title: Intrinsic Photosensitivity Enhances Motility of T Lymphocytes.
abstract: Sunlight has important biological effects in human skin. Ultraviolet (UV) light striking the epidermis catalyzes the synthesis of Vitamin D and triggers melanin production. Although a causative element in skin cancers, sunlight is also associated with positive health outcomes including reduced incidences of autoimmune diseases and cancers. The mechanisms, however, by which light affects immune function remain unclear. Here we describe direct photon sensing in human and mouse T lymphocytes, a cell-type highly abundant in skin. Blue light irradiation at low doses (<300 mJ cm-2) triggers synthesis of hydrogen peroxide (H2O2) in T cells revealed by the genetically encoded reporter HyPerRed. In turn, H2O2activates a Src kinase/phospholipase C-γ1 (PLC-γ1) signaling pathway and Ca2+mobilization. Pharmacologic inhibition or genetic disruption of Lck kinase, PLC-γ1 or the T cell receptor complex inhibits light-evoked Ca2+transients. Notably, both light and H2O2enhance T-cell motility in a Lck-dependent manner. Thus, T lymphocytes possess intrinsic photosensitivity and this property may enhance their motility in skin.
authors.affiliation: Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road, NW, Washington DC, 20007, USA.|Department of Biology, Vinh University, Vinh City, Vietnam.
authors.forename: Thieu X
authors.initials: TX
authors.lastname: Phan
authors.affiliation: Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road, NW, Washington DC, 20007, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Jaruga
authors.affiliation: Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road, NW, Washington DC, 20007, USA.
authors.forename: Sandeep C
authors.initials: SC
authors.lastname: Pingle
authors.affiliation: Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road, NW, Washington DC, 20007, USA.|Research Service, Veterans Affairs Medical Center, Washington, DC 20422, USA.
authors.forename: Bidhan C
authors.initials: BC
authors.lastname: Bandyopadhyay
authors.affiliation: Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road, NW, Washington DC, 20007, USA.
authors.forename: Gerard P
authors.initials: GP
authors.lastname: Ahern
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry; D002465:Cell Movement / Q000528:radiation effects*; D049109:Cell Proliferation; D002633:Chemotaxis; D006801:Humans; D006861:Hydrogen Peroxide; D019169:Jurkat Cells; D051379:Mice; D051966:Phospholipase C gamma / Q000378:metabolism; D010766:Phosphorylation; D017785:Photons; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects; D012867:Skin / Q000528:radiation effects*; D013154:Spleen / Q000166:cytology; D013472:Sunlight; D013601:T-Lymphocytes / Q000166:cytology* / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D006861:Hydrogen Peroxide; D051966:Phospholipase C gamma; D002118:Calcium