Jo-David Fine

Distribution, ultrastructural localization, and ontogeny of the core protein of a heparan sulfate proteoglycan in human skin and other basement membranes.

A variety of heparan sulfate proteoglycans (HSPG) have been identified on cell surfaces and in basement membrane (BM). To more fully characterize HSPG in human skin BM, we used two monoclonal antibodies (MAb) directed against epitopes of the core protein of a high molecular weight HSPG isolated from murine EHS tumor. Indirect immunofluorescence revealed linear distribution of HSPG within all skin BM, and within BM of all other human organs investigated. In a study of the ontogeny of HSPG in human skin BM, HSPG was detectable as early as 54 gestational days, comparable with other ubiquitous BM components, such as laminin and type IV collagen. Immunoelectron microscopy on adult skin and neonatal foreskin showed staining primarily within the lamina densa (LD) and sub-lamina densa regions of the dermoepidermal junction (DEJ) and vascular BM. In neonatal foreskin, additional staining was noted of basilar cytoplasmic membranes of keratinocytes, endothelial cells, and pericytes. We conclude that the core protein of a high molecular weight HSPG is ubiquitous in human BM, appears in fetal skin on or before 54 days, and is present primarily in the regions of the LD and sub-LD.

The TORCH syndrome: A clinical review

Several infections contracted in utero result in similar physical and laboratory findings during the neonatal period; the TORCH syndrome encompasses such patients. Skin lesions are a frequent finding and the dermatologist may play an important role in the early evaluation of these infants. In this review we discuss etiology, epidemiology, clinical, laboratory, radiologic, and pathologic findings, differential diagnosis, therapy, course, and prognosis of each of these congenital infections.

Cicatricial pemphigoid, bullous pemphigoid, and epidermolysis bullosa acquisita antigens: differences in organ and species specificities and localization in chemically-separated human skin of three basement membrane antigens.

Bullous pemphigoid, cicatricial pemphigoid, and epidermolysis bullosa acquisita are three autoimmune diseases characterized by the presence of subepidermal blisters, in vivo-bound immunoreactants along the dermoepidermal junction, and variably detectable circulating anti-basement membrane autoantibodies. In order to better characterize the antigen(s) defined by cicatricial pemphigoid sera, indirect immunofluorescence was performed on a variety of human organs, skins of different animals, and on human skin chemically-split within the lamina lucida, comparing sera from cicatricial pemphigoid patients with sera from these two other blistering diseases. Sera from patients with each disease bound to the dermoepidermal junction of every laboratory animal species examined. In contrast, more mucosal tissues were bound by anti-basement membrane autoantibodies from patients with cicatricial pemphigoid and epidermolysis bullosa acquisita than from patients with bullous pemphigoid, consistent with the marked tendency for mucosal involvement in patients with the former two diseases. In addition, one of the cicatricial pemphigoid sera stained basal cell surfaces as well as dermoepidermal junction. Differences were also apparent in the staining of chemically-split human skin. The combined findings suggest that cicatricial pemphigoid and bullous pemphigoid antigens are distinct despite their common localization within the lamina lucida of the dermoepidermal junction. These data also suggest the presence of at least two different cicatricial pemphigoid antigens.

Patients with severe forms of inherited epidermolysis bullosa exhibit decreased lymphokine and monokine production.

Peripheral blood mononuclear cells (PBMC) from patients with severe forms of inherited epidermolysis bullosa (EB) are deficient in functions governing cellular immunity. Very low levels of interferon-γ (IFN-γ), interleukin-1 (IL-1), and interleukin-2 (IL-2) were producedin vitro by PBMC from patients with severe forms of EB (recessive dystrophic and dominant dystrophic) as compared to sex- and age-matched controls. Lymphokine production by PBMC from patients with junctional EB was somewhat greater than that from patients with dystrophic forms of EB but was significantly less than that from controls. The production of interferon-α was not found to be altered in the severe forms of EB. The PBMC from dystrophic types of EB were also deficient in production of tumor necrosis factors (TNF-α and TNF-β). The degree of the reduction in immune functions was directly related to the severity of skin involvement, with recessive dystrophic EB having the lowest level of cytokine production. This reduced production of monokines and lymphokines may be partially responsible for the progression of cutaneous infections to septicemia and for the metastasis of cutaneous squamous cell carcinomas in patients with severe forms of dystrophic EB.

Ultrastructural localization of the core protein of a basement membrane-specific chondroitin sulfate proteoglycan in adult rat skin

SummaryBasement membranes are complex extracellular matrices present at epithelial/mesenchymal interfaces of tissues. The dermal-epidermal junction has been shown to contain numerous components, some of the most well known being laminin, types IV and VII collagens, heparan sulfate proteoglycan, fibronectin, and entactin/nidogen. In this paper we show, using core protein-specific antibodies, the presence of a newly described basement membrane-specific chondroitin sulfate proteoglycan at the epithelial/ mesenchymal interface of adult rat skin. Ultrastructurally, this antigen was proven to reside primarily within the basal lamina, apparently concentrated in the lamina densa. In addition, some of the proteoglycan was also present beneath the lamina densa, associated with the reticular lamina collagen fibrils.

Entactin: ultrastructural localization of an ubiquitous basement membrane glycoprotein in mouse skin

SummaryEntactin is a recently described sulfated glycoprotein component of mouse endodermal cell-derived extracellular matrix and is present in a number of basement membranes. It has been ultrastructurally localized to both lamina densa and adjacent epithelial cell membranes in rodent kidney. In the present study, we have sought to determine the localization of entactin in mouse skin. Indirect immunofluorescence and immunoelectron microscopy (the latter via immunoperoxidase technique) were performed on both intact and NaCl-separated mouse skin, using a well-characterized IgG class entactin-specific ratxmouse monoclonal antibody. At the light microscopic level, entactin was present in all skin basement membranes. On NaCl-split skin, staining was noted solely on the dermal portion. At the electron microscopic level, in intact skin, entactin was primarily localized to the lamina densa and adjacent upper papillary dermis. However, smaller amounts of immunoreaction products were also detectable within the lamina lucida and in close apposition to overlying hemidesmosomes. In partially separated skin, immunoreactants were similarly noted above the level of the lamina densa. However, in completely separated areas, hemidesmosomal or cell membrane staining was no longer visible. We conclude that entactin is an ubiquitous component of mouse skin basement membranes. Similar to previous findings in rodent kidney, entactin is present in multiple regions of skin basement membrane, although its primary localization remains within and directly beneath the lamina densa.

Autoantibodies to extracellular collagen matrix components in epidermolysis bullosa and other bullous diseases

SummaryIn order to determine whether autoantibodies are present in sera from normal individuals and/or patients with selected bullous disorders, a highly sensitive solid-phase radioimmune assay was established using purified native collagen types I–VI, laminin, and fibronectin as substrates. Sixty-four sera were utilized, representing 12 normal controls as well as 4 patients with extensive thermal burns, 18 with autoimmune bullous diseases (11 bullous pemphigoid, 5 pemphigus vulgaris, and 2 epidermolysis bullosa acquisita), and 30 with non-autoimmune mechanobullous diseases [epidermolysis bullosa (EB): 20 simplex, 4 junctional, and 6 dystrophic]. In general, autoantibodies to types I, II, and VI collagen and fibronectin were undetectable in any of the patient or control groups. In contrast, autoantibodies to types III and V collagen were noted in 87.5% (28/32) and 90.6% (29/32) of EB sera, respectively, while being only rarely noted in sera from other patient groups. Similarly, autoantibodies to type IV collagen and laminin were detected in 50% (16/32) and 40.6% (13/32) of EB sera, especially from patients with simplex and dystrophic forms of the disease. These data suggest that selected interstitial and basement membrane-associated collagens and laminin may become autoimmunogenic in all three forms of inherited EB in contrast to their relative lack of immunogenicity in at least some of the other intraepidermal and subepidermal blistering disorders. The role, if any, of these autoantibodies in the induction or perpetuation of blistering in EB awaits further studies.

The use of monoclonal antibodies in skin basement membrane research.

Recent experiments have indicated that it is possible to uncover new antigens within both the basement membrane zone and the epidermis of normal adult human skin by producing murine anti-human monoclonal antibodies following immunization with human skin preparations. Already one such monoclonal antibody has defined a biochemical defect that may be important in the pathogenesis of one of the more severe blistering skin diseases, dystrophic epidermolysis bullosa. It is likely that further attempts at hybridoma production using basement membrane extracts of skin will lead not only to the identification of other as yet unknown components of the human dermo-epidermal junction, but may also shed insight into the biochemical basis of one or more cutaneous diseases involving that region of the skin.

Review: Monoclonal Antibodies and the Skin Biopsy: Current and Potential Clinical Applications

Monoclonal antibodies are becoming increasingly useful in the clinical diagnosis and/or treatment of a number of unrelated diseases. Discussion will be directed to those monoclonal antibodies recognizing antigens within the skin which appear to have either proven or potential application in the diagnostic evaluation of the skin biopsy.

HLA and epidermolysis bullosa: evidence for independent assortment of Weber-Cockayne subtype of epidermolysis bullosa and HLA complex.

The purpose of this study was to examine the genetic linkage (but not the association) between HLA complex and Weber-Cockayne Subtype of epidermolysis bullosa (EBS-WC). We HLA typed 44 members of three multi-generation families in which 24 members have the clinical evidence of EBS-WC. The patterns of inheritance of various HLA haplotypes and the disease were mathematically analyzed to estimate frequency of recombination (i.e. genetic distance) between HLA complex and the disease by calculating Lod Scores for each family separately as well as all for three families combined. Our results show that only one family had a positive Lod Score. The Lod Scores for the remaining two families as well as the combined Lod Score for all three families were negative. These data suggest that odds are against the genetic linkage between HLA complex and Weber-Cockayne Subtype of epidermolysis bullosa and in favor of independent assortment of the disease and HLA complex.