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Biomedical subjects

U Reinhold

Publications and source records attributed to U Reinhold.

At least 91 records · Page 5Linked to original sources

Interleukin-4 promotes the expansion of skin-infiltrating lymphocytes from atopic dermatitis in vitro.

Functional studies of lymphocytes in atopic dermatitis (AD) have so far focused on peripheral blood mononuclear cells (PBMC), whereas cells at the involved site, the skin, have not been examined. Accordingly, we have developed methods to generate lymphocyte cultures from biopsies of inflammatory skin areas. Skin-infiltrating lymphocytes (SIL) were isolated from skin biopsies of 6 patients with severe AD and expanded in vitro in the presence of interleukin-2 (IL-2) without additional antigens. After 6-10 d in culture, outgrowth of mononuclear cells from biopsy tissue was observed in all cases. Phenotypic analysis of skin-derived cells revealed the predominance of CD4+ T-helper/inducer phenotype in SIL populations. Parallel cultures of SIL and PBMC showed an increase and expansion of CD8+ T cells in cultured PBMC, whereas the CD4+ phenotype was predominant in SIL cultures. As indicated by their expression of HLA-DR and CD25 antigens, most of the SIL were activated and the cells mainly expressed T-cell receptors (TCR) composed of alpha and beta chains. Different strategies for expansion of SIL in vitro were examined. High levels of IL-4 (1,000 U/ml) in combination with IL-2 (50 U/ml or 1,000 U/ml) preferentially promoted growth of SIL derived from AD and were much more effective than IL-2 alone. No cells expanded in cultures with IL-4 alone. SIL grown with high concentrations of IL-4 contained a significant proportion of double-positive CD4+8+ cells. No other marked differences were observed in the distribution of T cell subsets in cultures propagated under different conditions for 21 d. Our results demonstrate the feasibility of growing infiltrating T lymphocytes from inflammatory skin of AD patients. The use of high concentrations of IL-2 in combination with high levels of IL-4 allows a large expansion of these cells and thus represents a useful strategy to expand cells for further functional and molecular biologic studies.

Adult↗

Functional characterization of skin-infiltrating lymphocytes in atopic dermatitis.

Skin-infiltrating lymphocytes (SIL) were isolated from skin biopsies of patients with hyperimmunoglobulin E (IgE) atopic dermatitis (AD) and expanded in vitro in the presence of IL-2 in combination with IL-4. Phenotypic analysis of skin-derived cells revealed the predominance of CD4+ T helper/inducer phenotype in SIL populations. In 3H-thymidine incorporation assays, SIL showed proliferation in response to IL-2, IL-3, IL-4, ionomycin (Io) + 12-o-tetradecanoyl-phorbol-13-acetate (TPA) and OKT3 + TPA. OKT4 with and without TPA did not induce proliferation. Tumour necrosis factor alpha (TNF-alpha) did not block proliferative responses of SIL to IL-2 and IL-4. Cultured SIL showed no cytotoxic activity against K562 and Jurkat target cells. Expanded skin-derived T cells were tested for their capacity to secrete several cytokines in vitro. SIL secreted significant amounts of IL-4, GM-CSF and TNF-alpha upon stimulation with mitogens but failed to secrete IFN-gamma. Io in combination with phorbol-ester induced the secretion of larger amounts of IL-4, GM-CSF, TNF-alpha and low amounts of IFN-gamma. The data indicate that SIL derived from AD lesions were defective in their capacity to secrete IFN-gamma but were enriched in T cells capable of producing IL-4 upon stimulation. The results support the possibility of a predominant 'TH2-like' cell-mediated immune response in lesional skin of AD patients.

Antibodies, Monoclonal↗

Phenotypic and functional characterization of tumor infiltrating lymphocytes in mycosis fungoides: continuous growth of CD4+ CD45R+ T-cell clones with suppressor-inducer activity.

Tumor-infiltrating lymphocytes (TIL) were obtained by mechanical release from a solitary rapidly grown tumor of a patient with mycosis fungoides. The preparations separated by density gradient centrifugation contained a major portion of CD3+ CD8+ WT31+ CD5- large T-cell blasts and a minor portion of non-blastic TIL predominantly of the CD3+ CD4+ phenotype. Using cDNA-probes for the constant region of the T-cell receptor beta-genes, the large cell fraction was identified as tumor by its distinct monoclonal rearrangement. TIL were expanded by culture in recombinant interleukin 2 and cloned by limiting dilution. Phenotypic analysis of expanded TIL and two clones further analyzed in more detail showed CD3+, CD4+, CD8-, and 2H4+ (CD45R+) expression. Cloned and uncloned TIL showed no NK and LAK activity, no proliferative response, and no cytotoxic activity against autologous tumor cells. These cells were unable to suppress the proliferative response of alloreactive T-cell clones stimulated by B-lymphoblastoid cell lines (i.e., they had no suppressor-effector activity), but strongly suppressed proliferation responses in allogeneic mixed lymphocyte culture (i.e., they most likely had suppressor-inducer activity). This was not the case when irradiated tumor cells were added. The present results demonstrate continuous in vitro growth of CD4+ and 2H4+ T-cell clones with suppressor-inducer activity obtained from TIL, and indicate that a subpopulation of TIL may down-regulate immune responses which may lead to suppression of antitumor immunity.

Antigens, CD↗

Evidence that defective interferon-gamma production in atopic dermatitis patients is due to intrinsic abnormalities.

The in vitro production of interferon-gamma (IFN-gamma) in 19 atopic dermatitis (AD) patients was compared with that of 12 controls. IFN-gamma production by phytohaemagglutinin (PHA) stimulated peripheral blood mononuclear cells (PBMC) was profoundly diminished in AD patients, whereas the proliferative response was similar to that of control PBMC. The addition of 40 U/ml of interleukin-2 (IL-2) to the cultures failed to restore IFN-gamma production. Similarly, removal of adherent cells also had no effect. Reduced IFN-gamma secretion was observed after stimulation with the CD3 monoclonal antibody OKT3, ionomycin + 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or with high levels of IL-2 (200 U/ml). There were increased proportions of CD4+ T helper/inducer cells and decreased proportions of CD8+ T cytotoxic-/suppressor cells and CD16+ natural killer (NK) cells in AD patients. This resulted in an increased CD4/CD8 ratio as compared with controls, but no correlation was observed between numbers of T cell subpopulations and IFN-gamma generation. However, a significant correlation was found between IFN-gamma generation in vitro and IgE serum concentration in AD patients. The data suggest that the decreased production of IFN-gamma by AD patients is due to intrinsic differences in capacity to produce this cytokine and is not the result of differences in regulatory cell interactions. Moreover, the findings indicate that decreased production of IFN-gamma may be an important factor in the pathogenesis of this disease.

Adult↗

Selective alterations in natural killer cell subsets in patients with atopic dermatitis.

We examined the immunophenotypic characteristics of natural killer (NK) cell subsets in patients with severe atopic dermatitis (AD), rhinitis allergica (RA) and in healthy controls. Expression of CD16, CD56 and CD57 antigens on peripheral blood lymphocytes was evaluated by simultaneous double immunocytofluorometry. Our results showed significantly lower percentages of cells with CD16, CD56 and CD57 surface antigens in patients with AD. Furthermore subdivision of the AD group into two subgroups, AD1 and AD0 (with and without antigen-specific IgE antibodies against potent inhalative allergens, i.e. mite, grass, rye, birch, cat) revealed that patients of subgroup AD1 showed a more prominent decrease compared to that of subgroup AD0. Moreover, we found a significant negative correlation between the percentage of CD56 + CD16 + NK cells and total IgE levels in serum, which were significantly higher in patients of subgroup AD1 than in AD0. NK cell activity was deficient in patients with AD but there was no difference between both subgroups. These data indicate that considerable heterogeneity in immunologic regulation may exist in patients with AD with regard to their NK cell subsets.

