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1.
Clin Exp Dermatol ; 47(3): 553-560, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34674296

ABSTRACT

BACKGROUND: The landscape of dermatology services, already rapidly evolving into an increasingly digital one, has been irretrievably altered by the COVID-19 (SARS-CoV-2) pandemic. Data are needed to assess how best to deliver virtual dermatology services in specific patient subgroups in an era of ongoing social distancing and beyond. Initial studies of teledermatology in paediatric populations suggest that many of the problems experienced in adult telemedicine are more apparent when treating children and come with additional challenges. AIM: To evaluate the efficacy of a virtual paediatric dermatology telephone clinic in comparison to traditional face-to-face (FTF) clinics, both from the clinician and patient/parental perspective. METHODS: We carried out a prospective service evaluation examining a single centre cohort of paediatric dermatology patients managed during the COVID-19 pandemic via a telephone clinic supported by images. The study period covered June-September 2020. Data on outcomes were collected from clinicians and a qualitative patient/parental telephone survey was undertaken separately. A five-point Likert scale was used to assess both satisfaction and levels of agreement regarding whether a telephone clinic was more convenient than an FTF clinic. RESULTS: Of 116 patients included, 24% were new and 76% were follow-up patients, with a mixture of inflammatory dermatoses (75%) and lesions (25%). From the clinician's perspective, most consultations (91%) were successfully completed over the telephone. However, qualitative patient and parent feedback paradoxically illustrated that although nearly all (98%) respondents had no outstanding concerns, 52% felt highly unsatisfied and only 22% agreed that telephone clinics were more convenient. Most (65%) preferred FTF follow-up in the future. Statistical analysis using χ² test showed that among those with established follow-ups, the preference for future consultation type was independent of specific reasons for follow-up. CONCLUSIONS: Our study demonstrates a clear discrepancy between the practical successes of a virtual service from the clinician's perspective compared with the patient/parental perspective. Parental anxiety appears to be less effectively allayed virtually than with FTF. This raises the question of whether there is a role for virtual paediatric telephone clinics in the postpandemic future, which may be better left to patients/parents to decide on an individual basis.


Subject(s)
Attitude of Health Personnel , Dermatology , Patient Preference , Patient Satisfaction , Remote Consultation , Adolescent , Ambulatory Care Facilities , COVID-19 , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Pandemics , Prospective Studies , Surveys and Questionnaires
2.
Clin Exp Dermatol ; 46(3): 544-547, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33135201

ABSTRACT

The entire landscape of dermatology service provision has been transformed by the current SARS-CoV-2 (COVID) pandemic, with virtual working having become the new norm across the UK. A pre-pandemic UK-wide survey of dermatology registrars in training demonstrated a huge shortfall in trainee confidence in their teledermatology skills, with only 15% feeling even slightly confident, while 96% of trainees surveyed felt that more teaching in this area was needed. We carried out a follow-up trainee survey during the COVID-19 pandemic, which showed that the sudden thrust into virtual working had achieved dramatic gains in trainee confidence, propelling the percentage of trainees that now felt slightly confident to 58%. However, the shortfall remains, as does the pressing need to incorporate teledermatology into the trainee teaching timetable.


Subject(s)
COVID-19/epidemiology , Dermatology/education , Pandemics , Remote Consultation , Teleworking , Clinical Competence , Follow-Up Studies , Humans , SARS-CoV-2 , Surveys and Questionnaires , United Kingdom/epidemiology
4.
Clin Exp Dermatol ; 29(3): 328-30, 2004 May.
Article in English | MEDLINE | ID: mdl-15115532

ABSTRACT

Cancer registries are used to compare incidences between regions, plan for service provision, and to assess the impact of health interventions. Significant variation in data capture for skin cancers and reporting of results was evident between regional cancer registries in the UK when assessed in 1991. Using a postal questionnaire we sought to document methods of recording skin cancer incidence in the UK in 2000, and to assess if practice has changed from 1991. All UK cancer registries were asked for details of their method of skin cancer case registration and latest available incidence figures. Methodology was assessed against recently implemented national standards. All registries responded to the survey. Sources of data were more uniform than was the case 9 years ago. All registries except one attained national standards for basal cell carcinoma data collection, but only half of the registries attained standards for squamous cell carcinoma. Ten of the 12 correctly recorded numbers of malignant melanomas, but three still failed to record the Breslow thickness or Clarke's level. Wide variation is evident in the recorded incidences for each of the malignancies, and the efficiency at which figures are made available. Thus, although there has been improvement since 1991, variability still exists between UK registries in methods of data capture, the data recorded, and efficiency of data processing in skin cancer registration.


