Induction of viral and tumour specific CTL responses using antibody targeted HLA class I peptide complexes

The production of cytotoxic T cells with specificity for cancer cells is a rapidly evolving branch of cancer therapeutics. A variety of approaches aim to amplify anti-tumour cytotoxic T cell responses using purified peptides, tumour cell lysates or recombinant HLA/peptide complexes in differing antigen presenting systems. Using a two-step biotin-streptavidin antibody targeting system, recombinant HLA-class I/peptide complexes were attached to the surface of B cells via the anti-CD20 B9E9-scFvSA antibody-streptavidin fusion protein. Flow cytometry with a conformation dependant monoclonal antibody to HLA class I indicated that targeted HLA-class I/peptide complexes remain on the surface of B cells in culture for periods in excess of 72 h. PBMCs were stimulated in vitro for 8-14 days using the autologous B cells as antigen presenting cells. Following a single cycle of stimulation specific cytotoxic T cell responses to targeted HLA-A2 complexes containing the M1, BMLF1 and Melan A peptides could be demonstrated by tetramer staining and Cr release assays. With the HLA-A2/BMLF1 complex up to 2.99% of CD8+ve cells were tetramer positive producing 20% lysis (E : T 10 : 1) of CIR-A2 target cells in an in vitro cytotoxicity assay compared to baseline levels of 0.09% tetramer +ve and 2% lysis in the unstimulated population. PBMCs from a healthy donor treated with two cycles of stimulations with targeted HLA-A2/Melan A complexes, demonstrated expansion of the melanA tetramer +ve population from 0.03% to 1.4% producing 15% lysis of Melan A pulsed target cells. With further consideration to the key variables of HLA/peptide complex density, the ratio of stimulator to effector cells and optimum cytokine support, this system should offer an easy and effective method for the in vitro amplification of specific cytotoxic T cell responses and warrants development for the in vivo induction of cytotoxic T cell responses in cancer therapy.

Evaluating changes in sexual functioning in depressed patients: sensitivity to change of the CSFQ

Accurately evaluating alterations in sexual functioning requires a validated instrument that measures clinically relevant change over time. One-hundred one depressed patients from 15 Spanish out-patient clinics completed the Changes in Sexual Functioning Questionnaire (CFSQ; Clayton, McGarvey, & Clavet, 1997) at baseline and after 6 months of treatment with fluoxetine, nefazodone, paroxetine, or venlafaxine. Sexual desire/interest showed a nearly substantial floor effect (30% of patients indicated the maximum score) for women in the nefazodone group at baseline and in the paroxetine group at final visit. The percentage of dimensions recording change was greater for women (80%) than for men (20%) in the nefazodone group (improving changes) and greater for men (40%) than for women (20%) in the paroxetine group (worsening changes). Highest effect sizes were found on sexual desire/frequency with improvement in women in the nefazodone group (SES = 0.49), and on orgasm/ejaculation with worsening in men in the paroxetine group (SES = -1.45). In conclusion, the CSFQ is sensitive to bidirectional changes and is appropriate for measuring sexual dysfunction.

Compound effects of point mutations causing campomelic dysplasia/autosomal sex reversal upon SOX9 structure, nuclear transport, DNA binding, and transcriptional activation

Human mutations in the transcription factor SOX9 cause campomelic dysplasia/autosomal sex reversal. Here we identify and characterize two novel heterozygous mutations, F154L and A158T, that substitute conserved "hydrophobic core" amino acids of the high mobility group domain at positions thought to stabilize SOX9 conformation. Circular dichroism studies indicated that both mutations disrupt alpha-helicity within their high mobility group domain, whereas tertiary structure is essentially maintained as judged by fluorescence spectroscopy. In cultured cells, strictly nuclear localization was observed for wild type SOX9 and the F154L mutant; however, the A158T mutant showed a 2-fold reduction in nuclear import efficiency. Importin-beta was demonstrated to be the nuclear transport receptor recognized by SOX9, with both mutant proteins binding importin-beta with wild type affinity. Whereas DNA bending was unaffected, DNA binding was drastically reduced in both mutants (to 5% of wild type activity in F154L, 17% in A158T). Despite this large effect, transcriptional activation in cultured cells was only reduced to 26% in F154L and 62% in A158T of wild type activity, suggesting that a small loss of SOX9 transactivation activity could be sufficient to disrupt proper regulation of target genes during bone and testis formation. Thus, clinically relevant mutations of SOX9 affect protein structure leading to compound effects of reduced nuclear import and reduced DNA binding, the net effect being loss of transcriptional activation.

