La rage entraîne plus de 60,000 décès par an dans le Monde, dont 800 au Cambodge, pays fortement endémique pour la rage canine.La mort survient dans près de 100% des cas de rage, maladie évitable dans presque 100% des cas par l’accès à une prophylaxie post-exposition (PPE) antirabique adéquate et en temps utile. L’amélioration de l’accès à une PPE dans les zones rurales des pays endémiques permettra d’épargner des vies humaines à court terme. Cette thèse en épidémiologie a tiré parti des données collectées auprès des patients consultant au centre antirabique et les chiens testés à l’Institut Pasteur du Cambodge (IPC), Phnom Penh. Suite à un bilan épidémiologique de la situation et des obstacles auxquels sont confrontés les patients cherchant à accéder à la PPE adéquate et en temps utile, elle vise à contribuer à améliorer 1/ l’accès géographique et 2/ l’accès financier à une PPE pour les populations rurales du Cambodge. Nous avons développé une stratégie originale d’identification des poches de populations à haut risque d’incomplétude vaccinale après une exposition potentielle à la rage. Ceci devrait permettre d’améliorer l’accès géographique à la PPE et se concrétiser par l’ouverture en Juillet 2018 d’un centre périphérique de prévention de la rage dans l’Ouest du Cambodge. Cette stratégie d’identification de difficultés d’accès aux soins est applicable à d’autres thématiques de santé, sous certaines conditions. Notre rappel des patients et l’analyse des décès par rage parmi les patients n’ayant pas complété de leur propre chef le protocole PPE de 4 sessions intradermales sur 1 mois ne permettent pas de mettre en évidence une différence de mortalité par rage parmi les patients n’ayant reçu que 3 sessions sur 1 semaine, par rapport à au moins 4 sessions/1mois. Le raccourcissement du protocole à 1 semaine permet de réduire les coûts directs et indirects et l’absence de revenus pendant la durée du traitement en capitale. La mise en place de ce protocole doit s’accompagner d’un suivi d’au moins 6 mois des patients après leur prise en charge initiale. L’ensemble de ces travaux a des implications qui dépassent le cadre du Cambodge: Dans ses recommandations d’Avril 2018, l’OMS recommande désormais ce nouveau protocole IPC– le premier protocole PPE antirabique abrégé à 1 semaine. / Rabies causes more than 60,000 deaths worldwide each year, including 800 in Cambodia, where canine-mediated rabies virus circulates. Death occurs in nearly 100% of rabies cases, a disease which is nearly 100% avoidable by timely and adequate rabies post-exposure prophylaxis (PEP). Improving access to PEP in rural areas of endemic countries will spare human lives in the short term. This epidemiology PhD used the data collected in patients referred to the rabies prevention clinic and tested dogs at Institut Pasteur du Cambodge (IPC), Phnom Penh. After a baseline assessment of access to and obstacles to access timely and adequate PEP in Cambodia, this PhD aims to contribute to improving: 1/ geographical access and 2/ financial access to PEP for rural populations in Cambodia. We developed an original strategy to identify populations with a high risk of PEP noncompletion after a bite by a potentially rabid dog. This should help improve geographical access to PEP following the implementation in July 2018 of a peripheral rabies prevention center in Western Cambodia. This strategy can be applied to identify difficulties in accessing health services relevant to other health issues, under certain conditions. After patient callback and analysis of rabies deaths among those who did and did not complete the 4-sessions/1-month intradermal PEP regimen of their own accord, we were unable to demonstrate a difference in rabies mortality among patients who only received 3 vaccine sessions over the first week compared to those receiving at least 4 sessions/one month. Abridging the protocol to one week would reduce direct and indirect costs and the loss of income during PEP in the Capital. The adoption of this abridged regimen must be associated with a strengthened clinical monitoring system for at least 6 months following patients’ initial PEP.The work presented in this PhD has implications which reach beyond Cambodia: WHO recommends this new IPC regimen – the first approved one-week, abridged rabies PEP regimen – in its April 2018 guidelines.

No description available.

