Effects of immunological responsiveness on Langerhans cell behavior in contact sensitization

Kolde, G.

doi:10.1111/j.1600-0625.1994.tb00288.x

Cited by 6 publications

(2 citation statements)

References 31 publications

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“…We obtained additional information concerning the ultrastructural changes in LCs under incubation with chemical compounds and the route of internalization of HLA‐DR molecules by using electron microscopy. According to previous observations in contact dermatitis in mice 22 and guinea‐pigs, 42 there was an endocytotic activation of LCs in vitro after incubation with contact allergens. We observed an increase in mitochondria, Golgi apparatus, lysosomes, endocytotic vacuoles, BG and lamellar body‐like formation.…”

Section: Discussionmentioning

confidence: 75%

Contact allergens, but not irritants, alter receptor-mediated endocytosis by human epidermal Langerhans cells

Rizova

Carayon²,

Barbier

et al. 1999

British Journal of Dermatology

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Allergic contact dermatitis is a T-cell-mediated inflammation, induced by contact with sensitizers and occurring through the release of epidermal cytokines and the activation of epidermal Langerhans cells (LCs). The aim of this study was to analyse early events of LC activation induced either by contact allergens or by irritants devoid of any contact allergenic properties. in order to obtain an in vitro method to discriminate between these two groups of molecules. Various contact sensitizers and irritants were studied for their effects on the endocytosis of major histocompatibility complex class II (MHC-II) molecules by freshly-isolated human epidermal LCs. As observed by flow cytometry, a spontaneous decrease in the surface expression of MHC-II (HLA-DR) molecules, linked to spontaneous internalization of the MHC-II molecules by LCs, was obtained by moving freshly-isolated LCs from 4 degrees C to 37 degrees C. Pre-incubation of LCs with either sensitizers or irritants increased the spontaneous internalization of HLA-DR molecules with a similar magnitude, but no clear discrimination between sensitizer and irritant effects was obtained by flow cytometry analysis. In contrast, confocal microscopy enabled discrimination between the effects of sensitizers and irritants: sensitizer-treated samples showed internalized HLA-DR molecules aggregated in large vesicles with very bright fluorescence; irritant-treated samples were not different from untreated controls and showed compact HLA-DR molecules in small vesicles with diffuse fluorescence, and mostly localized in the submembranous zone. Electron microscopy demonstrated that sensitizer-treated LCs internalized HLA-DR molecules preferentially in lysosomes collected near the nucleus, whereas the irritant-treated and non-treated LCs internalized these molecules in the prelysosomes only near the cell membrane. We conclude that contact allergens and irritants induce distinct patterns of HLA-I)R endocytosis, which may be useful for the development of in vitro screening tests.

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Section: Discussionmentioning

confidence: 75%

Contact allergens, but not irritants, alter receptor-mediated endocytosis by human epidermal Langerhans cells

Rizova

Carayon²,

Barbier

et al. 1999

British Journal of Dermatology

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“…The epicutaneous application of DNCB is a well-established model for the study of cell-mediated immunity in both humans and laboratory animals. 4,8,22,25,26,32 Contact hypersensitivity may be considered to have two stages. There is an initial stage of sensitization resulting in the production of memory T cells and then, upon reexposure to the allergen, an elicitation phase characterized by the infiltration of the epidermis and dermis at the site of contact with mononuclear cells.…”

mentioning

confidence: 99%

Prominence of γδ T Cells in the Elicitation Phase of Dinitrochlorobenzene-induced Contact Hypersensitivity in Lambs

Jörundsson

Press

Ulvund³

et al. 1999

Vet Pathol

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Immunohistochemical techniques were used to identify T-cell subpopulations in the ear skin of lambs during the elicitation phase of dinitrochlorobenzene (DCNB)-induced contact hypersensitivity. Thirty lambs (21-26 weeks of age) were divided into groups of 10. The shaved right ear of one group was treated with DNCB. Two weeks later, this group was challenged with DNCB. One group was treated with the vehicle alone, and the remaining group was left untreated. The lambs were killed 48 hours after challenge, and tissue specimens were collected from the ears of the three groups. There was an increase in T-cell populations in the skin of the DNCB-treated lambs 48 hours after challenge. The majority of the T cells were CD8+ and associated predominantly with the blood vessels and adnexa of the superficial dermis. There was also an increased presence of CD4+ cells and gammadelta T cells in the superficial dermis. In the epidermis, clusters of gammadelta T cells and CD4+ cells were associated with microlesions. Computer-assisted morphometric analysis was used to estimate the relative presence of the T-cell subpopulations in the superficial and deep dermis and the entire dermis. Statistical analysis of the relative area of immunostaining showed that the significant increases in all T-cell subpopulations (CD4+, CD8+, and gammadelta T cells) in the entire dermis were accounted for by changes in the superficial dermis. The prominence of gammadelta T cells in delayed-type hypersensitivity in the skin of domestic ruminants has been the subject of conflicting reports. In the present study, CD4+ cell and gammadelta T-cell populations were of similar size in the normal and DNCB-treated lambs, suggesting an equal participation in the elicitation phase of contact hypersensitivity.

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High and low doses of haptens dictate whether dermal or epidermal antigen‐presenting cells promote contact hypersensitivity

et al. 1997

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In the induction of contact hypersensitivity (CH) to an epicutaneously applied hapten, we have previously proposed that low doses of hapten sensitize primarily through epidermal Langerhans' cells (LC), whereas high doses rely largely on dermal antigen-presenting cells (APC). To examine this issue further, we applied either high or low doses of dinitrofluorobenzene (DNFB) epicutaneously to mice. We observed reduced LC density at the site after 12 h (nadir), which returned to normal levels at 24 h only after a low dose of hapten. When a low dose of an unrelated hapten, oxazolone, was painted on skin that had been painted 12 h previously with high dose of DNFB, oxazolone-specific CH was impaired. When grafts of whole skin, dermis alone, and epidermis alone prepared from skin painted 2 h previously with low or high doses of DNFB were placed onto naive, syngeneic mice, CH was induced by whole skin after both types of doses, by epidermis only after a low dose, and by dermis only after high dose. When epidermal cell suspensions were derivatized in vitro with low or high doses of DNFB, only cells exposed to a low dose induced proliferation of hapten-specific Tcells. Thus, only a low dose of hapten reveals the APC functions of LC without the participation of dermal APC.

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Effects of immunological responsiveness on Langerhans cell behavior in contact sensitization

Cited by 6 publications

References 31 publications

Contact allergens, but not irritants, alter receptor-mediated endocytosis by human epidermal Langerhans cells

Contact allergens, but not irritants, alter receptor-mediated endocytosis by human epidermal Langerhans cells

Prominence of γδ T Cells in the Elicitation Phase of Dinitrochlorobenzene-induced Contact Hypersensitivity in Lambs

High and low doses of haptens dictate whether dermal or epidermal antigen‐presenting cells promote contact hypersensitivity

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