Contaminatiegraad van vaccinatiespuiten voor varkens en beïnvloedende factoren

Goede vaccinatiepraktijken dragen bij tot een goede werkzaamheid van een vaccin. Deze studie had als doelstelling om de hygiëne van vaccinatiespuiten op varkensbedrijven te onderzoeken. De contaminatiegraad met bacteriën, gisten en schimmels en mogelijke risicofactoren hiervoor van 79 vaccinatiespuiten werd onderzocht, alsook het effect van herhaaldelijk injecteren van de huid op contaminatie van de vaccinfles. Het percentage spuiten met een lage (<10 kolonievormende eenheden, KVE/ml), matige (11-10000 KVE/ml) en hoge (>10000 KVE/ml) contaminatie met bacteriën bedroeg respectievelijk 32, 27 en 42. Voor de gisten/schimmels was het percentage contaminatie van de spuiten respectievelijk 49, 37 en 14 voor de hogergenoemde categorieën. De contaminatie was significant lager bij spuiten die gereinigd en in de koelkast bewaard werden. Het aanprikken van de huid resulteerde in een variabele bacteriële contaminatie, maar had weinig invloed op de gisten/schimmeltelling. Het onderzoek toont aan dat vaccinatiespuiten voor varkens erg gecontamineerd kunnen zijn en dat bepaalde maatregelen zoals de spuit reinigen en in de koelkast bewaren, gunstig zijn.

Efficacy of three innovative bacterin vaccines against experimental infection with Mycoplasma hyopneumoniae

New vaccine formulations that include novel strains of Mycoplasma hyopneumoniae and innovative adjuvants designed to induce cellular immunity could improve vaccine efficacy against this pathogen. The aim of this experimental study was to assess the efficacy of three experimental bacterin formulations based on M. hyopneumoniae field strain F7.2C which were able to induce cellular immunity. The formulations included a cationic liposome formulation with the Mincle receptor ligand trehalose 6,6-dibehenate (Lipo_DDA:TDB), a squalene-in-water emulsion with Toll-like receptor (TLR) ligands targeting TLR1/2, TLR7/8 and TLR9 (SWE_TLR), and a poly(lactic-co-glycolic acid) micro-particle formulation with the same TLR ligands (PLGA_TLR). Four groups of 12 M. hyopneumoniae-free piglets were primo- (day (D) 0; 39 days of age) and booster vaccinated (D14) intramuscularly with either one of the three experimental bacterin formulations or PBS. The pigs were endotracheally inoculated with a highly and low virulent M. hyopneumoniae strain on D28 and D29, respectively, and euthanized on D56. The main efficacy parameters were: respiratory disease score (RDS; daily), macroscopic lung lesion score (D56) and log copies M. hyopneumoniae DNA determined with qPCR on bronchoalveolar lavage (BAL) fluid (D42, D56). All formulations were able to reduce clinical symptoms, lung lesions and the M. hyopneumoniae DNA load in the lung, with formulation SWE_TLR being the most effective (RDS_D28–D56 −61.90%, macroscopic lung lesions −88.38%, M. hyopneumoniae DNA load in BAL fluid (D42) −67.28%). Further experiments raised under field conditions are needed to confirm these results and to assess the effect of the vaccines on performance parameters.

Cytokines trigger disruption of endothelium barrier function and p38 MAP kinase activation in BMPR2-silenced human lung microvascular endothelial cells

The bone morphogenetic protein receptor II (BMPRII) signaling pathway is impaired in pulmonary arterial hypertension and mutations in the BMPR2 gene have been observed in both heritable and idiopathic pulmonary arterial hypertension. However, all BMPR2 mutation carriers do not develop pulmonary arterial hypertension, and inflammation could trigger the development of the disease in BMPR2 mutation carriers. Circulating levels and/or lung tissue expression of cytokines such as tumor necrosis factor-α or interleukin-18 are elevated in patients with pulmonary arterial hypertension and could be involved in the pathogenesis of pulmonary arterial hypertension. We consequently hypothesized that cytokines could trigger endothelial dysfunction in addition to impaired BMPRII signaling. Our aim was to determine whether impairment of BMPRII signaling might affect endothelium barrier function and adhesiveness to monocytes, in response to cytokines. BMPR2 was silenced in human lung microvascular endothelial cells (HLMVECs) using lentiviral vectors encoding microRNA-based hairpins. Effects of tumor necrosis factor-α and interleukin-18 on HLMVEC adhesiveness to the human monocyte cell line THP-1, adhesion molecule expression, endothelial barrier function and activation of P38MAPK were investigated in vitro. Stable BMPR2 silencing in HLMVECs resulted in impaired endothelial barrier function and constitutive activation of P38MAPK. Adhesiveness of BMPR2-silenced HLMVECs to THP-1 cells was enhanced by tumor necrosis factor-α and interleukin-18 through ICAM-1 adhesion molecule. Interestingly, tumor necrosis factor-α induced activation of P38MAPK and disrupted endothelial barrier function in BMPR2-silenced HLMVECs. Altogether, our findings showed that stable BMPR2 silencing resulted in impaired endothelial barrier function and activation of P38MAPK in HLMVECs. In BMPR2-silenced HLMVECs, cytokines enhanced adhesiveness capacities, activation of P38MAPK and impaired endothelial barrier function suggesting that cytokines could trigger the development of pulmonary arterial hypertension in a context of impaired BMPRII signaling pathway.

Systems Immunology Characterization of Novel Vaccine Formulations for Mycoplasma hyopneumoniae Bacterins

We characterized five different vaccine candidates and a commercial vaccine in terms of safety, immunogenicity and using a systems vaccinology approach, with the aim to select novel vaccine candidates against Mycoplasma hyopneumoniae. Seven groups of six M. hyopneumoniae-free piglets were primo- and booster vaccinated with the different experimental bacterin formulations, the commercial vaccine Hyogen® as a positive control or PBS as a negative control. The experimental bacterin was formulated with cationic liposomes + c-di-AMP (Lipo_AMP), cationic liposomes + Toll-like receptor (TLR) 2/1, TLR7, and TLR9 ligands (TLR ligands; Lipo_TLR), micro-particles + TLR ligands (PLGA_TLR), squalene-in-water emulsion + TLR ligands (SWE_TLR), or DDA:TDB liposomes (Lipo_DDA:TDB). Lipo_DDA:TDB and Lipo_AMP were the most potent in terms of serum antibody induction, and Lipo_DDA:TDB, Lipo_AMP, and SWE_TLR significantly induced Th1 cytokine-secreting T-cells. Only PLGA_TLR appeared to induce Th17 cells, but was unable to induce serum antibodies. The transcriptomic analyses demonstrated that the induction of inflammatory and myeloid cell blood transcriptional modules (BTM) in the first 24 h after vaccination correlated well with serum antibodies, while negative correlations with the same modules were found 7 days post-vaccination. Furthermore, many cell cycle and T-cell BTM upregulated at day seven correlated positively with adaptive immune responses. When comparing the delivery of the identical TLR ligands with the three formulations, we found SWE_TLR to be more potent in the induction of an early innate immune response, while the liposomal formulation more strongly promoted late cell cycle and T-cell BTM. For the PLGA formulation we found signs of a delayed and weak perturbation of these BTM. Lipo_AMP was found to be the most potent vaccine at inducing a BTM profile similar to that correlating with adaptive immune response in this and other studies. Taken together, we identified four promising vaccine candidates able to induce M. hyopneumoniae-specific antibody and T-cell responses. In addition, we have adapted a systems vaccinology approach developed for human to pigs and demonstrated its capacity in identifying early immune signatures in the blood relating to adaptive immune responses. This approach represents an important step in a more rational design of efficacious vaccines for pigs.

