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K Rappersberger

Publications and source records attributed to K Rappersberger.

At least 37 records · Page 2Linked to original sources
PubMed1998

Immunoelectron microscopic characterization of human dermal lymphatic microvascular endothelial cells. Differential expression of CD31, CD34, and type IV collagen with lymphatic endothelial cells vs blood capillary endothelial cells in normal human skin, lymphangioma, and hemangioma in situ.

We performed a comparative investigation of the immunomorphological characteristics of lymphatic and blood microvascular endothelial cells in normal human skin, cutaneous lymphangiomas, and hemangiomas, employing a pre-embedding immunogold electron microscopic technique. We stained for cell membrane proteins that are commonly used for light microscopic characterization of blood endothelial cells. With blood microvascular endothelial cells, we observed uniform labeling of the luminal cell membranes with monoclonal antibodies (MAbs) JC70 (CD31), EN-4 (CD31), BMA120, PAL-E, and QBEND-10 (CD34), and strong staining of the vascular basal lamina for Type IV collagen under normal and pathological conditions. In contrast, lymphatic microvascular endothelial cells in normal human skin and in lymphangiomas displayed, in addition to a luminal labeling, pronounced expression of CD31 and CD34 along the abluminal cell membranes. Moreover, CD31 was preferentially detected within intercellular junctions. The expression of CD34 was mostly confined to abluminal endothelial microprocesses and was upregulated in lymphangiomas and hemangiomas. Type IV collagen partially formed the luminal lining of initial lymphatics and occasionally formed bridges over interendothelial gaps. Our findings suggest a function of transmigration protein CD31 in recruitment of dendritic cells into the lymphatic vasculature. CD34 labeling may indicate early endothelial cell sprouting. The distribution of Type IV collagen also supports its role as a signal for migration and tube formation for lymphatic endothelial cells.

Antigens, CD34↗
PubMed1997

Prominent myofibroblastic differentiation. A pitfall in the diagnosis of dermatofibroma.

Myofibroblastic differentiation occurs in 10-20% of all dermatofibromas, affecting < 25% of cells. We report on a series of 36 dermatofibromas collected from > 1,500 fibrohistiocytic lesions (2%), with more prominent (> 25%) myofibroblastic differentiation characterized by markedly slender and elongated spindle cells positive for smooth muscle markers. While most of the lesions did not otherwise differ from ordinary dermatofibromas, three cases (0.2%) from the neck-shoulder region of male adults showed extensive myofibroblastic features (> 90%). Clinically, these three lesions measured approximately 1 cm and had a firm consistency, with the differential diagnosis of some fibrohistiocytic tissue response. Histologically, densely packed cells and prominent, partially nodular, stromal sclerosis with focal palisading of nuclei indicate some overlap with other rare variants of fibrohistiocytic tissue response, such as cellular benign and palisading cutaneous fibrous histiocytoma. Yet, these features together with focal whorled nesting of more epithelioid cells (one case) also caused considerable diagnostic problems to exclude other myofibroblastic as well as (malignant) spindle cell lesions such as (palisaded) myofibroblastoma, dermatofibrosarcoma protuberans, and neurothekeoma. Immunohistochemically, all lesions were markedly (> 90%) labeled for smooth muscle markers (HHF35, anti-SMA) and with NK1C3 (CD57), while a broad panel for other spindle cell tumors, such as pan-keratin, S100 protein, EMA, desmin, CD34, CD31, and KiM1p, were negative. Electron microscopy of two cases revealed prominent endoplasmic reticulum and Golgi complex, numerous intermediate filaments, attachment plaques, and focal basal lamina formation. No recurrence was seen during a follow-up of 9 (two cases) and two years, respectively.

Actin Cytoskeleton↗
PubMed1996

TGF-beta 1 promotes in vitro development of dendritic cells from CD34+ hemopoietic progenitors.

Several studies have demonstrated that dendritic cells (DC) can be generated in vitro from CD34+ hemopoietic progenitor cells. The growth requirements for these cells are poorly characterized, however. In particular, undefined serum/plasma components seem to significantly contribute to in vitro DC development. We report here that the cytokine combination granulocyte-macrophage CSF (GM-CSF) plus TNF-alpha and stem cell factor (SCF) commonly used for the in vitro generation of DC in serum/plasma-supplemented medium is, in the absence of serum supplementation, very inefficient in inducing DC development. We further demonstrate that supplementation with TGF-beta 1 is required for substantial DC development to occur in the absence of serum. Culture of CD34+ cells under serum-free conditions with TGF-beta 1 plus GM-CSF, TNF-alpha, and SCF strongly induces DC differentiation. This culture condition is even more efficient than culturing CD34+ cells with GM-CSF plus TNF-alpha and SCF in the presence of cord blood plasma. The proportions and total yields of cells with typical DC morphology and CD1a molecule expression are higher. The allostimulatory capacity of DC from TGF-beta 1-supplemented, cultures exceeds allostimulation by cells grown in plasma-containing medium. Substantial numbers (21 +/- 7%) of cells grown in TGF-beta 1-supplemented, but not plasma-supplemented, cultures express the Birbeck granule marker molecule Lag and display numerous Birbeck granules. Cells with distinct monocytic features are less frequently observed in TGF-beta 1-supplemented serum-free cultures. The addition of neutralizing anti-TGF-beta 1 Ab abrogates the observed TGF-beta 1 effects.

Animals↗
PubMed1996

Generation of human dendritic cells/Langerhans cells from circulating CD34+ hematopoietic progenitor cells.

Human Langerhans cells (LC) are CD1a+ dendritic cells (DC) that function as potent antigen-presenting cells for primary and secondary immune responses. Limitations in DC/LC numbers, imposed by difficult and tedious isolation procedures, have so far precluded their use as immunogens in the generation and/or augmentation of host responses against various pathogens. Therefore, we have developed a procedure for the generation of human DC/LC from CD34+ hematopoietic progenitor cells (HPC) isolated (mean: 0.7 x 10(6)/ buffy coat and 2.6 x 10(6)/leukapheresis product) and purified ( > 95%) from the peripheral blood of healthy adults. In vitro stimulation of these cells with granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor (TNF)-alpha led to their vigorous proliferation and differentiation resulting in the emergence of CD45+/CD68+/CD3-/CD19-/CD56- leukocytes some of which (mean: 12%) express CD1a and exhibit anti-CD4 and anti-major histocompatibility complex (MHC) class II reactivity. These CD1a- leukocytes include (1) LC as evidenced by the presence of Birbeck granules (BG), (2) CD14+ monocytes, and (3) Birbeck granule-negative cells with a dendritic morphology. Addition of interleukin (IL)-4 to the cytokine cocktail interfered with the development of monocytes and led to a reduction in the overall yield but, on the other hand, resulted in an increased percentage of CD1a+ cells (mean: 24%) among all cells generated. In vitro generated CD1a+, but not CD1a- HPC-derived cells are potent stimulators of the primary mixed leukocyte reaction and, as such, promising candidates for vaccination purposes.

Adult↗
PubMed1996

[Malignant blue nevus with metastasis to lymph nodes and brain].

We report a patient who developed malignant transformation of a cellular blue nevus. At the age of 19 years the congenital, pigmented tumor on the left buttock was histopathologically diagnosed as cellular blue nevus. Thirty years later the tumor dramatically increased in size, involving the entire left buttock within several months. Multiple biopsies revealed the presence of a cellular blue nevus within the papillary dermis and an invasive, pleomorphic pigmented sarcoma in the depth of the tissue spreading into subcutis and skeletal muscle. Both benign and malignant cells were S100+, vimentin+ and HMB-45+, but only the malignant tumor cells stained positive for the proliferating cell nuclear antigen. General examination disclosed multiple metastases in the paraaortal lymph nodes and the retroperitoneum as well as a single brain metastasis. Despite palliative therapy with ionizing radiation and chemotherapy, the patient developed generalized metastases and died within weeks. This case clearly confirms that cellular blue nevi have the potential for malignant transformation and that the malignant variant may behave aggressively just as a malignant melanoma.

Biomarkers, Tumor↗
PubMed1996

Autoantibodies against desmoplakin I and II define a subset of patients with erythema multiforme major.

