The immunotolerance role of HLA-G

HLA-G is a non-classical MHC class I molecule involved in immune tolerance. We present our results concerning the effects of HLA-G on the cellular immune response, where it impairs both NK and T cell functions. We describe the NK inhibitory properties of HLA-G ex vivo, demonstrating its role in materno-fetal tolerance, which is supported by our in vitro studies using membrane-bound HLA-G1- and HLA-G2-transfected cells and a full-length soluble HLA-G molecule. We also report how HLA-G interacts at the T cell level, here exemplified by its inhibitory effect on both T cell allogeneic proliferative and Ag-specific CTL responses.

Oligomerization and topology of the Golgi membrane protein glucosylceramide synthase

Glucosylceramide synthase (GCS) catalyzes the transfer of glucose from UDP-glucose to ceramide to form glucosylceramide, the precursor of most higher order glycosphingolipids. Recently, we characterized GCS activity in highly enriched fractions from rat liver Golgi membranes (Paul, P., Kamisaka, Y., Marks, D. L., and Pagano, R. E. (1996) J. Biol. Chem. 271, 2287-2293), and human GCS was cloned by others (Ichikawa, S., Sakiyama, H., Suzuki, G., Hidari, K. I.-P. J., and Hirabayashi, Y. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 4638-4643). However, the polypeptide responsible for GCS activity has never been identified or characterized. In this study, we made polyclonal antibodies against peptides based on the predicted amino acid sequence of human GCS and used these antibodies to characterize the GCS polypeptide in rat liver Golgi membranes. Western blotting of rat liver Golgi membranes, human cells, and recombinant rat GCS expressed in bacteria showed that GCS migrates as an approximately 38-kDa protein on SDS-polyacrylamide gels. Trypsinization and immunoprecipitation studies with Golgi membranes showed that both the C terminus and a hydrophilic loop near the N terminus of GCS are accessible from the cytosolic face of the Golgi membrane. Treatment of Golgi membranes with N-hydroxysuccinimide ester-based cross-linking reagents yielded an approximately 50-kDa polypeptide recognized by anti-GCS antibodies; however, treatment of approximately 10,000-fold purified Golgi GCS with the same reagents did not yield cross-linked GCS forms. These results suggest that GCS forms a dimer or oligomer with another protein in the Golgi membrane. The migration of solubilized Golgi GCS in glycerol gradients was also consistent with a predominantly oligomeric organization of GCS.

Down-regulation of human granzyme B expression by glucocorticoids. Dexamethasone inhibits binding to the Ikaros and AP-1 regulatory elements of the granzyme B promoter

The serine protease granzyme B is an essential component of the granule exocytosis pathway, a major apoptotic mechanism used by cytotoxic T lymphocytes and natural killer cells to induce target cell apoptosis. Granzyme B gene transcription is induced in activated lymphocytes upon antigenic stimulation, and several regulatory regions including CBF, AP-1, and Ikaros binding sites have been shown to be essential in the control of granzyme B promoter activation. Dexamethasone, a glucocorticoid that is widely used as an immunomodulatory and anti-inflammatory agent, inhibits granzyme B mRNA transcript in phytohemagglutinin-activated peripheral blood mononuclear cells. Transfection of a reporter construct containing the -148 to +60 region of the human granzyme B promoter demonstrated that this region was the target for dexamethasone repression. Mutation of Ikaros or AP-1 binding sites in the context of the granzyme B promoter demonstrated that both sites participate in dexamethasone-mediated inhibition of the granzyme B promoter activity. Electromobility shift assay revealed that dexamethasone abolished the binding of nuclear transcription factors to the Ikaros binding site and reduced AP-1 binding activity. These results indicate that dexamethasone is able to abrogate the transcriptional activity of the human granzyme B gene promoter by inhibiting the binding of nuclear factors at the AP-1 and Ikaros sites.