Effects of pre-farrowing sow vaccination against Mycoplasma hyopneumoniae on offspring colonisation and lung lesions

This study investigated Mycoplasma hyopneumoniae colonisation and lung lesions at slaughter in pigs from vaccinated (V) and non-vaccinated (NV) sows, in two herds (A and B). In each herd, two sow batches were V against M. hyopneumoniae with a commercial bacterin at six and three weeks before farrowing and two sow batches remained NV. From each sow batch, laryngeal swabs were collected from the litters of five primiparous sows at weaning and seven days post-weaning. All samples were tested for M. hyopneumoniae by nested PCR. In total, 488 piglets were sampled. At slaughter, the extent of Mycoplasma-like pneumonia lesions (lung lesion score (LLS)) was assessed. The colonisation rates with M. hyopneumoniae at weaning and seven days post-weaning were (V-A=14.2, NV-A=20.0 (P=0.225); V-B=0.9, NV-B=0.8 (P=0.948)) and (V-A=0.8, NV-A=7.0 (P=0.039); V-B=1.8, NV-B=2.5 (P=0.738)), respectively. The average LLS (in per cent) was V-A=15.5, NV-A=26.4 (P=0.021); V-B=9.7, NV-B=8.4 (P=0.541). In conclusion, in herd A, with a substantially higher level of piglet colonisation at weaning than herd B, offspring from V sows had a significantly lower colonisation rate seven days post-weaning and a significantly lower LLS at slaughter compared with the offspring of the NV sows. This implies that sow vaccination might be useful for control of M. hyopneumoniae infections, although significant results may not be achieved at all times (such as in herd B).

Clinical impact of deoxynivalenol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol on the severity of an experimental Mycoplasma hyopneumoniae infection in pigs

Background

The mycotoxin deoxynivalenol (DON) is highly prevalent in cereals in moderate climates and therefore pigs are often exposed to a DON-contaminated diet. Pigs are highly susceptible to DON and intake of DON-contaminated feed may lead to an altered immune response and may influence the pathogenesis of specific bacterial diseases. Therefore, the maximum guidance level in feed is lowest in this species and has been set at 900 μg/kg feed by the European Commission. This study aimed to determine the effect of in-feed administration of a moderately high DON concentration (1514 μg/kg) on the severity of an experimental Mycoplasma hyopneumoniae (M. hyopneumoniae) infection in weaned piglets. Fifty M. hyopneumoniae-free piglets were assigned at 30 days of age [study day (D)0] to four different groups: 1) negative control group (NCG; n = 5), 2) DON-contaminated group (DON; n = 15), 3) DON-contaminated and M. hyopneumoniae-inoculated group (DONMHYO; n = 15), 4) M. hyopneumoniae-inoculated group (MHYO; n = 15). The piglets were fed the experimental diets ad libitum for five weeks and were monitored during this period and euthanized at day 35 [27 days post infection (DPI)] or 36 (28 DPI). The main parameters under investigation were macroscopic lung lesions (MLL) at euthanasia, respiratory disease score (RDS) from day 8 until day 35, histopathologic lesions and log copies of M. hyopneumoniae DNA detected by qPCR, determined at the day of euthanasia.

Results

No significant difference was obtained for MLL at euthanasia, RDS (8–35), histopathologic lung lesions and log copies of M. hyopneumoniae DNA in the DONMHYO and MHYO group and consequently, no enhancement of the severity of the M. hyopneumoniae infection could be detected in the DONMHYO compared to the MHYO group.

Conclusions

Under present conditions, the findings imply that feed contaminated with DON (1514 μg/kg) provided to weaned pigs for five weeks did not increase the severity of an experimental M. hyopneumoniae infection. Further research is needed to investigate the impact of DON on M. hyopneumoniae infections in a multi-mycotoxin and multi-pathogen environment.

Role of mycotoxins in herds with and without problems with tail necrosis in neonatal pigs

This study aimed to investigate a possible involvement of mycotoxins in neonatal tail necrosis in piglets. Ten affected and 10 non-affected farms were selected. Sow feed samples were analysed for the presence of 23 mycotoxins by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Blood plasma samples of sows and their piglets were analysed for the presence of deoxynivalenol (DON), de-epoxydeoxynivalenol, T-2 and HT-2 toxin, zearalenone, alfa-zearalenol, and beta-zearalenol, using LC-MS/MS. Additionally, high-resolution mass spectrometry (HRMS) was performed to detect DON-glucuronide (DON-Glca). There was a significant difference between case herds and control herds for mean DON concentrations in feed and sow plasma. For piglet samples, concentrations of DON were above the limit of quantification of 0.1 ng/ml in only 12 samples. Positive correlations were found between DON concentrations in sow feed and plasma of sows; DON concentration in sow feed and DON-Glca concentration in plasma of sows; and between DON and DON-Glca concentration in sow-plasma. In conclusion, high prevalence of DON in feed samples was found, with significantly higher concentrations in case herds, as well as the presence of DON and DON-Glca in sow plasma. Additional research is needed to identify risk factors, including within-herd factors, associated with neonatal tail necrosis in piglets.

Efficacy of one dose vaccination against experimental infection with two Mycoplasma hyopneumoniae strains

Background

Mycoplasma hyopneumoniae (M. hyopneumoniae) is the primary agent of enzootic pneumonia in pigs. Pigs are often infected with different M. hyopneumoniae strains. This study assessed the efficacy of vaccination against experimental infection with two genetically different M. hyopneumoniae strains in weaned piglets. At 33 days of age (D0), 45 M. hyopneumoniae-free piglets were randomly assigned to three different groups: 1) negative control group (NCG; n = 5): not vaccinated, not infected, 2) positive control group (PCG; n = 20): not vaccinated, infected, and 3) vaccination group (VG; n = 20): single vaccination with an inactivated whole-cell M. hyopneumoniae vaccine (Hyogen®, Ceva) (D1), infected. The PCG and VG were endotracheally inoculated with 7 × 10⁷ CCU in 7 ml of the highly virulent M. hyopneumoniae strain F7.2C (D24) and 7 × 10⁷ CCU in 7 ml low virulent strain F1.12A (D25). A respiratory disease score (RDS) was assessed from D24 until D53. At D53 (euthanasia), macroscopic lung lesions (MLL) were scored, log copies of M. hyopneumoniae DNA (qPCR) and IL-1 and IL-6-concentrations (ELISA) on bronchoalveolar lavage fluid were determined.

Results

The RDS and MLL at euthanasia were respectively 0, 1.20 and 0.55 (P < 0.001) and 0, 7.56 and 0.68 (P < 0.001) for NCG, PCG and VG, respectively. The qPCR results for PCG and VG were 3.99 and 1.78 log copies (P < 0.001), respectively, with a significant difference between PCG and VG. The IL-1 and IL-6 results at euthanasia for NCG, PCG and VG were 17.61, 1283.39 and 53.04 pg/ml (P < 0.001) and 148.10, 493.35 and 259.80 pg/ml (P = 0.004), respectively with a significant difference between PCG and VG.

Conclusions

Vaccination with Hyogen® in pigs was efficacious against an experimental challenge with both a low and highly virulent M. hyopneumoniae strain as the vaccinated pigs coughed significantly less, and showed significantly less lung lesions compared to the non-vaccinated challenged pigs: the vaccinated animals showed a 52.9% lower RDS and 91.0% lower MLL compared to the PCG. In the bronchoalveolar lavage fluid collected at the necropsy of the vaccinated pigs, a significantly lower amount of M. hyopneumoniae-DNA and a significantly lower IL-1 and IL-6 concentration was found compared to the pigs of the PCG.

