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Zhang, T. L.

Publications and source records attributed to Zhang, T. L..

3 recordsLinked to original sources

Chemical proteomics reveals post-translational remodeling of endosomal pathways during macrophage activation.

Macrophages are central regulators of innate immunity, yet the post-translational mechanisms that enable rapid inflammatory responses remain incompletely understood. Here, we integrated transcriptomics, unenriched proteomics, phosphoproteomics, metabolomics, and cysteine reactivity profiling to comprehensively characterize primary human macrophages following Toll-like receptor and Stimulator of Interferon Genes (STING) activation. This approach revealed substantial discordance between transcript- and protein-level changes, as well as extensive post-translational remodeling. Differentially reactive cysteines were enriched in proteins involved in small-GTPase signaling, vesicular trafficking, and the endo-lysosomal system. Reactivity changes in two subunits of the endosomal mRNA-transport FERRY complex nominated it as a candidate target of inflammation-associated post-translational regulation. Biochemical and imaging analyses established FERRY complex assembly and early endosomal localization in primary human macrophages and identified DISC1 as a previously unrecognized FERRY-associated protein. This work provides a comprehensive resource of biochemical and post-translational remodeling during macrophage activation and implicates endosome-associated mRNA transport in innate immune regulation.

immunology↗

A post-translational regulatory map of chronic antigen-driven human T cell dysfunction.

T cells exposed to persistent antigen in the context of chronic viral infections or cancer lose self-renewal and cytotoxic capacity. Several transcriptional, epigenetic, and metabolic drivers of this process have been identified. However, the post-transcriptional regulatory mechanisms influencing the proteome of dysfunctional T cells are not well understood. Here we present a time-resolved molecular landscape of human T cells during the development of chronic antigen-driven dysfunction. Persistent T cell receptor stimulation significantly remodeled the proteome, including changes in canonical T cell exhaustion-associated proteins and proteins related to mitochondrial function, redox homeostasis, nucleotide metabolism, and cell-cycle progression. Dysfunctional T cells displayed activation of stress response pathways that were recapitulated in vivo; targeting these pathways altered the cytotoxic capacity of T cells during persistent tumor exposure. Our comprehensive proteomic resource reveals unique post-transcriptional changes in dysfunctional T cells and lays the groundwork for novel cysteine-directed therapeutics to enhance cancer immunotherapy.

immunology↗

Covalent Targeting of Splicing in T Cells.

Despite significant interest in therapeutic targeting of splicing, few chemical probes are available for the proteins involved in splicing. Here, we show that elaborated stereoisomeric acrylamide chemical probe EV96 and its analogues lead to a selective T cell state-dependent loss of interleukin 2-inducible T cell kinase (ITK) by targeting one of the core splicing factors SF3B1. Mechanistic investigations suggest that the state-dependency stems from a combination of differential protein turnover rates and availability of functional mRNA pools that can be depleted due to extensive alternative splicing. We further introduce a comprehensive list of proteins involved in splicing and leverage both cysteine- and protein-directed activity-based protein profiling (ABPP) data with electrophilic scout fragments to demonstrate covalent ligandability for many classes of splicing factors and splicing regulators in primary human T cells. Taken together, our findings show how chemical perturbation of splicing can lead to immune state-dependent changes in protein expression and provide evidence for the broad potential to target splicing factors with covalent chemistry.

immunology↗