Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Langerhans cell (LC) migrates between the epidermis and the regional lymph nodes to present antigens. This migration pattern requires the expression of a changing repertoire of cell-surface molecules. In this work, we have investigated the expression of the adhesion molecules CD 11/CD 18 and CD 58 on LCs. Human epidermal cell suspensions were enriched in LCs (mean enrichment 75%) using a two-step technique including a Ficoll-Hypaque gradient followed by Fc receptor panning with IgG-coated sheep erythrocytes. The number of cells obtained per experiment was 750,000 (extremes 280,000-1,800,000), and the following antibodies were tested on fresh suspensions and/or after 48 hours in culture: BB3 (antithyroglobulin negative control IgG2a), OKT6 (anti CD1a, Ortho), anti HLA-DR (Becton-Dickinson), MHM 24 (anti CD 11a, leukocyte typing workshop n(0)3), MO1 and 44 (anti CD 11b, leukocyte typing workshop n(0)3), anti CD 11c (Immunotech), 60.3 and MHM 23 (anti CD 18, leukocyte typing workshop n(0)2), TS2/9.1.1 (anti CD 58, leukocyte typing workshop n(0)3). We found that amongst CD 11 subunits, only CD 11c was expressed in fresh suspensions, but was weaker than CD 18, and disappeared with culture. CD 58 was not detected in fresh suspensions but appeared after 2 days of culture, confirming earlier work. Thus the LC exhibits cell surface characteristics similar to tissue macrophages (CD 18 and CD 11c) prior to culture. The expression of CD 58 after culture is in accordance with the interaction of LC with CD2 bearing T-lymphocytes during antigen presentation in peripheral lymph-nodes.
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PMID:Flow cytometry analysis of adhesion molecules on human Langerhans cells. 145 12

The functional activity of skin cells derived from an infant who died of multisystem Langerhans cell histiocytosis (LCH) was examined. Involved and non-involved skin was obtained at postmortem examination within three hours of death; normal epidermal Langerhans cells and 'LCH cells' were separated by means of dispase digestion. The functional activity of different populations of CD1a positive cells was assessed using the conventional six day allogeneic mixed cell reaction. Compared with Langerhans cells from a healthy control, LCH cells showed minimal functional activity. However, Langerhans cells from non-involved skin showed normal and Langerhans cells overlying involved skin showed augmented functional activity. These findings suggest that LCH is a disease in which abnormal Langerhans cells accumulate and/or proliferate in various tissues but it does not affect the entire Langerhans cell population.
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PMID:Defective alloantigen-presenting capacity of 'Langerhans cell histiocytosis cells'. 147 89

Left (LV) and right ventricular (RV) filling was evaluated by pulsed doppler echocardiography in 56 hypertensive (HTN) untreated patients and in 30 normotensive (N) subjects, matched for age, body surface and heart rate. HTN were classified in two groups: HTN1: with normal LV mass index (LV mi) (< 135 g.m-2 for men, < or = 115 g.m.-2 for women); HTN2: with increased LV mi (> or = 135 g.m-2 for men, > or = 115 g.m-2 for women). All subjects had normal systolic function by echo. We derived: LV wall thickness (h), antero-posterior radius (r), h/r ratio, LV mi, ratio of early to late filling (E/A) in both ventricle. RESULTS. h and h/r were significantly in HTN1 (p < 0.01 vs N) and particularly in HTN2 (p < 0.001 vs N and HTA1). E/ALV and E/ARV were significantly decreased (p < 0.001) in both HTA compared to N. There was no significant difference between HTN1 and HTN2 concerning E/ALV and E/ARV. Relations of E/ALV and E/ARV with age, systolic blood pressure (SBP), LV mi, h, h/r: [table: see text] E/ALV is correlated to E/ARV (r = 0.37; p < 0.01) only in HTA. CONCLUSIONS. 1) In HTN in comparison with N: h, h/r are higher in the presence but also in the absence of increased LV mi. 2) In N and HTN: E/ALV and E/ARV are better correlated to h (and also to h/r in N) than to LV mi. Though the respective values of E/ALV and E/ARV are identical, they are correlated significantly only in HTN. 3) In the absence of the direct measures of the RV pressures and volumes, the interpretation of the results concerning the RV filling in uncertain. Only in HTN, they could be explained at least in part by the diastolic interplay between the two ventricles.
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PMID:[Doppler echocardiographic evaluation of right and left ventricular filling in hypertension]. 148 38

