Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 158-168.

Thesis (M.S.)--Brigham Young University. Dept. of Microbiology and Molecular Biology, 2007. / Includes bibliographical references (p. 37-40).

Thesis (Ph. D.)--Lund University, 1995. / Published dissertation.

Thesis (Ph. D.)--Lund University, 1995. / Published dissertation.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-06-28T14:37:59Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) TESE_FABIANA_LETICIA_DIGITAL.pdf: 2539644 bytes, checksum: ffb2ea48912cab654c0a8e8bdc397ac2 (MD5) / Made available in DSpace on 2016-06-28T14:37:59Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) TESE_FABIANA_LETICIA_DIGITAL.pdf: 2539644 bytes, checksum: ffb2ea48912cab654c0a8e8bdc397ac2 (MD5) Previous issue date: 2014-08-27 / FACEPE / O contato prévio com o leite de mães esquistossomóticas induziu, em camundongos adultos, potencialização da produção de anticorpos e aumento da capacidade de apresentação de antígeno pelos linfócitos B, em resposta ao antígeno heterólogo ovalbumina (OVA). Considerando a imunização com OVA um modelo vacinal, as reações inflamatórias e a produção de anticorpos em resposta a esse antígeno são importantes para o desenvolvimento de uma imunidade satisfatória do hospedeiro. Nesse sentido, as células Th1 e Th17 são importantes fatores para o desenvolvimento dessas respostas. Dessa forma, os camundongos deficientes na produção de IL-12/IL-23 (12p40 knockout-KO) são predispostos a desenvolverem uma resposta Th2 polarizada, tornando-se menos responsivos às vacinações. Diante disso, o presente trabalho investigou o efeito da amamentação em mães infectadas pelo Schistosoma mansoni sobre as imunidades humoral e celular de camundongos adultos C57BL/6 12p40 KO, em resposta ao modelo vacinal acima citado. Foram avaliados: a cinética das reações de hipersensibilidade in vivo; os níveis plasmáticos das imunoglobulinas IgG1 e IgG2a; a produção das citocinas IFN-γ, IL-17, IL-5, IL-6, IL-10 e TGF- pelas células esplênicas e a reação inflamatória provocada no coxim plantar. Para isso, camundongos machos, deficientes na produção de IL-12 e IL-23 (IL-12p40 KO) e camundongos selvagens (wild-type/WT) foram divididos nos seguintes grupos: camundongos IL-12p40 KO amamentados em mães infectadas (AI IL-12p40 KO); camundongos IL-12p40 KO amamentados em mães sem infecção (NANI IL-12p40 KO); camundongos selvagens amamentados em mães infectadas (AI WT) e camundongos selvagens amamentados em mães sem infecção (NANI WT). Cinquenta por cento dos animais de cada grupo foram imunizados com OVA em adjuvante. Os outros 50% porcento restantes permaneceram sem imunização. No grupo AI WT houve aumentado de produção de IgG2a, IL-5, TGF-β e IL-6, com baixos níveis de IL-17, em comparação ao NANI WT. Nos animais AI IL-12p40 KO, a produção de IgG2a, IL-5 e TGF-β foi mais alta do que o grupo NANI IL-12p40 KO e similar ao grupo AI WT, mas a produção de IL-6 foi mais baixa. O grupo AI WT mostrou intenso infiltrado inflamatório de eosinófilos na reação de hipersensibilidade tardia (RHT), com acentuado edema em comparação com o edema menos intenso e infiltrado inflamatório de neutrófilos do grupo NANI WT. Os animais NANI IL-12p40 KO e AI IL-12p40 KO não apresentam RHT, porém a reação inflamatória no AI IL-12p40 KO foi menos intensa que nos NANI IL-12p40 KO. Em conclusão, o contato com antígenos do parasito, através da amamentação, induziu, no descendente adulto, uma melhor resposta de anticorpo neutralizante, mesmo diante da deficiência na produção de IL-12e IL-23. Nesta condição, embora tenha havido uma notável produção de IL-5, a lactação em mães infectadas atenuou a reação inflamatória, provavelmente através da regulação cruzada entre TGF-β e IL-6, modulando, desta forma, o status de hiperativação desses animais. / The previous contact with mothers milk schistosomiasis induced in adult mice enhancement of antibody production and increased antigen presentation capacity by B lymphocytes in response to the heterologous antigen ovalbumin (OA). Considering immunization with OA one vaccine model, inflammatory reactions and antibody production in response to antigen are important for the development of a suitable host immunity. In this sense, the Th1 and Th17 cells are important factors for the development of these responses. Thus, mice deficient in IL-12/IL-23 (12p40 knockout-KO) are likely to develop a polarized Th2 response, making it less responsive to vaccination. Therefore, the present study investigated the effect of breastfeeding in mothers infected with Schistosoma mansoni on the humoral and cellular adult C57BL/6 12p40 KO in response to vaccination model mentioned above. Were evaluated: the kinetics of in vivo hypersensitivity reactions; plasma levels of IgG1 and IgG2a immunoglobulins; the production of the cytokines IFN-γ, IL-17, IL-5, IL-6, IL-10 and TGF-β by spleen cells and the inflammatory reaction induced in the footpad. To this end, male mice deficient in IL-12 and IL-23 (IL-12p40 KO) and wild-type mice (Wild-type/WT) were divided into the following groups: IL-12p40 KO mice suckled by infected mothers (IL-12p40 KO- SIM); IL-12p40 KO mice suckled by uninfected mothers (IL-12p40 KO); Wild-type mice suckled by infected mothers (SIM) and wild-type mice suckled by uninfected mothers (CONTROL). Fifty percent of animals in each group were immunized with OA in adjuvant. The other 50% remaining percent remained without immunization. In the SIM group was increased production of IgG2a, IL-5, TGF-β and IL-6, IL-17 with low levels compared to CONTROL. In animals IL-12p40 KO-SIM the production of IgG2a, IL-5 and TGF-β was higher than the IL-12p40 KO similar to group SIM, but IL-6 production was lower. The SIM group showed intense inflammatory infiltrate of eosinophils in the delayed hypersensitivity reaction (DTH), with severe edema compared with the less intense edema and inflammatory infiltration of neutrophils CONTROL group. The animals IL-12p40 KO and IL-12p40KO-SIM not have DTH, but the inflammatory reaction in the IL-12p40KO-SIM was less intense than in IL-12p40 KO. In conclusion, contact with parasite antigens, through breastfeeding, induced in adult offspring, better neutralizing antibody response, despite the deficiency in the production of IL-12 and IL-23. In this condition, though there has been a remarkable IL-5 production in lactating mothers infected with attenuated inflammatory response, probably via cross regulation between TGF-β and IL-6 modulate thereby the status of hyperactivation of these animals.

