The Taste Receptor TAS1R3 Regulates Small Intestinal Tuft Cell Homeostasis

Tuft cells are an epithelial cell type critical for initiating type 2 immune responses to parasites and protozoa in the small intestine. To respond to these stimuli, intestinal tuft cells use taste chemosensory signaling pathways, but the role of taste receptors in type 2 immunity is poorly understood. In this study, we show that the taste receptor TAS1R3, which detects sweet and umami in the tongue, also regulates tuft cell responses in the distal small intestine. BALB/c mice, which have an inactive form of TAS1R3, as well as Tas1r3-deficient C57BL6/J mice both have severely impaired responses to tuft cell-inducing signals in the ileum, including the protozoa Tritrichomonas muris and succinate. In contrast, TAS1R3 is not required to mount an immune response to the helminth Heligmosomoides polygyrus, which infects the proximal small intestine. Examination of uninfected Tas1r3-/- mice revealed a modest reduction in the number of tuft cells in the proximal small intestine but a severe decrease in the distal small intestine at homeostasis. Together, these results suggest that TAS1R3 influences intestinal immunity by shaping the epithelial cell landscape at steady-state

Familial Exudative Vitreoretinopathy or Retinopathy of Prematurity

Retinopathy of prematurity (ROP) and familial exudative vitreoretinopathy (FEVR) can have very similar clinical presentations. Both diseases have abnormal development of retinal vessels and lead to severe vitreoretinopathy which causes blindness in newborn infants. The single most important difference is prematurity. In ROP, the most important risk factors are gestational age and low birth weight. In FEVR, it is the genetic mutation. Identifying the underlying mutations in the causative gene can predict the prognosis of patients with FEVR. ROP tends to resolve naturally or with treatment, but FEVR is a lifelong disease. Even we know that the clinical characteristics and risk factors between both diseases are different; the clinical similarity makes differential diagnosis difficult, especially in FEVR patients who were born prematurely. In such a scenario, patients could exhibit features of FEVR or ROP or both and found to have a discrepancy between birth history and fundus appearance, thus ROPER/fROP was used to describe these patients under such conditions