Mycoplasma hyopneumoniae vaccination at or shortly before weaning under field conditions: a randomised efficacy trial

This study assessed the efficacy of two different Mycoplasma hyopneumoniae vaccination programmes in relation to the time of weaning. Eight hundred and twenty-eight piglets were randomly divided into three groups: group V1 was vaccinated three days before weaning, group V2 at weaning (21 days of age) and group NV was left non-vaccinated. Vaccinations were performed using Ingelvac MycoFLEX. After the nursery period, 306 pigs were allocated to fattening unit (F1) and 501 pigs to a second unit (F2). Efficacy was evaluated using performance parameters and pneumonia lesions at slaughter. Statistically significant differences were obtained in F2 where group V1 had a higher average daily weight gain compared to groups V2 and NV for the entire study period (17 and 18 g/day, respectively) and the fattening period (26 and 36 g/day, respectively) (P<0.05). Considering respiratory disease scores for both fattening units, group V1 was the only group where coughing severity did not increase significantly between placement and the end of the fattening period (P>0.05). Between groups, there were no statistically significant differences for the average lung lesion scores (V1=3.44; V2=4.61; NV=4.55, P>0.05) and the prevalence of pneumonia (V1=35.0 per cent; V2=38.0 per cent; NV=41.4 per cent, P>0.05). Overall, vaccination against M hyopneumoniae before weaning provided numerically better performance than vaccination at weaning, but did not reach statistical significance. An influenza outbreak in F1 and the presence of coexisting mixed respiratory infections in both F1 and F2 could have possibly influenced the performance of both vaccinated groups across all measured parameters.

Impact of diversity of Mycoplasma hyopneumoniae strains on lung lesions in slaughter pigs

The importance of diversity of Mycoplasma hyopneumoniae (M. hyopneumoniae) strains is not yet fully known. This study investigated the genetic diversity of M. hyopneumoniae strains in ten pig herds, and assessed associations between the presence of different strains of M. hyopneumoniae and lung lesions at slaughter. Within each herd, three batches of slaughter pigs were investigated. At slaughter, from each batch, 20 post mortem bronchoalveolar lavage fluid samples were collected for multiple locus variable-number tandem repeat analysis (MLVA), and lung lesions (Mycoplasma-like lesions, fissures) were examined. Multivariable analyses including potential risk factors for respiratory disease were performed to assess associations between the number of different strains per batch (three categories: one strain, two-six strains, ≥seven strains), and the lung lesions as outcome variables. In total, 135 different M. hyopneumoniae strains were found. The mean (min.-max.) number of different strains per batch were 7 (1-13). Batches with two-six strains or more than six strains had more severe Mycoplasma-like lesions (P = 0.064 and P = 0.012, respectively), a higher prevalence of pneumonia [odds ratio (OR): 1.30, P = 0.33 and OR: 2.08, P = 0.012, respectively], and fissures (OR = 1.35, P = 0.094 and OR = 1.70, P = 0.007, respectively) compared to batches with only one strain. In conclusion, many different M. hyopneumoniae strains were found, and batches of slaughter pigs with different M. hyopneumoniae strains had a higher prevalence and severity of Mycoplasma-like lung lesions at slaughter, implying that reducing the number of different strains may lead to less lung lesions at slaughter and better respiratory health of the pigs.

Efficacy of Mycoplasma hyopneumoniae vaccination before and at weaning against experimental challenge infection in pigs

BACKGROUND

Commercial bacterins are widely used at weaning to control Mycoplasma hyopneumoniae infections in pigs. However, it is not known whether the efficacy of vaccinating against M. hyopneumoniae can be influenced by the weaning process when vaccination is applied at the day of weaning. The present study assessed the efficacy of a single M. hyopneumoniae vaccination (Ingelvac MycoFLEX®) three days before weaning (V1) or at weaning (V2) against experimental challenge infection. Four weeks after vaccination, groups V1 and V2 (n = 20 pigs each) and a non-vaccinated, positive control group (PCG) (n = 20) were endotracheally inoculated with a virulent M. hyopneumoniae field strain. Five pigs were used as a negative control group. All pigs were euthanized 5 weeks after challenge. The main parameters investigated included macroscopic and histopathological lung lesions at necropsy, immunofluorescence (IF) staining and quantitative real-time PCR (qPCR) on broncho-alveolar lavage (BAL) fluid for quantifying M. hyopneumoniae.

RESULTS

The average macroscopic lung lesion scores in groups V1, V2 and PCG were 0.54, 0.88 and 1.04, respectively (P > 0.05). The average lymphohistiocytic infiltration scores in groups V1, V2 and PCG were 2.95, 3.16 and 3.61, respectively (P < 0.05). The average IF scores were: V1 = 1.13, V2 = 1.19 and PCG = 1.25 (P > 0.05), the qPCR values were: V1 = 10(2.94), V2 = 10(2.76) and PCG = 10(3.23) (P > 0.05). All pigs of the negative control group remained negative throughout the study.

CONCLUSIONS

Both vaccinated groups had lower numbers of macroscopic and histopathological lung lesions, and lower numbers of M. hyopneumoniae organisms in the BAL fluid compared to the PCG. However, no firm conclusions could be made on whether weaning negatively influences the efficacy of M. hyopneumoniae vaccination, since significant differences between the treatment groups were only obtained for the histopathological lung lesions. This could be attributed to the fact that milder macroscopic lung lesions were produced in the inoculated pigs, when compared to previous trials conducted by the same group. Further research under field conditions is warranted to assess possible differences between the two vaccination strategies.

High-content analysis of α-synuclein aggregation and cell death in a cellular model of Parkinson's disease

BACKGROUND

Alpha-synuclein (α-SYN) aggregates represent a key feature of Parkinson's disease, but the exact relationship between α-SYN aggregation and neurodegeneration remains incompletely understood. Therefore, the availability of a cellular assay that allows medium-throughput analysis of α-SYN-linked pathology will be of great value for studying the aggregation process and for advancing α-SYN-based therapies.

NEW METHOD

Here we describe a high-content neuronal cell assay that simultaneously measures oxidative stress-induced α-SYN aggregation and apoptosis.

RESULTS

We optimized an automated and reproducible assay to quantify both α-SYN aggregation and cell death in human SH-SY5Y neuroblastoma cells.

COMPARISON WITH EXISTING METHODS

Quantification of α-SYN aggregates in cells has typically relied on manual imaging and counting or cell-free assays, which are time consuming and do not allow a concurrent analysis of cell viability. Our high-content analysis method for quantification of α-SYN aggregation allows simultaneous measurements of multiple cell parameters at a single-cell level in a fast, objective and automated manner.

CONCLUSIONS

The presented analysis approach offers a rapid, objective and multiparametric approach for the screening of compounds and genes that might alter α-SYN aggregation and/or toxicity.

Serotype-dependent transduction efficiencies of recombinant adeno-associated viral vectors in monkey neocortex

Viral vector-mediated expression of genes (e.g., coding for opsins and designer receptors) has grown increasingly popular. Cell-type specific expression is achieved by altering viral vector tropism through crosspackaging or by cell-specific promoters driving gene expression. Detailed information about transduction properties of most recombinant adeno-associated viral vector (rAAV) serotypes in macaque cortex is gradually becoming available. Here, we compare transduction efficiencies and expression patterns of reporter genes in two macaque neocortical areas employing different rAAV serotypes and promoters. A short version of the calmodulin-kinase-II (CaMKIIα0.4) promoter resulted in reporter gene expression in cortical neurons for all tested rAAVs, albeit with different efficiencies for spread: rAAV2/5>>rAAV2/7>rAAV2/8>rAAV2/9>>rAAV2/1 and proportion of transduced cells: rAAV2/1>rAAV2/5>rAAV2/7=rAAV2/9>rAAV2/8. In contrast to rodent studies, the cytomegalovirus (CMV) promoter appeared least efficient in macaque cortex. The human synapsin-1 promoter preceded by the CMV enhancer (enhSyn1) produced homogeneous reporter gene expression across all layers, while two variants of the CaMKIIα promoter resulted in different laminar transduction patterns and cell specificities. Finally, differences in expression patterns were observed when the same viral vector was injected in two neocortical areas. Our results corroborate previous findings that reporter-gene expression patterns and efficiency of rAAV transduction depend on serotype, promoter, cortical layer, and area.

