Nós isolamos e seqüenciamos genes que codificam Catepsina L-like em diversos isolados de T.rangeli de humano, mamíferos silvestres e Rhodnius spp., do centro e sul da América. Análises filogenéticas de seqüências que codificam a proteína madura de T. rangeli, outras espécies de Trypanosoma e Leishmania e duas espécies de bodonídeos, posicionaram T.rangeli próximo a T.cruzi de acordo com a ordem de divergência determinada em filogenias baseadas em SSUrDNA. Uma análise de 17 seqüências do domínio catalítico de CatL-like de isolados representativos da diversidade filogenética e distribuição geográfica de T. rangeli, apoiaram as mesmas linhagens filogenéticas previamente definidas. Seqüências do gene CatL-like também foram usados para padronizar ensaios de PCR para diagnóstico de T. cruzi e T. rangeli. Além disso, um método de genotipagem por PCR multiplex segregou os isolados de T. rangeli nas principais linhagens previamente estabelecidas. Este é o primeiro estudo usando um gene codificador de proteína para comparar isolados de T. rangeli de linhagens distintas. / We have isolated and sequenced genes encoding cathepsin L-like (CatL-like) cysteine proteases from isolates of T. rangeli from human, wild mammals and Rhodnius spp., from Central and South America. Phylogenetic analysis of sequences encoding the mature CatL-like enzymes from T. rangeli (Rangelipain), other Trypanosoma and Leishmania species, and two species of bodonids, positioned T. rangeli closest to T. cruzi corroborating the same order of divergence showed in phylogenies based on SSU rDNA. Analysis of 17 sequences of the catalytic domains of CatL-like genes isolates representative of the phylogenetic diversity and geographical range of T.rangeli supported previously defined phylogenetic lineages. Sequences of CatL-like genes were used to standardize PCR assays for the diagnosis of T. rangeli and T. cruzi, and a genotyping method of multiplex-PCR distributed of isolates of T. rangeli in the major phylogenetic lineages previously established. This is the first study using protein-encoding genes to compare isolates from T. rangeli of distinct lineages.

The hard tick Ixodes ricinus is an important blood-feeding parasite that transmits tick- borne diseases, such as tick-borne encephalitis and Lyme disease. Ticks employ a battery of proteolytic enzymes, including cathepsins, to digest their bloodmeal. These proteins are potential targets for the development of anti-tick vaccines. This work is focused on cathepsin L from I. ricinus (IrCL), namely its isoenzymes IrCL1 and IrCL3. IrCL1 was expressed in Pichia pastoris and chromatographically purified. Its substrate specifity was determined by the cleavage of (a) peptide fluorogenic substrates and (b) protein substrates analyzed by mass spectrometry. The proteolytic activity of IrCL1 was modulated by its interaction with glycosaminoglycans, which affected the pH optimum value. Futhermore, a proteolytically active mutant of IrCL1 with reduced number of N-glycosylation sites was prepared; this form will be used for crystallization experiments. IrCL3 was expressed in Escherichia coli, refolded and activated to its active form. The proteolytic activity of IrCL3 is in many ascpects similar to that of IrCL1, including substrate specifity, acidic pH optimum and activity modulation by glycosaminoglycans. Key words: cysteine proteases, cathepsin L, hard tick I. ricinus, substrate specifity, proteolytic activity...

This study focuses on the recombinant cysteine peptidases - cathepsin B originating in the bird schistosome Trichobilharzia regenti that is unique across the whole family for its ability to migrate through the nerve tissue to the final localization. For invasion, migration, degradation of nutritional proteins and/or evasion of host immune responses, schistosome employs peptidases. This study follows the research done by researchers of Department of parasitology, Faculty of Natural Sciences, Charles University. The main goal of this study was to deepen the characteristics of recombinant cathepsins B originating in T. regenti. In T. regenti, two cysteine peptidases - cathepsins B1 (TrCB1) and B2 (TrCB2) - have been previously characterized. TrCB1 is located in the gut of schistosomula and involved in digestion. TrCB2 occurs in post-acetabular penetration glands of cercariae and probably facilitates penetration. The recombinant pro-cathepsin B (isoforms TrCB1.1, TrCB1.4 and also TrCB2) were expressed in Pichia pastoris yeast system. An attempt was made to produce in P. pastoris the recombinant isoform TrCB1.6, in which the active site cysteine is substituted by glycine. While TrCB2 underwent self-processing in the expression medium, TrCB1.1 and TrC1.4 zymogens were effectively activated only after the...

Das Glioblastoma multiforme gehört zu den ZNS-Tumoren neuroepithelialen Ursprungs. Es zeichnet sich durch ein multiformes Zellbild, einen geringen Differenzierungsgrad und eine schnelle Krankheitsprogression aus. Trotz mikrochirurgischer Entfernung und anschließender Radiochemotherapie entwickeln die Patienten im Durchschnitt nach 7 Monaten einen Rezidivtumor und haben eine mittlere Überlebenszeit von 14,6 Monaten. Die Rezidivneigung stellt somit ein großes Problem in der Behandlung von Glioblastompatienten dar. In früheren Arbeiten konnte nachgewiesen werden, dass die Rezidivtumore eine andere Zellzusammensetzung und auch ein aggressiveres Wachstumsverhalten als deren Primärformen aufweisen. Ziel dieser Arbeit war es, zu prüfen ob mittels 2D-Gelelektrophorese und anschließender MALDI-TOF-Massenspektrometrie Unterschiede im Proteinexpressionsmuster zwischen Gewebeproben vom Primärtumor eines Glioblastoms WHO Grad IV und dem korrespondierendem Rezidivtumor eines Patienten detektierbar sind. Hierbei wurden 43 Proteine als differentiell exprimiert erkannt, von denen mit Hilfe der MALDI-TOF-Massenspektrometrie sechs genauer charakterisiert wurden. Vier der sechs Proteine waren im Rezidivtumor erhöht: EnoylCoA-Hydratase, ATP-Synthase Untereinheit d, Tropomyosin alpha-3-Kette Isoform 2 und Cathepsin D. Die anderen zwei waren im Rezidivtumor niedriger ausgeprägt: Nukleosid-Diphosphatkinase A und L-3-Phosphoserin-Phosphatase. Eine weitere Untersuchung mittels Western-Blot-Analyse bestätigte, dass Cathepsin D (als eines der sechs charakterisierten Proteine) tatsächlich auch in den Rezidivtumoren dreier weiterer Patienten stärker exprimiert war als in den korrespondierenden primären Glioblastomen.

Sterile particles underlie the pathogenesis of numerous inflammatory diseases. These diseases can often become chronic and debilitating. Moreover, they are common, and include silicosis (silica), asbestosis (asbestos), gout (monosodium urate), atherosclerosis (cholesterol crystals), and Alzeihmer’s disease (amyloid Aβ). Central to the pathology of these diseases is a repeating cycle of particle-induced cell death and inflammation. Macrophages are the key cellular mediators thought to drive this process, as they are especially sensitive to particle-induced cell death and they are also the dominant producers of the cytokine responsible for much of this inflammation, IL-1β. In response to cytokines or microbial cues, IL-1β is synthesized in an inactive form (pro-IL-1β) and requires an additional signal to be secreted as an active cytokine. Although a multimolecular complex, called the NLRP3 inflammasome, controls the activation/secretion of IL-1β (and has been thought to also control cell death) in response to particles in vitro, the in vivo inflammatory response to particles occurs independently of inflammasomes. Therefore, I sought to better understand the mechanisms governing IL-1β production and cell death in response to particles, focusing specifically on the role of lysosomal cathepsin proteases. Inhibitor studies have suggested that one of these proteases, cathepsin B, plays a role in promoting inflammasome activation subsequent to particle-induced lysosomal damage, however genetic models of cathepsin B deficiency have argued otherwise. Through the use of inhibitors, state-of-the-art biochemical tools, and multi-cathepsin-deficient genetic models, I found that multiple redundant cathepsins promote pro-IL-1β synthesis as well as particle-induced NLRP3 activation and cell death. Importantly, I also found that particle-induced cell death does not depend on inflammasomes, suggesting that this may be why inflammasomes do not contribute to particle-induced inflammation in vivo. Therefore, my observations suggest that cathepsins may be multifaceted therapeutic targets involved in the two key pathological aspects of particle-induced inflammatory disease, IL-1β production and cell death.

Tripanossomas de mamíferos constituem um dos grupos mais complexos da família Trypanosomatidae, abrangendo parasitas com ciclos de vida e estruturas populacionais heterogêneos. De acordo com a diversidade, filogenias baseadas em genes SSUrDNA e gGAPDH segregaram estes parasitas em 4 Clados principais: T. brucei, T. cruzi, T. theileri e T. lewisi. Catepsinas L e B (CATL e CATB), as principais atividades proteolíticas dos tripanossomas, participam não apenas na degradação de proteínas como também em eventos biológicos como diferenciação, invasão celular, virulência e evasão do sistema imune. Comparamos os perfis proteolíticos de enzimas CATL em tripanossomas patogênicos e não patogênicos e também isolamos e sequenciamos os domínios catalíticos dos genes CATL e CATB em diversas espécies dos principais clados. Os resultados provaram a utilidade destes marcadores no diagnóstico e genotipagem de T. cruzi, T. rangeli, T. theileri e T. congolense, assim como na construção de filogenias robustas da família Trypanosomatidae, congruentes com os marcadores tradicionais. / Trypanosomes of mammals comprise one of the most complex groups of the family Trypanosomatidae, including parasites with heterogeneous life cycles and population structures. According to such diversity, phylogenetic analyzes based on SSUrDNA and gGAPDH genes segregate these parasites in 4 major clades: T. brucei, T. cruzi, T. lewisi and T. theileri. Cathepsins L and B (CATL and CATB), the main proteolytic activities of trypanosomes, are not only involved in protein degradation but also in biological events such as cell differentiation, cell invasion, virulence, and evasion from the immune system. We comparatively analysed the CATL proteolytic profiles in pathogenic and non-pathogenic trypanosomes, and isolated and sequenced the catalytic domains of CATB and CATL genes in several species of the major clades. Our results demonstrated the usefulness of both markers in the diagnosis and genotyping of T. cruzi, T. rangeli, T. congolense and T. theileri as well as in the construction of robust phylogenies of the family Trypanosomatidae, congruent with traditional markers.

Tripanossomas de mamíferos constituem um dos grupos mais complexos da família Trypanosomatidae, abrangendo parasitas com ciclos de vida e estruturas populacionais heterogêneos. De acordo com a diversidade, filogenias baseadas em genes SSUrDNA e gGAPDH segregaram estes parasitas em 4 Clados principais: T. brucei, T. cruzi, T. theileri e T. lewisi. Catepsinas L e B (CATL e CATB), as principais atividades proteolíticas dos tripanossomas, participam não apenas na degradação de proteínas como também em eventos biológicos como diferenciação, invasão celular, virulência e evasão do sistema imune. Comparamos os perfis proteolíticos de enzimas CATL em tripanossomas patogênicos e não patogênicos e também isolamos e sequenciamos os domínios catalíticos dos genes CATL e CATB em diversas espécies dos principais clados. Os resultados provaram a utilidade destes marcadores no diagnóstico e genotipagem de T. cruzi, T. rangeli, T. theileri e T. congolense, assim como na construção de filogenias robustas da família Trypanosomatidae, congruentes com os marcadores tradicionais. / Trypanosomes of mammals comprise one of the most complex groups of the family Trypanosomatidae, including parasites with heterogeneous life cycles and population structures. According to such diversity, phylogenetic analyzes based on SSUrDNA and gGAPDH genes segregate these parasites in 4 major clades: T. brucei, T. cruzi, T. lewisi and T. theileri. Cathepsins L and B (CATL and CATB), the main proteolytic activities of trypanosomes, are not only involved in protein degradation but also in biological events such as cell differentiation, cell invasion, virulence, and evasion from the immune system. We comparatively analysed the CATL proteolytic profiles in pathogenic and non-pathogenic trypanosomes, and isolated and sequenced the catalytic domains of CATB and CATL genes in several species of the major clades. Our results demonstrated the usefulness of both markers in the diagnosis and genotyping of T. cruzi, T. rangeli, T. congolense and T. theileri as well as in the construction of robust phylogenies of the family Trypanosomatidae, congruent with traditional markers.

Migration within the body of an infected host is one of the most important parts in the life cycle of flukes, including schistosomes. Migration of avian and mammalian visceral schistosomes has been a quite well studied topic (Haas a Haeberlein, 2009), which became more attractive after the discovery of T. regenti, an avian schistosome which is able to migrate through the nervous tissues of infected birds and mammals as well. Migration of T. regenti and T. szidati schistosomula within the definitive (duck) and the accidental (mouse) hosts is the main topic of the diploma thesis. This work continues with the research of K. Blažová (Faculty of Science, Charles University in Prague) who studied migration of T. regenti within the definitive hosts infected perorally with cercariae or hepatopancreases of the infected intermediate snail, Radix lagotis (unpblished). She proved that T. regenti schistosomula are able to use the central nervous system for migration to the nasal mucosa of infected birds. In our work, we focused on the early phase of migration within the perorally infected birds and mice. Invasion of esophagus by T. regenti cercariae in vitro is not conditioned by secretion of glandular products, including cathepsin B2 of T. regenti (TrCB2). Activity of TrCB2 against mucins, the main components...

Chez la drosophile, l’activation du récepteur Toll menant à une réponse antimicrobienne peut se faire par deux voies différentes. Ces deux voies sont activées soit par des récepteurs dédiés, les Pattern Recognition Receptors (PRRs) reconnaissant des motifs moléculaires microbiens, soit par la coupure d’une molécule circulante appelée Perséphone par des protéases microbiennes extrêmement diverses sécrétées pendant une infection. Cependant, le mécanisme par lequel Perséphone est activée demeurait ambigu. Nous avons identifié une région unique dans Perséphone fonctionnant comme un appât pour les protéases exogènes indépendamment de leur origine, type ou spécificité. Une coupure dans cette région constitue la première étape d’une activation séquentielle de Perséphone ; elle permet de recruter la cathepsine circulante 26-29-p, qui va générer la forme active de Perséphone.Ces travaux montrent comment un récepteur de l’immunité innée, Perséphone, peut être activé par un signal de danger, en l’occurrence des enzymes microbiennes, et non par la détection de motifs moléculaires qui peuvent être présents dans la flore microbienne hébergée par les animaux. / In Drosophila, the antimicrobial response against infections can be triggered by two different extracellular mechanisms that both lead to the activation of the Toll receptor. These two mechanisms are activated either by the recognition of specific microbial determinants by Pattern Recognition Receptors (PRRs), or by the cleavage of the circulating serine protease Persephone by a wide range of microbial proteases secreted during infections. However, the molecular mechanism underlying Persephone activation remained ambiguous. We identified a unique region in Persephone pro-domain that functions as a bait for exogenous proteases independently of their origin, type or specificity. Cleavage of Persephone in this bait region constitutes the first step of a sequential activation and licenses the subsequent maturation of Persephone to the endogenous circulating cysteine cathepsin 26-29-p. Our data establish Persephone itself as an immune receptor able to sense a broad spectrum of microbes through the recognition of danger signals rather than molecular patterns.

La synthèse d'une nouvelle famille d'oligomères de motifs contraints de dipeptides est décrite dans ce manuscrit. Les monomères utilisés sont des motifs 3(S)-amino-5-carbonylméthyl-2,3-dihydro-1,5-benzothiazépine-4(5H)-one (DBT), acide 2-aminométhyl-phényl-acétique (AMPA) et α-amino γ-lactames. La structure secondaire de ces édifices a été étudiée par spectroscopies RMN, IR, CD et RX. Nous avons montré tout d'abord que les oligomères de DBT sont capables d'adopter des structures stables et définies en ruban. En se basant sur ces structures, nous avons conçu de nouveaux systèmes beaucoup plus versatiles qui permettent de répartir diverses fonctions (basiques, acides, aromatiques) de part et d'autre de l'axe du ruban. Une stratégie de synthèse originale a été développée à cet effet. Elle consiste en la conversion directe de séquences peptidiques, incorporant des méthionines, en oligomères d'α-amino γ-lactames. Ils sont capables, au même titre que ceux de DBT, d'adopter des structures en ruban et de pénétrer dans les cellules. Enfin une étude in vivo chez la souris a montré le fort potentiel anti-tumoral d'un bioconjugué associant des oligomères d'AMPA à un inhibiteur de la Cathepsine D, enzyme lysosomale surexprimée et sécrétée par de nombreuses tumeurs solides. / The synthesis of a new type of constrained dipeptide motif oligomers is described. Monomers used are the (3S)-amino-5-(carboxylmethyl)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one (DBT), the 2-aminomethyl-phenyl-acetic acid (AMPA) and α-amino γ-lactams. The secondary structure of those architectures has been studied by NMR, IR, CD and X-ray spectroscopies. Firstly, we demonstrated that DBT oligomers are able to adopt stable and well defined ribbon like structures. Based on these structures, we designed new systems, far more versatile which are able to distribute various functions (basic, acidic, aromatic) on each side of the ribbon axis. An original strategy has been developed for this purpose. It consists in the direct conversion of peptidic sequences, incorporating methionine, in α-amino γ-lactams oligomers. They are able, as the DBT, to adopt ribbon like structures and to be internalized into cells. Finally, an in vivo study in mice showed the high anti-tumoral potency of a bioconjugate linking AMPA oligomers to an inhibitor of the cathepsin D, a lysosomal enzyme overexpressed and secreted by numerous solid tumors.