Subject(s)
Registries/standards , Skin Neoplasms/epidemiology , Carcinoma, Basal Cell/epidemiology , Carcinoma, Squamous Cell/epidemiology , Humans , Incidence , Melanoma/epidemiology , United Kingdom/epidemiology
5.
Blood ; 98(10): 3058-65, 2001 Nov 15.
Article in English | MEDLINE | ID: mdl-11698291

ABSTRACT

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor (TNF) family, binds to several cell-surface receptors with distinct functions (agonistic receptors 1 and 2 [TRAIL-R1, TRAIL-R2]; decoy receptors 3 and 4 [TRAIL-R3, TRAIL-R4]). Expression and function was characterized in patients with myelodysplastic syndromes (MDSs). While normal marrow showed negligible expression of TRAIL and receptors (except TRAIL-R3), TRAIL and all receptors were constitutively expressed in MDS marrow. Following TRAIL exposure, MDS marrow showed significant increases in apoptosis, whereas normal marrow, except for a subset of CD34+ precursors, did not (P =.012). Marrow from 21 patients with MDS was then propagated in long-term cultures in the presence or absence of TRAIL. While in advanced MDS (refractory anemia with excess blasts in transformation [RAEB-T] and tAML [MDS transformed into AML]), colony numbers decreased in the presence of TRAIL (63.0% +/- 10.4% of untreated group [100%]), numbers increased in patients with RA or RAEB (160.2% +/- 90.5% of untreated group). TRAIL eliminated preferentially clonally abnormal cells as identified by chromosomal markers. Thus, TRAIL and receptor expression differed significantly between normal and MDS marrow, and TRAIL modulated in vitro hemopoiesis in MDS dependent upon disease stage but not, to a detectable extent, in normal marrow.


Subject(s)
Hematopoiesis , Intracellular Signaling Peptides and Proteins , Membrane Glycoproteins/biosynthesis , Myelodysplastic Syndromes/metabolism , Receptors, Tumor Necrosis Factor/biosynthesis , Tumor Necrosis Factor-alpha/biosynthesis , Aneuploidy , Apoptosis , Apoptosis Regulatory Proteins , Blotting, Western , Bone Marrow Cells/metabolism , CASP8 and FADD-Like Apoptosis Regulating Protein , Carrier Proteins/biosynthesis , Carrier Proteins/genetics , Cells, Cultured/metabolism , Chromosome Aberrations , Colony-Forming Units Assay , GPI-Linked Proteins , Gene Expression Regulation , Hematopoietic Cell Growth Factors/pharmacology , Humans , In Situ Hybridization, Fluorescence , Leucine Zippers , Membrane Glycoproteins/genetics , Membrane Glycoproteins/pharmacology , Myelodysplastic Syndromes/genetics , Myelodysplastic Syndromes/pathology , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/genetics , RNA, Messenger/biosynthesis , Receptors, TNF-Related Apoptosis-Inducing Ligand , Receptors, Tumor Necrosis Factor/genetics , Receptors, Tumor Necrosis Factor, Member 10c , Recombinant Fusion Proteins/pharmacology , Reverse Transcriptase Polymerase Chain Reaction , TNF-Related Apoptosis-Inducing Ligand , Tumor Necrosis Factor Decoy Receptors , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/pharmacology
7.
J Immunol ; 165(2): 786-94, 2000 Jul 15.
Article in English | MEDLINE | ID: mdl-10878352

ABSTRACT

CD153 (CD30 ligand) is a member of the TNF ligand/cytokine family expressed on the surface of human B cells. Upon exposure to IL-4, a critical Ig class switch-inducing cytokine, Ag-activated T cells express CD30, the CD153 receptor. The observation that dysregulated IgG, IgA, and/or IgE production is often associated with up-regulation of T cell CD30 prompted us to test the hypothesis that engagement of B cell CD153 by T cell CD30 modulates Ig class switching. In this study, we show that IgD+ IgM+ B cells up-regulate CD153 in the presence of CD154 (CD40 ligand), IL-4, and B cell Ag receptor engagement. In these cells, CD153 engagement by an agonistic anti-CD153 mAb or T cell CD30 inhibits S mu-->Sgamma, Smu-->Salpha, and S mu-->Sepsilon class switch DNA recombination (CSR). This inhibition is associated with decreased TNFR-associated factor-2 binding to CD40, decreased NF-kappaB binding to the CD40-responsive element of the Cgamma3 promoter, decreased Igamma3-Cgamma3 germline gene transcription, and decreased expression of Ku70, Ku80, DNA protein kinase, switch-associated protein-70, and Msh2 CSR-associated transcripts. In addition, CD153 engagement inhibits IgG, IgA, and IgE production, and this effect is associated with reduced levels of B lymphocyte maturation protein-1 transcripts, and increased binding of B cell-specific activation protein to the Ig 3' enhancer. These findings suggest that CD30+ T cells modulate CSR as well as IgG, IgA, and IgE production by inducing reverse signaling through B cell CD153.


Subject(s)
B-Lymphocyte Subsets/immunology , Immunoglobulin Class Switching/immunology , Immunoglobulin D/biosynthesis , Immunoglobulin M/biosynthesis , Ki-1 Antigen/biosynthesis , Membrane Glycoproteins/immunology , Recombination, Genetic/immunology , Repressor Proteins , T-Lymphocyte Subsets/immunology , B-Lymphocyte Subsets/metabolism , Binding, Competitive/immunology , CD28 Antigens/immunology , CD28 Antigens/metabolism , CD30 Ligand , CD40 Antigens/immunology , CD40 Antigens/metabolism , CD40 Ligand , Cell Differentiation/immunology , Cell Line , Cells, Cultured , Cytokines/physiology , DNA-Binding Proteins/metabolism , Germinal Center/cytology , Germinal Center/immunology , Germinal Center/metabolism , Humans , Immune Tolerance/genetics , Immunoglobulin Constant Regions/biosynthesis , Immunoglobulin Constant Regions/genetics , Immunoglobulin G/biosynthesis , Immunoglobulin alpha-Chains/biosynthesis , Immunoglobulin alpha-Chains/genetics , Immunoglobulin epsilon-Chains/biosynthesis , Immunoglobulin epsilon-Chains/genetics , Immunoglobulin gamma-Chains/biosynthesis , Immunoglobulin gamma-Chains/genetics , Immunoglobulin mu-Chains/biosynthesis , Immunoglobulin mu-Chains/genetics , Immunophenotyping , Interleukin-4/antagonists & inhibitors , Interleukin-4/physiology , Ki-1 Antigen/metabolism , Ligands , Membrane Glycoproteins/antagonists & inhibitors , Membrane Glycoproteins/biosynthesis , Membrane Glycoproteins/metabolism , Membrane Glycoproteins/physiology , Nuclear Proteins/metabolism , PAX5 Transcription Factor , Palatine Tonsil/cytology , Palatine Tonsil/immunology , Palatine Tonsil/metabolism , Plasma Cells/immunology , Positive Regulatory Domain I-Binding Factor 1 , Promoter Regions, Genetic/immunology , Protein Binding/immunology , Proteins/metabolism , Receptors, Antigen, T-Cell/immunology , Receptors, Antigen, T-Cell/metabolism
9.
Eur J Immunol ; 29(11): 3466-77, 1999 11.
Article in English | MEDLINE | ID: mdl-10556801

ABSTRACT

Using the monoclonal antibody C1.7, which recognizes a signaling, membrane-bound molecule on human NK and a proportion of CD8(+) T cells, we cloned a novel molecule we refer to as NK cell activation-inducing ligand (NAIL). It is a 365-amino acid protein that belongs to the immunoglobulin-like superfamily with closest homology to murine 2B4, and human CD84 and CD48. Using a soluble NAIL-Fc fusion protein, we determined the counterstructure for NAIL, CD48, which it binds with high affinity. Stimulation of human B cells with recombinant NAIL in the presence of a suboptimal concentration of human CD40 ligand or IL-4 resulted in increased proliferation. Treatment of human dendritic cells with soluble NAIL-leucine zipper protein resulted in an increased release of IL-12 and TNF-alpha. Using recombinant CD48 protein, we demonstrated the ability of this molecule to increase NK cell cytotoxicity and induce IFN-gamma production. We also showed that 2B4 binds to mouse CD48, suggesting that interaction of these receptors may play a similar role in both species. Taken together these results indicate that the NAIL-CD48 interaction may be an important mechanism regulating a variety of immune responses.


Subject(s)
Antigens, CD/metabolism , Killer Cells, Natural/metabolism , Membrane Proteins/metabolism , Amino Acid Sequence , Animals , B-Lymphocytes/cytology , CD48 Antigen , Cell Division , Cloning, Molecular , Cytokines/biosynthesis , Cytotoxicity, Immunologic , Humans , Immunoglobulin Fc Fragments/metabolism , Interferon-gamma/biosynthesis , Jurkat Cells , K562 Cells , Ligands , Membrane Glycoproteins/metabolism , Membrane Proteins/genetics , Membrane Proteins/immunology , Mice , Molecular Sequence Data , Phosphorylation , RNA, Messenger , Receptors, Immunologic/metabolism , Recombinant Fusion Proteins/metabolism , Signaling Lymphocytic Activation Molecule Family , Tyrosine/metabolism , U937 Cells , Up-Regulation
10.
J Immunol ; 163(2): 920-6, 1999 Jul 15.
Article in English | MEDLINE | ID: mdl-10395688

ABSTRACT

TNF-related apoptosis-inducing ligand (TRAIL) is able to kill many transformed cells of diverse tissue types. We show that TRAIL is inducible by IFN-gamma, by TNF-alpha, and by infection with human CMV, and has potent antiviral activity in vitro. CMV infection and IFN-gamma also reciprocally modulate TRAIL receptor (TRAIL-R) expression. CMV infection increased the expression of TRAIL-R1 and -R2, whereas IFN-gamma down-regulated the expression of TRAIL-Rs on uninfected fibroblasts. Moreover, IFN-gamma significantly decreased the basal level of NF-kappaB activation, a known survival factor that inhibits apoptosis. Thus, TRAIL selectively kills virus-infected cells while leaving uninfected cells intact, and IFN-gamma potentiates these effects by dynamic modulation of TRAIL and TRAIL-R expression and by sensitizing cells to apoptosis. The regulation of TRAIL and TRAIL-R expression may represent a general mechanism that contributes to the control of TRAIL-mediated apoptosis.


Subject(s)
Adjuvants, Immunologic/pharmacology , Antiviral Agents/pharmacology , Interferon-gamma/physiology , Membrane Glycoproteins/biosynthesis , Receptors, Tumor Necrosis Factor/biosynthesis , Tumor Necrosis Factor-alpha/biosynthesis , Apoptosis Regulatory Proteins , Cell Death/immunology , Cells, Cultured , Cytokines/physiology , Cytomegalovirus/immunology , Cytomegalovirus/physiology , Drug Synergism , Fibroblasts , Humans , Membrane Glycoproteins/genetics , Membrane Glycoproteins/physiology , NF-kappa B/metabolism , RNA, Messenger/biosynthesis , Receptors, Tumor Necrosis Factor/genetics , TNF-Related Apoptosis-Inducing Ligand , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/physiology , Virus Replication/immunology
11.
J Immunol ; 162(5): 2597-605, 1999 Mar 01.
Article in English | MEDLINE | ID: mdl-10072501

ABSTRACT

mAbs were generated against the extracellular domain of the four known TNF-related apoptosis-inducing ligand (TRAIL) receptors and tested on a panel of human melanoma cell lines. The specificity of the mAb permitted a precise evaluation of the TRAIL receptors that induce apoptosis (TRAIL-R1 and -R2) compared with the TRAIL receptors that potentially regulate TRAIL-mediated apoptosis (TRAIL-R3 and -R4). Immobilized anti-TRAIL-R1 or -R2 mAbs were cytotoxic to TRAIL-sensitive tumor cells, whereas tumor cells resistant to recombinant TRAIL were also resistant to these mAbs and only became sensitive when cultured with actinomycin D. The anti-TRAIL-R1 and -R2 mAb-induced death was characterized by the activation of intracellular caspases, which could be blocked by carbobenzyloxy-Val-Ala-Asp (OMe) fluoromethyl ketone (zVAD-fmk) and carbobenzyloxy-Ile-Glu(OMe)-Thr-Asp (OMe) fluoromethyl ketone (zIETD-fmk). When used in solution, one of the anti-TRAIL-R2 mAbs was capable of blocking leucine zipper-human TRAIL binding to TRAIL-R2-expressing cells and prevented TRAIL-induced death of these cells, whereas two of the anti-TRAIL-R1 mAbs could inhibit leucine zipper-human TRAIL binding to TRAIL-R1:Fc. Furthermore, use of the blocking anti-TRAIL-R2 mAb allowed us to demonstrate that the signals transduced through either TRAIL-R1 or TRAIL-R2 were necessary and sufficient to mediate cell death. In contrast, the expression of TRAIL-R3 or TRAIL-R4 did not appear to be a significant factor in determining the resistance or sensitivity of these tumor target cells to the effects of TRAIL.


Subject(s)
Antibodies, Monoclonal/immunology , Apoptosis , Receptors, Tumor Necrosis Factor/physiology , Animals , Apoptosis Regulatory Proteins , Caspase Inhibitors , GPI-Linked Proteins , Humans , Membrane Glycoproteins/antagonists & inhibitors , Mice , Mice, Inbred BALB C , Receptors, TNF-Related Apoptosis-Inducing Ligand , Receptors, Tumor Necrosis Factor, Member 10c , TNF-Related Apoptosis-Inducing Ligand , Tumor Cells, Cultured , Tumor Necrosis Factor Decoy Receptors , Tumor Necrosis Factor-alpha/antagonists & inhibitors
12.
Nat Med ; 5(2): 157-63, 1999 Feb.
Article in English | MEDLINE | ID: mdl-9930862

ABSTRACT

To evaluate the utility of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as a cancer therapeutic, we created leucine zipper (LZ) forms of human (hu) and murine (mu) TRAIL to promote and stabilize the formation of trimers. Both were biologically active, inducing apoptosis of both human and murine target cells in vitro with similar specific activities. In contrast to the fulminant hepatotoxicity of LZ-huCD95L in vivo, administration of either LZ-huTRAIL or LZ-muTRAIL did not seem toxic to normal tissues of mice. Finally, repeated treatments with LZ-huTRAIL actively suppressed growth of the TRAIL-sensitive human mammary adenocarcinoma cell line MDA-231 in CB.17 (SCID) mice, and histologic examination of tumors from SCID mice treated with LZ-huTRAIL demonstrated clear areas of apoptotic necrosis within 9-12 hours of injection.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Membrane Glycoproteins/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Animals , Apoptosis Regulatory Proteins , Dose-Response Relationship, Drug , Fas Ligand Protein , Humans , Membrane Glycoproteins/administration & dosage , Membrane Glycoproteins/chemical synthesis , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, SCID , Protein Conformation , TNF-Related Apoptosis-Inducing Ligand , Tumor Cells, Cultured , Tumor Necrosis Factor-alpha/administration & dosage , Tumor Necrosis Factor-alpha/chemical synthesis
13.
Eur Respir J ; 12(4): 926-31, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9817170

ABSTRACT

Receptors belonging to the tumour necrosis factor receptor (TNF-R) superfamily are implicated in a variety of important biological processes. Although messenger ribonucleic acid coding for many of these receptors has been detected in lung, little is known about their expression in this organ. In this study, immunohistochemical techniques were used to evaluate the expression of three receptors of this family (4-1BB, lymphotoxin-beta receptor (LTbeta-R), and Fas) in normal human lung, lung carcinomas and by tuberculous and sarcoid granulomas. The 4-1BB receptor was uniformly expressed by endothelial cells of small vessels and by basal epithelial cells within pseudostratified bronchial epithelium. LTbeta-R expression by parenchymal cells was limited to those of epithelial origin (bronchial and bronchiolar epithelium, hyperplastic alveolar epithelium and lung carcinomas). Fas was present on both fibroblasts and epithelial cells (bronchial and alveolar epithelium and most, but not all, carcinomas), but not on endothelial cells. A subpopulation of T-lymphocytes expressed these receptors, but only Fas was detected on normal alveolar macrophages and epithelioid cells. Thus, 4-1BB, LTbeta-R, and Fas have characteristic and only partially overlapping patterns of expression in the lung. The findings should facilitate further evaluation of their role in lung homeostasis and pathology.


Subject(s)
Lung/chemistry , Receptors, Tumor Necrosis Factor/analysis , fas Receptor/analysis , Adenocarcinoma/chemistry , Adult , Aged , Antigens, CD , Biomarkers/analysis , Biopsy, Needle , Carcinoma, Squamous Cell/chemistry , Culture Techniques , Female , Humans , Immunohistochemistry , Lung Neoplasms/chemistry , Lymphotoxin beta Receptor , Male , Membrane Glycoproteins/analysis , Middle Aged , Receptors, Nerve Growth Factor/analysis , Reference Values , Sarcoidosis, Pulmonary/pathology , Sensitivity and Specificity , Tuberculosis, Pulmonary/pathology , Tumor Necrosis Factor Receptor Superfamily, Member 9
14.
Immunity ; 9(2): 247-56, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9729045

ABSTRACT

We used our monoclonal model of germinal center maturation, CL-01 B cells, to investigate the role of CD30 in human B cell differentiation. CL-01 cells are IgM+ IgD+ CD30+ and switch to IgG, IgA, and IgE when exposed to CD40L and IL-4. Switching is hampered by CD30 coengagement, possibly through interference with the CD40-mediated NF-kappaB-dependent transcriptional activation of downstream C(H) genes. The physiological relevance of this phenomenon is emphasized by similar CD30-mediated effects in naive B cells. Expression of CD30 by these cells is induced by CD40L but is inhibited by B cell receptor coengagement and/or exposure to IL-6 and IL-12. Our data suggest that CD30 critically regulates the CD40-mediated differentiation of non-antigen-selected human B cells.


Subject(s)
B-Lymphocytes/immunology , CD40 Antigens/physiology , Immunoglobulin Class Switching/immunology , Ki-1 Antigen/physiology , Antibodies, Monoclonal/pharmacology , B-Lymphocytes/drug effects , B-Lymphocytes/metabolism , CD40 Antigens/genetics , CD40 Ligand , Cytokines/pharmacology , Down-Regulation/physiology , Gene Expression Regulation/drug effects , Gene Expression Regulation/genetics , Humans , Immunoglobulin A/biosynthesis , Immunoglobulin Constant Regions/genetics , Immunoglobulin D/analysis , Immunoglobulin E/biosynthesis , Immunoglobulin G/biosynthesis , Immunoglobulin G/genetics , Immunoglobulin Heavy Chains/genetics , Immunoglobulin M/analysis , Interleukin-12/pharmacology , Interleukin-6/pharmacology , Ki-1 Antigen/biosynthesis , Ki-1 Antigen/drug effects , Membrane Glycoproteins/pharmacology , NF-kappa B/pharmacology , NF-kappa B p50 Subunit , Phenotype , Promoter Regions, Genetic/drug effects , Receptors, Antigen, B-Cell/genetics , Receptors, Antigen, B-Cell/immunology , Transcription, Genetic
15.
Apoptosis ; 3(2): 83-8, 1998 Mar.
Article in English | MEDLINE | ID: mdl-14646505

ABSTRACT

The TNF ligand family member termed TRAIL has been shown to induce apoptosis in a wide variety of transformed cell lines. The normal functions of this cytokine in vivo remain, however, relatively unknown. The complexity of this biological system has now increased unexpectedly with the identification of four distinct receptors for TRAIL, two of which have cytoplasmic death domains. This review will describe the known biological effects of TRAIL, as well as the structure and possible functions of its recently identified receptors.

16.
Virology ; 236(2): 316-27, 1997 Sep 29.
Article in English | MEDLINE | ID: mdl-9325239

ABSTRACT

Poxvirus genomes encode several proteins which inhibit specific elements of the host immune response. We show the "35K" virulence gene in variola and cowpox viruses, whose vaccinia and Shope fibroma virus equivalents are strongly conserved in sequence, actually encodes a secreted soluble protein with high-affinity binding to virtually all known beta chemokines, but only weak or no affinity to the alpha and gamma classes. The viral protein completely inhibits the biological activity of monocyte chemotactic protein-1 (MCP-1) by competitive inhibition of chemokine binding to cellular receptors. As all beta chemokines are also shown to cross-compete with MCP1 binding to the viral protein, we conclude that this viral chemokine inhibitor (vCCI) not only interacts through a common binding site, but is likely a potent general inhibitor of beta chemokine activity. Unlike many poxvirus virulence genes to date, which are clearly altered forms of acquired cellular genes of the vertebrate immune system, this viral chemokine inhibitor (vCCI) shares no sequence homology with known proteins, including known cellular chemokine receptors, all of which are multiple membrane-spanning proteins. Thus, vCCI presumably has no cellular analogue and instead may be the product of unrelenting sequence variations which gave rise to a completely new protein with similar binding properties to native chemokine receptors. The proposed function of vCCI is inhibition of the proinflammatory (antiviral) activities of beta chemokines.