Impact of particulate matter and ammonia on average daily weight gain, mortality and lung lesions in pigs

The present study investigated the simultaneous influence of particulate matter (PM10) and ammonia (NH3) on performance, lung lesions and the presence of Mycoplasma hyopneumoniae (M. hyopneumoniae) in finishing pigs. A pig herd experiencing clinical problems of M. hyopneumoniae infections was selected. In total, 1095 finishing pigs of two replicates in eight compartments each were investigated during the entire finishing period (FP). Indoor PM10 and NH3 were measured at regular intervals during the FP with two Grimm spectrometers and two Graywolf Particle Counters (PM10) and an Innova photoacoustic gas monitor (NH3). Average daily weight gain (ADG) and mortality were calculated and associated with PM10 and NH3 during the FP. Nasal swabs (10 pigs/compartment) were collected one week prior to slaughter to detect DNA of M. hyopneumoniae with nested PCR (nPCR). The prevalence and extent of pneumonia lesions, and prevalence of fissures and pleurisy were examined at slaughter (29 weeks). The results from the nasal swabs and lung lesions were associated with PM10 and NH3 during the FP and the second half of the FP. In the univariable model, increasing PM10 concentrations resulted in a higher odds of pneumonia lesions (second half of the FP: OR=8.72; P=0.015), more severe pneumonia lesions (FP: P=0.04, second half of the FP: P=0.009), a higher odds of pleurisy lesions (FP: OR=20.91; P<0.001 and second half of the FP: OR=40.85; P<0.001) and a higher number of nPCR positive nasal samples (FP: OR=328.00; P=0.01 and second half of the FP: OR=185.49; P=0.02). Increasing NH3 concentrations in the univariable model resulted in a higher odds of pleurisy lesions (FP: OR=21.54; P=0.003) and a higher number of nPCR positive nasal samples (FP: OR=70.39; P=0.049; second half of the FP: OR=8275.05; P=0.01). In the multivariable model, an increasing PM10 concentration resulted in a higher odds of pleurisy lesions (FP: OR=8.85; P=0.049). These findings indicate that the respiratory health of finishing pigs was significantly affected by PM10.

Efficacy of vaccination against Actinobacillus pleuropneumoniae in two Belgian farrow-to-finish pig herds with a history of chronic pleurisy

The efficacy of an Actinobacillus pleuropneumoniae subunit vaccine based on ApxIA, ApxIIA, ApxIIIA and OMP-2 (Porcilis App, MSD) was investigated in two farrow-to-finish pig herds (A and B) affected by chronic pleurisy. In total, 1161 pigs were included. At three weeks of age, the pigs were randomly allocated to non-vaccinated control (NV; n=580) and vaccinated (V; n=581) groups. At 6 and 10 weeks of age, pigs were injected with Porcilis-APP (V group) or adjuvant (NV group). At slaughter (26 weeks), pleurisy and pneumonia lesions were assessed. All pigs were weighed individually at 6 and 26 weeks of age, and average daily weight gain (ADG; g/pig/day) was calculated. Mortality and days of additional treatment (DAT) were registered during the whole experiment. Data were analysed using binary logistic regression or analysis of variance for proportions or continuous variables, respectively. The prevalence of pleurisy and pneumonia was (NV-A=19.3, V-A=7.9, (P=0.000); NV-B=17.9, V-B=0.7, (P=0.000)) and (NV-A=42.4, V-A=21.2, (P=0.000); NV-B=46.7, V-B=19.0, (P=0.000)), respectively. The ADG was NV-A=632±157, V-A=647±91, (P=0.162); NV-B=660±115, V-B=670±82, (P=0.232). The mortality during the experiment was NV-A=5.7, V-A=1.8, (P=0.015); NV-B=2.3, V-B=1.0, (P=0.170) per cent. The DAT was: NV-A=15.04±1.41, V-A=14.95±0.67, (P=0.010); NV-B=21.68±2.43, V-B=16.99±0.62, (P=0.000). The present study showed a significant reduction of the prevalence of pleurisy and pneumonia, and antimicrobial use in V pigs from both herds, and in mortality in V pigs from one herd.

Exposure levels of farmers and veterinarians to particulate matter and gases during operational tasks in pig-fattening houses

The main objective of the study was to assess particulate matter (PM) exposure levels for both the farmer and the veterinarian during different operational tasks in pig-fattening houses, and to estimate their exposure levels on a daily working basis (time-weighted average (TWA)). The measured PM fractions were: inhalable and respirable PM, PM10, PM2.5 and PM1. The effects of pig age, pen floor type (conventional or low emission surface) and cleaning of the pens on the personal PM exposure were also investigated. Indoor concentrations of NH3, CH4, and CO2 were additionally measured during some operational tasks. The results showed that personal exposure levels can become extremely high during some operational tasks performed by the farmer or veterinarian. The highest concentration levels were observed during feed shovelling and blood sampling, the lowest during the weighing of the pigs. For the farmer, the estimated TWA exposure levels of inhalable and respirable PM were 6.0 and 0.29 mg m(-3), respectively. These exposure levels for the veterinarian were, respectively, 10.6 and 0.74 mg m(-3). The PM concentration levels were mainly determined by the performed operational tasks. There was no significant effect of pig age, pen floor type, nor cleaning of the pens on the personal exposure levels.

Viral vectors expressing a single microRNA-based short-hairpin RNA result in potent gene silencing in vitro and in vivo

The characterization of RNA interference and the accompanying microRNAs (miRs), together with the exogenous expression of artificial miR-like elements, has led to the development of strategies for specific and potent gene silencing. In turn, this allows manipulation of gene expression levels for target validation purposes in cell culture or for the generation of animal models. In this study we determined the optimal strategy to achieve the most potent knockdown using miR-based viral vectors. We studied polycistronic miRs in a viral vector context and evaluated knockdown potency of multiple-miRs targeting the same seed sequence in parallel with miRs targeting different seed sequences, both for a reporter and endogenous mRNA targets. We demonstrate that potent knockdown can be obtained in vitro and in vivo using viral vectors that encode a single miR-based short-hairpin RNA and report a generic and effective cloning platform for artificial miR30-based short-hairpin RNAs to generate potent knockdown viral vectors.

Lenalidomide in relapsed refractory myeloma patients: impact of previous response to bortezomib and thalidomide on treatment efficacy. Results of a medical need program in Belgium

The prognosis of multiple myeloma patients has significantly improved since the introduction of the novel agents thalidomide, bortezomib and lenalidomide. We report the data of a medical need programme with lenalidomide plus dexamethasone, conducted in Belgium between August 2007 and March 2008, and including 98 relapsed refractory multiple myeloma patients. In addition to chemotherapy and steroids, all patients had received prior treatment with bortezomib, and 84% of them had been exposed to thalidomide. In 52 patients response data could be retrieved by post-hoc analysis. A partial remission or better was achieved in 52% (49% partial and 3% complete response) of patients, despite a median of 5 previous anti-myeloma treatment lines. Responses were rapid while the majority of patients received lenalidomide with once weekly (also called low-dose) dexamethasone. Treatment with lenalidomide plus dexamethasone did prolong overall survival by nearly half a year in this population with end-stage myeloma. Overall response and quality of response were independent of previous response to thalidomide and bortezomib, although the time to progression tended to be shorter in thalidomide- and bortezomib-refractory patients. It can be concluded that lenalidomide plus dexamethasone is an effective and safe treatment regimen in highly refractory multiple myeloma patients, and that these responses are irrespective of previous exposure or sensitivity to thalidomide and bortezomib.