Adult↗

In vitro generation of IFN-gamma in relationship to in vivo concentration of IgE and IgG subclasses and Fc epsilon Rl/CD23 positive circulating lymphocytes in patients with severe atopic dermatitis (AD).

In fifteen patients with severe atopic dermatitis (AD) and ten healthy controls we investigated the in vitro generation of IFN-gamma and analysed the number of Fc epsilon RL/CD23 (low affinity Fc receptor for IgE) positive lymphocytes. We found a significantly impaired capacity to secrete IFN-gamma after PHA-stimulation compared to controls in a significant proportion of patients. Serum IgG4 levels in patients were higher compared to controls. A significant portion of lymphocytes bearing the low affinity Fc receptor for IgE (CD23) was observed with the moab Tü1 in patients. Lymphocytes from healthy donors were completely negative or less than 2% positive for Tü1. Despite small numbers of patients a significant correlation was found between IFN-gamma generation in vitro and IgE serum concentration in patients, whereas the IFN-gamma generation and IgG4 concentration were negatively correlated in the patient group. The number of Fc epsilon RL/CD23 positive lymphocytes in patients was positive correlated with the serum IgG4 and IgE concentration and negative correlated with IFN-gamma generation in vitro. Our data suggest that a possible dysregulation of IFN-gamma, Interleukin 4 or other lymphokine production may be related to increased IgE and IgG4 production.

Adolescent↗

Serum selenium levels in patients with malignant melanoma.

The incidence of malignant melanoma of the skin has increased rapidly among white people during the last decade. Although the pathogenesis of malignant melanoma is not clear, epidemiologic data and experimental work indicates that ultraviolet (UV) radiation plays a critical role in tumorigenesis. Recent data implicate peroxidative reactions in UV-carcinogenesis and clearly demonstrate that selenium (Se) confers protection, in part by inducing cellular-free radical scavenging systems and by enhancing peroxide breakdown, thus enhancing the capacity of the cell to cope with oxidant stress. With this in mind, we investigated the Se status of 101 patients with malignant melanoma. Our study revealed significantly lower Se levels in the sera of melanoma patients than of controls. Although patients in all clinical stages had lower Se levels than the controls, patients in stage III (disseminated melanoma) had the lowest levels. Separate analysis of histogenetic subtypes of melanoma revealed that lentigo maligna melanoma (LMM) and superficial spreading melanoma (SSM) had the strongest association with depressed Se serum levels. Our results, showing for the first time that malignant melanoma is associated with low Se concentrations, are consistent with results of epidemiologic studies showing an inverse correlation between serum Se levels and certain cancers.

Adult↗

Cytokine release from cultured peripheral blood mononuclear cells of patients with severe atopic dermatitis.

Peripheral blood mononuclear cells (PBMC) from 14 patients with severe atopic dermatitis (AD) and 11 healthy donors were tested for their capacity to produce tumour necrosis factor-alpha (TNF-alpha) after PHA stimulation and compared with their in vitro production of interferon-gamma (IFN-gamma). The mean TNF-alpha production in AD patients did not differ vis-à-vis controls. However, a significant portion of patients with AD which was defective in generating IFN-gamma in vitro showed in addition significantly a decreased production of TNF-alpha. No correlation could be found between TNF-alpha and neopterin production in either group, whereas there was a close overall correlation between the amount of TNF-alpha and IFN-gamma detectable in culture supernatants of patients and controls. Furthermore, a significant correlation was found between TNF-alpha and IFN-gamma generation in vitro and serum IgE concentration in AD. Based on cytokine production in vitro and IgE concentration in vivo, patients with severe AD could be divided into two groups. Furthermore, 3 AD patients with normal IFN-gamma generation and low serum IgE concentration but suffering from eczema herpeticum formed a subgroup which showed an increased TNF-alpha production in vitro. The data suggest alterations in cytokine production in a subgroup of patients with AD which bear a reciprocal relationship to abnormal IgE regulation.

