Biomedical subjects

C E Klein

Publications and source records attributed to C E Klein.

At least 55 records · Page 3Linked to original sources

PubMed1992

Migration of a human keratinocyte cell line (HACAT) to interstitial collagen type I is mediated by the alpha 2 beta 1-integrin receptor.

The migratory response of the human keratinocyte cell line HaCaT to collagen type I and the molecular mechanism underlying collagen-mediated migration have been analyzed. The migratory response of HaCaT cells to collagen type I consisted of a dose-dependent migration to insoluble step gradients of substratum-bound collagen (haptotaxis) and to gradients of soluble collagen (chemotaxis). Checkerboard analysis demonstrated a minor chemokinetic component. Denatured collagen type I was less chemoattractive than the native triple-helical form. Pre-treatment of cells with 25-250 micrograms/ml of synthetic peptides containing the fibronectin cell-recognition sequence RGD (Arg-Gly-Asp) resulted in a concentration-dependent inhibition of fibronectin-mediated chemotaxis, whereas chemotaxis to collagen was not affected. We then investigated the role of VLA/collagen-receptors for collagen type I-induced chemotaxis. Monoclonal antibody (MoAb) 5E8, which selectively blocks function of the alpha 2 subunit of the VLA-2/collagen receptor, dose-dependently inhibited the chemotactic response of HaCaT cells to collagen. This effect was specific for collagen-mediated chemotaxis because the chemotactic response to fibronectin remained unaffected. In contrast, a function blocking MoAb directed to the alpha 3 subunit of the coexpressed VLA-3 receptor, which is also capable of binding collagen, had no effect. However, function blocking MoAb directed to the beta 1-chain of integrins completely inhibited chemotaxis to collagen type I. Based on our results, we propose that the chemotactic migration of the human keratinocyte cell line (HaCaT) to collagen type I is specifically mediated by the RGD independent VLA-2/collagen receptor (alpha 2 beta 1) of the integrin family.

Amino Acid Sequence↗

PubMed1991

Cell surface glycoproteins define distinct states of eccrine gland differentiation.

The capability to distinguish eccrine gland cells of the ductal compartment from the secretory portion on the molecular level, as well as from epidermal keratinocytes and other skin cells, is of importance for the study of eccrine differentiation and function. Furthermore, the assessment of differences between the cell systems is useful for the characterization of benign and malignant neoplasms derived from eccrine glands. In the present study, we analysed the expression of four selected epithelial cell surface glycoproteins (gp 80, gp 38, gp 115 and gp 200) in eccrine glands using specific monoclonal antibodies. We found that the glycoproteins are differentially expressed in the ductal compartments and in the secretory portion of the glands, as well as in normal epidermis and other skin cells. This permitted the assignment of specific phenotypes to cells of the ductal compartment and to those of the secretory portion.

Antibodies, Monoclonal↗

PubMed1991

Integrin alpha 2 beta 1 is upregulated in fibroblasts and highly aggressive melanoma cells in three-dimensional collagen lattices and mediates the reorganization of collagen I fibrils.

The ability of cultured human fibroblasts to reorganize and contract three dimensional collagen I gels is regarded as an in vitro model for the reorganization of connective tissue during wound healing. We investigated whether adhesion receptors of the integrin family are involved. It was found that synthesis and transcription of the alpha 2 beta 1 integrin (but not of alpha 1 beta 1 or alpha 3 beta 1) is selectively upregulated when fibroblasts are seeded into type I collagen gels. Time course experiments revealed that high synthetic levels of alpha 2 beta 1 parallel the gel contraction process and return to "baseline" levels after the contraction has subsided. Furthermore, function-blocking mAbs directed to the alpha 2 and beta 1 chain of integrins inhibited gel contraction. Remodelling of connective tissue can be important for tumor cells during invasion and formation of metastases. Therefore, we tested human melanoma cell lines for this function. Five out of nine melanoma lines contracted collagen gels in vitro. Among these, two highly aggressive melanoma cell lines (MV3 and BLM) most efficiently contracted gels almost reaching the rate of normal adult fibroblasts. In these cells, synthesis of alpha 2 beta 1 was also significantly upregulated when seeded into collagen I gels. Moreover, function blocking anti-alpha 2 in conjunction with anti-beta 1 chain mAbs completely inhibited gel contraction for several days. Other melanoma cells (530) with lower metastatic potential which were not able to contract gels, showed no induction of alpha 2 beta 1 synthesis in gel culture. Our results suggest an important role of integrin alpha 2 beta 1 in the contraction of collagen I by normal diploid fibroblasts during wound healing and in the reorganization of collagen matrices by highly aggressive human melanoma cells.