Les cellules dendritiques plasmacytoïdes (pDCs) sont caractérisées par leur capacité unique de sécrétion massive d’interféron de type I (IFN-I) suite à la stimulation des Tolllike récepteurs (TLR) 7 et 9. Un rôle fondamental des pDCs a été démontré dans le lupus érythémateux systémique via la production d’IFN-I. Les pDC expriment le récepteur de forte affinité aux immunoglobulines de type E (IgE), FcεRI, impliqué dans la régulation négative de la sécrétion d’IFN-I. L’objectif de notre étude est d’explorer, dans le contexte lupique, les effets du traitement par les IgE sur les fonctions des pDC, particulièrement sur la production d’IFN-I. In vitro, le traitement des pDC par des IgE monoclonales permet la surexpression du FcεRI à leur surface et diminue le taux de transcrits des TLR7/9 et de l’IRF7. De plus, les pDC traitées par des IgE diminuent leur production d’IFN-I et l’expression de marqueurs de maturation, induites par leur stimulation par des ligands des TLR7/9 et des complexes immuns lupiques. En outre, ces pDC pré-traitées par des IgE induisent la différenciation de LT4 naïfs allogéniques en LT4 produisant de l’IL-10. In vivo, les patients lupiques en phase quiescente de la maladie présentent des taux plus élevés d’IgE totales comparés aux patients en phase active (indépendamment d’allergies et d’infestations parasitaires). Chez les patientslupiques, le taux d’IgE totales est inversement corrélé au taux d’anti-ADN et à l’activité de la maladie (SLEDAI). L’ensemble de nos résultats suggère un rôle protecteur des IgE dans le lupus à travers la modulation de la réponse inflammatoire des pDC. / Plasmacytoid dendritic cells (pDCs) are characterized by their unique ability to produce large amounts of type I interferon (IFN-I) upon Toll-like receptors (TLR) 7 and 9 triggering. A fundamental role for pDCs has been shown in systemic lupus erythematosus (SLE) through IFN-I production. pDCs express the high affinity Fc receptor for immunoglobulin E (IgE), FcεRI, involved in the negative regulation of IFN-I secretion. The objective of our study is to investigate, in the context of SLE, the effects of IgE treatment on pDCs functions, especially on IFN-I production. In vitro, monoclonal IgE treatment of pDCs upregulate their surface expression of FcεRI and decrease transcripts levels of TLR7/9 and IRF7. IgE-treated pDCs decrease IFN-α secretion and downregulate maturation markers expression induced by TLR7/9 and immune complexes triggering. Moreover, the coculture of IgE pretreated pDCs with allogeneic naive LT4 promotes their differentiation into IL-10-secreting cells. In vivo, patients with quiescent SLE have higher IgE levels than patients with active disease (independently of allergy or parasitic infection). In SLE patients, IgE levels are inversely correlated to anti-DNA antibodies and disease activity (SLEDAI). All together, our data suggest a protective role for IgE in SLE through the modulation of the inflammatory response by pDC.