The immune system is a complex network of cells and molecules that is a powerful and necessary defense mechanism to protect the host from pathogens. When this system is non-functional or dysregulated, the host is susceptible to takeover or attack against self, both with often lethal sequelae. Over the past century remarkable advances have been made in understanding how the immune system functions and how to manipulate this knowledge for human benefit. One strategy used to understand immune system function is to determine how the activity of immune system cells is modulated by the proteins these cells express on their surface. One rat T cell surface protein which was originally identified with antibodies almost two decades ago is the rat T cell alloantigen, RT6. During the intervening time enormous progress has been made in understanding the function of RT6+ T cells in normal and abnormal immune responses. In addition, during this time the characterization of RT6 genes, proteins, and homologues has occurred. One characterization of RT6 that is enigmatically missing is the function of this molecule. With this information it would be possible to determine how this molecule modulates T cell function. Therefore this project set out to begin to functionally characterize RT6 proteins. Part 1 of this project set out to determine if cell-surface RT6 proteins, like some other T cell surface proteins, could mediate T cell activation. Part 2 of this project was based on the recent observation that RT6 is homologous to NAD-catabolizing enzymes, and it was investigated whether RT6 proteins have ADP-ribosyltransferase activity. In Part 1 of this work it is demonstrated that cell-surface RT6 proteins are capable of delivering activation signals to T cells. Crosslinking cell-surface RT6 with antibodies potentiates the ability of PMA treated T cells to proliferate in response to the T cell growth factors IL-2 and/or IL-4. Crosslinking RT6 on these cells increases the surface expression of IL-2 receptors, suggesting that RT6-mediated signals selectively enhance growth factor receptor expression. This work also investigated the mechanism through which RT6 may deliver its signal. It is demonstrated that RT6 proteins are physically associated with five other proteins, including the src family tyrosine kinases p56lck and p60fyn. This work also suggests a novel mechanism to regulate T cell signaling by accessory molecules, since PKC activation causes qualitative and quantitative changes in the proteins physically associated with RT6. This work indicates that cell-surface RT6 is capable of delivering an accessory T cell activation signal. Therefore, RT6 proteins may be involved in vivo with the activation and proliferation of RT6+ T cells. Previous work in another laboratory has demonstrated that the RT6.2 protein possesses NAD glycohydrolase activity and indicated that RT6 proteins share overall sequence homology with ADP-ribosyltransferases. In Part 2 of this work, RT6 proteins are shown to possess NAD:arginine ADP-ribosyltransferase activity. ADP-ribosylation of proteins is a modification known to affect cell signaling and function. It is further demonstrated in this work that the substrate for RT6, extracellular NAD, inhibits T cell proliferation in a dose- and stimulus-dependent manner. Taken together, these studies suggest that through their enzymatic activities RT6 proteins modulate T cell activity. This work is the first to demonstrate that RT6 has two, possibly separate, functional characteristics. RT6 can therefore be described as a bifunctional T cell surface protein. RT6+ T cells play critical roles in regulating immune system responses in health and disease. Because of these functional studies on RT6 proteins, it can now be investigated how RT6 proteins may modulate T cell responses in different immunological situations. Thus, this work will provide the foundation to determine if and how RT6 proteins modulate immune system function in health and disease.