Cell surface heparan sulfate proteoglycans control the response of renal interstitial fibroblasts to fibroblast growth factor-2

BACKGROUND

While the progression of renal disease to end stage is strongly correlated with tubulointerstitial changes, the control of the fibrotic process within the interstitium is poorly understood. Basic fibroblast growth factor (FGF-2) has been implicated as a major growth factor involved in fibroblast activation and extracellular matrix synthesis. Furthermore, in many cells, the activity of FGF-2 is controlled by a low-affinity but high-capacity interaction with heparan sulfate (HS) proteoglycans (PGs), such as members of the syndecan family. These molecules are likely to be central to the control of interstitial fibrosis, but as yet, there has been no characterization of their synthesis by interstitial cells.

METHODS

The expression of HSPG on the surface of NRK 49F fibroblasts was demonstrated by immunohistochemistry and by metabolic labeling with [(35)S]-sulfate. HSs were characterized by specific enzymatic digestion, size exclusion chromatography, and anion exchange chromatography. The mRNA for syndecan 1 through syndecan 4 in the fibroblasts was detected by semiquantitative reverse transcription-polymerase chain reaction. Fibroblast proliferation was measured by the MTT assay.

RESULTS

Immunohistochemistry and [(35)S]-sulfate-labeling demonstrated that renal fibroblasts expressed HSPGs on their surface. Furthermore, enzymatic removal of these HS (but not chondroitin sulfate) glycosaminoglycan (GAG) chains, or inhibition of GAG sulfation, abolished the proliferative response of both NRK cells and primary human cortical fibroblasts to FGF-2 but not to platelet-derived growth factor. The addition of conditioned medium, containing HS-GAG fragments, restored the proliferative response to FGF-2, confirming the specificity of the interaction. Finally, the mRNA for all four syndecans was detected in the fibroblasts, and that for syndecan 1 in particular was up-regulated by FGF-2.

CONCLUSIONS

The present study demonstrates that the expression of cell surface HSPG was essential for the proliferation of renal fibroblasts in response to FGF-2, and therefore may play a major role in the development and persistence of a proliferating phenotype during interstitial nephritis.

Analysis of antigen presenting cell derived exosomes, based on immuno-magnetic isolation and flow cytometry

We present a simple yet powerful method for the isolation and analysis of exosomes released by antigen-presenting cells (APC). Exosomes are small vesicles (40-90 nm) released by APC, and may have an immuno-regulatory function in vivo. Such exosomes originate from MHC class II peptide loading compartments and, as such, express high levels of MHC Class II. We have utilised magnetic beads, coated with monoclonal antibodies specific for HLA DP, DQ, DR for the specific isolation of exosomes from cell-free supernatants. Beads coated with exosomes are subsequently stained with conjugated antibodies, and analysed by flow cytometry. Characterisation of exosomes by this method demonstrated that exosomes derived from B-lymphocytes express abundant MHC Class I and II molecules. Other immunologically important molecules detected included the co-stimulatory molecules B7.1 (CD80) and B7.2 (CD86). The adhesion molecule ICAM-1 (CD54) was also detected. These exosomes also expressed the B cell marker CD20, and the complement inhibitory protein CD59. The expression of CD63, a lysosomal marker, was variable, and there was no detectable expression of transferrin receptor (CD71). Monocyte derived dendritic cells (cultured for 7 days in GM-CSF/IL-4), demonstrated an immature phenotype, and secreted exosomes with a similar phenotype, with abundant MHC molecules. The expression of CD63 was consistently strong, and the MHC Class I-like molecule CD1a was also present, suggesting a possible function in the presentation of lipid antigens. Again CD59 was expressed suggesting a possible role for APC exosomes in complement regulation. There was no detectable CD71, CD40, CD14, CD20 or CD83. Modification of the extraction protocol allowed a comparative analysis of exosome secretion under various conditions. Treatment of cells with calcium ionophore, or phorbol ester resulted in apparent increases in exosome release, while the phosphatidyl inositol 3-kinase inhibitor, wortmannin, reduced exosome secretion. The immuno-magnetic isolation and analysis of exosomes is a versatile and rapid tool for the analysis of APC exosomes, and may prove a valuable tool for the study of exosome biology.