Diabetes mellitus Typ 1 und Allergien vom Soforttyp gehören zu den häufigsten chronischen Erkrankungen des Kindes- und Jugendalters. Diabetes mellitus Typ 1 wird verursacht durch eine autoimmune Zerstörung der Beta-Zellen des Pankreas. Aus immunologischer Sicht wird dieser Prozess durch TH1-Zellen dominiert. Im Gegensatz dazu wird vermutet, dass Allergien vom Soforttyp, wie die allergische Rhinitis, das allergische Asthma und die allergische Urtikaria mit TH2-Zellen assoziiert seien. Die Hypothese, dass TH1- und TH2-Zellen sich gegenseitig in ihrer Aktivität hemmen, ist immer noch gültig. Ziel unserer Fall-Kontroll-Studie war es, die Assoziation zwischen Typ 1 Diabetes und IgE-vermittelten Allergien zu untersuchen. Zur Prüfung unserer Forschungshypothese wurden ein standardisierter, evaluierter Fragebogen sowie verschiedene Laboranalysen herangezogen. Es konnte gezeigt werden, dass Diabetes mellitus Typ 1 mit einem erhöhten Risiko für das gleichzeitige anamnestische Vorliegen IgE-vermittelter allergischer Symptome assoziiert sein könnte. Somit konnten wir bestätigen, dass die noch heute weit verbreitete TH1/TH2-Hypothese eine Vereinfachung tatsächlich viel komplizierterer immunologischer Vorgänge darstellt. Um diese Assoziation im Detail zu prüfen, bedarf es jedoch weiteren populationsbasierten epidemiologischen Studien.:I. Bibliographische Beschreibung 7 II. Abkürzungsverzeichnis 9 1. Einführung 11 1.1 Epidemiologie und Pathogenese des Diabetes mellitus Typ 1 11 1.2 Epidemiologie und Pathogenese von Allergien vom Soforttyp 13 1.3 Aktueller Forschungsstand zum Thema 14 2. Das Promotionsprojekt 17 2.1 Forschungshypothese und Fragestellung 17 2.2 Patienten und Methoden 17 2.3 Statistische Datenauswertung 19 2.4 Ergebnisse 20 2.5 Einordnung in den aktuellen wissenschaftlichen Diskurs 23 3. Publikationsmanuskript 29 4. Zusammenfassung der Arbeit 43 5. Literaturverzeichnis 47 III. Erklärung über die eigenständige Abfassung der Arbeit 55 IV. Curriculum Vitae 57 V. Liste der Veröffentlichungen 59 VI. Danksagung 61

Introduction: Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most used drugs in equine medicine, mainly used to treat inflammation, endotoxemia, pain or fever. NSAIDs inhibit cyclooxygenases which induce to synthesize prostanoids. But NSAIDs have side effects to renal functions too. Objectives: The current study was carried out to investigate the effects of the most common used NSAIDs on urinary parameters in horses. Materials and Methods: Thirty healthy horses were used as a control group and 20 horses with left dorsal displacement, left ventral impaction or lameness of using either flunixin meglumine (FM), metamizole (MZ) or phenylbutazone (PHZ) have been assigned to groups 1, 2 or 3, respectively. Creatinine, urea nitrogen, glucose, protein and electrolytes were measured in serum and urine including GGT using an automatic analyzer. Fractional excretions (FE) of sodium, chloride, potassium, calcium, magnesium and inorganic phosphate, in addition to urinary protein (U-Pro):U-Cr and urinary gamma glutamyl transferase (U-GGT):U-Cr ratios were calculated. Urinary mucus and IgA concentrations were measured and their ratios to the urinary creatinine were calculated. The data were statistically analyzed using Shapiro-Wilks test, descriptive statistics, Kruskal-Wallis one-way analysis of variance and Dunn’s test. Significance was set at P £ 0.05. Results: The FEMg was significantly higher in group 3 (P < 0.033) compared to the control group. The U-GGT:U-Cr ratio was also significantly higher in group 3 (P < 0.001) compared with the control group. The U-Pro:U-Cr ratio was significantly higher in groups 1 and 2 (P < 0.007 and P < 0.001, respectively) than in the control group. PHZ group had a significantly increase in mucus:U-Cr ratio (P < 0.005). Significant increases were observed regarding the IgA:U-Cr ratio in groups 1 (P < 0.007) and 2 (P < 0.014). Conclusions: Long-term use of PHZ has an influence on the renal ascending limb of the loop of Henle, and all these drugs could have effects on the proximal tubules. Phenylbutazone causes an increase in urinary mucus secretion, probably as a protective mechanism against the necrotic effect in renal pelvis of PHZ. Parameters such as U-Pro:U-Cr and U-GGT:U-Cr ratios and FEMg are helpful in detecting these renal abnormalities.

