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Biomedical subjects

M Eisinger

Publications and source records attributed to M Eisinger.

At least 37 records · Page 2Linked to original sources

Immunochemical and functional analysis of HLA class II antigens induced by recombinant immune interferon on normal epidermal melanocytes.

The effect of recombinant immune interferon (IFN-gamma) on the expression and shedding of HLA antigens and of melanoma-associated antigens (MAA) by epidermal melanocytes was investigated by using serologic and immunochemical techniques. IFN-gamma enhances the expression and/or shedding of HLA class I antigens and of the cytoplasmic MAA defined by monoclonal antibody (MoAb) 465.12S and induces a slight reduction in the expression of the high m.w. melanoma-associated antigen (HMW-MAA). In agreement with the data in the literature, melanocytes incubated with IFN-gamma acquire HLA-DR, -DQ, and -DP antigens. Contrary to previous information in the literature, the effect is not restricted to HLA class II antigens, since IFN-gamma also induces the expression of the 96-kDa MAA recognized by MoAb CL203. The effect of IFN-gamma on HLA class II antigens and 96-kDa MAA is dose and time dependent and is specific, because recombinant leukocyte interferon affects the expression of neither type of antigen. In spite of the expression of HLA class II antigens, IFN-gamma-treated melanocytes do not acquire the ability to stimulate the proliferation of allogeneic lymphocytes. HLA-DR antigens are more susceptible to induction by IFN-gamma than HLA-DQ and -DP antigens, since the percentage of melanocytes acquiring HLA-DQ and -DP antigens is lower than that acquiring HLA-DR antigens. Furthermore, the dose of IFN-gamma is higher and the time of incubation is longer to induce HLA-DQ and -DP antigens than to induce HLA-DR antigens. The differential susceptibility of HLA-DR, -DQ, and -DP antigens as well as of melanocytes from various donors to the modulating effect of IFN-gamma may provide an explanation for the more frequent detection of HLA-DR than of HLA-DQ and -DP antigens in melanoma lesions and for the expression of HLA class II antigens by some, but not all, melanoma lesions.

Animals↗

Treatment of junctional epidermolysis bullosa with epidermal autografts.

We have successfully treated chronic facial erosions in three boys with junctional epidermolysis bullosa. In each patient, keratinocytes were harvested from the roof of suction blisters created on clinically uninvolved skin. They were grown in tissue culture on collagen sponges and grafted onto facial erosions that were previously treated with 2% mupirocin ointment. This experimental antibiotic ointment has proved efficacy in eradicating cutaneous pathogens such as Staphylococcus aureus from chronic wounds. In two patients, complete reepithelialization was achieved over 7 and 10 months, respectively, and partial reepithelialization occurred in another patient in whom treatment is ongoing. Epidermal autografts are a promising means for improving function and appearance in eroded skin caused by junctional epidermolysis bullosa.

Adolescent↗

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↗

Class II histocompatibility antigen expression in human melanocytes transformed by Harvey murine sarcoma virus (Ha-MSV) and Kirsten MSV retroviruses.

Human melanocytes infected with Ki-MSV or Ha-MSV, but not amphotropic MuLV, undergo a series of transformation-related changes that are characteristic of malignant melanoma. These are (a) expression of Ia antigens, in particular DP, DQ, and DR class II histocompatibility gene products, (b) a transformed morphology and ability to grow in soft agar, and (c) a 5-10-fold increase in the cell surface expression of GD3 ganglioside. However, other characteristics of melanoma, such as independence from specific growth factors and loss of adenosine deaminase binding protein were not observed. We conclude that viral ras oncogenes initiate early transformation events in melanocytes, and that Ia antigen expression is a transformation marker in this system.

Cell Division↗

Growth regulation of human melanocytes: mitogenic factors in extracts of melanoma, astrocytoma, and fibroblast cell lines.

Melanocytes derived from fetal or adult skin do not propagate in vitro unless cultured in the presence of factors such as 12-O-tetradecanoylphorbol 13-acetate (TPA). In a search for physiological factors regulating the growth of melanocytes, extracts of various cultured cell types were tested. Factors produced by melanoma and astrocytoma cell lines support continued proliferation of melanocytes in the absence of TPA. WI-38, a fibroblast cell line derived from human embryonic lung, was the most active source of melanocyte growth factors. No melanocyte growth-promoting activity was found in extracts of cultured neuroblastoma, renal cancer, normal keratinocytes, or renal epithelium. Nerve growth factor, epidermal growth factor, melanocyte-stimulating hormone, transforming growth factor-beta, and platelet-derived growth factor did not have growth-promoting activity for melanocytes. The presence of melanocyte growth factors and TPA together resulted in the strongest mitogenic activity for melanocytes, permitting the recovery (at 20 days) of 4 to 20 times as many cells as in growth factor or TPA alone.

Astrocytoma↗

Regeneration of epidermis by cells grown in tissue culture.