Deliberate self-harm and antidepressant drugs. Investigation of a possible link

BACKGROUND

It is not clear if the frequency of deliberate self-harm (DSH) is the same in patients taking different pharmacological classes of antidepressant drugs.

AIMS

To compare the frequency of DSH in patients who had been prescribed a tricyclic antidepressant (TCA) or a selective serotonin reuptake inhibitor (SSRI) prior to the DSH event.

METHOD

This was a prospective study in 2776 consecutive DSH cases attending an accident and emergency department. The incidence of DSH in TCA-treated cases and SSRI-treated cases is expressed as number of DSH events per 10 000 prescriptions of each antidepressant.

RESULTS

Significantly more DSH events occurred following the prescription of an SSRI than that of a TCA (P<0.001). The occurrence of DSH was highest with fluoxetine and lowest with amitriptyline.

CONCLUSIONS

Merely prescribing safer-in-overdose antidepressants is unlikely to reduce the overall morbidity from DSH.

A pilot study with simvastatin and folic acid/vitamin B12 in preparation for the Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine (SEARCH)

BACKGROUND AND AIM

This study was conducted in preparation for the Study Evaluating Additional Reduction in Cholesterol and Homocysteine (SEARCH). SEARCH is a 12,000 patient 2X2 factorial study in post-myocardial infarction patients that will compare simvastatin 20 mg with simvastatin 80 mg to evaluate whether greater LDL-C reductions with simvastatin provide greater coronary event reductions. SEARCH will also test the hypothesis that lowering plasma homocysteine with folic acid and vitamin B12 will reduce coronary events. This pilot study was performed to determine whether any clinically meaningful interaction between simvastatin and folic acid/vitamin B12 exists.

METHODS AND RESULTS

Following a 2-week diet/placebo run-in period, 141 patients with primary hypercholesterolaemia were randomised to one of three treatments for 6 weeks: 80 mg/day simvastatin and 2 mg folic acid/0.8 mg vitamin B12 daily (combination group); or 80 mg/day simvastatin and placebo vitamins (simvastatin alone group); or 2 mg folic acid/0.8 mg vitamin B12 daily and placebo simvastatin (vitamins alone group). The combination group and simvastatin alone group experienced similar serum lipid changes with reductions in LDL-cholesterol of 55.2% and 51.5% respectively. The combination group and vitamins alone group experienced similar homocysteine lowering with reductions in homocysteine of 25.3% and 23.1% respectively. All therapies were well tolerated.

CONCLUSIONS

There was no detectable antagonistic effect when simvastatin and folic acid/vitamin B12 were administered concomitantly.

Validation of the Spanish version of the Changes in Sexual Functioning Questionnaire (CSFQ)

The aim of this study is to adapt and validate the Changes in Sexual Functioning Questionnaire (CSFQ) in Spanish. The CSFQ was administered to 206 depressed patients in different Spanish cities, to 326 health sciences students at the University of Oviedo, and to 48 workers undergoing routine health check-ups. The Hamilton Depression Rating Scale (HAM-D) was administered to the depressed patients. The average time spent answering the CSFQ was 15.19 minutes. The CSFQ discriminated the depressed patients from the workers and university students. In the three areas of reliability (internal, test-retest, and inter-rater), the coefficients obtained were greater than 0.80. The factor analysis demonstrated differences in the internal construct of the American CSFQ and its Spanish equivalent. The psychometrc properties of the Spanish version of the CSFQ indicate that it is a valid instrument for clinical use in treating depressed patients.