Multiple myeloma is an incurable fatal neoplasm of plasma cells affecting mainly elderly people. There are many research laboratories in the world where multiple myeloma is studied. Permanent cell lines are indispensable tools for both basic and applied research. However, the establishment of new cell lines is difficult with poor success. We established 96 primary cultures of bone marrow samples from myeloma patients. Only one culture succeeded in permanet myeloma cell line. The novel plasmacytic cell line ÚHKT-893 was established from bone marrow sample of 57 years old female relapsed with multiple myeloma of IgGκ isotype. The cell line is however dependent on the continuous presence of interleukin-6 in culture media. ÚHKT-893 cells grow continuously already more than 1 year. The growth of cells was regularly monitored according to growth curves and by measurement of cell viability. Surface antigenic profile was repeatedly determined by flow cytometry. The simultaneous expression of both CD138 and CD38 surface molecules confirmed the plasma cell origin of cells. The establishment of the ÚHKT-893 myeloma cell line will extend the panel of existing myeloma cell lines as a new ex vivo model for the study of the etiology and pathogenesis of multiple myeloma. It will also provide the source of new...

Cancer treatments including chemotherapy and radiotherapy treat cancer by targeting rapidly dividing cells. Although these forms of treatment damage rapidly dividing cancer cells, they are also toxic to the cells of the gastrointestinal tract, leading to inflammation of the mucosal layer (mucositis) and causing nausea, vomiting, diarrhea, and abdominal pain. Improvement in symptoms may allow patients to have better performance status permitting ongoing treatment and possibly a better prognosis. This article describes the pathophysiology of chemotherapy-induced mucositis and includes 3 case reports of treatment of mucositis with serum bovine immunoglobulin.

<p>Kontrola zdravlja vimena krava je bitan element u procesu proizvodnje zdravstveno<br />bezbednog mleka, te se na farmama visokomlečnih krava, kroz program kontrole mastitisa,<br />redovno sprovode mere otkrivanja i prevencije bolesti vimena. Klinički pregled vimena<br />predstavlja osnovni metod koji pruţa korisne informacije o zdravstvenom statusu vimena<br />krava, ali nailazi na pote&scaron;koće u otkrivanju patolo&scaron;kih promena unutar parenhima i papile<br />vimena. U cilju otkrivanja promena u parenhimu vimena moţe se primeniti ultrazvučni<br />pregled koji omogućava vizualizaciju strukturnih promena vimena nastalih kao posledica<br />upalnih procesa i tako olak&scaron;ava dijagnostiku oboljenja.<br />Tokom poslednjih godina, javio se problem povećanja rezistencije bakterija na<br />antimikrobne lekove, &scaron;to oteţava lečenje bolesti, ali i ugroţava zdravlje ţivotinja i ljudi.<br />Najče&scaron;ći uzroci toga su nepravilna upotreba i eventualna zloupotreba antimikrobnih lekova.<br />Mnoga istraţivanja vr&scaron;ena su u in vitro i in vivo uslovima na primeni laktoferina samog ili u<br />kombinaciji sa antibioticima u terapiji i prevenciji mastitisa krava. Laktoferin, gvoţĎe<br />vezujući antimikrobni glikoprotein koji se nalazi u mleku i drugim sekretima, predstavlja<br />bitan deo sistema odbrane mlečne ţlezde.<br />Cilj istraţivanja u okviru ove disertacije je procena dijagnostičke mogućnosti<br />ultrazvučnog pregleda u detekciji subkliničkog mastitisa i poremećene sekrecije vimena,<br />kao i razmatranje opravdanosti primene laktoferina u prevenciji i lečenju mastitisa.<br />Kliničkim pregledom izvr&scaron;ena je procena op&scaron;teg zdravstvenog stanja krava, kao i<br />ispitivanje mlečne ţlezde adspekcijom i palpacijom. Za otkrivanje poremećene sekrecije<br />vimena i subkliničkih mastitisa kori&scaron;ćeni su brzi testovi, Kalifornija mastitis test i<br />Draminski test, kao i ultrazvučni pregled mlečne ţlezde krava. OdreĎivanje broja somatskih<br />ćelija u uzorcima mleka uraĎeno je metodom protočne citometrije. Za identifikaciju<br />uzročnika mastitisa kori&scaron;ćene su klasične mikrobiolo&scaron;ke metode. Krave sa pozitivnim<br />bakteriolo&scaron;kim nalazom podeljene su u dve ogledne grupe. Krave ogledne grupe I su<br />tretirane intramamarnom aplikacijom antibiotika, dok je kravama ogledne grupe II<br />aplikovana kombinacija antibiotika i laktoferina. OdreĎivanje koncentracije imunoglobulina<br />G u mlečnom serumu krava vr&scaron;eno je metodom radioimunodifuzije, a odreĎivanje<br />koncentracije laktoferina u mleku krava ELISA testom.