Pig epidermal cells were grown in vitro for 21 to 180 days, forming multilayered sheets of epidermis varying from thirteen to forty layers. For an evaluation of their use in wound coverage, they were transplanted onto surgically prepared full-thickness wound beds on domestic swine. Autologous epidermal cells were studied on twenty-five of the animals, and allogeneic epidermal cells were studied on thirteen. Autologous epidermal cells grown in vitro provided functional wound coverage 10 to 15 days post transplantation and inhibited scar formation. Allogeneic epidermal cells "melted" 15 days post transplantation. There was a 7-day prolongation of allograft survival with cultured, as compared with noncultured, epidermal allografts. Results obtained are related to other advances made in this field.

Animals↗

Monoclonal antibody 4F2 reactive with basal layer keratinocytes: studies in the normal and a hyperproliferative state.

To establish a method for separating different keratinocyte subpopulations in the epidermis, we studied the specificity of monoclonal antibody 4F2 for keratinocytes. Preliminary screening experiments had previously demonstrated 4F2 reactivity with the epidermis. 4F2 reacted with a subpopulation (19.29 +/- 5.23%) of human epidermal cells in suspension. The membrane antigen identified by 4F2 continues to be expressed by cultured keratinocytes. In frozen tissue section using an indirect immunofluorescence technique, the 4F2-positive cells in the basal layer are sharply demarcated from the negative suprabasilar layers. Even in the hyperproliferative state of psoriasis, the 4F2 reactivity is confined to the basal layer. Cell suspensions of psoriatic epidermis demonstrated a greater percentage of reactivity with 4F2 (49.51% +/- 6.50%), probably reflecting the expanded population of basal layer cells. Monoclonal 4F2, therefore, reacts with a membrane antigen present on basal keratinocytes, and provides a probe for use in the isolation of the basal keratinocyte subpopulation. Thus, this antibody should be useful in studies of normal and aberrant differentiation of the epidermis.

Antibodies, Monoclonal↗

Ultraviolet radiation induces changes in membrane metabolism of human keratinocytes in culture.

Human keratinocytes in culture were prelabeled with [3H]arachidonic acid (AA) and then exposed to ultraviolet B radiation. Irradiated cells released labeled AA metabolites into media in a dose-dependent manner when compared to sham-irradiated cells. The response began immediately and continued for 24 h. Extracts from media were examined by high-performance liquid chromatography for identification of specific AA metabolites. Irradiated cells were stimulated to produce prostaglandin-like material (PGE2 and PGF2 alpha). These findings support the concept that the cell membrane of keratinocytes participates directly or indirectly in initiating the sunburn response. It is also felt that the metabolites formed following injury to the membrane are an integral component in the mediation of that response.

Arachidonic Acids↗

Differentiation and shedding of surface macromolecules of human keratinocytes.

Macromolecules expressed on the external surface of human keratinocytes in tissue culture were radioiodinated by the lactoperoxidase technique and solubilized by lysing the cells in nonionic detergent. Soluble labeled proteins were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The pattern of proteins expressed by keratinocytes was distinct for these cells. The major labeled components had Mrs of 28K, 40K, 68K, 72K, and 77K. The expression of several macromolecules changed with the length of time the cells were in culture, suggesting that their expression was linked to epidermal differentiation. Lastly, many but not all of the macromolecules expressed on the surface of keratinocytes were selectively and rapidly released into medium by the cells.

Cell Differentiation↗

Antibodies to normal human melanocytes in vitiligo.

Most patients with active vitiligo (82% of 61) have antibodies to antigens of normal human melanocytes that can be detected by specific immunoprecipitation of radioiodinated, detergent-soluble, melanocyte macromolecules. Such antibodies were present in only 12% of patients with melanoma and in none of 35 patients with nonpigmentary skin diseases. The antibodies were directed to a common antigen(s) on melanocytes that was not present on normal fibroblasts or keratinocytes. These observations suggest that vitiligo is an autoimmune disease mediated by antibodies to melanocyte-associated antigen(s).

Antibodies↗

Stimulation of growth of human melanocytes by tumor promoters.

In previous studies we found that, when added to primary normal human epidermal cultures, 12-O-tetradecanoyl phorbol 13-acetate (TPA) (10 ng/ml) selectively suppresses the growth of the otherwise predominant keratinocyte cell population and that this is associated with the outgrowth of normal melanocytes. The present study indicates that these melanocytes can be subsequently grown for at least 30 passages if the medium contains TPA, but if the compound is removed the cells cease to divide. The ability of a series of phorbol esters to support the growth of normal human melanocytes correlates, in general, with their tumor promoting activity on mouse skin. Two structurally unrelated types of compounds which have recently been shown to have tumor promoting activity on mouse skin, teleocidin and aplysiatoxin, also support melanocyte growth. On the other hand, several polypeptide growth factors could not substitute for TPA. Since human melanoma cell lines grow vigorously in the absence of tumor promoters our results suggest that the malignant transformation of melanocytes is associated with the acquisition of autonomy from certain unidentified endogenus growth factors.

Alkaloids↗

Detection of antibodies to melanocytes in vitiligo by specific immunoprecipitation.