Functional T-cell responses generated by dendritic cells expressing the early HIV-1 proteins Tat, Rev and Nef

The limitations of highly active anti-retroviral therapy (HAART) have necessitated the development of alternative therapeutic strategies. One of the approaches that has gained prominence in recent years is therapeutic vaccination. We decided to assess the capacity of mature dendritic cells, derived from blood monocytes of HIV-1 infected patients, to generate functional T-cell responses. For this purpose, we constructed a chimeric mRNA encoding the proteins Tat, Rev and Nef. The TaReNef encoding information was linked to the HLA class II-targeting sequence of DC-LAMP. Broadly directed HIV-specific CD4(+) and CD8(+) cytotoxic T cells exhibiting a poly-functional cytokine secretion pattern were generated by co-culturing with autologous chimeric mRNA electroporated dendritic cells. Thus, administration of ex vivo generated dendritic cells expressing the early proteins Tat, Rev and Nef might offer a promising approach for therapeutic vaccination in HIV-1 infection.

Activation of immature monocyte-derived dendritic cells after transduction with high doses of lentiviral vectors

Dendritic cells (DCs) are an attractive tool for immunomodulation, targeting mature DCs (mDCs) for immunization or immature/semimature DCs (iDCs) for tolerization. Therefore, introducing antigens into DCs has become a prime topic in various immunological disciplines. Numerous studies have shown that lentiviruses are an efficient vehicle for this purpose. This study evaluates the effects of lentiviral transduction on iDC activation. Immature DCs are efficiently transduced with increasing doses of lentivirus without affecting cell viability. Transduction at low multiplicities of infection (MOIs) did not result in phenotypical or functional maturation. Higher doses of lentivirus, however, resulted in upregulation of adhesion, costimulatory, and HLA molecules, as well as in increased allostimulatory capacity and secretion of interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha. Production of IL-12 p70, IL-10, and interferon-alpha was observed only at extremely high doses. Protein kinase R phosphorylation on transduction at an MOI of 150 was demonstrated by Western blotting. A Toll-like receptor (TLR)-driven luciferase reporter assay showed dose-dependent activation of TLR2, TLR3, and TLR8, which was independent of the pseudotype, production, or transduction protocol and was abrogated on heat inactivation. These data show that lentiviral vectors provide not only the antigen but also appropriate activation signals to iDCs, favoring their use for immunotherapy and vaccine development.

Giant liposarcoma of the stomach involving the mediastinum

A case of a liposarcoma of the stomach in a 27-year old woman is described. Initially the patient consulted with epigastric pain. MRI showed a giant tumour of the stomach wall, invading the surrounding organs, as well as the mediastinal region. After surgical 'en-bloc' resection of the tumour, histopathologic examination yielded a diagnosis of pleiomorphic liposarcoma. Because of the bad prognosis of this histologic type, the patient received adjuvant chemotherapy: a combination of doxorubicin and ifosfamide (MAI). Nine months after surgery, she represented with a relapse of the tumour that had become inoperable. Palliative chemotherapy was started with the intent to prolong the young patient's life. However 6 months later, the patient died of the recurrent disease. Although liposarcoma is a very common soft tissue sarcoma, it is rarely seen in the stomach. The standard therapy is surgical excision. Over the last years, adjuvant therapy became more accepted. Drugs of choice are doxorubicin and ifosfamide, although the benefits of this therapy are still largely unknown and doubtful.

ESHRE PGD Consortium data collection VI: cycles from January to December 2003 with pregnancy follow-up to October 2004

The sixth report of the ESHRE PGD Consortium is presented, relating to cycles collected for the calendar year 2003 and follow-up of the pregnancies and babies born up to October 2004. Since the beginning of the data collections, there has been a steady rise in the number of cycles, pregnancies and babies reported. For this report, 50 centres participated, reporting on 2984 cycles, 501 pregnancies and 373 babies born. Five hundred and twenty-nine cycles were reported for chromosomal abnormalities, 516 cycles were reported for monogenic diseases, 137 cycles were reported for sexing for X-linked diseases, 1722 cycles were reported for preimplantation genetic screening (PGS) and 80 cycles were reported for social sexing. Data VI is compared to the cumulative data for data collections I-V.

Induction of antigen-specific CD8+ cytotoxic T cells by dendritic cells co-electroporated with a dsRNA analogue and tumor antigen mRNA

The maturation state of dendritic cells (DCs) is an important determinant for the initiation and regulation of adaptive immune responses. In this study, we wanted to assess whether functional activation of human monocyte-derived DCs can be achieved by electroporation of an activation signal in the form of double-stranded (ds) RNA and whether simultaneous electroporation of the dsRNA with tumor antigen encoding mRNA can lead to the induction of a cytotoxic T-lymphocyte (CTL) response. Electroporation of immature DCs with poly(I:C(12)U), a dsRNA analogue, resulted in phenotypic as well as functional changes, indicative of DC maturation. Co-electroporation of DCs with both poly(I:C(12)U) and Melan-A/MART-1 encoding mRNA induced strong anti-Melan-A/MART-1 CD8(+) T-cell responses in vitro. Higher numbers of Melan-A/MART-1-specific CTLs were consistently obtained with poly(I:C(12)U)-activated DCs compared to DCs matured in the presence of an inflammatory cytokine cocktail. These results indicate that DC co-electroporation with both dsRNA and tumor antigen encoding mRNA induces fully activated and antigen-loaded DCs that promote antigen-specific CTL responses and may provide the basis for future immunotherapeutic strategies.

Which patients with recurrent implantation failure after IVF benefit from PGD for aneuploidy screening?

Patients with recurrent IVF failure are defined as patients who are younger than 37 years and who had at least three consecutive unsuccessful IVF/intracytoplasmic sperm injection (ICSI) cycles with good quality embryos. These patients might be predisposed to chromosome errors in their embryos and therefore might benefit from preimplantation genetic diagnosis for aneuploidy screening (PGD-AS). This technique is, however, expensive and some normal embryos might be lost due to the error rate. The aim of this retrospective study was to define those patients who would benefit most from it. One hundred and twenty-one first PGD-AS cycles for recurrent IVF failure were analysed. The aneuploidy rate, 'no embryo transfer' rate, live birth rate per embryo transfer and implantation rate were respectively 48.3, 22.3, 29.7 and 19.5%. A multivariate logistic regression analysis gave us a predictive model demonstrating that to have a 90% probability of having an embryo transfer after PGD-AS, the patient should have at least 10 mature oocytes, eight normally fertilized oocytes and six embryos for biopsy. This study suggests that most patients with recurrent IVF failure may benefit from PGD-AS. Future studies, however, should more strictly define this heterogeneous group of patients, so that comparison is easier.

