1
|
Abstract
Soon after UV exposure, mast cells degranulate, possibly because of the release of the mediators and cytokines from the epidermis, and there are subsequent vascular changes and cellular infiltration. Within a few hours, the soluble mediator milieu of UV-exposed skin becomes exceedingly complex and replete with interactions. Leukocytes newly entering the skin, as well as those already in the skin, must respond to these inflammatory signals. Altered antigen presentation and immune suppression likely derive from alterations induced in the APC that comprise the post-UV leukocyte population of the skin. Many of these mechanisms may explain the effectiveness of phototherapy in atopic dermatitis and psoriasis.
Collapse
Affiliation(s)
- K D Cooper
- Department of Dermatology, Case Western Reserve University and University Hospitals of Cleveland, OH, USA
| |
Collapse
|
2
|
Chapman RS, Cooper KD, De Fabo EC, Frederick JE, Gelatt KN, Hammond SP, Hersey P, Koren HS, Ley RD, Noonan F. Solar ultraviolet radiation and the risk of infectious disease: summary of a workshop. Photochem Photobiol 1995; 61:223-47. [PMID: 7716186 DOI: 10.1111/j.1751-1097.1995.tb03966.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- R S Chapman
- U.S. Environmental Protection Agency, Research Triangle Park, NC 27711
| | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Yu RC, Abrams DC, Alaibac M, Chu AC. Morphological and quantitative analyses of normal epidermal Langerhans cells using confocal scanning laser microscopy. Br J Dermatol 1994; 131:843-8. [PMID: 7857837 DOI: 10.1111/j.1365-2133.1994.tb08587.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Confocal scanning laser microscopy (CSLM), when used in conjunction with computerized image processing systems, provides a powerful tool for morphological and quantitative analyses of biological tissues. In this study, normal human epidermal sheets were stained by an indirect immunofluorescence method using anti-CD1a monoclonal antibody. Positively stained epidermal Langerhans cells (LCs) were visualized using the Bio-Rad MRC-600 Confocal Imaging System. Images obtained from the confocal microscope were volumetrically rendered and quantitatively analysed using ANALYZE (Version 4.0) running on a Sun SPARC 2 Workstation. Normal epidermal LCs were shown to be large disc-like structures with five to nine long dendritic processes per cell, orientated with their flat surfaces parallel to the skin surface. LCs form a monolayer network of cells distributed evenly throughout the suprabasal layers of the epidermis, with no direct physical contact between dendritic processes. Mean LC density was estimated to be 582 per mm2 (95% confidence intervals, CI = 233-940), and mean cell volume was 612 microns3 (95% CI = 257-1020). LCs in sun-exposed sites were significantly lower in mean cell density, but larger in mean cell volume, than in covered sites. Mean surface area projected by LCs was estimated to be 26.8% (95% CI = 18.9-34.2), and this value did not show significant regional or individual variation. Our data support the notion that epidermal LCs are organized in such a way as to maximize their surface area for efficient trapping of antigens, and a reduction in LC density per unit area in sun-exposed sites is compensated for by an increase in the mean cell volume.
Collapse
Affiliation(s)
- R C Yu
- Unit of Dermatology, Royal Postgraduate Medical School, London, U.K
| | | | | | | |
Collapse
|
4
|
Spencer MJ, Vestey JP, Tidman MJ, McVittie E, Hunter JA. Major histocompatibility class II antigen expression on the surface of epidermal cells from normal and ultraviolet B irradiated subjects. J Invest Dermatol 1993; 100:16-22. [PMID: 8423384 DOI: 10.1111/1523-1747.ep12349920] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The influence of ultraviolet B irradiation in therapeutic doses on MHC II-positive epidermal cell numbers and their surface MHC II antigen expression was studied quantitatively using light microscopic immunoperoxidase and immunogold electron microscopic techniques. In multiple ultrathin sections through many MHC II-positive epidermal cells from five healthy subjects, prior to ultraviolet exposure, Langerhans cells and indeterminate cells were found to express similar densities of surface MHC II antigens, which were uniformly distributed over the cell surface. The variation in surface MHC II antigen expression on 97 dendritic epidermal cells from one subject was normally distributed. Following a 6-week course of ultraviolet B irradiation, in the same doses as those normally used for the treatment of psoriasis, MHC II-positive epidermal cell numbers were significantly reduced (mean decrease to 51% of the pre-UVB sample; p < 0.001 analysis of variance), but their surface MHC class II antigen density was significantly increased (p < 0.05 analysis of variance). No MHC II-negative Langerhans cells were detected in either the pre- or post-UVB samples.