Subject(s)
Chemokines/antagonists & inhibitors , Genome, Viral , Poxviridae/genetics , Poxviridae/immunology , Viral Proteins/genetics , Viral Proteins/immunology , Amino Acid Sequence , Animals , Base Sequence , Binding, Competitive , Calcium/metabolism , Cell Line , Chemokines/classification , Chemotaxis, Leukocyte , Chimera/genetics , Chimera/immunology , Cowpox virus/genetics , Cowpox virus/immunology , DNA Primers/genetics , Mice , Molecular Sequence Data , Polymerase Chain Reaction , Receptors, Chemokine/genetics , Sequence Homology, Amino Acid , Solubility , Variola virus/genetics , Variola virus/immunology , Viral Proteins/metabolism , Virulence/genetics
17.
EMBO J ; 16(17): 5386-97, 1997 Sep 01.
Article in English | MEDLINE | ID: mdl-9311998

ABSTRACT

TRAIL is a member of the tumor necrosis factor (TNF) family of cytokines and induces apoptosis in a wide variety of cells. Based on homology searching of a private database, a receptor for TRAIL (DR4 or TRAIL-R1) was recently identified. Here we report the identification of a distinct receptor for TRAIL, TRAIL-R2, by ligand-based affinity purification and subsequent molecular cloning. TRAIL-R2 was purified independently as the only receptor for TRAIL detectable on the surface of two different human cell lines that undergo apoptosis upon stimulation with TRAIL. TRAIL-R2 contains two extracellular cysteine-rich repeats, typical for TNF receptor (TNFR) family members, and a cytoplasmic death domain. TRAIL binds to recombinant cell-surface-expressed TRAIL-R2, and TRAIL-induced apoptosis is inhibited by a TRAIL-R2-Fc fusion protein. TRAIL-R2 mRNA is widely expressed and the gene encoding TRAIL-R2 is located on human chromosome 8p22-21. Like TRAIL-R1, TRAIL-R2 engages a caspase-dependent apoptotic pathway but, in contrast to TRAIL-R1, TRAIL-R2 mediates apoptosis via the intracellular adaptor molecule FADD/MORT1. The existence of two distinct receptors for the same ligand suggests an unexpected complexity to TRAIL biology, reminiscent of dual receptors for TNF, the canonical member of this family.


Subject(s)
Adaptor Proteins, Signal Transducing , Apoptosis , Membrane Glycoproteins/metabolism , Receptors, Tumor Necrosis Factor/metabolism , Tumor Necrosis Factor-alpha/metabolism , Amino Acid Sequence , Apoptosis Regulatory Proteins , B-Lymphocytes/metabolism , Base Sequence , Carrier Proteins/metabolism , Chromosome Mapping , Chromosomes, Human, Pair 8 , Cloning, Molecular , Cysteine Endopeptidases/metabolism , Fas-Associated Death Domain Protein , Humans , Molecular Sequence Data , RNA, Messenger/analysis , Receptors, TNF-Related Apoptosis-Inducing Ligand , Receptors, Tumor Necrosis Factor/genetics , Receptors, Tumor Necrosis Factor/isolation & purification , Sequence Analysis , Sequence Homology, Amino Acid , Serine Proteinase Inhibitors/pharmacology , Signal Transduction , TNF-Related Apoptosis-Inducing Ligand , Tissue Distribution
18.
J Exp Med ; 186(7): 1165-70, 1997 Oct 06.
Article in English | MEDLINE | ID: mdl-9314565

ABSTRACT

TRAIL-R3, a new member of the TRAIL receptor family, has been cloned and characterized. TRAIL-R3 encodes a 299 amino acid protein with 58 and 54% overall identity to TRAIL-R1 and -R2, respectively. Transient expression and quantitative binding studies show TRAIL-R3 to be a plasma membrane-bound protein capable of high affinity interaction with the TRAIL ligand. The TRAIL-R3 gene maps to human chromosome 8p22-21, clustered with the genes encoding two other TRAIL receptors. In contrast to TRAIL-R1 and -R2, this receptor shows restricted expression, with transcripts detectable only in peripheral blood lymphocytes and spleen. The structure of TRAIL-R3 is unique when compared to the other TRAIL receptors in that it lacks a cytoplasmic domain and appears to be glycosyl-phosphatidylinositol-linked. Moreover, unlike TRAIL-R1 and -R2, in a transient overexpression system TRAIL-R3 does not induce apoptosis.