<br />U istraţivanjima u okviru ove disertacije, najče&scaron;će izolovani major mastitis patogeni<br />bile su bakterije Staphylococcus aureus i Streptococcus agalactiae, a najče&scaron;će izolovani<br />minor mastitis patogeni Corynebacterium spp. i koagulaza negativne stafilokoke.<br />Ultrasonografija mlečne ţlezde krava pokazala se kao efikasna metoda u dijagnostici<br />poremećaja sekrecije vimena. Veće vrednosti koncentracije imunoglobulina G u mlečnom<br />serumu krava uočene su tokom perioda predzasu&scaron;enja i zasu&scaron;enja, u odnosu na period rane<br />laktacije. Najveći uticaj na porast koncentracije laktoferina u mleku krava su imali<br />bakterijski uzročnici mastitisa. Efikasnost antibiotske terapije primenjene tokom perioda<br />zasu&scaron;enja kod krava ogledne grupe I iznosila je 52,7%, dok je efikasnost primenjene terapije<br />sa goveĎim laktoferinom i antibiotikom kod krava ogledne grupe II iznosila 60%. Aplikacija<br />laktoferina tokom perioda zasu&scaron;enja doprinela je efikasnosti terapije intramamarnih<br />infekcija, ali nije imala uticaj na koncentraciju laktoferina u mleku tokom perioda rane<br />laktacije.<br />Dalja istraţivanja su neophodna kako bi se u potpunosti potvrdila efikasnost<br />intramamarne terapije sa goveĎim laktoferinom i antibiotikom u cilju eliminacije uzročnika<br />mastitisa i da se precizno odredi terapijska koncentracija laktoferina.</p> / <p>Control of udder health is an essential element in the process of safe milk<br />production, thus, through the mastitis control program, dairy farms regularly conduct<br />measures of detection and prevention of udder diseases. Clinical examination of the udder<br />is a basic method that provides useful information about the health status of cow udders,<br />but this method is limited in its ability to detect pathological changes in the udder<br />parenchyma and teat. In order to detect changes in the parenchyma of the udder, an<br />ultrasound can be applied which allows visualization of udder structural changes incurred<br />as a result of inflammatory processes, thus facilitating diagnosis of diseases.<br />Over the last few years, the problem of increasing resistance to antimicrobial drugs<br />has appeared, making it difficult to treat disease and also threaten the health of animals and<br />humans. The incorrect and widespread use of antimicrobial drugs are the most common<br />cause of this. Many studies were conducted in vitro and in vivo conditions on the use of<br />lactoferrin alone or in combination with antibiotics in the treatment and prevention of<br />mastitis. Lactoferrin, an iron-binding antimicrobial glycoprotein which is found in milk<br />and other secretions, represents an important part of the mammary gland defense system.<br />The aim of the research within this thesis was to evaluate the diagnostic<br />possibilities of udder ultrasonography in the detection of subclinical mastitis and udder<br />secretion disorders, as well as considering the feasibility of lactoferrin application in the<br />prevention and treatment of mastitis.<br />The general condition of the animals was evaluated by clinical examination, as<br />well as udder examination by adspection and palpation. The California mastitis test,<br />Draminski test and ultrasound examination of the cow&#39;s mammary glands were used for<br />detection of udder secretion disorders and subclinical mastitis. Somatic cell count in milk<br />samples was determined by flow cytometry method. Classical microbiological methods<br />were used for the isolation and identification of mastitis causative agents. Cows with<br />positive bacteriological findings were divided into two experimental groups. Cows in<br />experimental group I were treated with intramammary applications of antibiotics, while the<br />cows in experimental group II were treated with a combination of antibiotics and<br />lactoferrin. Immunoglobulin G concentration in bovine milk serum was determined by the<br />immunodiffusion method, while lactoferrin concentration in bovine milk was determined<br />using the ELISA test.