In a previous report, we described autoantibodies against the desmosomal plaque proteins desmoplakin I and II (dp I and II) in patients with erythema multiforme (EM) major. In the present study we investigated ten EM major and eight EM minor patients for circulating autoantibodies and performed clinical and immunomorphological evaluations. Seven out of ten EM major patients revealed anti-dp I and II autoantibodies. Antigens were biochemically characterized by Western blotting and immunoprecipitation of epithelial-cell-derived protein extracts. These autoantibodies bind in vivo to lesional skin/mucosa in a pemphigus-type dotted pattern along the cytoplasmic membranes of keratinocytes. Ultrastructural immunolocalization studies confine in vivo bound autoantibodies to the cytoplasmic desmosomal plaque. Autoantibody binding studies with the sera of such patients demonstrate that the target antigens are not restricted to squamous epithelia but are also expressed in simple and transitional epithelia, on hepatocytes, and on cells of mesenchymal origin, e.g., myocardial cells. Comparing the clinicopathological features of ten patients with EM major, we could not define any discriminating clinical symptoms among patients with or without autoantibodies. Histopathological examination, however, revealed that only patients with EM major and autoantibodies against dp I and II show suprabasal acantholysis in lesional skin and mucous membranes, suggesting a potential role of the humoral immune response in the pathogenesis of this disease. These findings suggest that these autoantibodies define a subset of patients within the clinical spectrum of EM.

Adult↗
PubMed1996

Clearing of psoriasis by a novel immunosuppressive macrolide.

Accumulating evidence suggests that psoriasis may be a genetically determined immunogenic, inflammatory disorder based on an ongoing autoreactive Th-1 response. Systemic immunosuppressive therapy is highly effective but fraught with longterm side effects. Our research therefore focuses on therapeutic strategies that induce local immunosuppression in the skin by topical, transepidermal delivery of immunosuppressive drugs. SDZ 281-240 is a newly developed macrolide of the ascomycin type. It is immunosuppressive by mechanism of action similar to that of FK506 but has no antiproliferative activity against keratinocytes in vitro. To evaluate whether SDZ 281-240 exhibits antipsoriatic activity when applied topically, we tested 15 patients with severe, recalcitrant psoriasis, using a microplaque assay in randomized, double-blind, placebo-controlled study, comparing the therapeutic efficacy of the macrolide with a potent halogenated corticosteroid and vehicle. All patients showed a significant improvement of psoriatic lesions treated with two concentrations of the macrolide and, as expected, with the corticosteroid but not with placebo. Both concentrations of the macrolide led to clearing of psoriasis after 10 days of treatment and biopsies confirmed a reversal of the histopathological and immunopathological phenotype of psoriasis to that of normal skin. Thus, an immunosuppressive agent that interferes with early T cell activation can be designed to penetrate into psoriatic lesions when applied topically and to be functionally active within the skin to suppress the ongoing psoriatic process.

Administration, Topical↗
PubMed1996

Bullous pemphigoid induced by PUVA therapy.

An 80-year-old psoriatic patient developed a blistering eruption during oral PUVA therapy. The diagnosis of bullous pemphigoid (BP) was established by routine histopathology, which demonstrated subepidermal blistering, and direct immunofluorescence, which revealed linear deposits of IgG, IgM and C3 along the basement membrane zone. Indirect immunofluorescence using normal human split skin revealed binding of IgG antibodies to the epidermal side, thus confirming a subepidermal blistering disorder. These proteins were identified by the immunoblotting technique as BP antigens I and II. Clinically, the lesions could be reproduced by phototesting using topical 8-methoxypsoralen. Again, the histopathological and immunopathological findings were consistent with the diagnosis of PUVA-induced BP. To the best of our knowledge, this is the first report demonstrating psoriasis-associated BP, in which the clinical diagnosis of BP is confirmed by immunoblotting analysis. The exact role of UV light in precipitating bullous lesions, particularly the question whether UV light may represent an unspecific epidermal injury leading to further attraction of autoantibodies to the basement membrane zone, as suggested recently by an experimental study in rodents, remains to be clarified in future studies.

Aged↗
PubMed1995

Autoantibodies to desmoplakin I and II in patients with erythema multiforme.

Erythema multiforme (EM) represents a syndrome of chronic recurrent inflammatory skin disease. Depending on the severity and extent of skin and mucosal involvement, it is defined either as EM minor or EM major. In this study we demonstrate the presence of autoantibodies (aAbs) against desmoplakin I and II, two major proteins of the desmosomal plaque, in six of six patients with the severe variant of EM, EM major. Light microscopic studies of lesional skin and mucous membranes localized in vivo bound immunoglobulin G (IgG) in a dotted desmosomal pattern along the cytoplasmic membranes of keratinocytes. By immunoelectronmicroscopy, in vivo bound IgG was confined to the desmosomal plaques. These findings were confirmed by indirect immunolocalization studies that demonstrated the presence of IgG aAbs in the serum of patients during active disease. These aAbs did not only bind to desmosomal plaques of epithelial cells where they colocalized with defined murine monoclonal antibodies directed against desmoplakin I and II, but also labeled the intercalated discs of myocardial cells. Biochemical characterization of circulating IgG aAbs revealed desmoplakin I and II as actual target autoantigens. By passive transfer of serum into newborn mice, in vivo binding of serum aAbs to keratinocytes was shown. The findings presented in this study imply a humoral immune response in certain patients with EM major and indicate a potential pathogenetic role of aAbs against desmoplakin I and II in this disease.

Animals↗
PubMed1994

Immunomorphologic characterization of Fc epsilon RI-bearing cells within the human dermis.

Recently we reported that the high-affinity receptor for IgE, Fc epsilon RI, is constitutively expressed on normal epidermal Langerhans cells (LC) and on certain cells within the dermis. To study the nature of these cells we performed immunofluorescence double-labeling experiments using an anti-Fc epsilon RI reagent (MoAb 15-1) as well as monoclonal antibodies (MoAb) against leukocyte differentiation antigens expressed on LC, interdigitating cells and macrophages. Avidin-fluorescein isothiocyanate was used to distinguish mast cells. We found that dermal Fc epsilon RI+ cells are bone marrow derived (CD45+). Further, we found that a subset of 15-1+ dermal cells coexpresses antigens present on certain members of the LC/DC family: the majority of Fc epsilon RI+ cells reacted with MoAb anti-HLA-DR and RFD1, the latter recognizes an antigenic moiety on interdigitating cells, and a small subpopulation coexpressed CD1a. In reverse fashion, virtually all CD1a+ cells and most RFD1+ cells reacted with the anti-Fc epsilon RI reagent. Approximately one third of 15-1+ cells represented avidin-FITC+ mast cells whereas Fc epsilon RI expression was not detected on FXIIIa+ dermal dendrocytes or CD3+ lymphocytes. By immunoelectronmicroscopy, we found that perivascularly located 15-1-reactive cells exhibited pronounced dendrites, an indented nucleus, numerous mitochondria, and abundant endo-/lysosomal structures. However, Birbeck granules or granules specific for basophils or eosinophils were never detected in these cells. Collectively, our data suggest that the pool of dermal Fc epsilon RI+ cells consists mainly of cells of the LC (CD1a+)/DC(RFD1+) lineage and mast cells but does not include FXIIIa+ dermal macrophages.

Antibodies, Monoclonal↗
PubMed1994

[Therapy of cutaneous T-cell lymphomas].

Cutaneous T-cell lymphomas (CTCL) show a wide clinical spectrum of cutaneous diseases caused by a clonal proliferation of malignant T-helper cells. In the early stages of CTCL diagnosis is challenging and may require a combination of clinical, pathological, immunomorphologic and molecular findings. The identification of early disease is crucial for the rapid implementation of adequate treatment, which may even be curative as has been reported with psoralen photochemotherapy (PUVA), total skin electron beam (TSEB) irradiation and topical chemotherapy. The combination of these treatment modalities with each other and, in addition, with management by synthetic retinoids and interferons has increased the therapeutic potential. Systemic (poly)-chemotherapy has been used so far exclusively for advanced stages of CTCL and may result in partial remission. Extracorporeal photochemotherapy (photopheresis) has been shown to be the most efficient mode of treatment for the Sézary syndrome.

Combined Modality Therapy↗
PubMed1993

Nonbullous pemphigoid: prodrome of bullous pemphigoid or a distinct pemphigoid variant?

We describe two patients with pruritic, mainly urticarial or eczematous lesions associated with peripheral blood eosinophilia. No vesicles or blisters developed in either patient throughout the course of the disease (29 and 38 months, respectively). To characterize the clinicopathologic features of these patients we performed histopathologic studies, direct and indirect immunofluorescence, immunoelectron microscopy (patient 2), and immunoprecipitation of both patients' serum. Histopathologic examination revealed a moderate eosinophilic infiltrate partly arranged along the basement membrane zone and focally invading the epidermis. Linear deposits of immunoglobulin and C3 along the dermoepidermal junction were localized within the lamina lucida and over the hemidesmosomal plaques. Immunoprecipitation revealed the presence of circulating autoantibodies against the 230 kd bullous pemphigoid antigen. These findings suggest that our patients had a distinct, nonbullous variant of the pemphigoid spectrum.

Aged↗
PubMed1993

Parasitism of epidermal Langerhans cells in experimental cutaneous leishmaniasis with Leishmania major.

Murine epidermal Langerhans cells (LC) have been demonstrated to stimulate a vigorous T cell response to Leishmania major, a cause of human cutaneous leishmaniasis. It was therefore of interest to analyze whether LC can take up viable parasites. Epidermal cells were obtained from mouse ear skin for incubation with L. major and subsequent detection of intracellular parasites by cytochemistry. Freshly isolated LC, but not cultured LC, phagocytosed L. major and the uptake was inhibited by antibodies to the complement receptor type 3. Electron microscopic studies revealed the presence of viable amastigotes within LC. Moreover, with double-labeling techniques, L. major-containing LC could also be detected in infected skin. The results demonstrate that LC can internalize L. major. Since the number of organisms per infected LC remained consistently low, the prime task of LC may not be the promotion of parasite spreading but the presentation of L. major antigen to T cells and, thus, the regulation of the cellular immunity during cutaneous leishmaniasis.

Acridine Orange↗
PubMed1993

CD68 positive epidermal dendritic cells.

In a pilot study designed to investigate immunopathologic events in the evolution of cutaneous lesions in pemphigus foliaceus, we found that in this condition the epidermis is replete with CD68+ dendritic cells. The present study was designed to investigate the nature of this novel intraepidermal CD68+ cell population. For that purpose lesional skin of five patients with PF and, for comparison, of patients with another acantholytic autoimmune disease, pemphigus vulgaris, were examined using a panel of monoclonal antibodies in a three-step immunoperoxidase technique, in an immunofluorescence double-labeling technique, and by immunoelectron microscopy. We found epidermal CD1a+ Langerhans cells significantly decreased in pemphigus foliaceus compared to pemphigus vulgaris, but pemphigus foliaceus and not pemphigus vulgaris epidermis harbored large amounts of bone marrow-derived (CD45+) cells that expressed CD68, HLA-DR, and beta 2-integrin antigens, the most pronounced expression being observed for CD11c and CD18. These epidermal CD68+ cells were of dendritic shape, were CD1a-, and lacked Birbeck granules (BG); however, a small portion of CD68+ cells was also CD1a+ and exhibited BG as revealed by immunoelectron microscopy. These findings demonstrate that in certain conditions, i.e., in pemphigus foliaceus but not in pemphigus vulgaris, there is a shift from CD1a+/CD68- epidermal Langerhans cells towards CD1a-/CD68+ dendritic epidermal cells. The detection of a small number of CD1a+/CD68+/BG+ dendritic epidermal cells may identify these cells as a link between the CD1a+/CD68+/BG+ Langerhans cells and the CD1a-/CD68+/BG- cell population and suggests that these cells represent a transitional form of myelomonocytic cells during their phenotypic and morphologic transformation into resident epidermal Langerhans cells.

Adolescent↗
PubMed1992

Isolation of human immunodeficiency virus type 1 from human epidermis: virus replication and transmission studies.