When screening skin cryosections with a panel of monoclonal antibodies (MoAb), we found that the anti-CD69 MoAb Leu-23 reacted with a subpopulation of epidermal dendritic cells, presumably Langerhans cells (LC). The staining intensity was enhanced by gentle trypsin pretreatment of the sections. Flow cytometric analysis of LC-enriched epidermal cells (EC) revealed that nearly all CD1a-bearing LC display anti-CD69 reactivity when tested briefly after termination of the enrichment procedure. Immunoprecipitation experiments showed that isolated LC specifically express a disulphide-linked dimer composed of 26/30kDa subunits that therefore slightly differs from the 28/32kDa CD69 complex described on activated T or natural killer (NK) cells. This difference is probably due to a different post-translational glycosylation pattern as evidenced by Endoglycosidase-F treatment of the immunoprecipitate disclosing the 24-kDa core protein of CD69. When freshly isolated LC-enriched EC were kept in culture, anti-CD69 reactivity gradually decreased but the addition of IFN-gamma to the culture medium sustained the CD69 expression on LC in vitro. These results strongly suggest that resident but not LC recovered from EC cultures bear CD69 moieties. It remains to be seen whether the expression of this antigen can be linked to (a) particular functional property (ies) of intraepidermal LC.
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PMID:CD69, an early activation antigen on lymphocytes, is constitutively expressed by human epidermal Langerhans cells. 156 26

We have cloned, mapped and sequenced the complete CDC14 gene of Saccharomyces cerevisiae and characterized its transcription during the cell cycle. CDC14 was found within a 3.5-kilobase pair XhoI-XbaI fragment of chromosome VI. The DNA sequence reveals an open reading frame capable of encoding a 423-amino acid polypeptide. Protein sequence comparisons through the Prosite, GenBank and EMBL databases allowed us to identify a conserved protein tyrosine phosphatase active site in the encoded CDC14 protein beginning at amino acid 153. Disruption demonstrates that CDC14 is an essential gene. The level of the CDC14 transcript appears to be weakly cell cycle-regulated and has a periodicity which lags approximately 15 min behind histone HTB1 mRNA accumulation levels. DNA sequence analysis has identified a region within the CDC14 promoter which bears a striking resemblance (15 out of 21 base pairs identity) to the cell cycle regulation region of the promoter of the histone H2A1-H2B1 (HTA1-HTB1) gene pair. The cell cycle regulation sequence is responsible for the periodic accumulation and hydroxyurea sensitivity of the histone HTA1-HTB1 message. However, unlike histone mRNA, which is repressed upon hydroxyurea arrest, CDC14 mRNA appears to be unaffected. This suggests that CDC14 and histone genes are regulated by different mechanisms during the cell cycle. Furthermore, superhelical density measurements suggest that CDC14 is not involved in nucleosome assembly.
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PMID:CDC14 of Saccharomyces cerevisiae. Cloning, sequence analysis, and transcription during the cell cycle. 159 62

Epidermal Langerhans cells express only very few Class I major histocompatibility complex (MHC) antigens, whose ability to present peptides released from the breakdown of endogenous proteins has not been investigated to date. Langerhans cells strongly express a "nonconventional" Class I molecule, the CD1a antigen. The role played by this antigen on the surface of Langerhans cells remains unelucidated: either release or uptake of peptides derived from the body has been speculated. Langerhans cells also express Class II MHC antigens and in vitro freshly recovered Langerhans cells are capable of capturing antigens, processing them and presenting the resulting peptides associated with Class II MHC molecules to immunocompetent cells. This property is not, however, permanent. Cultured Langerhans cells are no longer capable of processing antigens because they lose their ability to (i) acidify endosomes and (ii) produce the alpha, beta and invariant chains of class II MHC molecules. Cultured Langerhans cells acquire the capacity of stimulating T lymphocytes. This contrast between the in vitro properties of freshly recovered and cultured Langerhans cells may reflect in vivo differences between epidermal Langerhans cells and Langerhans cells which have migrated to regional lymph nodes.
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PMID:[Langerhans cells and presentation of antigens]. 160 51