Biopterins↗

Division of human helper T cells into two sets on the basis of the induction of anti-tumor cytotoxicity by phorbol ester and calcium ionophore.

Fourteen noncytotoxic human helper T cell clones were examined for autocrine proliferative responses and cytotoxicity to tumor cells after stimulation with 12-O-tetradecanoylphorbol 13-acetate (TPA) and ionomycin (Io). Although all clones responded to alloantigen, they could be divided into two groups based on their proliferative response or lack of it to TPA/Io. Nonresponders could not be converted to responder status by addition of interleukin (IL) 1 or indomethacin to the cultures. Responder status did not correlate with any of the following properties of the clones: originating donor, recognitive specificity, B cell helper activity, proliferative response to IL 2 or 4, lymphokine secretory capacity or density of expression of antigen receptors, CD4 or HLA class II molecules. Responder status did, however, correlate with the ability of TPA/Io to induce major histocompatibility complex-unrestricted cytolytic activity directed towards natural killer-resistant tumor cells. These results divide human helper cells into two types on the basis of induction of anti-tumor cytotoxicity.

Antigens, Differentiation, T-Lymphocyte↗

Immunoglobulin E and immunoglobulin G subclass distribution in vivo and relationship to in vitro generation of interferon-gamma and neopterin in patients with severe atopic dermatitis.

In vitro interferon-gamma (IFN gamma) and neopterin generation by peripheral blood mononuclear cells (PBMC) from 15 patients with severe atopic dermatitis (AD) and 10 healthy controls was investigated. A significant proportion of patients had an impaired capacity to secrete IFN gamma after phytohemagglutinin (PHA) stimulation in vitro and therefore IFN gamma production was significantly lower compared to controls. Neopterin generation in vitro did not differ significantly from that of controls and no correlation between in vitro IFN gamma and neopterin production could be observed in either group. Analysis of serum IgG subclass distribution showed that patients with AD. had increased IgG4 serum concentrations while IgG1, IgG2 and IgG3 levels did not differ significantly from those of controls. Surface marker analysis revealed increased numbers of CD23+ lymphocytes in patients with AD which was positively correlated with the serum IgG4 and IgE concentration. Furthermore, a significant correlation was found between IFN gamma generation in vitro and IgE and IgG4 concentration in vivo in AD. The data suggest that a possible dysregulation of IFN gamma, interleukin-4 or other lymphokine interleukin-4 or other lymphokine production may be related to increased IgE and IgG4 production and seems to be an important factor in the pathogenesis of AD.

Adult↗

[Clinico-immunological analysis of the significance of natural killer cells in skin diseases].

Natural killer (NK) cells comprise a heterogeneous subpopulation of mononuclear cells with the capacity to spontaneously lyse neoplastic, virus-infected and special physiological cells. As such, they have been widely implicated in the regulation of immune function by secretion of several cell-specific substances. Measurement of NK-cell activity in vitro and identification of NK-cell subsets using multi-colour immunofluorescence and flow cytometry analysis are helpful techniques for the recognition of abnormalities in the NK-cell system. Experimental and clinical studies have shown that NK cells may play an important role in natural resistance to tumours in vivo, certain viruses and other microbial diseases. Defective NK activity has been described in various dermatological diseases, such as cancer, infections and autoimmune diseases. Recent data have shown that several kinds of therapy influence NK-cell activity. This review describes the relationship between NK cells and dermatological diseases as well as clinical treatment.

Autoimmune Diseases↗

Specific application of single nutrients as a basic treatment in immunostimulating therapy.