Immunoprecipitation was used to assay for antibodies to normal human melanocytes in the sera of 12 patients with common vitiligo and 12 normal individuals. The procedure is based on the specific immunoprecipitation using protein A-sepharose of antibodies binding to detergent-soluble, radioiodinated macromolecules of normal human melanocytes grown in culture. Antibodies to melanocytes were found in all 12 patients with vitiligo but in none of the normal sera. None of the sera reacted specifically to normal human fibroblasts or to human melanoma cells radioiodinated in a similar manner. These observations suggest that antibodies to melanocyte-associated antigens are present in common vitiligo.

Antibody Specificity↗

Binding of phorbol dibutyrate and epidermal growth factor to cultured human epidermal cells.

Primary cell cultures of normal human epidermal keratinocytes and melanocytes and human cell lines established from a primary melanoma (SK-PM-4) and metastatic melanomas (HO#1, SK-MEL21, and SK-MEL37) contain specific and saturable receptors for the tumor promoter phorbol dibutyrate (PDBu). Scatchard analyses of the keratinocytes revealed two classes of binding sites: 1) a high-affinity class (affinity constant = 37 nM; 1.3 X 10(6) sites/cell) and a low-affinity class (affinity constant = 4,880 nM; 7 X 10(7) sites/cell). The melanoma cultures, likewise, showed high- and low-affinity classes of PDBu binding sites. However, the affinity constant values and total numbers of sites in the melanoma cells were lower than the corresponding values in the keratinocytes. The binding of [3H]PDBu to human keratinocytes was inhibited by the tumor promoters 12-O-tetradecanoylphorbol 13-acetate and teleocidin but not by phorbol, which lacks tumor-promoting activity. Human serum also inhibited binding. Specific receptors for epidermal growth factor (EGF) were demonstrated in the keratinocytes and primary melanoma cultures. In contrast, three metastatic melanoma cultures gave negligible levels of EGF binding. Among the various cell types, the extent of [3H]PDBu binding did not correlate with the extent of EGF binding, indicating that these two substances occupy distinctly separate types of receptors.

Caenorhabditis elegans Proteins↗

Glycoproteins as differentiation markers in human malignant melanoma and melanocytes.

Human malignant melanoma cell lines have been divided into three broad groups on the basis of morphology, pigmentation, tyrosinase levels, the 2-dimensional electrophoretic patterns of their [3H]glucosamine-labeled glycoproteins and the presence or absence of an extracellular matrix of fibronectin. The most pigmented cell lines were characterized by the synthesis of a novel glycoprotein with a molecular weight of 75,000 and the absence of a fibronectin matrix. As cultured skin melanocytes also had these characteristics, this group of melanomas appears to be the most differentiated. Melanoma cell lines in the amelanotic group were characterized by the synthesis of high levels of HLA-DR antigen and by the production of an extracellular fibronectin matrix.

Cell Division↗

Surface antigens of melanocytes and melanomas. Markers of melanocyte differentiation and melanoma subsets.

The surface antigens of melanocytes from newborn and adult skin have been analyzed with monoclonal antibodies detecting cell surface antigens of malignant melanoma. Antigenic markers that distinguish early, intermediate, and mature stages in melanocyte differentiation have been defined. The characteristics of the normal melanocyte precursor have been inferred from the features of melanomas that express early markers of melanocyte differentiation. A rudimentary surface antigen map of cells undergoing melanocyte differentiation and a new classification of melanomas based on the expression of melanocyte differentiation antigens are proposed.

Adult↗

Isolation of a human papillomavirus from a patient with epidermodysplasia verruciformis: presence of related viral DNA genomes in human urogenital tumors.

The DNA genome of a human papillomavirus (HPV), tentatively designated HPV-EV, was molecularly cloned from hand to leg lesions of a patient with epidermodysplasia verruciformis, a chronic skin disease associated with a 30% risk of developing cancer. Using stringent hybridization conditions, we observed less than 5% homology between HPV-EV and the cloned genomes of HPV-1, HPV-4, HPV-5, and HPV-5a. HPV-EV DNA showed approximately 6% homology with HPV-2 and 36% homology with HPV-3. These data suggest that HPV-EV is partially related to HPV-3. Using 32P-labeled cloned HPV-EV as probe in Southern blot hybridization experiments, we detected HPV-EV-related DNA in the carcinoma in situ (Bowenoid lesion) of the vulva of the patient from which HPV-EV was isolated. HPV-EV-related DNA was detected in 2 of 10 vulva carcinomas and in 2 of 31 cervical carcinomas. Related DNA sequences were found in papillomas from each of two patients with condyloma acuminata (anogenital warts), which is of interest considering that condylomas have been reported to convert occasionally to carcinomas. The positive vulva DNAs were also probed with other cloned HPV DNAs: HPV-1, HPV-4, and HPV-5a-related sequences were not detected; HPV-3 and HPV-2 DNA probes detected strong and weak DNA bands, respectively, of the same size as found with HPV-EV. The HPV DNA sequences were present in the positive tumors mainly as free viral DNA molecules; no evidence for integration into cellular DNA was found. The emerging biological picture with papillomaviruses is that cells transformed by these viruses are maintained in a transformed state by free episomal genomes. Thus, our findings are consistent with the idea, but by no means establish, that HPVs play a role in human cancer by a similar mechanism.

Adult↗