title: Development of intravital intermittent confocal imaging system for studying Langerhans cell turnover.
abstract: Although several studies have suggested relatively slow turnover of Langerhans cells (LCs), their actual lifespan remains elusive. Here we report the development of a new intravital imaging system for studying LC efflux and influx. Epidermal LCs expressing enhanced green fluorescent protein (EGFP) were visualized in anesthetized I-Abeta-EGFP knock-in mice by confocal microscopy. By overlaying two sets of EGFP+ LC images recorded in the same microscopic fields at time 0 and 24 hours later, we identified LC subpopulations that had disappeared from or newly emerged in the epidermis during that period. Of >10,000 LCs analyzed in this manner, an overwhelming majority (97.8+/-0.2%) of LCs showed no significant changes in the x-y locations, whereas 1.3+/-0.1% of the LCs that were found at time 0 became undetectable 24 hours later, representing LC efflux. Conversely, 0.9+/-0.1% of the LCs that were found at time 24 hours were not detectable at time 0, representing LC influx. From these frequencies, we estimated the half-life of epidermal LCs to range from 53 to 78 days, providing new insights into the immunobiology of LCs. Our intermittent imaging approach may be regarded as a technical breakthrough enabling direct visual assessment of LC turnover in living animals.
authors.affiliation: Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
authors.forename: Mridula
authors.initials: M
authors.lastname: Vishwanath
authors.forename: Akiko
authors.initials: A
authors.lastname: Nishibu
authors.forename: Sem
authors.initials: S
authors.lastname: Saeland
authors.forename: Brant R
authors.initials: BR
authors.lastname: Ward
authors.forename: Norikatsu
authors.initials: N
authors.lastname: Mizumoto
authors.forename: Hidde L
authors.initials: HL
authors.lastname: Ploegh
authors.forename: Marianne
authors.initials: M
authors.lastname: Boes
authors.forename: Akira
authors.initials: A
authors.lastname: Takashima
mesh_terms: D000818:Animals; D000078404:Epidermal Cells; D049452:Green Fluorescent Proteins / Q000032:analysis* / Q000235:genetics; D007801:Langerhans Cells / Q000737:chemistry / Q000166:cytology*; D051379:Mice; D008817:Mice, Mutant Strains; D018613:Microscopy, Confocal / Q000379:methods*
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins