The epidermal Merkel cell is an epithelial cell.
TROMA 1, a monoclonal antibody against cytokeratin, was found to react with epidermal Merkel cells. This demonstrates the epithelial origin of MC.
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Publications and source records attributed to L Didierjean.
TROMA 1, a monoclonal antibody against cytokeratin, was found to react with epidermal Merkel cells. This demonstrates the epithelial origin of MC.
Peritumoral lacunas of basal cell carcinoma (BCC) were for a long time misinterpreted as fixation artifacts. However, recent studies showed that they might be considered as a dynamic process related to degenerescence for the palisade cells. We studied three antigens of the epidermal basement membrane zone--type IV collagen, laminin, and bullous pemphigoid antigen--by indirect immunofluorescence in six cases of basal cell carcinoma. We could observe that type IV collagen as well as laminin were expressed as a linear continuous staining pattern surrounding each of the BCC buds. When there was a peritumoral lacuna, only the stroma side of the lacuna was stained. Bullous pemphigoid antigen showed either a linear continuous or discontinuous staining pattern along the basement membrane zone of the carcinomatous buds. At the site of a peritumoral lacuna bullous pemphigoid antigen abruptly disappeared. The loss of bullous pemphigoid antigen might be related to the lacuna formation.
The distribution of skin calcium-binding protein in squamous cell metaplasia of human endocervix, in normal human skin, and in ovarian cancer was determined by the immunofluorescence technique. A rabbit antiserum specific to rat SCaBP was characterized by Ouchterlony immunodiffusion and by immunoprecipitation of 125I-labeled SCaBP. The specificity of antibody labeling was demonstrated by using preimmune rabbit serum and SCaBP antiserum competitively absorbed with purified SCaBP. In normal human skin SCaBP was found exclusively in the basal layer cell cytoplasm. This protein was not detected in normal columnar epithelium of endocervix. Epithelial tissues in the zone of transition between the cylindrical epithelium of the endocervical mucosa and the stratified squamous epithelium of the exocervix were obtained from 14 patients with a wide variety of squamous cell metaplasia. In the early stage of metaplasia SCaBP was detected exclusively in the cytoplasm of reserve undifferentiated cells. In the terminal stage of metaplasia the SCaBP was present only in the basal cell layer. SCaBP was found in several layers of dysplastic tissue, and this distribution appeared to be related to the loss of normal maturation of the epithelium. SCaBP was also present in squamous cell carcinoma of endocervix especially in the least differentiated regions of the tumor. No SCaBP was detected in any ovarian cancer cells. These findings are potentially useful as a means of early detection of squamous metaplasia and of distinguishing premalignant anaplastic lesions from those that are benign and nonproliferative. In addition, the presence of SCaBP in tumors derived from metaplastic epithelia and its absence in the ovarian cancer indicate that immunohistochemical search for this protein might be of value in tumors in which an epidermoid origin is a possibility.
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A human monoclonal, mu, kappa, cold agglutinin antibody of the rare specificity Pr h (serum and proper eluates) was used in immunofluorescence and immunoperoxidase techniques and in immunoelectron microscopy on rabbit lip specimens. Pr h antibody strongly reacted with scattered cells in epidermis, which were demonstrated to be Merkel cells by electron microscopy; no nerve fibers were stained. In immunoelectron microscopy (IEM), a strong reaction was seen within the cytoplasm and around the granules. This is the first IEM staining of Merkel cells (MC) so far reported; it demonstrates the expression of a carbohydrate differentiation antigen in MC. The availability of a potent monoclonal antibody reacting with MC but not with neighboring epidermal cells in rabbit lip offers a new tool for the study of several aspects of MC biology, including antigenic properties and kinetics.
Skin calcium-binding protein (SCaBP) is a low molecular weight protein of unknown function which is localized in the cytoplasm of epidermal basal cells. We have examined SCaBP immunoreactivity in basal cell carcinoma (BCC) since BCC cells retain some of the characteristics of basal cells, including the capacity for proliferation and migration from the dermo-epidermal junction. We also examined immunoreactivity to basement membrane zone (BMZ) antigens (type IV collagen, laminin and bullous pemphigoid antigen) in BCC. We found that all BCC cells showed SCaBP immunoreactivity regardless of the histological type or position of the cells. BMZ antigens were expressed around tumourous buds, although bullous pemphigoid antigen may also present a cytoplasmic immunoreactivity. Our results suggest that SCaBP immunoreactivity is independent of the basal position of the cell, but may be related to the proliferative capacity and the undifferentiated state of the cell.
An unusual example of two different types of epidermal differentiation occurs side by side in adult mouse tail. The neonate shows only orthokeratotic differentiation, but develops parakeratotic scales in precise patterns over the first two weeks of life, retaining orthokeratotic differentiation at the necks of hair follicles. Certain human IgG antibodies from patients receiving bone marrow transplants bind only to cytoplasmic components of orthokeratotic epithelium. As markers of orthokeratotic differentiation in indirect immunofluorescent studies, these antibodies allowed the timing and location of the change in epidermal differentiation. A specific loss of 'orthokertotic' antigens in the natural switch from orthokeratosis to parakeratosis was demonstrated. The sequence of the orthokeratotic antigens disappearance suggested that the switch to parakeratotic differentiation occurred at a supra-basal level.
The distribution of epidermal calcium-binding protein was examined in rat tissues using immunodiffusion and immunofluorescence techniques to investigate its possible physiological role. Epidermal calcium-binding protein was demonstrated in the basal proliferative cell layer of all Malpighian epithelia and related tissues (epidermis, sebaceous glands, cornea, esophagus, and vagina) as well as in ependyma of brain and in the epithelia of the lens. No immunoreactivity for epidermal calcium-binding protein was found in other tissues including dermis, muscle, cartilage, blood vessels, nerve tissue, liver, endocrine glands, urogenital tract, and intestinal and respiratory epithelium. The presence of a protein immunologically indistinguishable from epidermal calcium-binding protein in proliferative cells suggests that it may be involved in the control of calcium-dependent processes perhaps related to mechanical damage and continued proliferation.
A patient with subcorneal pustular dermatosis was found to have a circulating monoclonal IgA kappa immunoglobulin. Direct immunofluorescence studies revealed IgA kappa deposits in the subcorneal zone of the epidermis. Circulating IgA kappa reacting with the subcorneal zone of normal human epidermis was demonstrated by indirect immunofluoresence. It is speculated that IgA deposition might be implicated in the pathogenesis of subcorneal pustular dermatosis.
In vivo, keratinocyte cytoplasmic antigens linked to keratinization have been traced with 2 distinct types of antibodies found in human sera. One type of antibody is specific for the basal cell compartment of keratinocytes while the other one is specific for upper keratinocytes. Using these markers, we followed a well-defined, in vitro human keratinocyte culture system that produces a keratinizing epithelial cell outgrowth juxtaposed to dead dermal substrate for the in vitro expression of keratinocyte cytoplasmic antigens. These antigens were found to be expressed in vitro independently from dermal influences. Their chronology, localization and topography in culture matched the in vivo situation.
Using a serum raised in rabbits against a calcium binding protein extracted from rat skin, the cutaneous localization of this protein was studied by indirect immunofluorescence. The skin calcium binding immunoreactivity was found in the epidermis but not in the dermis; it was localized in the cytoplasm of the basal cell layer of both skin and malpighian mucosa. There was not species specificity; this allowed the tracing of the protein in human epidermis as well where it was also expressed only in the basal cells. This is the first demonstration of the unique localization of a specific protein within the cytoplasm of the basal cell layer of the epidermis. This localization may help to elucidate the physiological role of this protein.
Pr antigens (Pr ags), glycoconjugates of the red blood cell surface, have been traced in stratified squamous epithelia (SSE) with homogeneous and serologically monospecific monoclonal antibodies. Pr ags were expressed either at the plasma membrane level or within the cytoplasm of the keratinocytes (associated with the cytoskeleton). Pr ags were expressed in the basal cells. The distribution within this germinative compartment was in accordance with the concept of a cellular heterogenicity in the basal cell layer. A neuraminidase resistant Pr ag was retained in the maturing compartment of epithelia undergoing parakeratotic differentiation (including psoriatic epidermis). Monoclonal cold agglutinins may serve as new markers for the study of glycoconjugates in keratinocytes during normal and pathological differentiation.
An ultrastructural study was performed on skin biopsies of eight patients with lichenoid eruption of chronic graft-versus-host disease (GVHD). The lichenoid eruption is similar to idiopathic lichen planus with the injury of the basal cells, the distribution of the numerous colloid bodies, and the presence of regenerative cells. Lymphocytes satellites of injured keratinocytes were observed in those lichenoid eruptions, as well as in the acute phase of GVHD. The numerous mast cells in the lichenoid eruption of GVHD may be related to the connective tissue changes of the patients progressing to a late sclerotic phase of chronic GVHD.
Cultured living human epidermal cells migrating on the surface of irradiated non-viable pig dermis, were found to produce bullous pemphigoid antigen at the epidermis-pig dermal junction between days 10 and 50 in culture. In certain series, the antigen was detected within the cytoplasm of the basal cells as well. These findings suggest that the bullous pemphigoid antigen is synthesized by epidermal cells.
By screening 1500 sera obtained from patients undergoing a bone marrow graft, five sera have been selected which contained antibodies to the basal cell layer (B.C.L.) of the outer root sheath (O.R.S.) of hair follicles. It was demonstrated that these sera reacted with the B.C.L. of the O.R.S. but not with the B.C.L. of the adjacent epidermis. The change in antigenic properties was situated at the orifice of the sebaceous gland canal; thus basal cells below this orifice express an antigen distinct from those expressed by the epidermal basal cells. This is a novel example of tissue specific differentiation antigens that are linked to the type of keratinocyte differentiation.
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Using direct immunofluorescence and in vitro complement fixation we have found antibodies with affinity to the cytoplasm of basal cells (B cyt Ab) in five out of sixteen well documented cases of herpes gestationis (HG). In one case B cyt Ab were found in the serum from a pregnancy whereas "HG factor" was found in a serum from a previous pregnancy. B cyt Ab were also detected in cord blood. These findings may be relevant to the fact that as suggested by histological ultrastructural studies, the basal cell may be the initial target in HG.