With a little help from a friend: increasing HIV transduction of monocyte-derived dendritic cells with virion-like particles of SIVMAC

Modification of dendritic cells (DCs) is a promising avenue for gene therapy purposes, given the versatility and the multiplicity of functions of these cells. In this study, we show that preincubation of monocyte-derived DCs with low amounts of non-infectious virion-like particles derived from the simian immunodeficiency virus (SIV(MAC) VLPs) increases up to 10-fold the efficiency of transduction by HIV-1 lentiviral vectors at low multiplicity of infections yielding up to 90% of transduced cells, in the absence of alterations of DCs behavior. This effect is restricted to DCs and specified by the viral accessory protein Vpx. Thus, preincubation with empty VLPs of SIV(MAC) can be used in transduction protocols to increase the efficacy of HIV-1-mediated modification of DCs.

Tumeur fibreuse solitaire de l’orbite : une cause inhabituelle d’exophtalmie unilatérale

BACKGROUND

The solitary fibrous tumor (SFT) is a spindle-cell tumor that very rarely involves the orbit. We report a new case that we compare to reports in the literature.

CASE

A 72-year-old woman presented a conjunctival inflammation of the right eye developing over 5 months with progressive proptosis. Magnetic resonance imaging revealed an extraconal and homogeneous mass, which showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images, without specificity. Histological examination of the lesion removed by anterior orbitotomy confirmed the diagnosis of the SFT of the orbit. The patient was doing well without recurrence after 9 months.

DISCUSSION

The diagnosis of SFT is histological. It is a mesenchymal tumor. Immunohistochemically, the tumor cells are strongly positive for CD34 and vimentin.

CONCLUSION

The SFT of the orbit is a very rare and generally benign tumor. It must be immunohistochemically differentiated from other spindle-cell tumors of the orbit. The treatment is a complete surgical excision, and long-term follow-up is necessary because recurrence may appear long after treatment.

"Dendritic cells in different animal species: an overview"

The comprehension of the immune system and the role of DC in the pathological diseases may contribute to their use in veterinary medicine in the prevention and treatment of many diseases. Currently, most dendritic cell (DC) research occurs in the human and murine model systems on the generation of cells from the bone marrow or peripheral blood mononuclear cells (PBMC) cultured in vitro. Despite the lack of available immunological reagents such as antibodies and cytokines, analogous cells have been generated and identified in many different species and reviewed in this study.

New Method for DNA Microarrays Development: Applied to Human Platelet Antigens Polymorphisms

DNA microarrays are a powerful experimental tool for the detection of specific genomic sequences and are invaluable to a broad array of applications: clinical diagnosis, personalized medicine, drug research and development, gene therapy, food control technologies, and environmental sciences. Alloimmunization to human platelet antigens (HPAs) is commonly responsible for neonatal alloimmune thrombocytopenia, post-transfusional purpura and platelet transfusion refractoriness. Using DNA microarrays, we developed a diagnosis to type the biallelic HPA-1 platelet group. The region for the human genomic DNA sequence that contains the polymorphism responsible for HPA-1 alleles was amplified by polymerase chain reaction (PCR). The expected DNA fragments were hybridized on DNA microarrays, and the data were analyzed using specially developed software. Our initial results show that the two HPA-1 antigens polymorphisms containing a single base difference were detected using DNA microarrays.

Greffe de membrane amniotique et traitement des ulcères de cornée lors des kératoconjonctivites chroniques allergiques

PURPOSE

To determine whether amniotic membrane implantation is a safe and effective alternative treatment for shield ulcers and persistent corneal epithelial defects associated with ulcers in chronic allergic keratoconjunctivitis (vernal or atopic keratoconjunctivitis).

METHODS

Amniotic membrane implantation was performed in four consecutive patients with persistent corneal epithelial defects or vernal plaques unresponsive to conventional medical treatment lasting an average of 18 weeks. Surgery was done under general anesthesia using amniotic membrane as a therapeutic contact lens.

RESULTS

A significant decrease in symptoms and complete reepithelialization of the corneal ulcers were observed in all cases within the first 7 days. These remained stable during a mean follow-up of 12 weeks, with no intraoperative or postoperative complications. Early detachment occurred in all cases with no negative consequences on ulcer healing.

CONCLUSION

Patients with severe chronic allergic keratoconjunctivitis derive benefits from amniotic membrane implantation used as a therapeutic contact lens in the treatment of persistent corneal epithelial defects and vernal plaques unresponsive to conventional medical treatment.

La photokératectomie thérapeutique dans le traitement de la dystrophie grillagée de type I

PURPOSE

Lattice corneal dystrophy type I is an autosomal dominant corneal dystrophy caused by allelic mutations of the BIGH3 gene. Type I dystrophy is recognized clinically by the characteristic net of linear opacities within the corneal stroma that results from an accumulation of amyloid. This study was designed to evaluate the therapeutic potential of phototherapeutic keratectomy (PTK) for the treatment of lattice corneal dystrophy type I.

PATIENTS AND METHODS

PTK was performed with the Chiron Technolas Chiron Keracor 217c on a series of 19 eyes of 13 patients with lattice dystrophy type I. Mean patient age was 38.9 years. The mean follow-up period was 36 months. Localization of central opacities was determined by analyzing Scheimpflug images. The changes in spherical equivalent and best corrected visual acuity were evaluated at 1, 3, 6, 9, 12, 18, 24 and 36 months.

RESULTS

The central depth of the deposits measured with the Scheimpflug camera was on average 74.14+/-31.03 microm in the primary dystrophies and 30.1+/-10 microm in graft recurrence. We noted a clear improvement in visual acuity, which increased by 0.257+/-0.120 to 0.600+/-0.178 as of the 3rd month and stabilized at 0.684+/-0.257 until the 36th month. A disappearance of repeating ulcerations was observed at month 30. We found a statistically significant correlation (R=0.6776; p=0.0109) between the improvement in vision (in lines) and the depth of opacities (with the Scheimpflug camera). The mean hyperopic shift caused by photoablation (69+/-15 microm) was +0.71+/-1 D at 36 months.

CONCLUSION

These results confirm that PTK is an effective method of managing corneal lattice dystrophy type I.

Intérêt d’une nouvelle formulation de diclofénac sans conservateur pour la surface oculaire

AIM

To compare the ocular tolerance of nonpreserved diclofenac versus thiomersal-preserved diclofenac in healthy volunteers.

MATERIALS AND METHODS

Forty healthy volunteers instilled Dicloabak in the randomised eye and thiomersal-preserved diclofenac in the other eye, according to a strictly identical dosing regimen, for 28 days. Each volunteer thus served as his or her own control. The dose regimen was five drops/day for 7 days followed by three drops/day for 20 days. Ocular tolerance was assessed by the discomfort upon instillation (measured on a visual analogue scale [VAS]), subjective ocular symptoms following instillation (irritation/burning/stinging, eye dryness and foreign body sensation) and finally by an objective examination of the ocular surface. These criteria were evaluated on days 0, 14, 21 and 28.

RESULTS

The subjective ocular symptoms following instillation were significantly lower in the nonpreserved group at Day 7 and nearly significantly lower until the end of the study. The biomicroscopy exam confirmed that there was better tolerance without thiomersal. There was less follicular-papillary conjunctivitis and a significantly better lissamine green score in the Dicloabak group.

CONCLUSION

The results of this study demonstrate that the nonpreserved formulation of diclofenac is better tolerated by the ocular surface and thus constitutes a therapeutic benefit.

HLA antibodies and neonatal alloimmune thrombocytopenia

A female baby with a severe thrombocytopenia at 18 x 10(9)/l was born to a 29-year-old (gestation 2/partum 2) mother. Scattered petechiae were present on her legs, arms, chest and face, but there was no bleeding, infection, fever or hepatosplenomegaly. A platelet antibody screening immunocapture test was positive, which was performed on the mother's serum 3, 12 and 38 days after delivery, but no platelet-specific antibodies were found by the monoclonal-antibody-specific immobilization of platelet antigen assay. The baby's platelets and lymphocytes and the father's platelets reacted strongly with the HLA antibodies present in the mother's serum. The neonate was treated with intravenous human immunoglobulin (Tegeline), 1 g/kg per day) 1, 2 and 3 days after delivery. The platelet count rose from 18 x 10(9)/l on day 0 to 37 x 10(9)/l on day 3 and to 227 x 10(9)/l on day 12. No platelet transfusion was needed. Several factors which developed hereafter lead us to think that this neonatal alloimmune thrombocytopenia is due to the transplacental passage of maternal HLA antibodies to the baby.

Récidive d’une dystrophie de Groenouw de type I après photokératectomie thérapeutique

PURPOSE

Granular corneal dystrophy Groenouw type 1 (GGI) is a rare autosomal dominant disease caused by allelic mutations of the BIGH3 gene. The specific phenotype is characterized by granular opacities (white, sharply demarcated spots resembling bread crumbs) in corneal stroma, which cause recurrent corneal erosions and blurred vision. Phototherapeutic keratectomy (PTK) is an effective procedure that improves visual acuity, but recurrences are unavoidable. Though GGI deposits are well described, their origin is not completely known. The production of mutated keratoepithelin protein (a product of the BIGH3 gene) is the first step necessary for deposits to appear. Molecular biology experiments were conducted to determine the role of corneal cell types in the genesis of early recurrent deposits of post-PTK GGI.