Many results of biochemical and animal experiments as well as clinical trials provide justification for the administration of essential fatty acids (EFAs) as a supplementary therapy in rheumatic diseases, atopic disorders and chronic infections. Defective regulation of inflammatory responses or disordered immune mechanisms are probably central to the pathologic processes encountered in chronic inflammatory diseases and immunologic disorders. Epidemiologic studies indicate that vitamins and trace elements are often provided at levels much below the currently accepted minimum requirement and therefore other factors, namely zinc, selenium, niacin, pyridoxine, vitamin A, E and folic acid must also be considered in substitution. In order to optimize immunostimulating therapy the negative influence of suboptimal levels of EFAs, vitamins and trace elements should always be taken into account.

Adjuvants, Immunologic↗

[Malnutrition and the immune system].

The immune system is governed by a large number of influences. An important support of the nutritional dependent changes of the reaction to immunity is represented by the prostaglandin and leukotriene system. The basis are essential and non-essential highly unsaturated fatty acids which are transformed by the body's own enzyme system in oxidative steps. As coenzyme and cosubstrate, for instance Vitamin B6 and zinc, are needed--tests show the influence of pyridoxine and folic acid on the immune system. The significance of minerals, especially zinc, iron and selenium, for the immune metabolism will be demonstrated. Selenium deficiency leads, evidently, to a reduction in the ability to stimulate the lymphocytes and decreases the phagocytosis index of the macrophages--some risk groups, responsible for the appearance of the state of malnutrition, will be pointed out and pharmaco-therapeutic prevention measures will be described.

Avitaminosis↗

[Deficit of natural killer cells (NK cells) in the peripheral blood of patients with atopic dermatitis].

Immunoregulatory T-cell subsets of the peripheral blood were measured using monoclonal antibodies (Leu series) in a group of 30 patients with atopic dermatitis and 20 healthy control persons. A highly significant reduction (P less than 0.001) in the percentage of Leu 11a+ (NK) and Leu 7+ (K/NK) cells was found in the peripheral blood of patients with atopic dermatitis. The proportion of Leu 2a+ cells (cytotoxic/suppressor) was significantly (P less than 0.001) lower in the patient group. The immunoregulatory ratio of Leu 3a+/Leu 2a+ T cells (helper/suppressor) was significantly (P less than 0.001) higher in the patient group (4.3 +/- 0.3) than in the blood of control persons (2.2 +/- 0.1). The percentage of Leu 11a+ cells was positively correlated with the percentage of Leu 2a+ cells (r = 0.67) and negatively correlated with the ratio of Leu 3a+/Leu 2a+ T cells (r = -0.63).

Adolescent↗

Class-specific effects of selenium on PWM-driven human antibody synthesis in vitro.

The influence of inorganic and organic forms of selenium (Se) on human antibody production was studied in a Pokeweed Mitogen (PWM)-driven in vitro system. Mitogen-stimulated peripheral blood mononuclear cells (PBMC) of eight healthy donors were cultured with different Se compounds at concentrations between 10(-3) and 10(-9) M. At high Se levels (10(-3)-10(-4) M), IgM and IgG production of all donors were strongly inhibited owing to reduced cell viability. However, in five of eight donors, low levels of Se enhanced IgG secretion. This was most effective in the presence of inorganic Se, whereas selenomethionine and selenocystine were less effective. In contrast to IgG, IgM synthesis was significantly reduced by low Se levels in five donors. No significant correlation between donor serum Se levels and antibody production in vitro was found. The addition of low levels of Se to PBMC, stimulated with PHA or PWM, showed no effect on proliferation, whereas a high concentration (5 x 10(-3) M) of sodium selenite and selenocystine suppressed proliferation owing to reduced cell viability. Thus, the present results show that Se supplementation can enhance human antibody production and, moreover, suggest some selectivity of Se action on human immune responses that may result in increased switching from IgM to IgG production.

Antibody Formation↗

Multiple granular cell tumors and growth hormone deficiency in a child.

Granular cell tumor is an uncommon benign tumor occurring on the skin as a single nodule. Multiple tumors are very rare, particularly in children. We describe a child with multiple granular cell tumors on the skin in association with growth hormone deficiency. The occurrence of multiple granular cell tumors in association with other clinical manifestations in childhood is discussed.

Child↗