<br />In this study, the most common isolated major mastitis pathogens were<br />Staphylococcus aureus and Streptococcus agalactiae, while Corynebacterium spp. and<br />coagulase-negatice staphilococci were the most commonly detected minor mastitis<br />pathogens. Ultrasonography of the bovine mammary gland proved to be an effective<br />method in the diagnosis of udder secretion disorders. Higher immunoglobulin G<br />concentrations were observed in milk serum from cows during pre-dry and dry period,<br />relative to early lactation period. The biggest influence on the increase in the concentration<br />of lactoferrin in the bovine milk had mastitis pathogens. The efficacy of antibiotic therapy<br />during the dry period in cows of experimental group I was 52.7%, while the efficacy of the<br />applied therapy with lactoferrina and antibiotics in cows of experimental group II was<br />60%. Application of lactoferrin during the dry period contributed to the effectiveness of<br />the treatment of intramammary infections, but had no influence on lactoferrin<br />concentration in the milk during the early lactation period.<br />Further studies are necessary to in order to fully confirm the efficacy of<br />intramammary therapy with bovine lactoferrin and antibiotic to eliminate the mastitis<br />pathogens and to determine the therapeutic concentration of lactoferrin.</p>

Parmi les cinq isotypes d’anticorps présents chez l’Homme, les immunoglobulines A (IgA) prédominent dans les muqueuses. Les IgA sont produites dans le chorion sous forme majoritairement polymérique (pIgA) et sécrétées dans la lumière des muqueuses. Leur transport trans-épithélial est assuré par le récepteur aux immunoglobulines polymériques (pIgR), exprimé au pôle basal des épithéliums. Les pIgA ainsi sécrétées conservent le domaine extracellulaire du pIgR et sont appelées IgA sécrétoires (SIgA). Une fonction essentielle des SIgA intestinales est de maintenir microorganismes et antigènes alimentaires dans la lumière des muqueuses afin d’empêcher leur pénétration dans l'organisme. Néanmoins, la transcytose inverse des SIgA couplées à des bactéries a été décrite dans les plaques de Peyer où elle participe à la génération de la réponse immune contre ces bactéries. En outre, les travaux passés du laboratoire ont suggéré que le récepteur de la transferrine (CD71), surexprimé au pôle apical des entérocytes chez les patients cœliaques, interagit avec les SIgA couplées à des peptides de gliadines et permet leur transcytose inverse à travers l’épithélium intestinal. Ce travail de thèse a eu pour objectif de mieux caractériser l’interaction SIgA-CD71 dans les entérocytes humains. Dans un premier temps, nous avons utilisé la technologie CRISPR-Cas9 pour générer une lignée cellulaire intestinale humaine (Caco-2 TC7) dépourvue du récepteur CD71 (CD71KO). De manière inattendue, nous n’avons observé aucune altération de la fixation des SIgA sur les cellules Caco-2 CD71KO. Ce résultat nous a amenés à réévaluer le rôle de CD71 comme récepteur aux SIgA. Dans un second temps, nous avons vérifié et confirmé que les SIgA interagissent avec CD71, mais nous avons montré que cette interaction est indirecte. Nous avons ensuite criblé les récepteurs aux IgA déjà décrits dans la littérature et montré qu'aucun n'est responsable de la fixation des SIgA à la surface des cellules Caco-2 TC7. Ces résultats nous ont amenés à chercher le(s) autre(s) partenaire(s) du complexe SIgA-CD71. Par immunoprécipitation couplée à la spectrométrie de masse, nous avons identifié les protéines Secretory Carrier Membrane Protein 3 (SCAMP3), B-Cell Receptor-Associated Protein 31 (BCAP31) et Histocompatibility minor 13 (HM13) comme membres du complexe SIgA-CD71. En nous appuyant à nouveau sur la technologie CRIPSR-Cas9, nous avons montré qu’aucun de ses partenaires n’interagit directement avec les SIgA. Néanmoins, nos résultats suggèrent que SCAMP3 est nécessaire à l’oligomérisation de surface des complexes de fixation des SIgA. Enfin, l’internalisation des SIgA n'est pas altérée par l’absence de chacun des partenaires du complexe, suggérant que leur rôle advient durant le transport trans-épithélial des SIgA. L’ensemble de nos travaux montre que les SIgA interagissent avec l'épithélium intestinal via un complexe protéique composé d'au moins cinq membres : CD71, SCAMP3, BCAP31, HM13 et le(s) récepteur(s) inconnu(s) aux SIgA. Ces résultats complètent les travaux antérieurs sur le rôle physiopathologique des SIgA dans la maladie cœliaque et contribuent à souligner la complexité des interactions entre IgA et entérocytes. Une question importante sera d’identifier le(s) récepteur(s) aux SIgA et de déterminer le rôle des partenaires identifiés dans la transcytose inverse des SIgA par l’entérocyte. / Among the five isotypes of antibodies found in Humans, immunoglobulins A (IgA) are the most abundant in the mucosae. In the lamina propria, IgA are produced mainly as polymeric IgA (pIgA) and then secreted in the lumen. In fact, pIgA are translocated across the epithelium via the polymeric immunoglobulin receptor (pIgR), which is expressed at the basolateral side of the epithelium. Once secreted in the lumen, pIgA retain the extracellular domain of the pIgR and are called secretory IgA (SIgA). One of the main functions of intestinal SIgA is to restrain microorganisms and dietary antigens in the lumen, therefore, preventing their uptake through the epithelial barrier. However, retrotranscytosis of SIgA conjugated to bacteria has been described in Peyer’s patches where it participates to immune response. Moreover, previous works from the laboratory have suggested that transferrin receptor (CD71), which is overexpressed at the apical side of enterocytes from coeliac patients, interacts with SIgA bound to gliadin peptides and allows their retrotranscytosis across the intestinal epithelium. This thesis work aimed to further characterize the interaction between SIgA and CD71 in human enterocytes. We, first, generated a human epithelial intestinal cell line (Caco-2 TC7) devoid of CD71 expression (CD71KO) using the CRISPR/Cas9 genome editing method. Unexpectedly, flow cytometry experiments did not reveal a significant reduction of SIgA binding at the cell surface of CD71KO cells. Overall, our results indicated that CD71-SIgA interaction is indirect and may occur via additional protein partners through the assembly of a multifactorial protein complex. Therefore, we screened IgA receptors already known in the literature and showed that all are dispensable for SIgA binding at the surface of Caco-2 TC7 cells. In the effort to identify partner(s) within SIgA-CD71 complex, we set out mass spectrometry-based immunoprecipitation proteomics experiments and identified secretory carrier membrane protein 3 (SCAMP3), B-cell receptor-associated protein 31 (BCAP31) and histocompatibility minor 13 (HM13) as members of SIgA-CD71 complex. By generating knockout cell lines with the CRISPR/Cas9 system, we showed that none of these partners directly interacts with SIgA. However, our results suggest that SCAMP3 is required for the oligomerization of SIgA complexes at cell surface. Finally, we did not find any role in SIgA internalization for the different members of the complex, suggesting that they may play a role later on during SIgA retrotranscytosis. In conclusion, our work shows that SIgA interact with the intestinal epithelium via a proteic complex composed of at least five members: CD71, SCAMP3, BCAP31, HM13 and one or more unknown SIgA receptor(s). These results complement the previous works on the pathophysiologic role of SIgA in coeliac disease and underline the highly complex interaction between IgA and enterocytes. An important point to address will be to identify SIgA receptor(s) and to determine the role of the four other identified partners in SIgA retrotranscytosis across the intestinal epithelium.

京都大学 / 0048 / 新制・課程博士 / 博士(医科学) / 甲第20758号 / 医科博第81号 / 新制||医科||6(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 江藤 浩之, 教授 三森 経世, 教授 杉田 昌彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM