Background: Storage mites are frequently found in our daily environment. Nevertheless, storage mite allergy is often neglected in allergological diagnostics and possible allergies requiring therapy are thus overlooked. Methods: Recommendations for action are made based on a literature review from March 2021 to August 2021 in PubMed, Medline, and GoogleScholar. Results: This review article provides an overview of the species of storage mites, sensitization rates in different countries and occupations, and co-sensitization rates to house dust mite. Recommendations for diagnosis as well as therapy are given. The importance of provocation testing as well as causal therapy by allergen immunotherapy (AIT) is presented. Conclusion: The position paper gives recommendations for the diagnosis and therapy of allergic rhinitis in case of storage mite allergy. AIT is recommended in symptomatic allergy and proven storage mite allergy. Reliable detection by provocation testing is advised in this persistent allergy. The therapy should be carried out independently of the treatment of a possible house dust mite allergy.

<p>Allergic asthma is a chronic and complex disease of the airways characterized by dysregulated immune-inflammatory responses to aeroallergens and reversible airflow obstruction. The prevalence and economic burden of allergic asthma have increased substantially over the last five decades. Despite remarkable progress in our understanding of the immunobiology and pathophysiology of asthma, the ontogeny of the disease remains elusive. As a result, there is a lack of effective preventative strategies. Here, we used a murine model of allergic asthma to house dust mite (HDM), the most pervasive indoor aeroallergen worldwide to address issues pertaining to the development of allergic asthma. First, we provided a comprehensive computational view of the impact of dose and length of HDM exposure on both local and systemic allergic outcomes (Chapter 2). Parameters, such as thresholds of responsiveness, and non-linear relationships between allergen exposure, allergic sensitization and airway inflammation were identified. We, then, investigated molecular signatures implicated in the onset of allergic responses (Chapter 3). HDM exposure was associated with production of the epithelial-associated cytokines TSLP, IL-25 and IL-33. However, only IL-33 signaling was necessary for intact Th2 immunity to HDM, likely because of its superior ability to induce the critical co-stimulatory molecule OX40L on dendritic cells and expand innate lymphoid cells. Lastly, as individuals are most likely exposed to allergens concomitantly to other environmental immunogenic agents, we studied the impact of an initial immune perturbation on allergic responses to sub-threshold amounts of HDM (Chapter 4). We showed that transient expression of GM-CSF in the airway substantially lowers the threshold of allergen required to generate robust, HDM-specific Th2 immunity, likely through increasing IL-33 production from alveolar type II cells. These studies favor a paradigm whereby distinct molecular pathways can elicit type 2 immunity, intimating the need to classify asthma into distinct clinical subsets.</p> / Doctor of Philosophy (PhD)

The aim of this study was to investigate the usefulness of image analysis for studying mite behaviour. Image analysis was used to convert video recordings of mites' locomotory behaviour into a series of x,y coordinates that, when joined, closely resemble the paths of mites. The coordinates were also used to calculate walking speed, direction of travel, turning frequency, turn bias and tortuosity. Two experimental arenas were developed and used to study the movement of three mite species: 1) a leaf disc arena for two-spotted spider mite, Tetranychus urticae Koch and European red mite, Panonychus ulmi (Koch); and 2), a cover-slip/tack-trap arena for Typhlodromus pyri Scheuten. Two-spotted spider mite exhibited a change in locomotory behaviour through a 48 minute period. Mites exhibited a significant decline in distance travelled, whereas the mean stationary time (per four minute interval) more than doubled, and the duration of stationary events increased steadily over the same period. A reduction in sampling frequency of mite coordinates from one per second to one every two seconds and every four seconds produced a 5% and 12% 'loss' in path length respectively. Sample period length was shown to greatly influence the results produced for some of the mean parameters calculated, however, a reduction in sample length from 3000 to 1500 coordinates was not considered to cause a major loss in information. The influence of the inherent mite movement could not be ignored and made it difficult to make decisions on the 'best' sample length to use. Some strong correlations were found between parameters used to analyse mite locomotory behaviour. In particular, arithmetic mean vector length, speed, total stationary time and total distance travelled were significantly correlated with each other. Mean angular deviation and weighted mean vector length, which both measure the degree of clustering around the mean heading angle, were strongly negatively correlated. Parameters which differentiated between 'straight' and 'tortuous' mite movement were found to be mean meander, absolute mean turn and fractal dimensions. Mean meander was thought to be the most 'powerful', while coefficient of a straight line, a commonly used parameter for measuring tortuosity, did not significantly differentiate between the two different behaviours. Frequency distributions of turns and standard deviations of the three mite species were very similar. All three species had a slight bias to turning right (clockwise) rather than to the left (counter-clockwise) and for each species certain angles occurred more often than would be expected in a 'perfect' normal distribution. A similar pattern also occurred with the frequency distribution of two-spotted spider mite heading angles, in that angles which were expected to occur more often, did not, and vice versa. The potential to use saturated salt solutions to control relative humidity on the arena was` demonstrated and indicated that relative humidity is likely to have an important influence on mite behaviour. Two-spotted spider mites appeared to move more quickly in an attempt to escape the unfavourable, extreme (10% and 95% R.H. at 25°C) moisture conditions. All three mite species displayed a characteristic edge-walking behaviour around the arenas. However, when 'edge' and 'non-edge' behaviours were compared, mean meander was the only parameter (of the parameters tested) which gave a significant difference. Behavioural responses of European red mite and T. pyri to sub-lethal (field rate) esfenvalerate were investigated and the results indicated that these mites did not seek the unsprayed halves of the arenas during the first 48 minutes. However, significant differences in most behavioural parameters to esfenvalerate residues were found with European red mite when whole arenas were compared. Image analysis is an extremely useful research tool for studying mite behaviour because of its ability to measure many parameters quickly. Careful choice of the environmental conditions, the sampling framework, and interpretation of data is essential for meaningful results.

The aim of this study was to investigate the usefulness of image analysis for studying mite behaviour. Image analysis was used to convert video recordings of mites' locomotory behaviour into a series of x,y coordinates that, when joined, closely resemble the paths of mites. The coordinates were also used to calculate walking speed, direction of travel, turning frequency, turn bias and tortuosity. Two experimental arenas were developed and used to study the movement of three mite species: 1) a leaf disc arena for two-spotted spider mite, Tetranychus urticae Koch and European red mite, Panonychus ulmi (Koch); and 2), a cover-slip/tack-trap arena for Typhlodromus pyri Scheuten. Two-spotted spider mite exhibited a change in locomotory behaviour through a 48 minute period. Mites exhibited a significant decline in distance travelled, whereas the mean stationary time (per four minute interval) more than doubled, and the duration of stationary events increased steadily over the same period. A reduction in sampling frequency of mite coordinates from one per second to one every two seconds and every four seconds produced a 5% and 12% 'loss' in path length respectively. Sample period length was shown to greatly influence the results produced for some of the mean parameters calculated, however, a reduction in sample length from 3000 to 1500 coordinates was not considered to cause a major loss in information. The influence of the inherent mite movement could not be ignored and made it difficult to make decisions on the 'best' sample length to use. Some strong correlations were found between parameters used to analyse mite locomotory behaviour. In particular, arithmetic mean vector length, speed, total stationary time and total distance travelled were significantly correlated with each other. Mean angular deviation and weighted mean vector length, which both measure the degree of clustering around the mean heading angle, were strongly negatively correlated. Parameters which differentiated between 'straight' and 'tortuous' mite movement were found to be mean meander, absolute mean turn and fractal dimensions. Mean meander was thought to be the most 'powerful', while coefficient of a straight line, a commonly used parameter for measuring tortuosity, did not significantly differentiate between the two different behaviours. Frequency distributions of turns and standard deviations of the three mite species were very similar. All three species had a slight bias to turning right (clockwise) rather than to the left (counter-clockwise) and for each species certain angles occurred more often than would be expected in a 'perfect' normal distribution. A similar pattern also occurred with the frequency distribution of two-spotted spider mite heading angles, in that angles which were expected to occur more often, did not, and vice versa. The potential to use saturated salt solutions to control relative humidity on the arena was` demonstrated and indicated that relative humidity is likely to have an important influence on mite behaviour. Two-spotted spider mites appeared to move more quickly in an attempt to escape the unfavourable, extreme (10% and 95% R.H. at 25°C) moisture conditions. All three mite species displayed a characteristic edge-walking behaviour around the arenas. However, when 'edge' and 'non-edge' behaviours were compared, mean meander was the only parameter (of the parameters tested) which gave a significant difference. Behavioural responses of European red mite and T. pyri to sub-lethal (field rate) esfenvalerate were investigated and the results indicated that these mites did not seek the unsprayed halves of the arenas during the first 48 minutes. However, significant differences in most behavioural parameters to esfenvalerate residues were found with European red mite when whole arenas were compared. Image analysis is an extremely useful research tool for studying mite behaviour because of its ability to measure many parameters quickly. Careful choice of the environmental conditions, the sampling framework, and interpretation of data is essential for meaningful results.

Thesis (M. Tech) --Central University of Technology, Free State, 2008 / Aphids (Hemiptera: Aphididae) are amongst the most destructive insects in agricultural crop production systems. This reputation stems from their complex life cycles which are mostly linked to a parthenogenetic mode of reproduction, allowing them to reach immense population sizes within a short period of time. They are also notorious as important and efficient vectors of several plant viral diseases. Their short fecund life cycles allow them to be pests on crops with a short growth period, e.g. lettuce (Lactuca sativa L.). It is common practice to provide this crop with some degree of protection from environmental extremes on the South African Highveld. Shadehouses are popular in this regard, but aphids are small enough to find their way into these structures, and their presence on lettuce is discouraged due to phytosanitary issues. In addition, the excessive use of insecticides is criticized due to the negative influence on human health, and because aphids can rapidly develop resistance. This necessitates the use of alternative control options in order to suppress aphid numbers. Biological control is popular in this regard and the use of predatory ladybirds (Coleoptera: Coccinellidae) is a popular choice. This study investigated the aphid and coccinellid species complex encountered under varying shadehouse conditions on cultivated head lettuce in the central Free State Province (South Africa). Their seasonality was also examined, along with variations in their population size throughout a one-year period. Finally, the impact of varying aphid populations on some physical characteristics of head lettuce was examined, and recommendations for aphid control (using naturally occurring coccinellid predators) were made. Two shadehouse structures were evaluated during this study. One was fully covered with shade netting and designed to exclude the pugnacious ant, Anoplolepis custodiens (Hymenoptera: Formicidae), while the other was partially covered with shade netting (on the roof area) allowing access to the ants. Six cycles of head lettuce were planted and sampled four times during each cycle. These were scheduled to monitor the seedling, vegetative and heading stage of lettuce. Four important aphid species were recorded on the lettuce, namely Acyrthosiphon lactucae, Nasonovia ribisnigri, Myzus persicae and Macrosiphum euphorbiae. Both structures harboured similar aphid and coccinellid species, but their population dynamics differed. A. lactucae dominated in the absence of A. custodiens in the fully covered structure (whole study), while N. ribisnigri dominated in the partially covered structure in the presence of these ants during the warmer months (December – January). M. euphorbiae replaced this species as the dominant species in the absence of A. custodiens (April – September). M. persicae occured during the winter (May – August) in the fully covered structure. Promising coccinellid predators were Hippodamia variegata and Scymnus sp. 1, and to a lesser extent, Exochomus flavipes and Cheilomenes lunata. However, the fully covered structure hampered the entrance of the larger adult coccinellid species, resulting in their lower occurrence. Aphid and coccinellid activity peaked during the summer months (October – January), and the fully covered structure attained the highest aphid infestation levels and coccinellid larval numbers during this time. On the other hand, aphid numbers were higher in the partially covered structure during the cooler months of the year (April – July) and this structure also harboured more adult coccinellids. In most cases, aphid infestation levels did not affect the amount of leaves formed. However, symptomatic damage in terms of head weight reduction did occur under severe infestation levels. Specific environmental conditions within a shadehouse structure concurrently contributed to this reduction, with less favourable conditions accelerating this condition. Results from this study have shown that even though the type of shadehouse structure does not influence the insect species complex found on lettuce, it does have an influence on detrimental and beneficial insect population dynamics. Aphid species infesting lettuce have been identified, along with coccinellid predators that could potentially be used in their control. Both types of structures had advantages and disadvantages, and therefore, decisions concerning shadehouses should not be focused on which type of structure to use, but rather which type of structure to use during different seasons of the year.

Les maladies allergiques sont de plus en plus fréquentent. Elles atteignent souvent l’enfant jeune chez qui l’allergie respiratoire et l’allergie alimentaire sont les principales pathologies. L’unique traitement curatif est l’immunothérapie spécifique d’antigène (ITA), largement développée dans l’allergie respiratoire et encore à ses débuts dans l’allergie alimentaire. Pour adapter au mieux la prise en charge du patient, le diagnostic précis de l’allergie est indispensable et il n’existe actuellement pas d’examen biologique totalement fiable. Seul, la présence d’IgE spécifiques permet de diagnostiquer une sensibilisation à un allergène mais pas une allergie cliniquement symptomatique. Dans une première partie, nous avons étudié l’intérêt d’un test fonctionnel, l’ELISpot (Enzyme-linked immunosorbent spot), dans le diagnostic de l’allergie aux acariens chez l’enfant asthmatique. Le nombre de lymphocytes T circulants spécifiques d’acariens sécréteur d’interleukine (IL)-4 ou d’IL-13 était associé à la présence d’une allergie symptomatique, indépendamment des IgE spécifiques. Il était plus élevé dans le cas d’une rhinite allergique sévère et plus faible dans le cas d’une rhinite allergique légère. De plus, il variait au cours de l’année en fonction des saisons avec un pic en automne et un pic en début de printemps. Dans une deuxième partie, nous avons étudié l’intérêt de l’ELISpot dans le diagnostic de l’allergie au lait de vache chez l’enfant, confirmée par un test de provocation orale en double aveugle. Nous avons décrit que le nombre de lymphocytes T spécifiques de la caséine et sécréteurs d’IL-4 et d’IL-13 était associé à l’allergie au lait de vache avec une sensibilité de 100%. Par ailleurs, le nombre de lymphocytes T spécifiques de la caséine était également associé à la dose maximale de lait tolérée par l’enfant.Enfin, dans une troisième partie, nous avons étudié la réponse lymphocytaire T au cours d’une ITA sub-linguale (SLIT) d’une part et sous-cutanée (SCIT) d’autre part, chez des enfants asthmatiques allergiques aux acariens suivis pendant une année. Nous avons décrit une diminution des lymphocytes Th2 (sécréteurs d’IL-4 et IL-13) spécifiques d’acariens après 12 mois de SLIT associée à une augmentation des cellules sécrétrices d’IL-10 (Tr1) spécifiques d’acariens après 6 mois de SLIT. De plus, les lymphocytes T régulateurs (CD4+CD25hiCD127loFoxp3+) étaient augmentés après 12 mois de SCIT. Nous n’avons pas retrouvé de production accrue d’interféron γ (IFNγ) par les lymphocytes T spécifiques d’acariens au cours de la désensibilisation.Au total, ce travail nous a permis de décrire qu’un test fonctionnel, l’ELISpot, permet de réaliser un diagnostic fiable de l’allergie aux acariens et de l’allergie au lait de vache chez l’enfant. Par ailleurs, l’ITA induit une diminution des cellules Th2 et une augmentation des cellules Tr1 par voie sub-linguale ainsi qu’une augmentation des Treg Foxp3+ par voie sous-cutanée sans immunodéviation Th2/Th1, chez l’enfant allergique aux acariens. / Allergic diseases are steadily increasing steadily and especially in children. Allergen specific immunotherapy (desensitization) is the only curative treatment for which accurate diagnosis of allergy is essential. Currently, the presence of specific IgE diagnoses a sensitization to an allergen but not a clinically symptomatic allergy. In a first part, we studied the value of a functional test, the ELISpot (Enzyme-linked immunosorbent spot) in the diagnosis of allergy to house dust mites (HDM). The number of circulating HDM-specific IL-4 and IL-13 secreting T cells was associated with the presence of symptoms, regardless of specific IgE and was higher in severe rhinitis than in mild rhinitis. In addition, it varied according to the season with a peak in autumn and a peak in early spring (wet periods with greater allergen exposure). In a second part, we studied the value of ELISpot for the diagnosis of cow's milk allergy in children, confirmed by double blind placebo control food challenge. We found that the number of casein-specific IL-4 and IL -13 secreting T-cells was associated with allergy to cow's milk. It was also inversely correlated to the cow’s milk tolerated cumulative dose. Receiver-operating characteristic (ROC) curve of combined IL-4 and IL-13 analysis was generated. AUC was 0,98 (95% CI 0.90-1.06). For a cut-off of 10 IL-4- and 12 IL-13 secreting T-cells, sensitivity and negative predictive value were 100%.Finally, in the third part, we monitored antigen specific T-cell response in HDM allergic children treated with sublingual ITA (SLIT) on the one hand and subcutaneous ITA (SCIT) on the other hand, during one year. We found a decrease in HDM specific Th2 cells after 12 months of SLIT associated with an increase in HDM specific IL-10 secreting T-cells after 6 months of SLIT. In addition, regulatory T cells (CD4 + CD25hiCD127loFoxp3+) were increased after 12 months of SCIT. In conclusion, this work has allowed us to describe a functional test, the ELISpot, as a reliable tool for the diagnosis of mite allergy and cow's milk allergy in children. In addition, in HDM allergic children, a decrease of Th2 cells and an increase of IL-10 secreting T-cells was found in children treated with SLIT to HDM as well as an increase in Foxp3+ Treg in children treated with SCIT.

Floating-gate transistors similar to those used in FLASH and EEPROM can be used to build reconfigurable analog arrays. The charge on the floating gate can be modified to pass or block a signal in a cross-bar switch matrix, or it can be finely tuned to eliminate a threshold difference across a chip or set a bias. By using such a compact and versatile reconfigurable analog memory element, the number of analog circuit components included on an integrated circuit that is field-programmable is significantly higher. As a result, large-scale FPAAs can be built with the same impact on analog design that FPGAs have had on digital design. In my research, I investigate the areas floating-gate transistors can be used to impact FPAA design and implementation. An FPAA can be broken up into two basic components, elements of connection and elements of computation. With respect to connection, I show that a floating-gate switch can be used in a cross-bar matrix in place of a transmission gate resulting in less parasitic capacitance and a more linear resistance for the same size transistor. I illuminate the programming issues relating to injecting a floating-gate for use as a switch, including the drain selection circuitry and rogue injection due to gate induced drain leakage. With respect to computation, I explain how a Multiple-Input Translinear Element, or MITE, can be augmented to fit in an FPAA framework. I also discuss two different MITE implementations compatible with CMOS technology, a subthreshold MOS design and a BJT MITE that uses a lateral BJT. Beyond FPAA components, I present two alternative FPAA systems. The first is a general purpose reconfigurable analog system that uses standard analog design components that have been augmented with floating-gates. The second FPAA is built upon MITE circuits, and is focused on supporting direct system synthesis. I conclude with a discussion of a future large-scale MITE FPAA.

Made available in DSpace on 2016-12-23T14:37:39Z (GMT). No. of bitstreams: 1 Larrissa Bernardino Moro.pdf: 381207 bytes, checksum: 5b08b4099b28c73e3fab34be979d1512 (MD5) Previous issue date: 2009-12-10 / O Brasil é o primeiro produtor mundial e terceiro exportador de mamão Carica papaya L., com destaque para o Estado do Espírito Santo que responde a 70% da exportação. As condições climáticas necessárias ao desenvolvimento do mamoeiro são altamente favoráveis para a ocorrência de problemas fitossanitários, sendo a espécie Tetranychus urticae (KOCH, 1836) (Acari: Tetranychidae) uma das pragas-chave, infestando o mamoeiro durante todo o ano. Este ácaro tem sido controlado por agrotóxicos, mas o uso em larga escala destes produtos pode levar ao rápido desenvolvimento de resistência, além de serem danosos ao ambiente. A utilização de cultivares resistentes e de fungos entomopatogênicos são alternativas de controle para esta praga, reduzindo os riscos de resistência do ácaro a acaricidas e a toxicidade ao ambiente. Este trabalho avalia o desenvolvimento e reprodução de T. urticae em cultivares de mamão e verifica se essas cultivares interferem na patogenicidade de Beauveria bassiana, Metarhizium anisopliae e Lecanicillium longisporum. Foram utilizados quatro cultivares de mamão, dois do grupo Formosa (Tainung 01 e Calimosa) e dois do grupo Solo (Golden e Sunrise). Para iniciar o bioensaio foi transferida uma fêmea fertilizada de T. urticae ao disco de folhas e a mesma foi retirada após um período de 12 horas, deixando um ovo por disco, que foi avaliado a cada 12h, registrando-se o período de incubação, duração do estágio de imaturo, longevidade e fecundidade dos adultos e viabilidade desses estágios. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey, a 5% de probabilidade. Para o bioensaio com fungos entomopatogênicos foram utilizadas fêmeas adultas de T. urticae provenientes da criação sobre feijão-de-porco Canavalia ensiformis (L.) e ácaros que permaneceram sobre folhas das cultivares de mamão por pelo menos uma geração. Foram transferidas dez fêmeas para as placas de Petri com disco de folha de C. ensiformis ou de C. papaya com a face abaxial voltada para cima sobre uma camada de algodão hidrófilo umedecida. Em seguida, os ácaros foram pulverizados com suspensões de conídios em Torre de Potter, utilizando-se volume de 5 mL de suspensão 5x107 conídios.mL-1. As suspensões de conídios foram preparadas a partir das formulações comerciais (Boveril® B. bassiana; Metarril® M. anisopliae; Vertirril® L. longisporum). Foi avaliada a mortalidade corrigida e confirmada. A duração do período de ovo na variedade Tainung 01 foi menor (4,0 dias) em relação às outras variedades. O mesmo ocorreu para a duração dos estágios de larva, protoninfa e período ovo-adulto entre as variedades analisadas, sendo maior para as variedades Calimosa, Sunrise e Golden. Esses resultados indicam que as variedades de mamão, Tainung 01, Calimosa, Sunrise e Golden são bons hospedeiros para T. urticae com destaque para Tainung 01, pois esta apresentou menor duração aos estágios de ovo, larva, protoninfa e período ovo-adulto. Os resultados indicaram que os fungos entomopatogênicos comerciais são promissores para o controle de T. urticae em mamoeiro. Testes de estimativa da CL50 e bioensaios em semi-campo e campo são necessários para a adoção desta tática de controle microbiano / Brazil is the worlds largest producer and third exporter of Papaya Carica papaya L., especially the state of Espírito Santo, which accounts for about 70% of exports. Climatic conditions necessary to the development of papaya are also highly favorable for the occurrence of phytosanitary problems, and the species Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) one of the key pest, infesting papaya plant throughout the year. This mite has been controlled by pesticides, but the widespread use of these products can lead to rapid development of resistance, besides being harmful to the environment. The use of resistant cultivars and entomopathogenic fungi are alternatives to control this pest, reducing the risk of mite resistance to acaricides and also the toxicity to the environment. The study was conducted to evaluate the development and reproduction of T. urticae in papaya cultivars and to verify if these cultivars interfere with the pathogenicity of Beauveria bassiana, Metarhizium anisopliae and Lecanicillium longisporum. Were assayed four varieties of papaya, two of the group "Formosa" (Tainung 01 and Calimosa) and two from the "Solo" (Golden and Sunrise). To initiate the bioassay, it was transferred a fertilized female T. urticae to a leaf dish and the female was removed after a period of 12 hours, leaving one egg per disc, that was evaluated every 12 hours recording the incubation period, length of immature stage, longevity and fecundity of adults and viability of these stages. Data were subjected to analysis of variance and means compared by Tukey test at 5% probability. For the bioassay with entomopathogenic fungi were used adult females of T. urticae from the rearing of jack bean Canavalia ensiformis (L.) and mites that remained on leaves of cultivars of papaya for at least a generation. Ten females were transferred to Petri dishes with leaf disk of C. ensiformis or C. papaya with the abaxial side up on a layer of cotton wool moistened. After that mites were sprayed with conidial suspension in a Potter Tower, using a volume of 5 mL of inoculum suspension 5x107 conidia.mL-1. Conidial suspensions were prepared from the commercial formulations (Boveril ® B. bassiana, Metarril ® M. anisopliae; Vertirril ® L. longisporum). We evaluated the mortality corrected and confirmed. The duration of the egg in the variety Tainung 01 was smaller (4.0 days) than to the other varieties. The same occurred for the duration of the larval stages, protonymph and egg-adult period between the varieties analyzed, being higher for varieties Calimosa, Sunrise and Golden. These results indicate that the varieties of papaya, Tainung 01, Calimosa, Sunrise and Golden are good hosts for T. urticae, especially Tainung 01, which showed a shorter duration of the egg, larva, protonymph and egg-adult period. The results also indicate that the fungi are promising for commercial control of T. urticae in papaya. Tests of estimation of the CL50 bioassays and in semi-field and field are required to use this tactic of microbial control

Les effets anti-allergiques des bactéries lactiques sont suggérés par plusieurs études épidémiologiques, des essais cliniques et des modèles expérimentaux d’allergie. Cependant, les propriétés immunomodulatrices des bactéries lactiques sont sous-exploitées par les stratégies vaccinales développées pour combattre l’allergie et les mécanismes empruntés par ces bactéries pour moduler l’allergie restent peu caractérisés.<p>Dès lors, nous avons caractérisé les propriétés immunomodulatrices qu’exerce Lactobacillus plantarum NCIMB8826, une bactérie lactique modèle, sur la cellule dendritique étant donné le rôle déterminant de cette cellule sur la réponse allergique. Nous montrons que L. plantarum induit une forte sécrétion d’IL-12 p40, d’IL-12 p70, de TNF-a mais une faible production d’IL-10. Cette faculté à induire la sécrétion de cytokines polarisantes dépend de TLR2, de TLR9, de MyD88, de NF-kB, des MAPKs (en particulier JNK, p38 et ERK 1/2), de la composition de l’acide lipotéichoïque de L. plantarum et de CD14. Nous montrons aussi que l’ADN génomique de L. plantarum est un agoniste de TLR9 et que CD14 et CD36 facilitent la liaison de la cellule dendritique avec L. plantarum.<p>Ensuite, nous avons évalué le potentiel vaccinal d’une coadministration L. plantarum + Der p 1 dans un modèle murin d’allergie à Der p 1. Cette formulation vaccinale prévient la production d’IgE Der p 1-spécifique et atténue l’éosinophilie pulmonaire tout en stimulant une forte production d’anticorps IgG2a Der p 1-spécifiques et d’IFN-g par les cellules spléniques. Ces effets bénéfiques nous ont conduit à élaborer une bactérie lactique recombinante dérivée de L. plantarum produisant Der p 1 pour la vaccination contre l’allergie aux acariens. La forme antigénique que nous avons réussi à faire produire par L. plantarum correspond à une protéine de fusion entre la Maltose Binding Protein de E. coli et ProDer p 1 (le zymogène de Der p 1), la présence de ce partenaire de fusion étant indispensable à la production de ProDer p 1. En prophylaxie, la vaccination par cette bactérie recombinante prévient la production d’anticorps IgE-Der p 1-spécifiques et stimule la production d’anticorps IgG2a spécifiques, reproduisant les effets de la coadministration L. plantarum + Der p 1. Elle réduit de manière drastique la production d’IL-5 des cellules spléniques et des cellules ganglionnaires médiastinales et prévient l’éosinophilie pulmonaire mais n’a pas d’effet sur l’hyperréactivité bronchique. Der p 1 étant un des allergènes d’acarien les plus immunodominants, cet ensemble de données montre donc que cette bactérie recombinante constitue un vaccin prophylactique prometteur pour la prévention de l’allergie aux acariens. Des résultats préliminaires obtenus à partir de cellules dendritiques humaines et lymphocytes T autologues montrent la forte capacité de cette bactérie recombinante à induire le développement d’une réponse Th1 fortement polarisée (production d’IFN-g en l’absence de production d’IL-4 et d’IL-5), ce qui suggère que l’utilisation de cette bactérie recombinante pourrait être envisagée pour le traitement de l’allergie chez l’homme. <p> / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished

A major goal of evolutionary developmental biology is to explore mechanisms and events underlying evolution of the myriad body plan morphologies expressed both genetically and phenotypically within the animal kingdom. Arthropods exhibit an astounding array of morphological diversity both within and between representative sub-phyla, thus providing an ideal phylum through which to address questions of body plan innovation and diversification. Major arthropod groups are recognised and defined by the distinct form and number of articulated appendages present along the antero-posterior axis of their segmented bodies. A great deal is known about the developmental genetics of limb development in the model insect Drosophila melanogaster, added to which, much comparative gene expression data and a growing body of functional genetic data is emerging for other arthropod species. Arthropod limb primordia are consistently marked by expression of the homeobox gene Distal-less (Dll), and the focus of this thesis is to compare signalling mediated by early Dll regulatory genes activity along antero-posterior and dorso-ventral embryonic axes during limb specification in Drosophila, with the activity of their orthologs in the widely disparate chelicerate, the spider mite Tetranychus urticae - interpreting new data with that available for other arthropods. Having made a detailed study of spider mite embryonic (and post-embryonic) development, to provide a basis for understanding mRNA transcription and protein activity patterns, I confirmed typical expression of Tetranychus Dll in prosomal limb primordia. I obtained limited results for the candidate antero-posterior positioning genes wingless and engrailed, although one of the two engrailed paralogs I identified is reportedly expressed in posterior segmental compartments, consistent with possible conservation of Engrailed-Wingless interactions in metameric patterning and positive regulation of Dll in arthropod limb specification. In Drosophila, wingless-dependent Dll transcription is restricted along the dorso-ventral axis by dorsal Dpp-mediated and ventral EGFR-mediated signalling gradients. Based on data from Tetranychus and other arthropods, neither dorsal nor ventral signalling regimes appear conserved outside the Drosophila system. Dll suppression in fly abdominal segments occurs due to powerful Hox (Ubx/AbdA) repression of the early Dll cis-regulatory element; this is discussed in relation to the independently evolved limbless chelicerate opisthosoma, informed by hypothetical scenarios of cis (regulatory DNA) and trans (coding sequence) evolution. Given practical difficulties and limitations encountered while working with spider mites, I offer a final assessment of the place of Tetranychus urticae as a non-model, and yet still valuable chelicerate species to consider carrying into the exciting future of evolutionary developmental biology.