Adult↗

PubMed1991

Identification of a melanoma progression antigen as integrin VLA-2.

The expression of the integrin receptors VLA-1, -2, -3, and -6 was studied in normal cultured melanocytes and in five melanoma cell lines. Normal melanocytes synthesized VLA-3, but did not reveal detectable levels of VLA-1, -2, and -6. All melanoma cell lines, however, expressed VLA-2, -3, and -6. VLA-1 was synthesized by two of five melanoma lines. In parallel, we had analyzed the expression of four previously characterized melanoma cell surface antigens. One of them (antigen A.1.43), which is associated with tumor progression of human melanoma, revealed a striking similarity to VLA-2. In sequential immunoprecipitation experiments, we show that A.1.43 is identical with the integrin VLA-2, a cell surface receptor for collagen, laminin, and fibronectin.

Antibodies, Monoclonal↗

PubMed1991

Type IV allergy to amide-type local anesthetics.

The case of a 45-year-old woman is reported, who developed intense erythema and itching 1 day after subcutaneous (s.c.) injection of a local anesthetic containing mepivacaine and methylparaben. The reaction was attributed to a delayed-type sensitivity to mepivacaine, since mepivacaine gave a positive patch test response and also elicited a delayed sensitivity reaction after s.c. challenges, whereas prick and patch tests with methylparaben, as well as oral challenges, were negative. Interestingly, the patient also showed sensitization to lidocaine, a compound to which she had previously also been exposed.

Anesthetics, Local↗

PubMed1990

The T cell triggering molecule Tp103 is associated with dipeptidyl aminopeptidase IV activity.

Tp103 is a 103-kDa T cell activation molecule that defines an alternative activation signal for human T lymphocytes. It is absent from or present in only low amounts on resting T cells but is expressed strongly after activation. Cross-linking of Tp103 via a mAb CB.1 leads to triggering of functional activities in preactivated CD3+ T lymphocytes. By using mAb CB.1 in immunohistology we found that Tp103 is expressed in epithelial cells of various tissues, such as kidney, prostate, epidermis and on endothelia of liver, spleen, lungs, and most vessels, and in bile duct canaliculi in the liver. We found a carcinoma cell line expressing Tp103 and could precipitate a 110-kDa molecule from the surface of these cells. We considered several known molecules of similar distribution and molecular mass for identity with Tp103 and show here that Tp103 is probably identical to the proteolytic enzyme dipeptidyl aminopeptidase IV. When we purified Tp103 by affinity chromatography, typical dipeptidyl aminopeptidase IV activity copurified with Tp103. On activated T cells the enzymatic activity associated with Tp103 is expressed on the outside of the cell. We show that mAb CB.1 recognizes the same molecule as the anti-CD26 mAb anti-Ta1. The anti-Ta1 mAb was found to have T cell-activating activity too, but to differ in its requirements for triggering of T lymphocytes.

Antibodies, Monoclonal↗

PubMed1990

Lack of an effect of age on the response to clonidine.

The plasma concentration and appearance rate of norepinephrine are increased in the elderly. A hypothesis to explain this observation is that the elderly have a diminished response of the alpha 2-adrenoreceptor in the brainstem that modulates peripheral sympathetic tone. To evaluate the effect of age on alpha 2-adrenoreceptor function, we studied 12 healthy elderly subjects and 12 healthy young volunteers and compared the decrease in plasma norepinephrine and blood pressure in response to increasing doses of orally administered clonidine. We found that, for the same plasma clonidine concentration, the blood pressure and plasma norepinephrine concentration fell equivalently in both groups. These data imply that the increased plasma norepinephrine and the elevated blood pressure in the healthy elderly population do not appear to be secondary to a decrease in alpha 2-adrenergic response to an agonist in the central nervous system.

Adult↗

PubMed1990

Expression of 38-kD cell-surface glycoprotein in transformed human keratinocyte cell lines, basal cell carcinomas, and epithelial germs.

In this study, we attempted to identify and characterize transformation-induced cell-surface glycoproteins of human keratinocytes. Therefore, we first searched for glycoproteins which are significantly elevated in human keratinocytes after transformation and immortalization by SV40 virus and which are also found at high levels in keratinocytic cell lines derived from squamous cell carcinomas of the skin. Out of at least 80 different cell-surface antigenic systems of human tumor cells, only three glycoproteins showed elevated expression in transformed keratinocytes. Among these, a 38-kD glycoprotein (gp 38) was highly increased in all transformed keratinocyte cell lines tested, but was not elevated in transformed fibroblasts. The expression of gp 38 was further characterized in normal epidermis and in its benign and malignant hyperproliferative disorders: gp 38 was generally not expressed in normal epidermis and in benign hyperproliferative disorders. In contrast, strong and homogeneous reactivity was found in solid and fibrosing basal cell carcinomas whereas no or low reactivity was detected in squamous cell carcinomas and in those parts of BCC revealing keratotic differentiation. Interestingly, high expression of gp 38 was also found in primary epithelial germs of fetal skin, secondary germ cells of the telogenic hair follicle and secretory tubules of sweat glands. The immunohistologic data suggest that gp 38 is preferentially expressed by epidermal cells which lack squamous and pilosebaceous differentiation.

Basal Cell Carcinoma↗

PubMed1990

Integrins of normal human epidermis: differential expression, synthesis and molecular structure.

The expression of integrin cell surface receptors in normal skin and their synthesis and molecular structure in keratinocyte cultures was investigated. The reactivity of four different polypeptides of the integrin family (alpha 2-, alpha 3-, alpha 6- and beta 1-chains) was demonstrated in the basal cell layer of normal epidermis. Studies of labelled keratinocyte cell lines showed that the polypeptides were expressed as alpha 2 beta 1, alpha 3 beta 1 and alpha 6 beta 4 integrins. Only the alpha 6 beta 4 integrin showed polarization towards the basement membrane attachment site of basal layer keratinocytes, and was preferentially expressed at microvillous projections. In contrast, alpha 2 beta 1 and alpha 3 beta 1 integrins were equally expressed throughout the basal cell plasma membrane.

Basement Membrane↗

PubMed1990

[Integrins--new receptor molecules: their significance for the differentiation, regeneration and immune response of the skin].

The integrins are a newly defined family of cell surface receptors. They are involved in the adhesion of cells to the extracellular matrix and to other cells. Integrins and their ligands may be required for complex physiological and pathophysiological events, such as epidermal differentiation, inflammation, immune response, wound healing or tumour progression. Some of the integrin receptor molecules are expressed in a distinct distribution pattern within the skin. Three of them are found selectively in the basal layer of the epidermis, suggesting an important role in establishment of the functional integrity of the dermo-epidermal junction. In the present paper we summarize the available data on the structure and function of integrins and report on the expression of these molecules within the skin and their regulation in cell cultures.

Cell Adhesion↗

PubMed1989

Antigenic phenotypes of cultured malignant astrocytomas: identification of lineage-consistent, lineage-independent and putative tumor-restricted antigenic expression.

The treatment of CNS neoplasms with monoclonal antibody-mediated immunotherapy optimally requires the identification of tumor restricted cell surface antigens. However, little is known regarding the antigenic phenotype(s) of malignant astrocytomas. The interrelated expression of four neuroectodermal tumor antigens, CNT/11, AJ8, A010 and CNT/2, has been studied in cultured malignant gliomas and correlated with anchorage independent growth, morphology, glial fibrillary acidic protein, and the surface expression of other antigens. Many of these latter antigens have been reported to be expressed by specific fetal and differentiated adult cell lineages or tissues, as well as certain classes of malignant tumors. The tumor-associated expression of these antigens may be broadly classified as lineage-consistent, lineage-independent or putatively tumor-restricted. Malignant glioma tumor antigenic heterogeneity represents the expression of neuroectodermal and non-neuroectodermal cell surface markers. The importance of this observation is 2-fold. Lineage-independent antigen expression may be an indication of altered genome regulatory processes within tumor cells, and thus reflect the degree of anaplasia. The identification of lineage-consistent and lineage-independent tumor associated antigens may contribute to the selection of "target" antigens and the prediction of toxicity for monoclonal antibody mediated immunotherapy.

Antigens, Neoplasm↗

PubMed1989

Integrin VLA-3: ultrastructural localization at cell-cell contact sites of human cell cultures.

The integrin VLA-3 is a cell surface receptor, which binds to fibronectin, laminin, collagen type I and VI (Takada, Y., E. A. Wayner, W. G. Carter, and M. E. Hemler. 1988. J. Cell. Biochem. 37:385-393) and is highly expressed in substrate adherent cultures of almost all human cell types. The ligand specificity of VLA-3 and the inhibition of cell adhesion by anti-VLA-3 monoclonal antibodies suggest its involvement in cell-substrate interaction. In normal tissues, VLA-3 is restricted to few cell types, notably the kidney glomeruli and basal cells of the epidermis. In the epidermis, VLA-3 is generally strongly expressed on the entire plasma membrane of basal cells and is not polarized towards the basement membrane (Klein, C. E., C. Cardon-Cardo, R. Soehnchen, R. J. Cote, H. F. Oettgen, M. Eisinger, and L. J. Old. 1987. J. Invest. Dermatol. 89:500-507). Based on this finding we speculated that, in addition to a role of VLA-3 for adhesion of cells to substrate, it could also be relevant for cell-cell interaction. To investigate this, we ultrastructurally localized VLA-3 on the surface of cultured cells by immunoelectron microscopy. In accordance with our concept, we found VLA-3 strongly associated with intercellular contact sites. Interestingly, very little immunoreactivity was detected at the under-surface of cells which had been cultured for 18-32 h. This observation was unexpected but is consistent with previous findings (Kantor, R. R. S., M. J. Mattes, K. D. Lloyd, L. J. Old, and A. P. Albino. 1987. J. Biol. Chem. 262:15158-15165) which suggest that the association of VLA-3 with the basal surface of substrate adherent tumor cells is a late event occurring after days of culture under confluent conditions. However, we cannot formally rule out VLA-3 expression at the undersurface of cells under our experimental conditions, since VLA-3 molecules at this location could be inaccessible for in situ labeling of unfixed cells because of spatial interferences. In conclusion, our results demonstrate the expression of VLA-3 at intercellular contact sites of cultured cells supporting the concept that it may be relevant for intercellular interactions also.

Animals↗

PubMed1989

[Infantile acropustulosis].

Infantile acropustulosis starts in the first few months of life with the recurrent appearance of pruritic intraepidermal pustules containing neutrophils. Predilection sites are the hands and feet. Episodes of pustular eruptions lasting from 8 to 14 days are followed by longer intervals with no symptoms. However, some infants present with skin lesions more widely distributed over the body and with eosinophils as a major constituent of the pustules. In these cases differentiation from other eosinophilic pustular dermatoses of infancy, e.g., the pustular variant of toxic erythema, eosinophilic pustular folliculitis, and transient neonatal pustular melanosis, may become difficult. The etiology of infantile acropustulosis is unknown. The disease clears up spontaneously within the first few years of life. In some cases DADPS therapy has been of benefit.

Acrodermatitis↗

PubMed1988

Cystathionine metabolism in neuroblastoma.

Cystathioninuria is a frequent and highly specific marker of neuroblastoma, but the etiology of this abnormality has not been well studied. To investigate this phenomenon, we analyzed 27 human neuroblastoma tissue specimens for the presence of cystathionine synthase and cystathionase. Levels of cystathionine synthase varied from undetectable to 622 pmol/mg protein, but no specimen had cystathionase measurable by rocket radioimmunoassay or catalytic assay. In addition, we assayed neuroblastoma cell lines exposed to a variety of differentiating agents: butyric acid, dimethyl sulfoxide, serum-free medium, or sodium citrate to induce differentiation. In each case we were unable to demonstrate cystathionase induction. These data are consistent with the hypothesis that neuroblastomas have a biochemical block in the transsulfuration enzymes at the level of cystathionase and that expression of cystathionine synthase in the absence of cystathionase may account for the presence of cystathioninuria in patients with neuroblastoma.

Cell Differentiation↗

PubMed1988

A transformation-associated 130-kD cell surface glycoprotein is growth controlled in normal human cells.

Two characteristics of cell surface molecules involved in the regulation of cell proliferation are altered expression in relation to growth phase in normal cells and overexpression in transformed cells. Here, we describe a similar pattern of expression for a 130-kD cell surface glycoprotein (gp 130) in human cells. Synthesis and cell surface expression of gp130 were greatly increased in both virally and chemically transformed fibroblasts, fibrosarcomas, a squamous cell carcinoma of the skin, and T cell leukemia lines. Furthermore, gp130 expression was induced in serum-starved fetal fibroblasts by serum stimulation, and in fresh T cells by various activating agents. Expression in response to serum stimulation was associated primarily with the transition from a quiescent state (G0) into the cell cycle (G1).

Carcinoma, Squamous Cell↗

PubMed1988

[Sterile eosinophilic pustulosis (Ofuji)].

In recent years there has been an increase in the information available on "eosinophilic pustular folliculitis (Ofuji)". A significant feature of this disease is extensive tissue eosinophilia in association with follicular, intraepidermal or subcorneal pustules containing eosinophils. A review of the current literature reveals that the skin lesions vary widely. Some patients present with pustules on an erythematous base; in others, annular or circinate papulonodular lesions predominate, which may become crusted. Even vesicular lesions have been reported. The extensive tissue eosinophilia itself suggests that the condition is not caused by an exogenous infectious agent. Most data implicate an immunopathological event that is still not well understood.

Biopsy↗

PubMed1987

Changes in cell surface glycoprotein expression during differentiation of human keratinocytes.

Six cell surface glycoproteins defined by monoclonal antibodies were selected for study on human epidermal cells. In tests on tissue sections, three of the glycoproteins [J143 (gp140/30); T43 (gp85/36); H99 (gp38)] were expressed in the basal cell layer of the epidermis, whereas the other three glycoproteins [T179 (gp140/95); T16 (gp40/50); BT15 (gp80)] were preferentially expressed in maturing keratinocytes above the basal layer. We compared synthesis of these glycoproteins in fresh epidermis and in primary epidermal short term cultures using [35S]methionine for metabolic labeling. Synthesis of J143 was 8- to 20-fold higher and synthesis of T43 was 4- to 10-fold lower in cultured cells compared with fresh epidermis. BT15, an antigen strongly expressed on terminally differentiating keratinocytes, was synthesized at 5- to 15-fold higher levels in fresh epidermis than in cultured cells. Biosynthesis levels of H99, T179, and T16 did not change in cultured epidermal cells. Based on our findings, we propose a model of surface antigenic changes that occur during keratinocyte differentiation in vivo.

Adult↗

PubMed1983

Primary polycythaemia in childhood and adolescence.

Four adolescents with polycythaemia are described where symptoms typical of the disease had already existed in childhood. Three patients fulfilled the criteria of a polycythaemia vera. In one female patient the possibility of familial erythrocytosis is discussed. Polycythaemia vera mononuclear cells formed erythroid colonies in cultures in the absence of erythropoietin. The patients were phlebotomized to maintain haematocrit readings of 40 to 45%. No case has yet progressed to myeloid metaplasia or acute leukaemia.

Adolescent↗