摘要:

AbstractIncreasing cell size, lipid accumulation, and altered antigen expression are features of sebaceous differentiationin vivo. Enhanced lipid synthesis with progressive differentiation is also present in cultured human sebocytes. This study was conducted to investigate the evolution of cell size and antigen expression of human sebocyles with progressive differentiationin vitro. Subconlluent human sebocyte cultures were examined for sebocyte differentiation evaluated on cytocentrifuge preparations by light microscopy and classified in stages according to morphological criteria described for sebocytesin vivo. Rates of 5.1 ±2. 2% undifferentiated sebocytes. 29.2 ±4.9% early differentiated, 20.7 ±4.1% advanced differentiated, 37.6±6.4% fully differentiated, and 5.9± 1.9% mature sebocytes were calculated in secondary cultures. The size of cultured sebocytes measured by computer‐assisted planimetry significantly increased with progressive differentiation up to 4‐5.5 times. The low rates of mature sebocytes and the only moderate increase of their size with progressive differentiation indicate an incomplete terminal differentiationin vitro. Sebocytes were subsequently stained with a series of monoclonal antibodies (mAb) to determine antigen expression using the alkaline phosphatase anti‐alkaline phosphatase technique. The number of sebocytes labeled with the anti‐keratin mAb CK8.12 and KLI, and the mAb 34DII (82 kD protein) increased with progressive differentiation; significant differences were found after comparing early and advanced differentiated sebocytes. Sebocytes were positively stained with the anti‐keratin mAb 6BIO (K 4). RPNI162 (K 7), CK.I3 (K 13), RPNI165 (K 19). CK.8.60, and the mAb 115F5 (MAM‐6c). OM‐I (sebaceous gland antigen), and 24F10 (basic polypeptides) only at late‐stage differentiation. The expression of keratins 4, 7, 13, and 19 was confirmed by gel electrophoresis and immunoblotting. The data obtained were used to study the effects of the duration of cultivation and of the retinoids isotretinoin and tretinoin on sebocyte differentiationin vitro. Subcultivalion of sebocytes upregulaled, and treatment with isotretinoin but not with tretinoin downregulated labeling with mAb which recognize indicating progressive and late

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1994.tb00271.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractTo investigate the role of T cells in psoriasis, we analyzed the T‐cell receptor (TCR) repertoire in peripheral blood lymphocytes (PBLs) and in skin lesions of 9 patients with chronic plaque‐stage psoriasis by means of immunohistochemistry. An extended panel of monoclonal antibodies detecting 11 different V(3 families was employed in this study. In the peripheral blood, no predominant TCR Vβ expression was detected and interindividual differences were small. Skin‐infiltrating T cells showed only marginal differences in the TCR Vβ usage when compared with PBLs. However, in 3 patients the intraepidermal infiltrate comprised up to 40% of T cells expressing a TCR Vβ region which was virtually absent in the peripheral blood and the dermal infiltrate. Thus, although the TCR Vβ usage of skin‐infiltrating T cells showed little difference compared to PBLs, several cases exhibited a significant increase of epider‐motrophie T cells using one particu

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1994.tb00272.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe effects of prostaglandin E, (PGE) on cell growth, cytokine production and interaction of cultured normal human keratinocytes (NHKs) and human dermal fibroblasts (HDFs) were investigated. When NHKs were treated with PGE, directly, only a slight increase in cell growth and a transient decrease in interleukin 1 alpha (IL‐lα) secretion were observed. No IL‐6 was detected either before or after PGE, treatment. In addition, IL‐8 and transforming growth factor alpha (TGFα) production were uninfluenced by PGE. The response of HDFs to PGE, differed from that of NHKs. Following PGE1, treatment, IL‐lα and TGFα. from HDFs remained undetectable while IL‐6 production was enhanced markedly. IL‐8 production was also slightly enhanced. Exposure of HDFs to PGE, for 96 hours significantly promoted cell proliferation. Two kinds of conditioned media (CM) were prepared by a brief feeding of HDFs with keratinocyte basic medium or Dulbecco's modified Eagle's medium supplemented with 5% PCS with or without PGE. NHKs proliferated more rapidly in CM than in corresponding basic medium. Moreover, CM prepared with PGE, treatment showed a stronger effect in promoting NHK proliferation than CM without PGE, treatment. This promoting effect was inhibited by anti‐human IL‐6 monoclonal antibody dose‐dependently. These results indicate that fibroblasts are more sensitive than keratinocytes in response to PGE, and that, upon PGE, stimulation. HDF‐derived IL‐6 may play an essential role in NHK cell proliferation which may at least partly account for the beneficial effects of PGE, in the treatment