Specific binding of nuclear factors to the HLA-G gene promoter correlates with a lack of HLA-G transcripts in first trimester human fetal liver

The nonclassical MHC class I HLA-G antigen is expressed in cytotrophoblasts during pregnancy and may play a role in inhibiting lysis by maternal natural killer cells. HLA-G gene transcription was analyzed in human fetal liver of 6-8 wk of gestation, a development stage where classical HLA class I expression is very reduced. We demonstrated that HLA-G transcription is undetectable in these cells and we investigated the molecular mechanisms that control the lack of HLA-G gene transcription. We compared protein interactions of nuclear extracts from first trimester fetal livers, YT2C2-PR (HLA-G negative) and JEG-3 (HLA-G positive) cell lines to a 244-bp EcoR I/Hind III DNA region located 1.2 kb from the HLA-G gene, previously shown to direct HLA-G expression in transgenic mouse placenta. A strong specific C7-factor was specifically detected in first trimester fetal liver that could account for the inhibition of HLA-G transcription. Interaction of C7-factor and cell-specific factors previously detected in YT2C2 cell line (C5, C6) with two distinct regulatory regions identify this 244-bp EcoR I/Hind III fragment as a putative target for inhibition of HLA-G transcription.

Molecular and immunologic aspects of the nonclassical HLA class I antigen HLA-G: evidence for an important role in the maternal tolerance of the fetal allograft

PROBLEM

Human leukocyte antigen (HLA)-G is a major histocompatibility complex class I antigen, which is referred to as nonclassical because it displays a tissue-restricted distribution in the placenta, a reduced cytoplasmic domain, a limited polymorphism, and several isoforms. The HLA-G antigen is thought to play an essential role during pregnancy by protecting the semi-allogeneic fetus from recognition and destruction by maternal immune cells.

METHOD OF STUDY

Alternative splicing of HLA-G mRNA was analyzed by Southern blot of reverse transcriptase-polymerase chain reaction products from trophoblasts of the first trimester of gestation and term placenta. The regulation of HLA-G gene expression was investigated by electrophoretic mobility shift assays using nuclear extracts from cells expressing different levels of HLA-G gene activity. Using polymerase chain reaction-single strand conformational polymorphism and sequencing, we studied HLA-G gene polymorphism in families from the Centre d'Etude du Polymorphisme Humain in Paris. To understand the function of the HLA-G molecule, cytotoxicity assays were carried out with peripheral blood mononuclear cells or polyclonal natural killer effectors cells from 30 different donors against HLA-G1 and HLA-G2 transfectants.

RESULTS

Four main aspects have been elucidated: 1) The primary transcript of the HLA-G gene is alternatively spliced into five main mRNA forms: HLA-G1 (full length), HLA-G2 (minus exon 3), which encodes a membrane-bound isoform associated with beta-2 microglobulin, HLA-G3 (minus exons 3 and 4), HLA-G4 (minus exon 4), and HLA-G5 (plus intron 4), which encodes a soluble form of the HLA-G antigen; 2) specific nuclear factors bind to an important regulatory element located more than 1.2 kb from the HLA-G gene. Three specific complexes are observed in cells that show HLA-G transcriptional activity and an additional factor that could correlate with the repression of HLA-G gene expression that is detected in natural killer cells; 3) we observed an important genomic polymorphism in exon 3 but a very low polymorphism at the protein level; 4) HLA-G1 and HLA-G2 transfectants clearly demonstrated that both HLA-G isoforms are capable of inhibiting natural killer lytic activity.

CONCLUSION

These results suggest that HLA-G acts as the public ligand for natural killer inhibitory receptors, thus protecting the fetus against maternal rejection.

Teaching and maintaining behavior management skills with nursing assistants in a nursing home

This article describes a nursing staff training program in basic behavior management skills and a formal staff management system to encourage the application of these basic skills on the nursing unit. Behavioral skills training consists of a 5-hour in-service followed by three weeks of on-the-job training to ensure accurate application of behavior management skills. Following training, a staff management system is used to facilitate long-term use of the skills. Components of the staff management system include supervisory monitoring of the nursing assistants (NAs) by licensed practical nurses (LPNs), NA self-monitoring, verbal and written performance feedback, and incentives.

Up-regulation of glucosylceramide synthase expression and activity during human keratinocyte differentiation

During keratinocyte differentiation, the glycolipid, glucosylceramide (GlcCer), is thought to be synthesized, stored in intracellular lamellar granules and eventually extruded into the intercellular space where GlcCer is hydrolyzed to ceramide, a major component of the epidermal permeability barrier. Previous studies showed that GlcCer synthase (GCS) activity increases during keratinocyte differentiation; however, the mechanism by which GCS activity is regulated was not established. In the present study, we prepared anti-peptide antibodies and amplified cDNA probes based on the cDNA sequence for human GCS (Ichikawa, S., Sakiyama, H., Suzuki, G., Hidari, K. I.-P. J., and Hirabayashi, Y. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 4638-4643) in order to study GCS expression during keratinocyte differentiation. Confluent human keratinocytes in culture were induced to terminally differentiate by elevation of Ca+2 in the medium without exogenous hormones or growth factors. GlcCer synthesis assayed in situ using a fluorescent ceramide analog increased approximately 5-fold during keratinocyte differentiation, peaking at day 6. Fluorescence microscopy studies of living keratinocytes showed that fluorescent ceramide and/or its metabolites accumulated in the Golgi in undifferentiated cells but targeted to unique vesicular structures that may be derived from the trans-Golgi region. Expression of both GCS mRNA, a approximately 3. 8-kilobase transcript on Northern blots, and GCS protein, a approximately 38-kDa polypeptide detected by Western blotting, increased dramatically (approximately 5-fold) during differentiation, reaching a maximum at about day 8. These results suggest that GCS is up-regulated at the transcriptional level during keratinocyte differentiation and provide the first direct evidence for GCS up-regulation in any cell type.

HLA-G expression in melanoma: a way for tumor cells to escape from immunosurveillance

Considering the well established role of nonclassical HLA-G class I molecules in inhibiting natural killer (NK) cell function, the consequence of abnormal HLA-G expression in malignant cells should be the escape of tumors from immunosurveillance. To examine this hypothesis, we analyzed HLA-G expression and NK sensitivity in human malignant melanoma cells. Our analysis of three melanoma cell lines and ex vivo biopsy demonstrated that (i) IGR and M74 human melanoma cell lines exhibit a high level of HLA-G transcription with differential HLA-G isoform transcription and protein expression patterns, (ii) a higher level of HLA-G transcription ex vivo is detected in a skin melanoma metastasis biopsy compared with a healthy skin fragment from the same individual, and (iii) HLA-G protein isoforms other than membrane-bound HLA-G1 protect IGR from NK lysis. It thus appears of critical importance to consider the specific role of HLA-G expression in tumors in the design of future cancer immunotherapies.

APC genotype, polyp number, and surgical options in familial adenomatous polyposis

OBJECTIVE

This study was performed to examine the relation between phenotypic expression in patients with familial adenomatous polyposis (FAP) and the site of mutations in the APC (adenomatous polyposis coli) gene. The ability of APC mutations to predict surgical outcome was also investigated.

SUMMARY BACKGROUND DATA

Germline mutations in the APC gene cause FAP and can now be identified by direct mutational analysis. Such an analysis can identify affected persons for close surveillance and spare unaffected persons. Phenotypic expression varies within and among FAP kindreds, but certain mutations have been associated with severe disease. Patients with severe polyposis are frequently offered total proctocolectomy rather than colectomy and ileorectal anastomosis out of concern for increased rectal cancer risk. Mutation analysis may offer a more rational basis for these decisions.

METHODS

The postsurgical courses of 58 patients from 19 FAP kindreds with identified APC gene mutations were reviewed. APC gene mutations were identified by analysis of leukocyte DNA using single-strand conformational analysis and DNA sequencing. FAP severity was defined according to the number of polyps in the colon at the time of resection (< 1000, mild; > 1000, severe). Operations included subtotal colectomy with ileorectal anastomosis (IRA), total proctocolectomy with ileal pouch/anal anastomosis, total proctocolectomy with end ileostomy, and partial colectomy (PC).

RESULTS

Eight different APC mutations were identified. Mutations at codons 1309 and 1328 in exon 15G were associated with a uniformly severe polyposis phenotype. For other mutations, the phenotype was more variable. Patients with APC mutations at codons 1309 and 1328 more commonly underwent proctectomy. Among the 43 patients who initially underwent either IRA or PC, the rectum was later removed in 8. Seven of these patients had a mutation at codon 1309 or 1328. With one exception, all patients with mutations outside the 1309 or 1328 site who initially had IRA have retained their rectum.

