Neoantigen-targeted CD8 T cell responses with PD-1 blockade therapy.

Neoantigens are peptides derived from non-synonymous mutations presented by human leukocyte antigens (HLAs), which are recognized by antitumour T cells. The large HLA allele diversity and limiting clinical samples have restricted the study of the landscape of neoantigen-targeted T cell responses in patients over their treatment course. Here we applied recently developed technologies to capture neoantigen-specific T cells from blood and tumours from patients with metastatic melanoma with or without response to anti-programmed death receptor 1 (PD-1) immunotherapy.

Mitochondrial dysfunction remodels one-carbon metabolism in human cells.

Mitochondrial dysfunction is associated with a spectrum of human disorders, ranging from rare, inborn errors of metabolism to common, age-associated diseases such as neurodegeneration. How these lesions give rise to diverse pathology is not well understood, partly because their proximal consequences have not been well-studied in mammalian cells. Here we provide two lines of evidence that mitochondrial respiratory chain dysfunction leads to alterations in one-carbon metabolism pathways.

Variability in G-protein-coupled signaling studied with microfluidic devices.

Different cells, even those that are genetically identical, can respond differently to identical stimuli, but the precise source of this variability remains obscure. To study this problem, we built a microfluidic experimental system which can track responses of individual cells across multiple stimulations. We used this system to determine that amplitude variation in G-protein-activated calcium release in RAW264.

Suppression of LPS-induced TNF-alpha production in macrophages by cAMP is mediated by PKA-AKAP95-p105.

The activation of macrophages through Toll-like receptor (TLR) pathways leads to the production of a broad array of cytokines and mediators that coordinate the immune response. The inflammatory potential of this response can be reduced by compounds, such as prostaglandin E(2), that induce the production of cyclic adenosine monophosphate (cAMP). Through experiments with cAMP analogs and multigene RNA interference (RNAi), we showed that key anti-inflammatory effects of cAMP were mediated specifically by cAMP-dependent protein kinase (PKA).

Behavior of complex knots in single DNA molecules.

We used optical tweezers to tie individual DNA molecules in knots. Although these knots become highly localized under tension, they remain surprisingly mobile and undergo thermal diffusion with classical random walk statistics. The diffusion constants of knots with different complexities correlate with theoretical calculations of knot sizes.