate and adaptive immune dysregulations associated with cerebrovascular events provides the basis for the design of precisely tailored cardiovascular immunotherapies.

immunology↗