For a better understanding of the pathogenetic events operative in the cutaneous manifestations of human immunodeficiency virus type 1 (HIV-1) disease, we investigated whether epidermal cells (EC) from HIV-1-seronegative persons can be infected with HIV-1 and, vice versa, whether HIV-1 can be rescued from the epidermis of HIV-1-infected individuals. In a series of three experiments, we consistently found that exposure of EC from HIV-1-seronegative donors to HIV-1 led to viral replication in these cells as evidenced by the detection of HIV-1 p24 in culture fluids. Because EC had been substantially enriched for Langerhans cells (LC) before being exposed to HIV-1, it is reasonable to assume that these CD1a+/CD4+/MHC class II+ antigen-presenting cells of the epidermis represented the actual targets of infection. This assumption is further strengthened by the observation that T cell-depleted cell suspensions from Langerhans cell histiocytosis (LCH) lesions could be productively infected with HIV-1. Conversely, co-culture of epidermal sheets from HIV-1-seropositive individuals with mononuclear phagocytes (MNP) from HIV-1-seronegative donors resulted, after 3 to 5 weeks, in the detection of HIV-1 p24 in 12 of 23 cases. Immunocytochemical analysis, using a monoclonal antibody specific for p24, revealed the presence of HIV-1 in adherent MNP in three cocultures tested. In addition, cellular DNA from these cultures showed strong signals when hybridized to a HIV-1-specific DNA probe. The further finding that two isolates examined exhibited different restriction enzyme patterns indicates that they are separate entities rather than contaminants. Transmission of these isolates to MNP, B- or T-cell lines resulted in cultures strongly positive for p24 and, in the case of H9 cells, for viral particles as detected by electron microscopy. Our results therefore strongly suggest that EC not only can serve as targets for HIV-1, but also can allow efficient virus replication and transmit HIV-1 to various cell types of the hematopoietic lineage.

Cell Line↗
PubMed1992

Immunomorphologic and biochemical identification of the pemphigus foliaceous autoantigen within desmosomes.

Desmosomes are specialized domains of the plasma membrane that play a fundamental role in intercellular adhesion. This adhesive function is mediated at least in part by the cadherin homologous cell adhesion molecule (CAM) desmoglein (dg). Autoantibodies (aab) from patients with pemphigus foliaceous (pf), a blistering disease of the epidermis, have been shown by immunochemical methods to bind to desmoglein. However, the molecular localization of the binding sites of these antibodies, especially as it relates to the ultrastructure of the desmosomes, has not been definitively characterized. We therefore performed pre-embedding direct immunoelectron microscopy (IEM) on perilesional skin of patients with pf and post-embedding indirect IEM using sera from five patients with pf. We first confirmed by immunoprecipitation and immunoblotting that these sera bound dg. Both IEM methods showed that pf-aab exclusively bind to desmosomes. Double-labeling IEM of several other constitutive desmosomal proteins further suggests that most likely pf-aab bind to an extracellular domain of the transmembrane CAM dg. Our studies suggest one possible pathophysiologic mechanism for the clinical manifestations of pf: namely, that the binding of aab to an extracellular epitope of desmoglein might impair the adhesive properties of desmosomes mediated by dg and result in the loss of cell adhesion leading to acantholysis and blister formation.

Autoantigens↗
PubMed1992

Middermal elastolysis in an elderly man with evidence of elastic fiber phagocytosis.

BACKGROUND: Middermal elastolysis is a clinically and histologically distinct entity. This idiopathic loss of dermal elastic fibers has mostly been reported in younger adults. To our knowledge, the present case, which has been followed up for 4 years, is the first to occur in an elderly man. OBSERVATIONS: Two years after the onset of progressive wrinkling of the upper aspect of the thorax, the patient underwent a biopsy. Histologic examination of the specimens confirmed previous findings of middermal elastolysis. Examination of extracutaneous elastic tissue showed normal findings. Electron microscopy demonstrated elastic fibers embraced by macrophages, which is suggestive of elastic fiber phagocytosis. For the following 4 years, the patient has remained in stable clinical condition. CONCLUSIONS: Middermal elastolysis is probably more common than has been assumed so far. It does not affect nondermal elastic tissue. After progressive loss of dermal elasticity in a circumscribed area, a benign course follows, with a stable condition over several years. Electron microscopic findings indicate that elastic fiber phagocytosis is operative in the disappearance of the middermal elastic tissue.

Aged↗