METHODS

Tissue specimens from a patient undergoing penetrating keratoplasty for recurrence of GGI (12 months after PTK) and five normal corneas were examined by hybridization in situ and immunohistology to study the expression of BIGH3 and location of keratoepithelin.

RESULTS

Only one healthy cornea expressed BIGH3 mainly in the epithelium and less in keratinocytes and endothelial cells. In the GGI corneas, BIGH3 was highly expressed in the modified, hyperplastic epithelium. The keratoepithelin was accumulated under the epithelium where deposits were formed.

CONCLUSION

This observation confirms that corneal epithelium is the main producer of mutated keratoepithelin on the cellular scale and thus constitutes the principal source of dystrophic deposit formation during recurrence.

Efficacité et tolérance d’un gel de carbomère fluide versus un gel de carbomère classique lors du traitement du syndrome sec

AIM

To compare the risk/benefit for C974P (a 0.25% fluid carbomer gel in a vial allowing dropwise instillation) versus a conventional carbomer gel.

MATERIAL AND METHODS

During this multicenter, randomized, investigator-masked trial, patients with dry eye syndrome were treated with C974P or C940. Control visits were planned on day 7, day 28 (efficacy evaluation) and day 56 (tolerance evaluation). The main criterion was dry eye symptoms globally assessed by a visual analog scale (VAS). The non-inferiority limit for the between-group difference of VAS changes was 10 mm.

RESULTS

In the population of 169 patients (87 patients for C974P, 82 for C940), C974P was at least as effective as C940 on symptoms (non-inferiority hypothesis confirmed). The mean VAS value fell by one third in the two groups. The objective signs improved identically in the two groups: corneal staining by fluorescein (p=0.96), rose Bengal score (p=0.73), and lacrimal break-up time (p=0.73). The dosage adaptation was slightly lower than three instillations per day (p=0.16). The adverse events were mild or moderate.

CONCLUSION

C974P galenic changes are able to reach the same level of efficacy on dry eye symptoms and ocular surface damages as the conventional tube carbomer gels.

[Treatment of conjunctival epithelial tumors: brachytherapy with ruthenium-106]

INTRODUCTION

Treatment of conjunctival epithelial tumors is not standardized because it is difficult to compare large series in this rare disease. Surgical excision is usual, but the recurrence rate has led several authors to propose alternative therapies.

PATIENTS AND METHODS

During the past 20 years, brachytherapy using ophthalmic applicators has been developed and the results of different studies have confirmed the usefulness of this therapy. We report a retrospective study of 13 patients presenting with a conjunctival epithelial tumor treated with ruthenium106 applicators and followed up in our department since 1987.

RESULTS AND CONCLUSION

There was no recurrence during a mean follow-up of 48 months. Complications depended on the size of the area treated and the dose of radiation.

[Efficacy and safety of substituting a twice-daily regimen of timolol with a single daily instillation of nonpreserved beta-blocker in patients with chronic glaucoma or ocular hypertension]

AIM

To evaluate the efficacy and safety of a single daily instillation of nonpreserved timolol in patients with chronic glaucoma or ocular hypertension previously treated with a twice-daily regimen of timolol 0.25% or 0.50%.

PATIENTS AND METHODS

A prospective open clinical trial was undertaken by 220 ophthalmologists in 435 patients with chronic glaucoma or ocular hypertension controlled with twice-daily instillations of timolol 0.25% or 0.50%. In this population, the previous regimen was substituted with a single daily instillation of preservative-free timolol 0.25% or 0.50% for 3 months. The changes in intraocular pressure (IOP) were recorded as well as local and systemic tolerance and patient compliance.

RESULTS

It was found that 398 patients (93.6%) maintained stable IOP: in 92%, IOP increased no more than 2 mmHg. The mean IOP was 17.0 +/- 2.2 mmHg at D0, 16.5 +/- 2.4 mmHg at D28/42 and 16.6 +/- 2.4 mmHg at D84. The proportion of patients with at least one ocular symptom upon instillation or at another time decreased (p<0.0001 and p=0.03, respectively). The proportion of conjunctival hyperemia reduced from 24.4% to 14.6% (p=0.0002). The rate of folliculopapillar reactions and superficial punctate keratitis was halved (p=0.005 and p=0.02, respectively).

CONCLUSION

During this study in daily practice, the switch from a twice-daily regimen of timolol to a once-daily application maintained stable intraocular pressure with a notable improvement in tolerance.

ABO and Rh(D) blood typing on the PK 7200 with ready-to-use kits

The performance of ready-to-use kits was evaluated on the PK 7200 blood grouping system. The Olymp Group (kit 1) and Olymp Group II (kit 2) containing anti-A, -B, -AB, and -D reagents were tested for first and second determinations of A, B, and D antigens. More than 500 RBC samples, including several variant ABO and D phenotypes, were evaluated for specificity, repeatability, reproducibility, and sensitivity. Specificity was tested with well-characterized reagent RBCs. Repeatability was established by at least 12 assays per run with three reagent RBCs, and reproducibility was established on one run per day for 5 days. No discrepancy was observed in ABO and D determinations with either kit. In repeatability, three discrepancies were found with group A and B RBCs with kit 1. In reproducibility, no discrepancies were observed. The kit 1 anti-A reagent detected A3 but not Ax RBCs and anti-AB detected both. A B3 RBC was detected by both kits. Among eight weak D phenotypes, six were positive with kit 1. With kit 2, only one of five weak D phenotypes was detected.

Cyclosporin A inhibits dendritic cell maturation promoted by TNF-alpha or LPS but not by double-stranded RNA or CD40L

Here, we investigated the influence of cyclosporin A (CsA) on dendritic cell (DC) generation. With this aim, human DC were propagated from monocytes in serum-free medium with granulocyte macrophage-colony stimulating factor and interleukin-4. DC were then exposed to tumor necrosis factor alpha (TNF-alpha) for maturation. Our results show that CsA does not impair commitment of monocytes into DC, as assessed by loss of CD14 and increase of CD40 and CD1a. However, TNF-alpha-induced DC maturation was affected, as CsA-treated DC expressed lower levels of human leukocyte antigen and costimulatory molecules but sustained levels of CD1a, and less DC expressed DC-lysosomal-associated-membrane-protein (LAMP) and CD83. Accordingly, CsA inhibited the allostimulatory and accessory cell functions of DC. Surprisingly, when other maturation stimuli were used, we observed that CsA significantly inhibited maturation induced by lipopolysaccharides but not by polyribocytidylic acid or CD40 ligand, as assessed by DC phenotype and functions. Therefore, our results indicate that CsA may differentially affect DC maturation.

Genomic organization and restricted expression of the human Mona/Gads gene suggests regulation by two specific promoters

Monocytic adaptor (Mona) also known as Gads is a Grb2-related adaptor whose expression is restricted to hematopoietic cells. It plays an important role in intracellular signaling in T cells, monocytic cells, and platelets. Here we investigated the regulatory aspects of Mona expression in human hematopoietic cells. This was carried out by combining nucleotide sequence analyzes and experimental approaches. We confirmed that Mona expression is restricted to T-cell, myeloid and platelet lineages. In the various cells examined, we detected two major Mona transcripts (1.9 and 4 kb), likely resulting from the alternative use of two polyadenylation sites. Consequently, Mona transcripts of the same size have identical 3' untranslated region (UTR), irrespective of the cell type. In contrast, Mona transcripts contain either 5' UTR-1A or -1B exons, that were detected in a cell-lineage specific manner. Thus, T cells and several myeloid cell lines express 5' UTR-1A-containing transcripts, whereas platelets and cell lines exhibiting megakaryocytic potential express 5' UTR-1B-containing transcripts. Interestingly, 5' UTR-1A is generated from an exon located approximately 45 kb upstream of exon 1B. This suggested that lineage-restricted transcription of the Mona gene is controlled by specific promoters. Indeed, 2-kb genomic fragments upstream of each 5'-UTR showed lineage-restricted ability to drive expression of luc reporter gene.

Nrh, a human homologue of Nr-13 associates with Bcl-Xs and is an inhibitor of apoptosis

In search of human homologues of the anti-apoptotic protein Nr-13, we have characterized a human EST clone that potentially encodes a protein, which is the closest homologue of Nr-13 among the Bcl-2 family members, to date known, in humans. Phylogenetic analyses suggest Human nrh, Mouse diva/boo and Quail nr-13 to be orthologous genes. The nrh gene has the same overall organization as nr-13 and diva/boo with one single intron interrupting the ORF at the level of the Bcl-2-homology domain BH2. RT-PCR-based analysis of nrh expression indicated that this gene is preferentially expressed in the lungs, the liver and the kidneys. Interestingly, two in frame ATG codons can lead potentially to the synthesis of two products, one of them lacking 10 aminoacids at the N-terminal end. Sequence alignment with Nr-13 and Diva/Boo in addition to secondary structure prediction of the nrh transcript suggested that the shortest protein will be preferentially synthetized. Immunohistochemical analyses have revealed that Nrh is associated with mitochondria and the nuclear envelope. Moreover, Nrh preferentially associates with the apoptosis accelerator Bcl-Xs and behaves as an inhibitor of apoptosis both in yeast and vertebrate cells.

Generation of helper and cytotoxic CD4+T cell clones specific for the minor histocompatibility antigen H-Y, after in vitro priming of human T cells by HLA-identical monocyte-derived dendritic cells

BACKGROUND

There is now convincing evidence that minor histocompatibility antigens (mHag) may play a significant role in the pathogenesis of graft-versus-host disease after HLA-identical bone marrow transplantation. Indeed, in this clinical situation, T cells specific for mHag have been isolated. Here, we addressed whether one can generate mHag-specific T cells in vitro, without any in vivo immunization, among healthy blood donors.

METHODS

We used monocyte-derived dendritic cells (Mo-DCs) as antigen presenting cells to induce primary responses between healthy HLA-identical siblings, in mixed lymphocyte dendritic cell reactions (MLDCRs).

RESULTS

We show that CD4+ T-cell clones, specific for the mHag H-Y, can be generated in vitro. These clones were derived from a gender-mismatched positive MLDCR pair of HLA-identical siblings and were restricted by the HLA DQB1*0502 molecule. In addition, these CD4+ T clones were also able to lyse allogeneic targets with the same pattern of restriction and specificity than helper function. Finally, acute myeloid leukemia (AML) blast cells were susceptible to lysis by these clones.

CONCLUSIONS

Altogether, these results predict that Mo-DCs could help to generate class II-associated, mHag-specific, T-cell lines or clones in vitro, between healthy blood donors, without any need of transplantation-mediated immunization.

Clinical applications of flow cytometry and cell immunophenotyping to companion animals (dog and cat)

Clinical applications of flow cytometry to certain diseases of the dog and cat are now possible. The utility of such applications for diagnosis, prognosis and follow-up are illustrated here by a number of examples: feline AIDS resulting from FIV infection, Leukocyte Adhesion Deficiency in Irish setters, deep pyoderma in German shepherds, Immune-mediated Thrombocytopenia, canine Systemic Lupus Erythematosus and Leishmaniasis, Leukemia and Lymphoma.

Heparins and blood polymorphonuclear stimulation in haemodialysis: an expansion of the biocompatibility concept

BACKGROUND

At the concentrations used in haemodialysis and in a dose-dependent way, unfractionated heparin (UFH) and, to a lesser degree, a low-molecular-weight heparin (LMWH) stimulate polymorphonuclear cells (PMN) in vitro, and could act in synergy with the stimulatory effect of dialysis membranes in vivo. To examine this hypothesis, we studied the effects of different heparin types and regimens on blood PMNs during haemodialysis sessions.

METHODS

Ten haemodialysed patients were studied during regular dialysis sessions on a cellulose triacetate membrane (CT 110 G; 1.10 m(2); Baxter), with four different random heparin protocols: one high-UFH regimen (HHR) at 90 IU/kg body-weight (b.w.) and one low-UFH regimen (LHR) at 50 IU/kg b.w., and with a LMWH (nadroparin calcium) at 85 (HHR) or 45 (LHR) IU/kg b.w. Blood granulocytes, platelet counts, and plasma granulocyte degranulation products (elastase, lactoferrin) were measured serially during 4 h dialysis sessions.

RESULTS

After 10 min, the reduction in PMNs with UFH was 29.5% for HHR (P<0.01) and 28.5% for LHR (P<0.01), and only 16.8 and 18.6% with LMWH (NS), significantly higher for HHR with UFH than with LMWH (P<0.01). At 60 min, the elastase increase with HHR was greater, 61% with UFH (P<0.01) and 37.8% with LMWH (P<0.01), significantly higher than LHR for UFH (P<0.05) or LMWH (P<0.05). The overall decrease in platelets (with LMWH P<0.01) and the overall increase in lactoferrin (P<0.001) were not different between heparinization procedures.

CONCLUSION

Under a conventional heparin regimen, the PMN variation during the course of the dialysis session suggests a more biocompatible effect of LMWH over UFH. In addition, the variation of elastase favours the lower dose, whatever the type of heparin. Heparin type and dose should therefore be considered in studies addressing biocompatibility in haemodialysis: a low dose of LMWH may be viewed as a better biocompatible treatment with regard to leukocyte stimulation.