CONCLUSIONS

Our data support an association between severe polyposis phenotype and mutations at APC gene codons 1309 and 1328. For patients with these mutations, the prognosis for retaining the rectum is poor.

Use of arsenic trioxide (As2O3) in the treatment of acute promyelocytic leukemia (APL): I. As2O3 exerts dose-dependent dual effects on APL cells

Recent clinical studies in China showed that As2O3 is an effective and relatively safe drug in the treatment of acute promyelocytic leukemia (APL). We found previously that As2O3 can trigger apoptosis of APL cell line NB4 cells, which is associated with downregulation of bcl-2 gene expression and modulation of PML-RAR alpha chimeric protein. To further understand the mechanisms of this alternative therapy for APL, we investigated in this report the effects of a wide range of concentrations of As2O2 on cultured primary APL cells, all-trans retinoic acid (ATRA)-susceptible (NB4 cells) and ATRA-resistant (MR2 subclone) APL cell lines. The results indicated that As2O3 had dose-dependent dual effects on APL cells: inducing preferentially apoptosis at relatively high concentrations (0.5 to 2 micromol/L) and inducing partial differentiation at low concentrations (0.1 to 0.5 micromol/L). The rapid modulation and degradation of PML-RAR alpha proteins, which was induced by As2O3 at 0.1 to 2 micromol/L, could contribute to these two effects. Bone marrow and peripheral blood examination showed that myelocyte-like cells, probably as a result of partial in vivo differentiation, and degenerative cells increased after 2 to 3 weeks of continuous in vivo As2O3 treatment when leukemic promyelocytes decreased. In conclusion, combination of induction of apoptosis and partial differention could be the main cellular mechanisms of As2O3 in the treatment of APL, and PML-RAR alpha could play an important role in determining the specific effects of As2O3 on APL cells.

A historical review of selected nursing and medical literature on urinary incontinence between 1850 and 1976

The nursing and medical literature on urinary incontinence from 1850 to 1976 was reviewed to provide a historic perspective on care patterns before the current surge in interest in this common condition. Relevant nursing and medical journals and a number of textbooks from both fields were systematically examined to document the evolution of treatments and practices regarding urinary incontinence. Throughout the article, findings are examined in light of the broader historical context to reveal how and why practices were favored or disfavored at given times during the years under investigation. As expected, attitudes, values, and practices in the field reflected the state of knowledge and beliefs commonly held by nurses, physicians, and the general population.

HLA-G gene transcriptional regulation in trophoblasts and blood cells: differential binding of nuclear factors to a regulatory element located 1.1 kb from exon 1

The HLA-G antigen is specifically expressed on trophoblasts at the maternal-fetal interface, while expression of classical class I HLA-A, -B, -C products is repressed in this tissue. The transcriptional level of the HLA-G gene is high in trophoblast cells and in JEG-3 choriocarcinoma cells, is markedly reduced in blood cells, and is shown here to be undetectable in the YT2C2 NK cell line. In an attempt to understand molecular mechanisms controlling cell-specific transcriptional regulation of the HLA-G gene in these cells, we focused our study on protein interaction with a 244-bp region located over 1.1 kb from exon 1, which has been shown to direct HLA-G expression in transgenic mouse trophoblast. Three specific complexes were detected, two of which are found exclusively in cells showing HLA-G transcriptional activity. The YT2C2 nuclear extracts contain restricted DNA-binding activity of an additional factor which could correlate with repression of HLA-G transcription in these cells.

Prior knowledge and reading comprehension ability of deaf adolescents

Fifty-one severely to profoundly deaf students (mean dB hearing loss = 89) were randomly assigned to two groups that differed by the type of probes (short or long) used to elicit prior knowledge (PK). PK scores were used to predict reading comprehension (RC), which was assessed by students' responses to three types of questions: test-explicit (TE), text-implicit (TI), and script-implicit (SI). Multiple regression models with PK scores and scores from a standardized achievement test (Stanford Achievement Test - Hearing Impaired Version, reading subtest) were also used to predict RC. The regression model showed that, for the group pretested with an in-depth, or long, probe of PK, the best predictor of RC was the ability to answer TE and SI questions. We present discussions of the observed differences in comprehension as a function of long and short knowledge probes and the use of three question types, together with implications for instruction.