Collapse
Affiliation(s)
- M J Spencer
- University Department of Dermatology, Royal Infirmary of Edinburgh, Scotland, U.K
| | | | | | | | | |
Collapse
|
5
|
Cooper KD, Voorhees JJ, Fisher GJ, Chan LS, Gupta AK, Baadsgaard O. Effects of cyclosporine on immunologic mechanisms in psoriasis. J Am Acad Dermatol 1990; 23:1318-26; discussion 1326-8. [PMID: 2277141 DOI: 10.1016/0190-9622(90)70360-t] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A major impetus for further investigation of cellular immunologic mechanisms in psoriasis has been the discovery that cyclosporine, a potent immunosuppressive, is highly effective in the treatment of psoriasis. Cyclosporine has significant inhibitory effects on the ability of T cells to become activated. However, a direct activity of this drug on human keratinocyte signal transduction or growth has been difficult to demonstrate at relevant concentrations. Nevertheless, treatment of psoriasis or of 12-O-tetradecanoyl phorbol-13-acetate-treated murine skin with cyclosporine does reverse many epidermal abnormalities that are common to these two systems. This suggests that the compound exerts an indirect effect on epidermal keratinocytes in vivo, perhaps through immunocyte inhibition. During treatment of psoriasis patients, cyclosporine therapy resulted in selective changes in the numbers and functions of certain antigen-presenting cell subsets (which were distinct from Langerhans cells) and T-cell subsets. These changes were accompanied by indirect evidence of decreased T-cell lymphokine release. Lesional activity of cyclosporine-treated psoriasis patients was closely correlated with the degree of T-cell activation caused by antigen-presenting cells. Cyclosporine inhibition of lymphokine or cytokine release may result in decreased recruitment of non-Langerhans antigen-presenting cells into the epidermis and thus decreased immunoreactivity in the lesion.
Collapse
Affiliation(s)
- K D Cooper
- Department of Dermatology, University of Michigan Medical Center, Ann Arbor 48109
| | | | | | | | | | | |
Collapse
|
6
|
Abstract
In experimental animals, exposure to UV-B radiation produces selective alterations of immune function which are mainly in the form of suppression of normal immune responses. This immune suppression is important in the development of nonmelanoma skin cancer, may influence the development and course of infectious disease and possibly protects against autoimmune reactions. The evidence that this form of immune suppression occurs in humans is less compelling and very incomplete. The wavelengths of radiation most affected by a depletion of the stratospheric ozone layer are those known to be most immunosuppressive in animals and it is likely that such depletion will increase any suppressive effect of sunlight on immunity in humans. In addition to establishing whether or not UV-B radiation can cause suppression of immune function in humans, studies are required to determine if melanin can provide protection against such suppression, the role of this suppression in the pathogenesis of skin cancer, the development of infectious disease and vaccine effectiveness, and the capacity for humans to develop adaptive, protective mechanisms which may limit damage from continued exposure to UV-B radiation.
Collapse
|
7
|
Ashworth J, Kahan MC, Breathnach SM. PUVA therapy decreases HLA-DR+ CDIa+ Langerhans cells and epidermal cell antigen-presenting capacity in human skin, but flow cytometrically-sorted residual HLA-DR+ CDIa+ Langerhans cells exhibit normal alloantigen-presenting function. Br J Dermatol 1989; 120:329-39. [PMID: 2469456 DOI: 10.1111/j.1365-2133.1989.tb04157.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have investigated the effects of PUVA therapy on human Langerhans cell (LC) immunophenotype and function. Epidermal sheets were obtained from exposed, and control shielded, forearm skin at the end of a course of PUVA therapy, in patients receiving treatment routinely for a variety of dermatoses. PUVA therapy decreased the overall number of HLA-DR+CDIa+ LCs in epidermal sheets, and in epidermal cell (EC) suspensions examined using a fluorescence activated cell sorter (FACS). PUVA therapy also reduced the overall EC allostimulatory capacity in the allogeneic epidermal cell-lymphocyte reaction (ELR), and the capacity of ECs to present tetanus toxoid to, and augment concanavalin A-mediated stimulation of, lymphocytes in the autologous ELR. Depressed allostimulation by ECs from PUVA-treated skin could not be restored by indomethacin (added to block prostaglandin synthesis). The reductions in LC numbers and EC allostimulatory capacity varied according to dose, and time since cessation, of PUVA therapy, and in individual patients were of comparable degree. By contrast, the allostimulatory capacity of residual LCs from PUVA-treated skin (purified using the FACS) did not differ from that of purified control LCs. PUVA-induced suppression of cutaneous immune responses, therefore, results at least in part from an overall impairment of EC antigen-presenting capacity. Residual HLA-DR+CDIa+ LCs in PUVA-treated skin which retain their alloantigen-presenting function may represent a subgroup of PUVA-resistant LCs; alternatively, these cells may be as yet unaffected because they have only recently migrated into the epidermis.
Collapse
Affiliation(s)
- J Ashworth
- Department of Medicine, Dermatology, Charing Cross and Westminster Medical School, London, U.K
| | | | | |
Collapse
|
8
|
Koulu L, Jansén CT. In vivo PUVA and UVB sensitivity of various human epidermal Langerhans cell markers (ATPase, HLA-DR and T6)--dose-response and time-sequence studies. Clin Exp Dermatol 1988; 13:173-6. [PMID: 2977575 DOI: 10.1111/j.1365-2230.1988.tb01963.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
9
|
Bieber T, Ring J, Braun-Falco O. Comparison of different methods for enumeration of Langerhans cells in vertical cryosections of human skin. Br J Dermatol 1988; 118:385-92. [PMID: 3355780 DOI: 10.1111/j.1365-2133.1988.tb02432.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have quantified Langerhans cells (LC) in cryosections of normal human skin and lesional skin from patients with atopic eczema and psoriasis vulgaris using six different methods. The results from the different methods varied considerably and were sometimes contradictory, for example when LC numbers in psoriatic skin were compared with those in normal skin. Thus, in addition to the staining technique used and the selection of the dendritic cell type to be counted, the enumeration method used can also influence the quantitation of LC in normal and pathological skin.
Collapse
Affiliation(s)
- T Bieber
- Department of Dermatology, Ludwig-Maximilian University, Munich, West Germany
| | | | | |
Collapse
|
10
|
Becker Y. Does radiation-induced abrogation of skin Langerhans cell functions lead to enhanced incidence of skin tumors in patients with genetic disorders of DNA repair? Cancer Invest 1987; 5:507-15. [PMID: 3322514 DOI: 10.3109/07357908709032907] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A hypothesis is presented which states that persons with the genetic disorders xeroderma pigmentosum and ataxia-telangiectasia, manifested by a deficiency of DNA repair, develop cutaneous tumors due to the elimination of reticuloendothelial system cells (Langerhans cells) in the skin, and the subsequent loss of control of epidermal cellular elements.
Collapse
Affiliation(s)
- Y Becker
- Department of Molecular Virology, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| |
Collapse
|
11
|
de Jong MC, Blanken R, Nanninga J, Van Voorst Vader PC, Poppema S. Defined in situ enumeration of T6 and HLA-DR expressing epidermal Langerhans cells: morphologic and methodologic aspects. J Invest Dermatol 1986; 87:698-702. [PMID: 2431069 DOI: 10.1111/1523-1747.ep12456649] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An essential prerequisite for the in situ enumeration of epidermal Langerhans cells (LCs) is the unequivocal identification of the desired cell type. We have examined over 250 cryostat sections of normal human skin to analyze morphologic and methodologic problems underlying the quantification of epidermal LCs, defined by anti-T6 (OKT6) and anti-HLA-DR (OKIal) immunoperoxidase staining. Our findings show that OKT6 reactivity of dendritic processes in cross-sectioned epidermis yields microscopic images which are not easy to analyze objectively. The morphology that we find leads us to categorize dendritic cells into 3 arbitrary types of T6+ LC profiles. In addition we describe criteria for the assessment of OKT6 staining patterns relating to the dendritic state of epidermal LCs. Preliminary quantitative data on this issue are discussed in relation to: epidermal thickness; the thickness of skin tissue sections; and the discrepancy between the number of T6+ and HLA-DR+ LCs. We hope that the principles outlined in this report may serve to overcome potential methodologic problems with quantitation of T6+ epidermal LCs in skin sections.
