Migration of Langerhans cells in an in vitro organ culture system: IL-6 and TNF-alpha are partially responsible for migration into the epidermis.

Although it is well established that epidermal Langerhans cells (LC) originate from bone marrow, little is known about the mechanism of this migration into the epidermis from bone marrow. In order to clarify the mechanism of this migration, we constructed an in vitro model. LC were depleted by daily topical application of clobetazole propionate (CP) solution onto the ear of Balb/c mice. Seven days later, ear skin was cut off, separated and co-cultured dermal-side-up with syngeneic (Balb/c), semisyngeneic ((C3H x Balb/c)F1), or allogeneic (C3H) epidermal cells (EC) for 3 days. We found (1) that a marked migration of donor LC into the recipient epidermis was observed in the LC-depleted skin, (2) that only syngeneic LC actively migrated into the recipient epidermis; however, the migration of semisyngeneic and allogeneic LC was detected at very low levels, (3) that the migratory capacity of donor LC was directly proved by a biolabeling technique using donor EC labeled with PKH-26, and (4) that anti-IL-6 and anti-TNF-alpha antibodies inhibited the migration of donor LC into the recipient epidermis. These data demonstrate that the resident LC have the potential to traffic through the dermis into the epidermis in a highly syngeneic-specific fashion, and that IL-6 and TNF-alpha are partially responsible for promoting this migration.

Increased numbers of CD68 antigen positive dendritic epidermal cells and upregulation of CLA (cutaneous lymphocyte-associated antigen) expression on these cells in various skin diseases.

CD68 is a myelomonocytic marker identified in human dermal macrophages. Although the existence of CD68 + dendritic epidermal cells has been reported, their characteristics have not been well elucidated. Cutaneous lymphocyte-associated antigen (CLA) is a homing receptor of cutaneous inflammatory T cells. Our recent report suggested that CLA was a homing molecule of CD1a+ Langerhans cells (LC) in the skin. In the present study we tested whether CD68 and CLA+ dendritic epidermal cells were present in skin specimens of normal skin and diseased skin such as lichen planus (LP), psoriasis vulgaris (PS), discoid lupus erythematosus (DLE), basal cell epithelioma (BCE), squamous cell carcinoma (SCC), irritated seborrheic keratosis (iSK), and Bowen's disease (BD). CD68+ dendritic epidermal cells were identified in normal skin and consisted of half the population of CD1a+ LC. These data indicate that CD68+ dendritic epidermal cells constitute a subpopulation of CD1a+ LC. CLA was expressed on a small percentage of CD68+ dendritic epidermal cells in normal skin. A remarkably increased number of CD68+ dendritic epidermal cells and upregulation of CLA on CD68+ dendritic epidermal cells were observed in diseased skin. The percentage of CLA+ cells among all CD68+ dendritic epidermal cells was less than that of CLA+ cells among all CD1a+ LC in diseased skin. The percentage of CLA+ cells among all CD68+ dendritic dermal cells was much less than that of CLA+ cells among all CD1a+ dendritic dermal cells. In normal skin, the epidermis showed minimal expression of monocyte chemoattractant protein (MCP)-1 and TGF-beta2, and no expression of TGF-beta1. In diseased skin, the epidermis showed elevated, but still moderate immunoreactivity for MCP-1. Slightly enhanced immunoreactivity for TGF-beta2, but not for TGF-beta1, was observed in the epidermis of diseased skin. Increased epidermal MCP-1 immunohistochemical staining was associated with the increased number of CD68 dendritic epidermal cells. These data suggest the possibility that MCP-1 secretion from the epidermis can affect the migration of CD68; Cutaneous lymphocyte-associated antigen; Monocyte chemoattractant protein-1; TAF-beta.

Pseudoxanthomatous lesions with membranocystic changes of collagen fibers in an SLE patient receiving long-term steroid treatment.

We report a 50-year-old Japanese woman with a 3-year history of systemic lupus erythematosus treated with prednisolone, who had diffuse plane yellowish macules mainly on the upper arm. The lesion was clinically diagnosed as diffuse plane xanthomatosis. However, the histopathological findings from both the yellowish macules and the normal-appearing skin revealed a heavy degeneration of collagen fibers with membranocystic structure throughout the entire dermis and the collagenous septum of the subcutaneous tissue. Ultrastructurally, the membranocystic structure was not due to the degenerative change of fat cells as seen in membranous lipodystrophy but was caused by the degenerative change of collagen fibers with fat deposit.

Expression of cutaneous lymphocyte-associated antigen defined by monoclonal antibody HECA-452 on human Langerhans cells.

Cutaneous lymphocyte-associated antigen (CLA) defined by monoclonal antibody (MoAb) HECA-452 has been shown to be preferentially expressed on cutaneous T cells. The CLA expression has been regarded as a homing molecule of T cells to the skin in various inflammatory cutaneous disorders. In this paper we investigated the significance of CLA expression on Langerhans cells (LC) and found that, in normal skin, some epidermal LC express CLA, and that most dermal CD1a positive cells express CLA. When normal skin was organ cultured, the percentage of CLA positive cells in LC and dermal CD1a positive cells decreased appreciably. In diseased skin, epidermal LC increased in number and most LC expressed CLA. Thus, this study suggests that the CLA expression on LC may play as a homing molecule of LC to the skin.

Histopathological evaluation of halo phenomenon in Spitz nevus.

We saw a patient with a Spitz nevus surrounded by a halo of depigmentation. Although the halo phenomenon is often seen in pigmented melanocytic nevus, an association of this phenomenon with Spitz nevus seems to be rare. Moreover, histopathological findings showed focal lymphoid infiltration in the epidermis of the depigmented halo and marked infiltration in dermal epithelioid nevus cell nests. Thus, it is suggested that identical mechanisms are involved in the destruction of epidermal melanocytes and dermal nevus cells in halo Spitz nevus.

CD44 expression in normal human skin and skin tumors.

CD44 is thought to be a principal cell surface receptor for hyaluronic acid. Although the distribution of hyalulonic acid has been studied, little is known about the distribution of the CD44 molecule in the human skin and skin tumors. This study was undertaken to investigate the distribution of the CD44 molecule in normal human skin as well as in benign and malignant skin tumors. In normal skin, CD44 was expressed on 1) keratinocyte cell surfaces throughout the epidermis except for the granular and horny layers, 2) hair follicular cells, 3) eccrine sweat gland cells, and 4) cell surfaces of dendritic cells in the dermis. In skin tumors, although CD44 was expressed on the tumor cell surface of seborreic keratosis, Bowen's disease, and squamous cell carcinoma as in normal skin, we could not detect any CD44 expression on the cell surface of the tumor cells of basal cell carcinoma. However, CD44 positive dendritic cells were observed in the tumor islands of basal cell carcinoma. Phenotypic analysis suggested that these CD44 positive cells were melanocytes.

Primary cutaneous CD30(Ki-1)-positive lymphoma of non-T, non-B origin.

A 71-year-old Japanese woman had two dome-shaped tumors on her right buttock with several surrounding papules. Histological examination revealed that large anaplastic cells and atypical lymphoid cells densely infiltrated the entire dermis. On immunohistochemical examination, Ki-1, HLA-DR, CD25 (IL-2 receptor alpha), CD122 (IL-2 receptor beta), CD4, CD11c and CD68 were all positive in the tumor cells, whereas CD1a, CD3, CD5, CD8 and CD19 were negative. Neither rearrangement of the T-cell receptor beta, T-cell receptor gamma nor the immunoglobulin heavy-chain was seen. Ultrastructurally, most of the tumor cells contained thick bundles of intermediate filaments in the perinuclear cytoplasm. Thus, this patient was diagnosed as having Ki-1-positive lymphoma of non-T, non-B origin. No recurrence or metastasis of the tumor has been observed in the last 2 years, although surgical resection was required 3 times before control was achieved.

Migration of Thy-1+ dendritic epidermal cells (Thy-1+DEC): Ly48 and TNF-alpha are responsible for the migration of Thy-1+DEC to the epidermis.

Thy-1+ dendritic epidermal cells (Thy-1+DEC) are mainly T cells that express T-cell receptor gamma and delta chains with limited diversity of gamma delta, mainly gamma 3 delta 1; such gamma 3 delta 1 TCR-bearing Thy-1+DEC originate from day 16 fetal thymic cells. To understand the migratory capability of Thy-1+DEC, we developed an in vitro model, using skin organ culture. First, emigration of Thy-1+DEC from the epidermis was examined. Ear skin from C3H/He mice was separated into two parts and incubated for 3 d with dermal side down. Thy-1+DEC emigrated from the epidermis into the dermis and then migrated out of the skin into the culture medium. Next, immigration of Thy-1+DEC into the epidermis was examined. Thy-1+DEC were depleted in vivo by daily application of clobetazole propionate solution topically onto the ears of C3H/He mice. Seven days later, ear skin was harvested, separated, and cultured with the dermal side up with syngeneic epidermal cell suspensions with a migration chamber for 3 d. It was found that 1) Thy-1+DEC immigrated into the Thy-1+DEC depleted epidermis as well as into untreated epidermis, and 2) the migratory capability of Thy-1+DEC was directly proved by a biolabeling technique with PKH-26. Blocking studies with various antibodies revealed that leukosialin (S11 monoclonal antibodies) and TNF alpha were important for Thy-1+DEC migration. Thus, Thy-1+DEC retain the potential for migration in vitro, and leukosialin and TNF alpha are partially responsible for the migration of Thy-1+DEC into the epidermis.

Bilateral periorbital eccrine hidrocystoma.

We saw four patients showing identical features as cystic lesions on the bilateral external canthi. Histological examination showed cystic cavities in the dermis. Histological and enzyme histochemical findings suggest that these cystic tumors are of eccrine origin. Thus we diagnosed these cystic tumors as eccrine hidrocystoma with characteristic clinical feature. The recognition of this feature would help to correctly diagnose these eccrine hidrocystoma.

Altered expression of NU-T2-BMZ antigen and type VII collagen in basal cell epithelioma.

The cutaneous basement membrane zone (BMZ) is composed of a large number of molecular components. We have recently reported that one of the CD1b monoclonal antibodies (MoAb), NU-T2, reacts to the BMZ of the normal human skin, esophagus and stomach. In order to further elucidate the biological properties of the NU-T2-BMZ antigen, we investigated the expression of NU-T2-BMZ antigen and type VII collagen (well identified component of anchoring fibrils) in various skin tumors such as basal cell epithelioma (BCE), squamous cell carcinoma, Bowen's disease, actinic keratosis and seborrheic keratosis. NU-T2 MoAb failed to react to the BMZ in all BCE. Anti-type VII collagen MoAb showed reduced staining of the BMZ in some nests of BCE. Both antigens, however, were preserved in the BMZ of other skin tumors as in the normal adjacent skin. Furthermore, anti-type VII collagen MoAb demonstrated the clear intratumoral staining in all BCE examined. The abnormal expression of NU-T2-BMZ antigen and type VII collagen may partly explain the space formation between the BCE nests and the surrounding stroma frequently observed in histology.