In Vivo Depletion of CD4+CD25+ Regulatory T Cells Enhances the Antigen-Specific Primary and Memory CTL Response Elicited by Mature mRNA-Electroporated Dendritic Cells

We previously described mRNA electroporation as an efficient gene delivery method to introduce tumor-antigens (Ag) into murine immature dendritic cells (DC). Here, we further optimize the protocol and evaluate the capacity of mRNA-electroporated DC as a vaccine for immunotherapy. First, the early DC maturation kinetics and the effect of different lipopolysaccharide incubation periods on the phenotypic maturation profile of DC are determined. Next, we show that either immature or mature DC are equally well electroporated and express and present the transgene at a comparable level after electroporation. We point out that the mRNA electroporation results in a negative effect on the interleukin (IL)-12p70, IL-6, and tumor necrosis factor-alpha secretion after maturation. Nevertheless, mRNA-electroporated DC induce an effective cytotoxic T lymphocyte (CTL) response in vivo. Mature electroporated DC are significantly more potent in eliciting an Ag-specific CD8+ CTL response compared to their immature electroporated counterparts. In addition, a significant improvement in CTL response is obtained both in the primary and in the memory effector phases when CD4+CD25+ regulatory T cells (Treg) are depleted in vivo prior to immunization. These findings are further substantiated in tumor protection experiments and hold convincing evidence for the merit of Treg cell depletion prior to immunization with mRNA-electroporated DC.

Electroporation of immature and mature dendritic cells: implications for dendritic cell-based vaccines

Until now, studies utilizing mRNA electroporation as a tool for the delivery of tumor antigens to human monocyte-derived dendritic cells (DC) have focused on DC electroporated in an immature state. Immature DC are considered to be specialized in antigen capture and processing, whereas mature DC present antigen and have an increased T-cell stimulatory capacity. Therefore, the consensus has been to electroporate DC before maturation. We show that the transfection efficiency of DC electroporated either before or after maturation was similarly high. Both immature and mature electroporated DC, matured in the presence of an inflammatory cytokine cocktail, expressed mature DC surface markers and preserved their capacity to secrete cytokines and chemokines upon CD40 ligation. In addition, both immature and mature DC can be efficiently cryopreserved before or after electroporation without deleterious effects on viability, phenotype or T-cell stimulatory capacity including in vitro antigen-specific T-cell activation. However, DC electroporated after maturation are more efficient in in vitro migration assays and at least as effective in antigen presentation as DC electroporated before maturation. These results are important for vaccination strategies where an optimal antigen presentation by DC after migration to the lymphoid organs is crucial.

Dendritic cells differentiated in the presence of IFN-β and IL-3 are potent inducers of an antigen-specific CD8+T cell response

Dendritic cells (DC) are professional antigen-presenting cells that are used in vaccine approaches to cancer. Classically, mature monocyte-derived DC are generated in vitro in the presence of interleukin (IL)-4, granulocyte macrophage-colony stimulating factor, and inflammatory cytokines (G4-DC). Recently, it has been described that DC can also be generated in the presence of IL-3 and interferon (IFN)-beta and that these DC are efficiently matured using polyriboinosinic polyribocytidylic acid (I3-DC). In this study, a series of in vitro experiments was performed to compare side-by-side I3-DC and G4-DC as vaccine adjuvants. Phenotypic characterization of the DC revealed differences in the expression of the monocyte marker CD14 and the maturation marker CD83. Low expression of CD14 and high expression of CD83 characterized G4-DC, whereas I3-DC displayed intermediate expression of CD14 and CD83. Both types of DC were as potent in the induction of allogeneic T cell proliferation. Upon CD40 ligation, G4-DC produced lower amounts of IFN-alpha and pulmonary and activation-regulated chemokine, similar amounts of IL-6, macrophage-inflammatory protein (MIP)-1alpha, and MIP-1beta, and higher amounts of IL-12 p70, tumor necrosis factor alpha, and MIP-3beta than I3-DC. We further evaluated whether the DC could be frozen/thawed without loss of cell number, viability, phenotype, and function. After freezing/thawing, 56.0% +/- 9.0% of I3-DC and 77.0% +/- 3.0% of G4-DC (n=9) were recovered as viable cells, displaying the same phenotype as their fresh counterparts. Finally, in vitro stimulations showed that fresh and frozen peptide-loaded I3-DC are more potent inducers of Melan-A-specific CD8(+) T cell responses than G4-DC. The antigen-specific T cells were functional as shown in cytotoxicity and IFN-gamma secretion assay.

Side-by-side comparison of lentivirally transduced and mRNA-electroporated dendritic cells: implications for cancer immunotherapy protocols

The use of tumor antigen-loaded dendritic cells (DC) is one of the most promising approaches to inducing a tumor-specific immune response. We compared electroporation of mRNA to lentiviral transduction for the delivery of tumor antigens to human monocyte-derived and murine bone marrow-derived DC. Both lentiviral transduction and mRNA electroporation induced eGFP expression in on average 81% of human DC. For murine DC, eGFP mRNA electroporation (62%) proved to be more efficient than lentiviral transduction (47%). When we used tNGFR as a transgene we observed lentiviral pseudotransduction that overestimated lentiviral efficiency. Neither gene transfer method had an adverse effect on viability, phenotype, or allostimulatory capacity of either human or murine DC. Yet, the mRNA-electroporated DC showed a reduced production of IL-12p70 compared to their lentivirally transduced and unmodified counterparts. Human Ii80MAGE-A3-modified DC and murine Ii80tOVA-modified DC were able to present antigenic epitopes in the context of MHC class I and class II. Both types of modified murine DC were able to induce OVA-specific cytotoxic T cells in vivo; however, the mRNA-electroporated DC were less potent. Our data indicate that this may be related to their impaired IL-12 production.

ESHRE PGD Consortium data collection IV: May–December 2001

The ESHRE PGD Consortium was formed in 1997 to survey the practice of preimplantation genetic diagnosis (PGD). Since then, three reports have been published giving an overview on PGD from an ever-increasing number of centres and reporting on an increasing number of PGD cycles and pregnancies and babies born after PGD. After these initial influential publications, important shortcomings were identified primarily on the method of data collection, i.e. with Excel spreadsheets, and in the timing of the collection (cycles were collected in a different time frame from pregnancies and babies, making the follow-up of cycles very difficult). This is why the Steering Committee has made a major investment in developing and implementing a new database in FileMaker Pro 6. It was also decided that cycles would be collected from one calendar year, as well as the pregnancies and babies ensuing from that particular calendar year. This gave us the opportunity to take a closer look at the data collected earlier, and to attempt to improve their quality. This is a report on the corrected data from the first three data collections (I-III) as well as the result of the last data collection (IV) that was completely carried out using the new database.

Activation of monocytes via the CD14 receptor leads to the enhanced lentiviral transduction of immature dendritic cells

In this study, we compared dendritic cells (DCs) differentiated from positively selected monocytes (CD14-DCs) to DCs differentiated from adherence-selected monocytes (adh-DCs) with emphasis on lentiviral transduction. Using a second-generation, triple-helix containing, self-inactivating lentiviral vector at a multiplicity of infection (MOI) of 15, we observed enhanced transduction of CD14-DCs (72.8 +/- 5.3%, mean fluorescence intensity [MFI] = 166 +/- 76) compared to adh-DCs (32.3 +/- 13.1%, MFI = 119 +/- 76, n = 5). More importantly, the efficiency to transduce adh-DCs was significantly increased when monocytes were incubated with antiCD14 antibody coupled beads, anti-CD14 antibodies, or lipopolysaccharide (LPS), reaching transduction efficiencies up to 86.6%, 53.3%, and 80.9%, respectively. We showed that this enhanced transduction was correlated to an activation of the monocytes, characterized by the up regulation of the cytokines interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha and the de novo synthesis of IL-6 and IL-10. However, the enhanced transduction of immature CD14-DCs was not correlated with a progression in the cell cycle from G(0) to G(1). We further showed that CD14-DCs were phenotypically comparable to adh-DCs. Functional analysis revealed that there were no differences in allostimulatory capacity, production of IL-12 p70 on CD40 ligation or expression of IL-1beta, IL-6, IL-8, IL-10, IL-12, and TNF-alpha as evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR). Finally, we showed that lentivirally transduced CD14-DCs were equally capable as adh-DCs in stimulating MAGE-A3 antigen-specific CD4(+) and CD8(+) T cells in vitro.

Comparison of the aneuploidy frequency in embryos derived from testicular sperm extraction in obstructive and non-obstructive azoospermic men

BACKGROUND

The use of ICSI has been a major breakthrough in the treatment of male infertility. Even azoospermic patients with focal spermatogenesis in the testis (not sufficient to spill over into the ejaculate) may benefit from the technique. Previous reports suggest a higher pregnancy rate after ICSI treatment in patients with obstructive azoospermia (OA) compared to their non-obstructive azoospermia (NOA) counterparts, which could be due to a higher aneuploidy frequency in the embryos of the latter group. We therefore conducted a prospective cohort study to compare the aneuploidy frequency of the screened embryos between the two groups.

METHODS

From May 2001 until September 2003, we offered couples with an OA or NOA partner ICSI in combination with preimplantation genetic diagnosis for aneuploidy screening.

RESULTS

No difference in age (30.6 and 33.5 years) or stimulation parameters was observed between the two groups; 53 and 60% of the embryos were abnormal in the NOA and OA groups respectively (P = not significant).

CONCLUSIONS

The aneuploidy frequency in embryos obtained from NOA as well as OA men is similar and very high, despite the young age of their female partners.

Messenger RNA-electroporated dendritic cells presenting MAGE-A3 simultaneously in HLA class I and class II molecules

An optimal anticancer vaccine probably requires the cooperation of both CD4(+) Th cells and CD8(+) CTLs. A promising tool in cancer immunotherapy is, therefore, the genetic modification of dendritic cells (DCs) by introducing the coding region of a tumor Ag, of which the antigenic peptides will be presented in both HLA class I and class II molecules. This can be achieved by linking the tumor Ag to the HLA class II-targeting sequence of an endosomal or lysosomal protein. In this study we compared the efficiency of the targeting signals of invariant chain, lysosome-associated membrane protein-1 (LAMP1) and DC-LAMP. Human DCs were electroporated before or after maturation with mRNA encoding unmodified enhanced green fluorescent protein (eGFP) or eGFP linked to various targeting signals. The lysosomal degradation inhibitor chloroquine was added, and eGFP expression was evaluated at different time points after electroporation. DCs were also electroporated with unmodified MAGE-A3 or MAGE-A3 linked to the targeting signals, and the presentation of MAGE-A3-derived epitopes in the context of HLA class I and class II molecules was investigated. Our data suggest that proteins linked to the different targeting signals are targeted to the lysosomes and are indeed presented in the context of HLA class I and class II molecules, but with different efficiencies. Proteins linked to the LAMP1 or DC-LAMP signal are more efficiently presented than proteins linked to the invariant chain-targeting signal. Furthermore, DCs electroporated after maturation are more efficient in Ag presentation than DCs electroporated before maturation.

Recovery, survival and functional evaluation by transplantation of frozen-thawed mouse germ cells

BACKGROUND

Establishing a successful method for testicular stem cell transplantation of frozen-thawed testicular cells would be of immense benefit to boys with childhood cancer undergoing a sterilizing treatment. In this study, we evaluated different cryopreservation protocols in a mouse model by means of testicular germ cell transplantation (TGCT), in order to establish an optimal freezing protocol.

METHODS AND RESULTS

In a first series of experiments, we compared an uncontrolled protocol with 1.5 mol/l dimethyl sulphoxide (DMSO) versus a controlled long protocol (cooling to -80 degrees C) and observed a better viability with the latter protocol (36% versus 48%, P < 0.05). We then compared survival after two thawing methods (37 degrees C water versus ice water) in either a DMSO- or an ethylene glycol (EG)-based protocol, and found no difference. In order to evaluate the functional capacity of the cryopreserved testicular suspension, TGCT was performed with both fresh and frozen-thawed suspensions. In 90% of the successfully injected testes, spermatogenesis was reinitiated using fresh suspensions. In contrast, this figure was only 12.5 and 22.7% after cryopreservation, for the short controlled EG protocol and the uncontrolled DMSO protocol, respectively.

CONCLUSION

Reinitiation of spermatogenesis is possible after cryopreservation of testicular germ cell suspensions. Although cell survival was acceptable, our results after TGCT show that our protocols need further improvement.

Induction of Influenza Matrix Protein 1 and MelanA-specific T lymphocytes in vitro using mRNA-electroporated dendritic cells

Genetically modified dendritic cells (DC) constitute a promising approach in cancer immunotherapy. Viral gene delivery systems have been shown to be very efficient strategies, but safety concerns for their clinical use in immunotherapy remain an important issue. Recently, the technique of mRNA electroporation was described as a very efficient tool for the genetic modification of human monocyte-derived DC. Here, we show that transgene expression can be modulated by varying the amount of mRNA used for electroporation. We document that CD40 ligation leads to a significant production of IL-12 by the electroporated DC, although the level of IL-12 production is somewhat lower than for non- or mock-electroporated DC. Furthermore, we show that the electroporated DC can be frozen and thawed without loss of viability or function and that Influenza virus Matrix Protein 1 mRNA electroporated DC are capable of inducing a memory cytotoxic T lymphocyte response and are more potent in doing so than mRNA-pulsed DC. Similar results were obtained with MelanA/MART-1 mRNA electroporated DC. These results clearly indicate that mRNA-electroporated DC represent powerful candidates for use as tumor vaccines and could constitute an improvement compared with vaccines using peptide-pulsed DC.

Efficient presentation of known HLA class II-restricted MAGE-A3 epitopes by dendritic cells electroporated with messenger RNA encoding an invariant chain with genetic exchange of class II-associated invariant chain peptide

For the induction of an optimal immune response against cancer or infections not only CD8(+) CTLs but also CD4(+) T helper cells must be induced, in particular IFN-gamma-secreting type 1 T helper cells. Several strategies have been explored to target tumor-associated antigens to the HLA class II processing compartments. We engineered a genetic construct encoding an invariant chain (Ii) protein where the CLIP region has been replaced by sequences encoding HLA class II-restricted MAGE-A3 epitopes. Monocyte-derived dendritic cells (DCs) were electroporated with in vitro transcribed mRNA encoding a modified Ii protein containing the HLA-DP4-restricted MAGE-A3 epitope. The capacity of these electroporated DCs to stimulate a MAGE-A3-specific T-cell clone was compared at different stages of DC maturation with the T-cell stimulatory capacity of DCs pulsed with the synthetic peptide. After electroporation, the T-cell stimulatory capacity was shown to be high and long lasting, whereas the stimulatory capacity of peptide-pulsed DCs decreased rapidly. Upon coculture with epitope-specific T cells, electroporated immature DCs expressed enhanced levels of costimulatory molecules, HLA class II molecules, and CD83, suggesting the induction of maturation. The electroporated DCs can be frozen and thawed without losing their capability to stimulate the specific T-cell clone in vitro, and they are able to stimulate unprimed CD4(+) T cells specific to the HLA-DP4-restricted MAGE-A3 epitope in vitro. Similar results were obtained with a recombinant Ii containing the MAGE-A3 epitope presented in the context of HLA-DR13.

PGD in 47,XXY Klinefelter's syndrome patients

The use of ICSI has been a major breakthrough in the treatment of male infertility. Even azoospermic patients with focal spermatogenesis in the testis, may benefit from the ICSI technique in order to father a child. As ICSI use has become more common, centres have introduced infertility treatment for Klinefelter patients. To date, 34 healthy children have been born using ICSI without PGD, and the conception of one 47,XXY fetus has been reported. In view of the possible risk of an increased gonosome number in the spermatozoa of Klinefelter patients, a safer approach--offering these couples ICSI combined with PGD--has been used, and has resulted in the birth of three healthy children. Couples in which the male suffered from Klinefelter's syndrome were first treated in 1995; these patients were offered ICSI + PGD using FISH technology, notably to enumerate the X and Y chromosomes. ICSI + PGD was performed in 32 cycles of 20 couples with spermatozoa originating from a fresh ejaculate (n = 1), testicular biopsy (n = 21) or frozen-thawed testicular biopsy (n = 10). Normal fertilization occurred in 56.0 +/- 22.4% of the successfully injected oocytes. On day 3 of development, 119 embryos from 29 cycles were of sufficient quality to undergo biopsy and subsequent PGD; a positive result was obtained in 113 embryos. Embryos were available for transfer in 26 cycles, with a mean of 1.6 +/- 0.6 embryos per transfer. Eight pregnancies were obtained, and five resulted in a delivery. A total of 113 embryos from couples with Klinefelter's syndrome was compared with 578 embryos from control couples with X-linked disease where PGD was used to determine gender. A significant fall occurred in the rate of normal embryos for couples with Klinefelter's syndrome (54.0%) compared with controls (77.2%). Moreover, a significantly increased risk of abnormalities was observed for sex chromosomes and autosomes; for each autosome separately, this reached significance level for chromosomes 18 and 21 only. Hence, a cautious approach is warranted in advising couples with non-mosaic Klinefelter's syndrome. Moreover, the use of ICSI + PGD or prenatal diagnosis should be carefully considered.

Defoliation induces fructan 1-exohydrolase II in Witloof chicory roots. Cloning and purification of two isoforms, fructan 1-exohydrolase IIa and fructan 1-exohydrolase IIb. Mass fingerprint of the fructan 1-exohydrolase II enzymes

The cloning of two highly homologous chicory (Cichorium intybus var. foliosum cv Flash) fructan 1-exohydrolase cDNAs (1-FEH IIa and 1-FEH IIb) is described. Both isoenzymes could be purified from forced chicory roots as well as from the etiolated "Belgian endive" leaves where the 1-FEH IIa isoform is present in higher concentrations. Full-length cDNAs were obtained by a combination of reverse transcriptase-polymerase chain reaction (PCR), PCR and 5'- and 3'-rapid amplification of cDNA ends using primers based on N-terminal and conserved amino acid sequences. 1-FEH IIa and 1-FEH IIb cDNA-derived amino acid sequences are most homologous to a new group of plant glycosyl hydrolases harboring cell wall-type enzymes with acid isoelectric points. Unlike the observed expression profiles of chicory 1-FEH I, northern analysis revealed that 1-FEH II is expressed when young chicory plants are defoliated, suggesting that this enzyme can be induced at any developmental stage when large energy supplies are necessary (regrowth after defoliation).

Cloning and functional analysis of chicory root fructan1-exohydrolase I (1-FEH I): a vacuolar enzyme derivedfrom a cell-wall invertase ancestor? Mass fingerprint of the 1-FEH I enzyme

This paper describes the cloning and functional analysis of chicory (Cichorium intybus L.) fructan 1-exohydrolase I cDNA (1-FEH I). To our knowledge it is the first plant FEH cloned. Full-length cDNA was obtained by a combination of RT-PCR, 5' and 3' RACE using primers based on N-terminal and conserved amino acid sequences. Electrophoretically purified 1-FEH I enzyme was further analyzed by in-gel trypsin digestion followed by matrix-assisted laser desorption ionization and electrospray time-of-flight tandem mass spectrometry. Functionality of the cDNA was demonstrated by heterologous expression in potato tubers. 1-FEH I takes a new, distinct position in the phylogenetic tree of plant glycosyl hydrolases being more homologous to cell-wall invertases (44-53%) than to vacuolar invertases (38-41%) and fructosyl transferases (33-38%). The 1-FEH I enzyme could not be purified from the apoplastic fluid at significantly higher levels than can be explained by cellular leakage. These and other data suggest a vacuolar localization for 1-FEH I. Also, the pI of the enzyme (6.5) is lower than expected from a typical cell-wall invertase. Unlike plant fructosyl transferases that are believed to have evolved from a vacuolar invertase, 1-FEH I might have evolved from a cell-wall invertase-like ancestor gene that later obtained a vacuolar targeting signal. 1-FEH I mRNA quantities increase in the roots throughout autumn, and especially when roots are stored at low temperature.

Cloning, developmental, and tissue-specific expression of sucrose:sucrose 1-fructosyl transferase from Taraxacum officinale. Fructan localization in roots

Sucrose:sucrose 1-fructosyl transferase (1-SST) is the key enzyme initiating fructan synthesis in Asteraceae. Using reverse transcriptase-PCR, we isolated the cDNA for 1-SST from Taraxacum officinale. The cDNA-derived amino acid sequence showed very high homology to other Asteracean 1-SSTs (Cichorium intybus 86%, Cynara scolymus 82%, Helianthus tuberosus 80%), but homology to 1-SST from Allium cepa (46%) and Aspergillus foetidus (18%) was much lower. Fructan concentrations, 1-SST activities, 1-SST protein, and mRNA concentrations were compared in different organs during vegetative and generative development of T. officinale plants. Expression of 1-SST was abundant in young roots but very low in leaves. 1-SST was also expressed at the flowering stages in roots, stalks, and receptacles. A good correlation was found between northern and western blots showing transcriptional regulation of 1-SST. At the pre-flowering stage, 1-SST mRNA concentrations and 1-SST activities were higher in the root phloem than in the xylem, resulting in the higher fructan concentrations in the phloem. Fructan localization studies indicated that fructan is preferentially stored in phloem parenchyma cells in the vicinity of the secondary sieve tube elements. However, inulin-like crystals occasionally appeared in xylem vessels.

Efficacy and safety of vancomycin constant-rate infusion in the treatment of chronic Gram-positive bone and joint infections

OBJECTIVE: To evaluate the efficacy and safety of vancomycin constant-rate infusion over 24 h in the treatment of Gram-positive bone infections, METHODS: Vancomycin (40 mg/kg/day) was administered without a loading dose to 15 patients (12 male, three female) aged 23--90 years, weighing 46--85 kg, with postoperative chronic bone and joint infections. The 24-h dose was adjusted to maintain plasma levels between 25 and 35 mg/L. Mean duration of therapy was 6.2 months (4--8.5) via a portable infusion pump. Sites of infection included hip and femur (10), tibia (three), patella (one) and vertebrae (one). Sequestrectomy (two), removal of material (7/8 prosthetic hips, 1/5 metal implants) and debridement (two) were performed at the beginning of the treatment. Involved bacteria included Staphylococcus aureus (eight, six methicillin resistant), S. epidermidis (four methicillin-resistant), Enterococcus faecalis (one), Enterococcus avium (one) and Streptococcus bovis (one). RESULTS: MIC of vancomycin ranged from 1 to 4 mg/L. The mean vancomycin bone concentration when available was 67.7plus minus38.9 microg/L. Based on a mean post-treatment follow-up of 14plus minus4 months (6--20.6), cure was achieved in 10 patients (66.6%). Failures were related to the inability to remove the infected prosthesis (one) or implants (three) and to the persistence of a deep wound abcess (one). Adverse events included pruritus (four cases), tinnitus (two), mild transient elevation of creatinine level (three) and transient neutropenia (two). Vancomycin was maintained in all the patients. CONCLUSIONS: Prolonged treatment with vancomycin constant-rate infusion is effective and safe for treatment of Gram-positive chronic bone and joint infections, providing that complete surgical débridement and prosthetic material removal are performed.