Our knowledge of the functional activity of the epidermal Langerhans cell has been severely hampered by the lack of an easy method of purification of these cells that is both efficient and reproducible. In the present study we have used immunomagnetic beads directly conjugated to an IgM class mouse anti-human human leukocyte antigen DR monoclonal antibody to positively select human Langerhans cells from an epidermal cell suspension. Cells were then treated with a high-affinity polyclonal anti-mouse immunoglobulin that detached the beads by competing with the antigen for the antigen-binding site on the monoclonal antibody. This procedure allowed removal of the immunomagnetic beads, leaving Langerhans cells free from bound antibody. Recovery of Langerhans cells ranged from 40 to 80% of the starting number of Langerhans cells. The resulting cells were up to 99% CD1a positive and showed potent functional activity in the allogeneic mixed epidermal cell - lymphocyte reaction. Keratinocytes were shown to exert a profound inhibitory effect on Langerhans cell function that could not be prevented by indomethacin. This method is technically simple and allows good recovery of a highly purified population of Langerhans cells that are functionally active.
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PMID:Purification of functional active epidermal Langerhans cells: a simple and efficient new technique. 162 35

Changes in histone gene dosage as well as mutations within some histone genes suppress delta insertion mutations in the HIS4 and LYS2 loci of Saccharomyces cerevisiae by altering the site of transcription initiation. We have found that three histone regulatory (hir) mutations, identified by their effects on the regulation of histone gene expression, suppress the same insertion mutations. In addition, we have examined whether any previously identified spt (suppressor of Ty) mutations might suppress the delta insertion alleles because of effects on histone gene regulation. Our results demonstrate that mutations in the histone genes SPT11/HTA1 and SPT12/HTB1 and in three other SPT genes, SPT1, SPT10 and SPT21, confer Hir- phenotypes. The spt1 mutation was found to be an allele of HIR2 while the spt10 and spt21 mutations are not in any of the known HIR genes.
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PMID:Histone regulatory (hir) mutations suppress delta insertion alleles in Saccharomyces cerevisiae. 165 65

The cellular and molecular events taking place during epidermal antigen exposure in sensitized individuals are principally well understood. Epidermal Langerhans cells (LC) are supposed to take up, process, and express a given foreign substance on their cell surface. The antigen is then recognized by T cells bearing the appropriate T-cell receptor (TCR). Because LC do not bear variable antigen (Ag)-specific binding sites, one could postulate that the epidermal exposure of any substance should activate LC and other cells of the skin immune system. To test this hypothesis, we analyzed immunophenotypically the cellular trafficking events in positive (n = 5) and negative epicutaneous patch-test reactions (n = 10), using a panel of monoclonal antibodies against CD1a, CD11c (Ki-M1, LeuM5), CD68 (Ki-M6), Ki-M8, and CD3 (Leu4). We can demonstrate that irrespective of whether or not an antigen will be responded to by the immune system (i.e., positive or negative test reaction), epidermal antigen exposure causes a decrease of LC density in the epidermis and simultaneously causes an increase of LC in the dermis. Moreover, monocytes and T cells immigrate into the dermis both in positive and negative patch-test reactions. As is to be expected, the degree of this cellular traffic is more pronounced in positive test reactions, which may be due to amplification mechanisms caused by antigen recognition of sensitized T cells. This finding demonstrates that human skin contains cell migration programs that ensure that any foreign substance will be accessible to the skin immune and phagocytic system.
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PMID:Cell trafficking in positive and negative patch-test reactions: demonstration of a stereotypic migration pathway. 167 41

Normal human skin was exposed to two different detergents, sodium lauryl sulphate in distilled water and non-anoic acid in isopropanol at different concentrations. The detergents were applied under occlusion in epicutaneous tests for 24 h and biopsies were taken at 24 or 48 h. Frozen sections were labelled with monoclonal antibodies against CD1a, CD3 and ICAM-1. The evaluation of the labelled sections showed that there were differential effects on the expression of ICAM-1 and CD1a+ cells in epidermis. After non-anoic acid application ICAM-reactivity could not be detected and there was a decrease of staining for CD1a after exposure to 80% non-anoic acid. Sodium lauryl sulphate treatment, however, induced ICAM-1 expression on keratinocytes and had minor effects on the number of CD1a+ cells. ICAM-1 expression was also detected in normal epidermis in 3 of 9 unexposed control biopsies and after occlusion with the vehicles distilled water and isopropanol. An increased amount of CD3+ cells was found in the skin exposed to both detergents. The results show that there are dose and time dependent variations in the epidermal response to irritants which might influence the immunological events taken place in the epidermis.
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PMID:Differential effects of sodium lauryl sulphate and non-anoic acid on the expression of CD1a and ICAM-1 in human epidermis. 168 65


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