Subject(s)
Membrane Glycoproteins/metabolism , Receptors, Cell Surface/chemistry , Receptors, Cell Surface/metabolism , Receptors, Tumor Necrosis Factor , Tumor Necrosis Factor-alpha/metabolism , Amino Acid Sequence , Apoptosis/physiology , Apoptosis Regulatory Proteins , Base Sequence , Blotting, Northern , Chromosome Mapping , Chromosomes, Human, Pair 8/genetics , Cloning, Molecular , GPI-Linked Proteins , Gene Expression Regulation , Glycosylphosphatidylinositols , Humans , Immunoglobulin Fc Fragments/genetics , Jurkat Cells , Lymphocytes/chemistry , Lymphocytes/metabolism , Membrane Glycoproteins/pharmacology , Molecular Sequence Data , Protein Binding , Receptors, Cell Surface/genetics , Receptors, Tumor Necrosis Factor, Member 10c , Recombinant Fusion Proteins/pharmacology , Sequence Analysis, DNA , Sequence Homology, Amino Acid , TNF-Related Apoptosis-Inducing Ligand , Tumor Necrosis Factor Decoy Receptors , Tumor Necrosis Factor-alpha/pharmacology
19.
J Immunol ; 158(4): 1756-62, 1997 Feb 15.
Article in English | MEDLINE | ID: mdl-9029113

ABSTRACT

The lymphotoxin beta receptor (LT beta R) was originally described as a transcribed sequence encoded on human chromosome 12p, with homology to the TNF receptor family. Subsequently, a recombinant LT beta R was shown to bind LT alpha LT beta heteromeric complexes. In this study, we have shown that LT beta R is expressed in a variety of tissues and cell lines of monocytic lineage, as well as in fibroblast and human melanoma cell lines. Unlike other members of the TNF receptor family, LT beta R is not expressed by peripheral blood T cells. A chimeric fusion protein consisting of the extracellular domain of LT beta R fused to the Fc region of human IgG1 was used to develop mAbs against LT beta R. Cross-linking LT beta R on A375 melanoma cells with these Abs generated an antiproliferative signal. In addition, the IL-8 and RANTES chemokines, early indicators of inflammation, were secreted by the A375 melanoma line and the WI38VA13 fibroblast line in response to cross-linking of LT beta R. These same activities could be induced by membrane-bound and soluble LT beta and LT alpha LT beta oligomers.


Subject(s)
Chemokines/biosynthesis , Growth Inhibitors/physiology , Lymphotoxin-alpha/metabolism , Lymphotoxin-alpha/physiology , Melanoma/immunology , Melanoma/pathology , Membrane Proteins/metabolism , Membrane Proteins/physiology , Receptors, Tumor Necrosis Factor/metabolism , Receptors, Tumor Necrosis Factor/physiology , Adult , Antibodies, Monoclonal/biosynthesis , Biopolymers , Cross-Linking Reagents , Fetus , Growth Inhibitors/metabolism , Humans , Immunoglobulin Fc Fragments/biosynthesis , Lymphotoxin beta Receptor , Lymphotoxin-alpha/immunology , Lymphotoxin-beta , Melanoma/metabolism , Membrane Proteins/immunology , Membrane Proteins/pharmacology , Receptors, Tumor Necrosis Factor/immunology , Solubility , Tissue Distribution , Tumor Cells, Cultured
20.
Immunity ; 7(6): 813-20, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9430226

ABSTRACT

A fourth member of the emerging TRAIL receptor family, TRAIL-R4, has been cloned and characterized. TRAIL-R4 encodes a 386-amino acid protein with an extracellular domain showing 58%-70% identity to those of TRAIL-R1, TRAIL-R2, and TRAIL-R3. The signaling capacity of TRAIL-R4 is similar to that of TRAIL-R1 and TRAIL-R2 with respect to NF-kappaB activation, but differs in its inability to induce apoptosis. Yet TRAIL-R4 retains a C-terminal element containing one third of a consensus death domain motif. Transient overexpression of TRAIL-R4 in cells normally sensitive to TRAIL-mediated killing confers complete protection, suggesting that one function of TRAIL-R4 may be inhibition of TRAIL cytotoxicity. Like TRAIL-R1 and TRAIL-R2, this receptor shows widespread tissue expression. The human TRAIL-R4 gene has been mapped to chromosome 8p22-21, clustered with three other TRAIL receptors.


Subject(s)
Apoptosis , Membrane Glycoproteins/metabolism , NF-kappa B/metabolism , Receptors, Tumor Necrosis Factor/metabolism , Tumor Necrosis Factor-alpha/metabolism , Amino Acid Sequence , Apoptosis Regulatory Proteins , Base Sequence , Binding Sites , DNA, Complementary , Humans , Jurkat Cells , Molecular Sequence Data , Receptors, TNF-Related Apoptosis-Inducing Ligand , Receptors, Tumor Necrosis Factor/genetics , Sequence Homology, Amino Acid , TNF-Related Apoptosis-Inducing Ligand , Tissue Distribution
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