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Thompson, A. A.

Publications and source records attributed to Thompson, A. A..

2 recordsLinked to original sources

Antigen presentation by discrete class I molecules on brain endothelium dynamically regulates T-cell mediated neuropathology in experimental cerebral malaria

CD8 T cell engagement of brain vasculature is a putative mechanism of neuropathology in human cerebral malaria. To define contributions of brain endothelial cell MHC class I antigen-presentation to CD8 T cells in establishing this pathology, we developed novel H-2Kb LoxP and H-2Db LoxP mice crossed with Cdh5-Cre mice to achieve targeted deletion of discrete class I molecules on brain endothelium. Using the Plasmodium berghei ANKA model of experimental cerebral malaria (ECM), we observe that H-2Kb and H-2Db regulate distinct patterns of disease onset, CD8 T cell infiltration, targeted cell death, and regional blood-brain barrier (BBB) disruption. Strikingly, ablation of H-2Kb or H-2Db from brain endothelial cells resulted in reduced CD8 T cell activation, attenuated T cell interaction with brain vasculature, lessened targeted cell death, preserved BBB integrity, and prevented ECM and the death of the animal. These data demonstrate that interactions of CD8 T cells with discrete MHC class I molecules on brain endothelium regulate development of ECM neuropathology. Therefore, targeting MHC class I interactions therapeutically may hold potential for treatment of cases of severe malaria.

neuroscience↗

Structures of human Malic Enzyme 3

Malic enzymes (ME1, ME2, and ME3) are involved in cellular energy regulation, redox homeostasis, and biosynthetic processes, through the production of pyruvate and reducing agent NAD(P)H. Recent studies have implicated the third and least well-characterized isoform, mitochondrial NADP+-dependent malic enzyme 3 (ME3), as a therapeutic target for pancreatic cancers. Here, we utilized an integrated structure approach to capture the structures of ME3 in various ligand binding states. ME3 exists as a stable tetramer and its dynamic Domain C is critical for activity. Catalytic assay results reveal that ME3 is a non-allosteric enzyme and does not require modulators for activity while structural analysis suggests that the inner stability of ME3 domain A relative to ME2 disables allostery in ME3. With structural information available for all three malic enzymes, the foundation has been laid to understand the structural and biochemical differences of these enzymes and could aid in the development of specific malic enzyme small molecule drugs.

molecular biology↗