Development and clinical assessment of an artificial cornea

Keratoprosthesis research has been a gradual, rather fragmentary process with advances being made by isolated groups of researchers. This has arisen partly because of poor funding in the area; research groups which have achieved commercial support have often had constraints upon the full disclosure of their findings. Despite these difficulties there has been real progress over the last decade by several independent groups. This article concentrates upon our own development of a hydrogel core-and-skirt keratoprosthesis, the Chirila KPro, in order to illustrate the scientific and clinical problems common to keratoprosthesis research. Pilot data from a clinical trial is presented and the priorities for future research are discussed.

Responses to the region 5 NHEXAS time/activity diary. National Human Exposure Assessment Survey

The time/activity diary developed for use in the National Human Exposure Assessment Survey (NHEXAS) was completed by 249 participants in the Research Triangle Institute/Environmental and Occupational Health Sciences Institute (RTI/EOHSI) NHEXAS population-based pilot project conducted in the upper Midwest (EPA Region 5). The majority of participants successfully completed the diary during the 6-day study period. Participant responses showed internal consistency between related questions within the diary and between instruments used within the study. Comparison of response rates with the National Human Activity Pattern Survey, a nationwide population-based study, found consistent results when the same questions were used in both studies. Several questions identified age-specific activities. The value of the 6-day diary over 1-day surveys was apparent in discriminating between episodic and regularly conducted activities and in identifying subpopulations whose behavior may contribute to exposure to environmental pollutants.

ICAM-1 interactions in the renal interstitium: a novel activator of fibroblasts during nephritis

Chronic renal diseases often degenerate towards end-stage failure, requiring replacement renal therapy. The progressive decline of such diseases is a highly complex, multi-factorial process, which is poorly understood. Indeed, not all chronic conditions take on a progressive course, some may recover to regain normal function, while others may remain functionally impaired yet stable. The structural features of progressive decline, however, show common histological features, despite the diverse nature of the primary injury. These aberrant structural alterations are characterised essentially by a dramatic expansion of the tubulointerstitium, with accompanying tubular atrophy, resulting from interstitial fibrosis. These changes are thought to be a uniform response to prolonged inflammation which may originate in the glomerulus, the vasculature or the interstitial space (Strutz et al., 1995). A histomorphometric analysis of renal diseases, initially performed by Risdon et al. (1968), and supported by Bohle et al. (1987) and others (Eknoyan et al., 1990), revealed that the severity of abnormal glomerular pathology did not always correlate directly with impaired renal function. The extent of interstitial inflammation and the degree of interstitial fibrosis, however, were both shown to be more accurate predictors of renal function (Bohle et al., 1992). Furthermore there was a high probability of irreversible functional decline, in the presence of interstitial fibrotic lesions and tubular atrophy. Interstitial fibrosis is therefore considered an important histological marker for end stage renal failure, and is believed to be functionally more significant than primary changes within the glomerulus. In most tissues, resident fibroblasts are believed to be the cells principally responsible for the synthesis and breakdown of extracellular matrix (ECM) within connective tissues. Indeed in fibrotic diseases of lung and skin, the resident fibroblast has been identified as the most important cell responsible for the abnormal deposition of ECM components during the disease process (Phan et al., 1985). In the kidney, there are probably several sources of matrix components during fibrosis including tubular epithelial cells, inflammatory macrophages (Vaage and Linbland, 1990) as well as interstitial fibroblasts. Although the precise cellular source of the bulk of this matrix requires clarification, there is mounting evidence supporting a significant contribution from resident or infiltrating fibroblasts (Rodemann and Muller, 1990, 1991a,b; Strutz and Muller, 1995).