Ethical and practice considerations for biofeedback therapists in the treatment of urinary incontinence

The treatment of incontinence presents many unique issues for biofeedback therapists that are routine for professionals in fields such as nursing or medicine. Although all professional practice is guided by ethical standards, the unique circumstances encountered during biofeedback treatments for this disorder warrant the development of specific guidelines. This is true whether insertable or surface EMG devices are used. Therefore, the purpose of this article is to propose a set of ethical guidelines for biofeedback therapists. The intended audience includes professionals such as psychologists, clinical psychophysiologists, and other mental health-care providers who use biofeedback techniques. These are not formally endorsed by any professional organizations (e.g., APA, AAPB) at this time. Ethical considerations include proper medical evaluation, informed consent, patient instruction, disrobing, nonerotic physical contact, patient safety, and patient satisfaction.

Transcriptional regulation of the MHC class I HLA-A11 promoter by the zinc finger protein ZFX

Regulation of the human MHC class I HLA-A11 promoter is governed by a complex array of regulatory elements. One of these elements, shown here to be critical for the transcriptional activity of the promoter, was used to screen a lambda gt11 library and allowed the identification of a cDNA which coded for the zinc finger protein ZFX. ZFX was shown to bind the sequences AGGGCCCCA and AGGCCCCGA, located respectively at positions -271 to -263 and -242 to -234 of the HLA-A11 promoter, with similar affinities through its three C-terminal zinc fingers. ZFX575, a short isoform of ZFX, activates transcription from the HLA-All promoter in a Leydig cell line.

A historical review of the depiction of women in cardiovascular literature

A historical review of the literature demonstrates that women have long been acknowledged as suffering from cardiac disease and disorder. Until recently, women's experience with cardiac disease was investigated primarily as the cardiac disease impinged on pregnancy or women's ability to carry out home-related duties. Only in the last decade has a more appropriate and more holistic view of women's unique experience with cardiac disease been undertaken. The authors attribute this new perspective in health literature, in large part, to the advancement of feminist approach and critique.

Purification and characterization of UDP-glucose:ceramide glucosyltransferase from rat liver Golgi membranes

We present a method for solubilizing and purifying UDP-Glc:ceramide glucosyltransferase (EC 2.4.1.80; glucosylceramide synthase (GCS) from a rat liver and present data on its substrate specificity. A Golgi membrane fraction was isolated, washed with N-lauroylsarcosine, and subsequently treated with 3[3-cholamidopropyl)-dimethylammonio]-2-hydroxy-1-propanesulfonate to solubilize the enzyme. GCS activity was monitored throughout purification using UDP-Glc and a fluorescent ceramide analog as substrates. Purification of GCS was achieved via a two-step dye-agarose chromatography procedure using UDP-Glc to elute the enzyme. This resulted in an enrichment > 10,000-fold relative to the starting homogenate. The enzyme was further characterized by sedimentation on a glycerol gradient, I labeling, and SDS-polyacrylamide gel electrophoresis. which demonstrated that two polypeptides (60-70 kDa) corresponded closely with GCS activity. Purified GCS was found to require exogenous phospholipids for activity, and optimal results were obtained using dioleoyl phosphatidylcholine. Studies of the substrate specificity of the purified enzyme demonstrated that it was stereospecific and dependent on the nature and chain length of the N-acyl-spingosine or -sphinganine substrate. UDP-Glc was the preferred hexose donor, but TDP-glucose and CDP-glucose were also efficiently used. This study provides a basis for molecular characterization of this key enzyme in glycosphingolipid biosynthesis.

