D-mannose, a C-2 epimer of glucose, exists naturally in many plants and fruits, and is found in human blood at concentrations less than one-fiftieth of that of glucose. However, although the roles of glucose in T cell metabolism, diabetes and obesity are well characterized, the function of D-mannose in T cell immune responses remains unknown. Here we show that supraphysiological levels of D-mannose safely achievable by drinking-water supplementation suppressed immunopathology in mouse models of autoimmune diabetes and airway inflammation, and increased the proportion of Foxp3 regulatory T cells (T cells) in mice. In vitro, D-mannose stimulated T cell differentiation in human and mouse cells by promoting TGF-β activation, which in turn was mediated by upregulation of integrin αβ and reactive oxygen species generated by increased fatty acid oxidation. This previously unrecognized immunoregulatory function of D-mannose may have clinical applications for immunopathology.

We applied pulse-shape analysis (PulSA) to monitor protein localization changes in mammalian cells by flow cytometry. PulSA enabled high-throughput tracking of protein aggregation, translocation from the cytoplasm to the nucleus and trafficking from the plasma membrane to the Golgi as well as stress-granule formation. Combining PulSA with tetracysteine-based oligomer sensors in a cell model of Huntington's disease enabled further separation of cells enriched with monomers, oligomers and inclusion bodies.

Regulatory T cells (Treg cells) perform suppressive functions in disparate tissue environments and against many inflammatory insults, yet the tissue-enriched factor(s) that influence Treg cell phenotype and function remain largely unknown. We have shown a vital role for transforming growth factor-β (TGF-β) signals in safe-guarding specific Treg cell functions. TGF-β signals were dispensable for steady-state Treg cell homeostasis and for Treg cell suppression of T cell proliferation and T helper-1 (Th1) cell differentiation. However, Treg cells require TGF-β signals to appropriately dampen Th17 cells and regulate responses in the gastrointestinal tract. TGF-β signaling maintains CD103 expression, promotes expression of the colon-specific trafficking molecule GPR15, and inhibits expression of GPR174, a receptor for lysophosphatidylserine, on Treg cells, collectively supporting the accumulation and retention of Treg cells in the colon and control of colitogenic responses. Thus, we reveal an unrecognized function for TGF-β signaling as an upstream factor controlling Treg cell activity in specific tissue environments.

Through a trans-institutional transdisciplinary approach, we managed to achieve a significantly shorter hospital stay in frail patients having colorectal surgery. All elective patients who received prehabilitation achieved full functional recovery.