Compulsive voyeurism and exhibitionism: a clinical response to paroxetine

The compulsive behaviors seen in sexual paraphilias may be related to those of obsessive-compulsive disorder (OCD). Based primarily upon case reports as well as studies indicating the effectiveness of serotonin reuptake inhibitors in the treatment of sexual paraphilias, it has been speculated that sexual paraphilias lie within the obsessive-compulsive spectrum. There have been no reports of the use of paroxetine in the treatment of sexual paraphilias. This is a report of two patients, the first a voyeur and the second an exhibitionist, both of whom responded to treatment with paroxetine. The discussion addresses the need for further comparative studies investigating the role of the serotonin system in the pathogenesis of sexual paraphilias and OCD as well as the effect of serotonin reuptake inhibitors in comparison to other pharmacologic modalities used in the treatment of paraphilias.

CD34+AC133+ cells isolated from cord blood are highly enriched in long-term culture-initiating cells, NOD/SCID-repopulating cells and dendritic cell progenitors

The AC133 antigen is a novel antigen selectively expressed on a subset of CD34+ cells in human fetal liver, bone marrow, and blood as demonstrated by flow cytometric analyses. In this study, we have further assessed the expression of AC133 on CD34+ cells in hemopoietic samples and found that there was a highly significant difference between normal bone marrow and cord blood versus aphereses (p <0.0001) but not between bone marrow and cord blood. Most of the clonogenic cells (67%) were contained in the CD34+AC133+ fraction. Compared with cultures of the CD34+AC133- cells, generation of progenitor cells in long-term culture on bone marrow stroma was consistently 10- to 100-fold higher in cultures initiated with CD34+AC133+ cells and was maintained for the 8-10 weeks of culture. Only the CD34+AC133+ cells were capable of repopulating NOD/SCID mice. Human cells were detectable as early as day 20, with increased levels (67%) apparent 40 days post-transplantation. Five thousand CD34+AC133+ cells engrafted about 20% of the mice, while no engraftment was observed in animals transplanted with up to 1.2 x 10(5) CD34+AC133- cells. The CD34+AC133+ population was also enriched (seven-fold) in dendritic cell precursors, and the dendritic cells generated were functionally active in a mixed lymphocyte reaction assay. AC133+ cells should be useful in the study of cellular and molecular mechanisms regulating primitive hemopoietic cells.

Cellular activation through the ligation of intercellular adhesion molecule-1

In addition to its role in mediating leukocyte adherence to and migration across the endothelium, intercellular adhesion molecule (ICAM)-1 on the surface of interstitial cells has been implicated as a principal adhesion molecule controlling leukocyte infiltration at inflammatory sites. The present study demonstrates that leukocyte binding to fibroblasts isolated from both the human renal cortex and lung and to endothelial cells induced the de novo synthesis of ICAM-1 mRNA and protein through the ICAM-1-dependent activation of the cultured cells. This was mimicked by specifically cross-linking the ICAM-1 receptor with anti-ICAM-1 antibodies. Following cross-linking there was a two- to threefold increase in the steady state levels of ICAM-1 mRNA isolated from the cells. The expression of this mRNA peaked at 1–3 hours and was dose-dependent on the concentration of secondary cross-linking antibody. Peak protein expression was between 18 and 48 hours after cross-linking. Additional data demonstrated a similar increase in the expression of VCAM-1 following ICAM-1 cross-linking. In contrast, there was no reponse as a result of incubation with an isotype-matched control antibody. Both the binding of leukocytes and the cross-linking of ICAM-1 triggered a rise in cytosolic free calcium as the result, in part, of a calcium influx from the extracellular medium. Using BAPTA-AM to chelate intracellular calcium ions indicated that this increase in cytosolic free calcium was directly involved in the initiation of adhesion molecule upregulation. The present study demonstrates that both endothelial cells and fibroblasts can be stimulated by the direct cell surface interaction of ICAM-1 with its ligands on inflammatory cells. One phenotypic change resulting from this interaction is the upregulated synthesis and expression of more cellular adhesion molecules. This may have profound implications for the control and persistence of a leukocyte infiltrate and the progression of inflammatory disease.

Cells isolated from the human cortical interstitium resemble myofibroblasts and bind neutrophils in an ICAM-1--dependent manner

Progressive renal disease is frequently accompanied by renal interstitial inflammation and fibrosis in which the activity of resident fibroblasts may be of central importance. Because there are relatively few fibroblasts in the normal cortical interstitium and there is no specific marker to permit their identification, these cells have proved difficult to characterize in vitro. In this study, these cells were isolated and established in culture, using CD90 as a positive selection marker. Antibodies to CD90 bound to tubular epithelial cells and fibroblasts, but not to glomerular cells in kidney sections. In culture, only fibroblasts were CD90-positive. These normal renal cortical fibroblasts (RCF) were alpha-smooth muscle actin- and vimentin-positive, but desmin-, cytokeratin-, and factor VIII-negative, identifying them as myofibroblasts. They expressed platelet-derived growth factor alpha and beta receptors; CD44; and alpha 2, beta 1, and beta 3 integrin chains: this combination of markers was also characteristic of fibroblasts in sections of normal cortex. These cells were positive for ICAM-1 but negative for VCAM-1. Similarly, proliferating or growth-arrested renal cortical fibroblasts (RCF) in culture expressed ICAM-1 but not VCAM-1. The expression of VCAM-1 was detected, however, and that of ICAM-1 was increased on fibroblasts associated with inflammatory infiltrates in sections from fibrotic kidneys, and ICAM-1 and VCAM-1 were up-regulated on RCF in culture after incubation with increasing doses of interleukin-1 beta or tumor necrosis factor alpha (maximum between 24 and 48 h). These adhesion molecules were functional, and neutrophils adhered to resting and cytokine-activated RCF. Binding was maximal between 24 and 48 h after cytokine treatment and was inhibited by anti-CD18 antibodies. ICAM-1 is the principal adhesion molecule controlling inflammatory cell infiltration of the interstitium. The study presented here suggests that cortical fibroblasts may be central to the control of this infiltration.

Population-based exposure measurements in EPA region 5: a phase I field study in support of the National Human Exposure Assessment Survey

The National Human Exposure Assessment Survey (NHEXAS) Phase I study is designed to be part of the total NHEXAS framework developed from a series of scientific discussions and workshops conducted by the U.S. Environmental Protection Agency (EPA) during 1992 and 1993. NHEXAS examines total human exposure and is structured to include: Phase I, scoping studies; Phase II, a full national exposure survey; and Phase III, a series of highly focused characterization modules. Our research program examines the scientific issues important to Phase II, including statistical sampling, methods evaluation, media concentration measurements, formulating quality assurance goals, and identification of important pathways leading to exposure. To determine the feasibility of NHEXAS in characterizing human exposure for a representative population, a hypothesis-driven design is used to answer important questions about human exposure to specific environmental contaminants. This paper describes: (1) hypotheses to be tested; (2) contaminants selected for study; (3) strategies for measuring exposure; (4) study area and population; (5) population sampling design; (6) media sampling and analysis procedures; and (7) data analysis. The contaminants of concern in this Phase I study include selected metals and volatile organic compounds. From these classes the first-tier contaminants to be measured are lead, arsenic, benzene, chloroform, perchloroethylene, and trichloroethylene. Contaminants selected for examination may potentially be found in many media (personal-nonoccupational, personal-occupational, indoor, and outdoor residential air; dust; potable water; food/beverages; soil; blood; hair; and urine) and exposures may occur by multiple routes (inhalation, ingestion, dermal). The central hypothesis of our field study is to discover whether individual and population exposures determined by modeled or extant data are/are not significantly different from those determined directly from multipathway and multimedia measurements. In addition, there are a series of subhypotheses ranging from pollutant-specific exposure measurement and body burden hypotheses to the optimization of exposure models. In keeping with the NHEXAS framework, a probability-based population sample for total exposure and the field study will be conducted in counties located throughout EPA Region 5 (Minnesota, Wisconsin, Illinois, Indiana, Ohio, and Michigan). Sampling units will be households and an individual residing within each household. Environmental, exposure, and biological media sample collection will be performed by this consortium. Analyses of the external media and biological media samples will be completed by this consortium or Federal laboratories of the Centers for Disease Control and Prevention (CDC), Food and Drug Administration (FDA), or EPA. The protocols and analytical techniques selected for use represent the best available for total exposure assessment at this time.