Collapse
|
12
|
|
13
|
MESH Headings
- Animals
- Antibody Formation/drug effects
- Antibody Formation/radiation effects
- Biomechanical Phenomena
- Dermatitis, Atopic/immunology
- Dermatitis, Contact/immunology
- Dermatitis, Contact/pathology
- Gamma Rays
- Graft vs Host Disease/immunology
- Graft vs Host Disease/pathology
- Humans
- Hypersensitivity, Delayed/immunology
- Hypersensitivity, Delayed/pathology
- Immunity, Cellular
- Interleukin-1/immunology
- Langerhans Cells/immunology
- Lichen Planus/immunology
- Lichen Planus/pathology
- Lupus Erythematosus, Discoid/immunology
- Lupus Erythematosus, Discoid/pathology
- Lupus Erythematosus, Systemic/immunology
- Lupus Erythematosus, Systemic/pathology
- Lymphocyte Culture Test, Mixed
- Lymphoma/immunology
- Skin/immunology
- Skin Diseases/immunology
- Skin Neoplasms/immunology
- Steroids/therapeutic use
- T-Lymphocytes/immunology
- Ultraviolet Rays
Collapse
|
14
|
Meissner K, Haftek M, Arlot M, Mauduit G, Thivolet J. Quantitative analysis of T6-positive Langerhans cells in human skin cancers. VIRCHOWS ARCHIV. A, PATHOLOGICAL ANATOMY AND HISTOPATHOLOGY 1986; 410:57-63. [PMID: 3097953 DOI: 10.1007/bf00710906] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Epidermal Langerhans cells (LC) are required for antigen-presentation and for stimulating antigen-specific T cell activation. Similar functions may be important in the immune response to malignant skin tumours. Monoclonal anti-T6 antibody was used to examine LC population in basal and squamous cell carcinomas. Positive control labeling was performed with monoclonal anti-HLA-DR antibody. The number of T6-positive LC per mm2 of section was significantly decreased (p less than 0.01) in the tumour group in comparison with a sex and age-matched control group. The number of sun-exposed and covered regions was taken into consideration in each respective group. Within the tumours, LC were found more frequently in the tumour periphery and in most differentiated tumour areas (horn pearls) than in the rest of the tumour mass. T6-positive LC were rarely found in the dermis. Moreover, LC exhibited morphological changes in specimens from tumours. Staining with anti-HLA-DR antibody revealed less numerous positive cells within tumour nests than labeling with OKT6. A relationship between T6-positive LC quantities and extent of HLA-DR-positive infiltrates around tumours could not be established. These results suggest that immunological surveillance of neoantigen-bearing tumour cells may be impaired in skin cancer. A reason for the reduced LC number may be an altered microenvironment in tumour tissue.
Collapse
|
15
|
Koulu L, Söderström KO, Jansén CT. Relation of antipsoriatic and Langerhans cell depleting effects of systemic psoralen photochemotherapy: a clinical, enzyme histochemical, and electron microscopic study. J Invest Dermatol 1984; 82:591-3. [PMID: 6202803 DOI: 10.1111/1523-1747.ep12261358] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The possible relation between the therapeutic action and Langerhans cell (LC) depleting effect of psoralen photochemotherapy (PUVA) was investigated in 9 psoriatic patients by parallel recording of the clinical status, using the psoriasis area and severity index ( PASI ), and the epidermal LC counts of uninvolved skin, using light (ATPase staining) and electron microscopy (EM). Both light and electron microscopically recorded LC numbers decreased significantly during the PUVA course of, on the average, 21 exposures and a mean cumulative UVA dose of 77 J/cm2. At the end of the treatment period, both the PASI score and the light microscopically recorded LC density had reduced to about one-tenth of original, i.e., from 7.5 +/- 5.7 to 0.8 +/- 0.8 points and from 787 +/- 70 to 60 +/- 48 cells/mm2, respectively. After cessation of the PUVA course, the PASI scores remained low during the 3-7 week follow-up period, while the LC counts returned to normal, and even exceeded the starting value by 12%. Although a possible functional impairment of LC in the post-PUVA period cannot be excluded, the data are interpreted as speaking against the hypothesis that the therapeutic action of PUVA would be mediated through its LC effects.
Collapse
|
16
|
de Jongh G, Bergers M, Boezeman JB, Verhagen AR, Mier PD. The lethal effect of longwave ultraviolet light and PUVA. An analysis based upon human mesenchymal cells in vitro. Photochem Photobiol 1984; 39:625-9. [PMID: 6739554 DOI: 10.1111/j.1751-1097.1984.tb03901.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
17
|
|
18
|
Verhagen AR, Bergers M, de Jongh G, Mier PD. Effects of PUVA on human blood monocytes in vitro. J Invest Dermatol 1983; 81:201-3. [PMID: 6886471 DOI: 10.1111/1523-1747.ep12517970] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Adherent monolayer cultures of monocytes at two stages of maturation were exposed to long-wave ultra-violet radiation in the presence and absence of 8-methoxypsoralen. A remarkably predictable, dose-related lethal effect was seen, suggesting that mesenchymal cells in general may be sensitive to photochemotherapy (PUVA). Both monocytes and macrophages were lethally damaged with doses that may reach the dermis in the course of normal clinical therapy.
Collapse
|
19
|
Haftek M, Faure M, Schmitt D, Thivolet J. Langerhans cells in skin from patients with psoriasis: quantitative and qualitative study of T6 and HLA-DR antigen-expressing cells and changes with aromatic retinoid administration. J Invest Dermatol 1983; 81:10-4. [PMID: 6345681 DOI: 10.1111/1523-1747.ep12537454] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Using a monoclonal antibody against human HLA-DR antigens and OKT6, we investigated by indirect immunofluorescence the distribution of Langerhans cells in normal human skin and involved and uninvolved skin from patients with psoriasis before, during, and after systemic aromatic retinoid administration. In parallel, enumeration of HLA-DR and of OKT6+ cells was also performed. In involved psoriatic epidermis the distribution of positive cells was disturbed; OKT6+ cells were reduced in number, as were HLA-DR+ cells which were seen in clusters. In control skin sections, a regular pattern of fluorescent dendritic epidermal cells was noted. In normal-appearing human skin, in nonlesional psoriatic skin, but not in diseased psoriatic skin, the number of OKT6+ cells per epidermal section surface unit was higher than that of HLA-DR expressing cells. Changes in the number and distribution of OKT6 and HLA-DR+ cells in psoriatic involved epidermis were corrected by oral retinoid treatment.
Collapse
|
20
|
Morhenn VB, Orenberg EK, Kaplan J, Pfendt E, Terrell C, Engleman EG. Inhibition of a Langerhans cell-mediated immune response by treatment modalities useful in psoriasis. J Invest Dermatol 1983; 81:23-7. [PMID: 6863976 DOI: 10.1111/1523-1747.ep12537586] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Neither the pathogenesis of psoriasis nor the mechanism whereby seemingly diverse therapies alter the disease is understood. In this study, several antipsoriatic agents were tested for their effects on the skin cell lymphocyte reaction (SLR), an immunologic assay in which HLA-DR antigens on Langerhans cells (LC) stimulate proliferation of allogeneic lymphocytes. Every agent tested (cortisol, methotrexate, hyperthermia, anthralin) inhibited the SLR at therapeutic dose levels. By contrast, a variety of antibiotics, an anti-inflammatory agent, and lithium carbonate and propranolol, two drugs known to be ineffective in psoriasis, failed to inhibit the SLR. Finally, we have shown that hyperthermia and anthralin treatments are toxic for LC whereas they have little or no effect on keratinocyte viability. These results suggest that antipsoriatic agents may act in psoriasis by alteration or killing of LC.
Collapse
|