Reading vocabulary knowledge and deafness

With respect to reading vocabulary knowledge and deafness, this article addresses two broad questions: (1) Why is vocabulary knowledge related to reading comprehension ability? (2) How is reading vocabulary (i.e., word meanings) acquired? The article argues that the answers to these questions are best addressed by a vocabulary acquisition model labeled the knowledge model. In essence, this model asserts that both breadth and depth of vocabulary knowledge are critical. It is necessary to teach vocabulary, especially to poor readers, who are not likely to derive many word meanings from the use of context during natural or deliberate reading situations. On the basis of theoretical and research syntheses, the article offers implications for vocabulary instruction for deaf children and adolescents.

All-trans retinoic acid rapidly decreases cathepsin G synthesis and mRNA expression in acute promyelocytic leukemia

The cells from patients with acute promyelocytic leukemia (AML M3) undergo terminal differentiation when treated with all-trans retinoic acid (ATRA). We have analyzed the expression of the mRNA for cathepsin G, a promyelocyte stage-specific transcript, in the leukemia and in retinoic acid responsive cell lines. We showed that the transcript is perpetually synthesized in patients' cells and that it rapidly disappears when the cells are treated with ATRA. In ATRA-sensitive (HL-60, NB4) cell lines and an ATRA-resistant (HL-60R) cell line we have shown that this process is dependent on proteins synthesized during the first 6h of ATRA-triggered differentiation and may involve both pre- and post-transcriptional mechanisms. A corresponding decrease in cathepsin G protein synthesis then follows. These findings indicate that the maturation arrest in AML M3 results in cells that may constitutively continue to produce proteins whose production is temporally confined during normal hemopoiesis. This would explain the elevated plasma-free serine protease activity we have demonstrated in this disease, and has implications for both the coagulopathy and the 'retinoic acid syndrome' in AML M3.

Juvenile Nasopharyngeal Angiofibroma and Familial Adenomatous Polyposis: An Association?

Juvenile nasopharyngeal angiofibroma is a benign neoplasm affecting the nasopharynx of male adolescents. Two patients treated at Temple University Hospital for this condition were also diagnosed with familial adenomatous polyposis. Familial adenomatous polyposis results from the inheritance of a mutated adenomatous polyposis coli gene in an autosomal dominant pattern. The development of colorectal carcinoma in middle age is seen almost invariably in familial adenomatous polyposis, if a prophylactic colectomy is not performed. To identify a possible association between juvenile nasopharyngeal angiofibroma and familial adenomatous polyposis, chart reviews and patient interviews were carried out for all patients treated for juvenile nasopharyngeal angiofibroma at Temple University Hospital between 1985 and 1993. Single-strand conformational polymorphism was performed to detect the presence of certain adenomatous polyposis coli gene mutations within the germline DNA of those juvenile nasopharyngeal angiofibroma patients not previously found to have familial adenomatous polyposis. Although no more patients with both juvenile nasopharyngeal angiofibroma and familial adenomatous polyposis were found by these methods, the two patients with both disorders previously identified constitute 22% of our juvenile nasopharyngeal angiofibroma series. The implications of these findings are discussed.

Juvenile nasopharyngeal angiofibroma and familial adenomatous polyposis: an association?

Juvenile nasopharyngeal angiofibroma is a benign neoplasm affecting the nasopharynx of male adolescents. Two patients treated at Temple University Hospital for this condition were also diagnosed with familial adenomatous polyposis. Familial adenomatous polyposis results from the inheritance of a mutated adenomatous polyposis coli gene in an autosomal dominant pattern. The development of colorectal carcinoma in middle age is seen almost invariably in familial adenomatous polyposis, if a prophylactic colectomy is not performed. To identify a possible association between juvenile nasopharyngeal angiofibroma and familial adenomatous polyposis, chart reviews and patient interviews were carried out for all patients treated for juvenile nasopharyngeal angiofibroma at Temple University Hospital between 1985 and 1993. Single-strand conformational polymorphism was performed to detect the presence of certain adenomatous polyposis coli gene mutations within the germline DNA of those juvenile nasopharyngeal angiofibroma patients not previously found to have familial adenomatous polyposis. Although no more patients with both juvenile nasopharyngeal angiofibroma and familial adenomatous polyposis were found by these methods, the two patients with both disorders previously identified constitute 22% of our juvenile nasopharyngeal angiofibroma series. The implications of these findings are discussed.