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1994.tb00273.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe sequence of maturation of nerves and appearance of neuropeptides was investigated in skin from fetal and neonatal rats by immunocytochemistry using antisera to protein gene product 9.5, substance P, calcitonin gene‐related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). Immunoreactivity for PGP 9.5 appeared on fetal day 16 in face and nose, somewhat later (fetal day 19) in paws and tail. The sensory neuropeptides, CGRP/substance P (fetal day 19 and postnatal day 1, respectively) appeared earlier than the autonomic peptides VIP and NPY (postnatal day 7). Thus, the study shows that neuropeptides do not appear simultaneously with nerves and that the development is rostrocauda

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1994.tb00274.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractHuman dermal mast cells are capable of releasing cytokines, particularly preformed TNFα, upon appropriate stimulation. Masl cell activationin vivowas shown to be associated with an influx and activation of inflammatory cells, initially PMN “polymorphonuclear neutrophilic granulocytes” then eosinophils. In order to learn more about the mechanisms by which TNFα is capable of activating eosinophils, in the present study the effect of TNFα on morphology and function of highly purified normal eosinophils “≥95%” was examined. As estimated by transmission and scanning electron microscopy, TNFα‐stimulated eosinophils appeared to be strictly adherent and flattened exhibiting a characteristic “hemispheric” shape. TNFα induced a dose‐dependent, long‐lasting production of reactive oxygen species as measured by lucigenin‐dependent chemiluminescence (CL). even at a concentration of 0.001 U/ml. The maximal response upon stimulation with TNFα, however, was significantly lower than optimal effects induced by IL‐5. TNFα‐induced responses were completely inhibited by cytochalasin B and staurosporin, and partially blocked by pertussis toxin. Separation of eosinophils by discontinuous density gradients revealed the existence of at least two hypodense eosinophil populations with a distinct susceptibility to stimulation with TNFα. Based on functional assay systems, in contrast to a significant extracellular, only a small intracellular H2O2: production was detected. Accordingly, H2O2production, detected by an ultrastructural technique, was observed only on the outer surface of the plasma membrane in the contact zones in between adjacent cells. Extracellular as well as intracellular production of H2O2; was completely inhibited by cytochalasin B. TNFα‐induced activation of eosinophils is most probably mediated by binding to the 55 kD and the 75 kD TNF‐receptor since both receptor molecules could be detected by FACS analysis and immune electron microscopy using receptor‐specific antibodies. However, in contrast to its effect on eosinophil oxidative response, TNFα did not induce the release of significant concentrations of eosinophil cationic protein or eosinophil peroxidase in supernatants of cytokine‐stimulated eosinophils, as detected by functional as well as immunological assay systems. These results clearly indicate that TNFα represents a potent eosinophil‐activating cytokine which may be of r

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1994.tb00275.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractTo characterize the T cells that are activated during the induction of contact hypersensitivity (CH), two sets of studies were conducted: 1) dinitrophenol (DNP)‐specific proliferative responses of T cells in draining lymph nodes of BALB/c mice sensitized epicutaneously to dinitro‐fluorobenzene (DNFB) were examined, and 2) from these lymph node cells, DNP‐specific T cells were cloned by limiting dilution microculture and analyzed by FACS for surface markers, by RT‐PCR, HT2 bioassay and ELISA for cytokine expression at mRNA and protein levels respectively, and by proliferation assay for cytokine and antigen‐presenting cell (APC) requirements. Our results show that αβ TCR‐bearing T cells of both the CD4+and CD8+subtypes from lymph nodes of DNFB‐skin‐painted mice proliferate specifically to dinitrobenzene sulfonate (DNBS) in vitro. Four DNP‐specific, CD4+T‐cell clones were characterized: clone 5S4 secreted IL‐4 and required 11‐4 for optimal growth; clone 5S10 secreted IL‐2 and required 1L‐2 for optimal growth; clone 5S2 secreted IL‐4 but required IL‐2 for optimal growth; and clone 5S8 secreted IL‐2 predominantly at 5 months, but switched to production of IL‐4 at 7 months. All four clones secreted IL‐10, and proliferated to DNBS when Langerhans cell (LC)‐enriched epidermal cells were used as APC. These findings indicate that heterogeneous populations of DNP‐specific T cells are activated in draining lymph nodes during

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1994.tb00276.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY