title: CD1a+ and CD1a- accessory cells from human bronchoalveolar lavage differ in allostimulatory potential and cytokine production.
abstract: Recently, we described the isolation through fluorescent-activated cell sorting (FACS) of low autofluorescent (LAF) cells from human bronchoalveolar lavage (BAL). These LAF cells displayed an immunophenotype comparable with that of dendritic cells (DC), and showed a high potency to stimulate naive T cells. In the study reported here we investigated the capability of LAF cells to produce interleukin-1 (IL-1), IL-6, and tumor necrosis factor alpha (TNF-alpha), and the role of these cytokines in allogeneic T-cell stimulation by LAF cells. Lipopolysaccharide (LPS)-stimulated LAF cells released biologically active IL-1, IL-6, and TNF, and also showed intracellular immunoreactivity for IL-1, IL-6, and TNF-alpha. A neutralizing antibody against IL-1 slightly but statistically significantly (P < 0.05, Wilcoxon's test) inhibited the ability of the LAF cells to stimulate allogeneic T-cell proliferation (89% of stimulation in the absence of the antibody). Neutralizing antibodies against IL-6 and TNF-alpha had no effect. An antibody to granulocyte-macrophage colony-stimulating factor (GM-CSF) also interfered with the accessory function of the LAF cells (79% of stimulation in the absence of the antibody, P < 0.05). We also investigated whether subsets of LAF cells (i.e., positive or negative for CD1a and purified by FACS sorting) differed in T-cell stimulatory capacity and in the ability to produce IL-1, IL-6, TNF-alpha, and S100. CD1a+ LAF cells were positive for and produced S100, CD1a- LAF cells were negative in this respect. The CD1a+ subset exhibited a clearly higher and very strong accessory capability as compared with the CD1a- subset. Despite this, CD1a+ LAF cells were poor producers of IL-1, IL-6, and TNF-alpha. The neutralizing antibody to IL-1, however, inhibited the ability of CD1a+ cells to stimulate allogeneic T-cell proliferation (43% of stimulation in the absence of the antibody, P < 0.01). Anti-IL-6 and alpha-GM-CSF had no effects. CD1a- LAF cells were potent producers of IL-1, IL-6, and TNF-alpha, and antibodies to IL-1, IL-6, and GM-CSF strongly interfered with their weaker accessory capability. In conclusion, two different subsets of LAF cells could be identified on the basis of accessory capability and cytokine profile. CD1a+ LAF cells (S100+; very potent T-cell stimulators, poor cytokine producers) are the "Langerhans cells" of the lung. CD1a- LAF cells (S100-; lower T-cell stimulatory capability, potent producers of IL-1, IL-6, and TNF-alpha) displayed a marker pattern intermediate between that of monocytes and monocyte-derived DC.
authors.affiliation: Department of Immunology, Erasmus University, Rotterdam, the Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: van Haarst
authors.forename: G T
authors.initials: GT
authors.lastname: Verhoeven
authors.forename: H J
authors.initials: HJ
authors.lastname: de Wit
authors.forename: H C
authors.initials: HC
authors.lastname: Hoogsteden
authors.forename: R
authors.initials: R
authors.lastname: Debets
authors.forename: H A
authors.initials: HA
authors.lastname: Drexhage
mesh_terms: D000293:Adolescent; D000328:Adult; D000906:Antibodies / Q000494:pharmacology; D018949:Antigens, CD1 / Q000032:analysis*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D002469:Cell Separation; D016207:Cytokines / Q000096:biosynthesis* / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000032:analysis / Q000096:biosynthesis; D015850:Interleukin-6 / Q000032:analysis / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008875:Middle Aged; D009418:S100 Proteins / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000096:biosynthesis
chemical_list: D000906:Antibodies; D018949:Antigens, CD1; D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D009418:S100 Proteins; D014409:Tumor Necrosis Factor-alpha