HLA-DO transduced in human monocyte-derived dendritic cells modulates MHC class II antigen processing.

Through the regulation of human leukocyte antigen (HLA)-DM (DM) in B cells, HLA-DO (DO) modulates positively or negatively the presentation of specific peptides. Transduction of DO into human blood monocyte-derived dendritic cells (MoDC) has been proposed as a mean of modifying the peptide repertoire of major histocompatibility complex class II molecules. However, maturation of DC induced by inflammatory stimuli or possibly the adenoviral vector itself triggers acidification of vesicles and shuts down transcription of the class II transactivator gene as well as de novo biosynthesis of class II-related molecules and DM activity. In these conditions, it is unclear that transduced DO could alter the peptide repertoire. Our Western blot and reverse transcriptase-polymerase chain reaction analyses revealed that human DC derived from blood monocytes express small amounts of DOalpha. Transduction of DObeta alone resulted in the accumulation of a small pool of DO in DM(+) CD63(+) vesicles and at the plasma membrane of mature DC. The cell-surface increase in class II-associated invariant chain peptide (CLIP)/class II complexes is in line with an inhibitory role of DO on DM. Cotransduction of DOalpha and DObeta only slightly increased CLIP and DO levels at the cell surface. Together with the fact that a large fraction of transduced DO remains in the endoplasmic reticulum, this suggests that DM is limiting in these conditions. DO expression did not affect a mixed lymphocyte reaction but reduced presentation of the exogenous gp100 antigen to a specific T cell clone. These results show that transduced DO modulates antigen presentation in human mature MoDC, evoking the possible use of this chaperone for immunotherapy.

RNA interference blocks gene expression and RNA synthesis from hepatitis C replicons propagated in human liver cells.

RNA interference represents an exciting new technology that could have therapeutic applications for the treatment of viral infections. Hepatitis C virus (HCV) is a major cause of chronic liver disease and affects >270 million individuals worldwide. The HCV genome is a single-stranded RNA that functions as both a messenger RNA and replication template, making it an attractive target for the study of RNA interference. Double-stranded small interfering RNA (siRNA) molecules designed to target the HCV genome were introduced through electroporation into a human hepatoma cell line (Huh-7) that contained an HCV subgenomic replicon. Two siRNAs dramatically reduced virus-specific protein expression and RNA synthesis to levels that were 90% less than those seen in cells treated with negative control siRNAs. These same siRNAs protected naive Huh-7 cells from challenge with HCV replicon RNA. Treatment of cells with synthetic siRNA was effective >72 h, but the duration of RNA interference could be extended beyond 3 weeks through stable expression of complementary strands of the interfering RNA by using a bicistronic expression vector. These results suggest that a gene-therapeutic approach with siRNA could ultimately be used to treat HCV.

Expression of a functional eotaxin (CC chemokine ligand 11) receptor CCR3 by human dendritic cells.

Critical to the function of Ag-presenting dendritic cells (DCs) is their capacity to migrate to lymphoid organs and to sites of inflammation. A final stage of development, termed maturation, yields DCs that are strong stimulators of T cell-mediated immunity and is associated with a remodeling of the cell surface that includes a change in the levels of expression of many molecules, including chemokine receptors. We show in this study that CCR3, a chemokine receptor initially discovered on eosinophils, is also expressed by human DCs that differentiate from blood monocytes, DCs that emigrate from skin (epidermal and dermal DCs), and DCs derived from CD34+ hemopoietic precursors in bone marrow, umbilical cord blood, and cytokine-elicited peripheral blood leukapheresis. Unlike other chemokine receptors, such as CCR5 and CCR7, the expression of CCR3 is not dependent on the state of maturation. All DC subsets contain a large intracellular pool of CCR3. The surface expression of CCR3 is not modulated following uptake of particulate substances such as zymosan or latex beads. CCR3 mediates in vitro chemotactic responses to the known ligands, eotaxin and eotaxin-2, because the DC response to these chemokines is inhibited by CCR3-specific mAbs. We postulate that expression of CCR3 may underlie situations where both DCs and eosinophils accumulate in vivo, such as the lesions of patients with Langerhans cell granulomatosis.

Quality of life assessment in men and women with urinary incontinence.

PURPOSE: The literature on assessment of quality of life from 1993 to 2001 was reviewed to evaluate and compare existing measures through their psychometric value and make adequate recommendations on their clinical use and future research. MATERIALS AND METHODS: We selected quality of life articles and abstracts from Current Content 1996 to 1997 and MEDLINE 1993 to 1996 for our first report presented at the first consultation on incontinence in Monaco in 1998. This report was then updated up to September 2001 using the same strategy. We made our recommendations based on our clinical and research experience with these tools. RESULTS: Several quality of life generic or disease specific questionnaires have been published for male and female urinary incontinence. However, their psychometric value is far from uniform and for most of them responsiveness is weak or has never been reported. CONCLUSIONS: Few quality of life questionnaires are at an advanced enough stage of development to be applied in clinical practice. However, even with these questionnaires more study remains to be done to make them shorter, sometimes even more specific and easier to use in different populations.

Identifying cut-off scores with neural networks for interpretation of the incontinence impact questionnaire.

We propose to determine cut-off scores for the Incontinence Impact Questionnaire (IIQ) based on the neural network (NN) approach. These cut-off scores should discriminate between patients having poor, moderate, or good quality of life (QoL) secondary to their incontinence problems. Data from two prospectively completed QoL questionnaires, the IIQ (n = 237) and the MOS 36-Item Short-Form Health Survey (SF-36) (n = 237), were analyzed using NN and conventional statistical tools. Kohonen networks identified three distinct clusters of IIQ scores. The three clusters represent the full spectrum of possible scores on the IIQ. We interpreted these clusters as reflecting good, moderate, and poor QoL. We estimated that a score of less than 50 on the IIQ would be representative of good QoL, between 50 and 70 would be moderate QoL, and greater than 70 would be indicative of poor QoL. Validation with the SF-36 data confirmed these categories. The present study demonstrated that the NN approach is opening new areas in the interpretation and clinical usefulness of QoL questionnaires. NN allowed the identification of three levels of QoL and should be useful in clinical decision making.

Performance of the Incontinence Impact Questionnaire in Canada.

The Incontinence Impact Questionnaire (IIQ) was developed in the US and has been shown to be a valid and reliable measure of how urinary incontinence (UI) affects a woman's quality of life. This study aimed to test the performance of the IIQ in Canada with English and French-speaking Canadians. The IIQ underwent professional forwards-backwards translation and psychometric testing. Women (36 English and 34 French-speaking) consulting a urologist for stress urinary incontinence underwent routine multichannel urodynamic testing and completed the SF-36 and the IIQ. Test-retest reliability was moderate (ICC =.73) and each IIQ subscale demonstrated good internal consistency (a=.83 to.91). Moderate correlations between IIQ scores and number of pads/day and severity ratings support construct validity in both languages. In English, correlations with Physical and Social Functioning scales of the SF-36 were also moderate. The IIQ has demonstrated strong reliability and adequate validity with English-speaking Canadian women. Moreover, similar psychometric properties in both English and French provide evidence that the IIQ has been successfully translated into Canadian French.