title: Temporal correlation between UV radiation locally-inducible tolerance and the sequential appearance of dermal, then epidermal, class II MHC+CD11b+ monocytic/macrophagic cells.
abstract: We performed a time course study in order to define the in vivo relationship between the induction of active suppression of contact sensitization and the presence of various cells in ultraviolet-exposed dermis and epidermis implicated in locally inducible immune tolerance: class II major histocompatibility complex (MHC)+CD11b(lo)Gr-1- Langerhans cells (LC), class II MHC-CD45+CD3+ dendritic epidermal T cells, class II MHC+CD11b+Gr-1- monocytes or class II MHC+CD11b+Gr-1+ monocytic/macrophagic cells. Partial tolerance (50%) was first detectable 6 h after a single 72 mJ/cm2 ultraviolet B exposure and maximum tolerance at 48 h post-ultraviolet exposure. By flow cytometry, a low granularity LC subset had disappeared from the epidermis within 6 h after ultraviolet exposure, followed by a slower decrease in the high granularity Langerhans cells subset. Within the dermis at the 6-h time point, small numbers of infiltrating monocytic/macrophagic cells are already apparent. By 24 h post-ultraviolet exposure, at which time tolerance has increased to 70%, the infiltrating monocytic/macrophagic population had risen to 1.2% of the total dermal cell population and was observed for the first time in the epidermis along with other infiltrating leukocytes (i.e., polymorphonuclear leukocytes). By 48 h post-ultraviolet exposure, when a state of maximum tolerance is obtained, both constitutive epidermal and dermal antigen-presenting cell populations were at or near their nadir of depletion. The infiltrating monocyte/macrophage population, however, exhibited a dramatic increase in the epidermis at 48 and 72 h. Thus, the ability to locally induce a state of in vivo tolerance is closely associated with the expansion of class II MHC+CD11b+Gr-1+ and -monocytic/macrophagic cells in the dermis and epidermis.
authors.affiliation: Department of Dermatology, University of Michigan, Ann Arbor, USA.
authors.forename: C
authors.initials: C
authors.lastname: Hammerberg
authors.forename: N
authors.initials: N
authors.lastname: Duraiswamy
authors.forename: K D
authors.initials: KD
authors.lastname: Cooper
mesh_terms: D000818:Animals; D018845:CD11 Antigens / Q000032:analysis*; D004139:Dinitrofluorobenzene / Q000276:immunology; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D007108:Immune Tolerance / Q000528:radiation effects*; D007801:Langerhans Cells / Q000528:radiation effects; D008264:Macrophages / Q000276:immunology / Q000528:radiation effects*; D051379:Mice; D008809:Mice, Inbred C3H; D009000:Monocytes / Q000276:immunology / Q000528:radiation effects*; D009504:Neutrophils / Q000276:immunology / Q000528:radiation effects; D012867:Skin / Q000276:immunology / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D018845:CD11 Antigens; D000949:Histocompatibility Antigens Class II; D004139:Dinitrofluorobenzene