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- ItemAcesso aberto (Open Access)Análise da resposta imune celular após o direcionamento in vivo de antígenos do HIV para células dendríticas(Universidade Federal de São Paulo (UNIFESP), 2017-11-30) Apostolico, Juliana de Souza [UNIFESP]; Rosa, Daniela Santoro [UNIFESP]; Boscardin, Silvia Beatriz [UNIFESP]; http://lattes.cnpq.br/0930830632147222; http://lattes.cnpq.br/1472798853821902; http://lattes.cnpq.br/3697678570561187; Universidade Federal de São Paulo (UNIFESP)A epidemia causada pelo vírus da imunodeficiência humana (HIV) é uma infecção emergente das últimas décadas e, até o momento, não existe uma vacina profilática eficaz disponível. Diferentes estratégias vem sendo avaliadas como proteínas recombinantes, vetores virais, vacinas de DNA e mais recentemente, o direcionamento de antígenos para as células dendríticas (DCs). Esta estratégia é baseada em diversas características das DCs, que desempenham um papel central na indução da imunidade. O direcionamento é realizado através do uso de anticorpos quiméricos monoclonais (mAb)fusionados aos antígenos de interesse diretamente apara receptores de superfície das DCs. Em estudos prévios, nosso grupo demonstrou que a imunização de camundongos com uma vacina de DNA, codificando epítopos promíscuos para LT CD4+ do HIV-1, foi capaz de induzir resposta ampla e polifuncional de LT CD4+ e CD8+. Apesar dos resultados obtidos serem bastante promissores, as vacinas de DNA apresentam limitada imunogenicidade em humanos. Neste contexto, o presente trabalho teve como objetivo produzir um mAb quimérico contra um receptor de superfície das DCs (DEC205) em fusão com oito epítopos para linfócitos T CD4+ do HIV (αDECHIVBr8) e uma vacina de DNA codificando os mesmos epítopos (pVAXHIVBr8). Os resultados mostraram que camundongos imunizados com αDECHIVBr8 na presença do adjuvante poly (I:C) pela via intraperitoneal (I.P) apresentaram maior frequência de LT CD4+ e T CD8+ quando comparados aos camundongos imunizados com a vacina de DNA pVAXHIVBr8. Além disso, animais imunizados com a estratégia de prime/boost heteróloga ou seja, que receberam uma dose inicial (prime) com pVAXHIVBr8 seguida de reforço (boost) com αDECHIVBr8 apresentaram superior magnitude e amplitude de células T que proliferam e produziram citocinas em resposta aos peptídeos do HIV-1 do que os animais imunizados com a estratégia de prime/boost homóloga com HIVBr8 ou a estratégia heteróloga com prime com αDEC e boost com DNA. Por último, foi avaliado a influência dos adjuvantes poly I:C, Monofosforil lipídeo A (MPL), CpG ODN e αGalactosil-ceramida (αGalcer) nas imunizações com o αDECHIVBr8. Foi possível observar que a imunização com αDECHIVBr8 na presença de poly I:C foi capaz de aumentar a expressão de moléculas coestimulatórias nas populações de DCs e induzir maior frequência de linfócitos T CD4+ e T CD8+ polifuncionais quando comparado as imunizações assistidas pelos demais adjuvantes. Baseados nestes resultados, podemos concluir que estratégias de imunização que utilizam o direcionamento de epítopos para DCs na presença do adjuvante poly I:C induzem resposta imune celular de magnitude superior. Além disso, os resultados reforçam o conceito de que o direcionamento de antígenos para DCs é uma estratégia eficiente para aumentar a resposta imune antígeno-específica, especialmente no contexto de vacinas de DNA.
- ItemSomente MetadadadosCytotoxic T cells and mycobacteria(Elsevier B.V., 2001-04-01) Silva, Celio L.; Bonato, Vania LD; Lima, Karla M.; Coelho-Castelo, Arlete AM; Faccioli, Lucia H.; Sartori, Alexandrina; De Souza, Ana O.; Leao, Sylvia Cardoso [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)How the immune system kills Mycobacterium tuberculosis is still a puzzle. the classical picture of killing due to phagocytosis by activated macrophages may be only partly correct. Based on recent evidence, we express here the view that cytotoxic T lymphocytes also make an important contribution and suggest that DNA vaccines might be a good way to enhance this. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
- ItemSomente MetadadadosHumoral immune response after genetic immunization is consistently improved by electroporation(Elsevier B.V., 2008-07-23) Parise, Carolina Bellini [UNIFESP]; Lisboa, Bianca [UNIFESP]; Takeshita, Daniela [UNIFESP]; Sacramento, Chester Bittencourt [UNIFESP]; Moraes, Jane Zveiter de [UNIFESP]; Han, Sang Won [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Aiming to evaluate some parameters to influence the immune response to DNA vaccination, we compare three protocols of DNA immunization (i.m. injections, i.m. injections followed by electroporation, and the effect of i.p. injection of stably antigen-transfected cells before DNA administration), using three different antigens. Statistical analyses showed that electroporation after intramuscular injections provided an immune response comparable to that obtained by pre-treatment with antigen-transfected cells and similar to that obtained by protein immunization. the results allowed us selecting a protocol that worked well for all three antigens and reinforced the idea that high level of gene expression is essential to get good immunization. (c) 2008 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosPreventive DNA vaccination against CEA-expressing tumors with anti-idiotypic scFv6.C4 DNA in CEA-expressing transgenic mice(Springer, 2017) Denapoli, Priscila M. A. [UNIFESP]; Zanetti, Bianca F. [UNIFESP]; dos Santos, Adara A. [UNIFESP]; de Moraes, Jane Z. [UNIFESP]; Han, Sang W. [UNIFESP]Carcinoembryonic antigen (CEA) is expressed during embryonic life and in low level during adult life. Consequently, the CEA is recognized by the immune system as a self-antigen and thus CEA-expressing tumors are tolerated. Previously, we constructed a single chain variable fragment using the 6.C4 (scFv6.C4) hybridoma cell line, which gave rise to antibodies able to recognize CEA when C57/Bl6 mice were immunized. Here, the scFv6.C4 ability to prevent the CEA-expressing tumor growth was assessed in CEA-expressing transgenic mice CEA2682. CEA2682 mice immunized with the scFv6.C4 expressing plasmid vector (uP/PS-scFv6.C4) by electroporation gave rise to the CEA-specific AB3 antibody after the third immunization. Sera from immunized mice reacted with CEA-expressing human colorectal cell lines CO112, HCT-8, and LISP-1, as well as with murine melanoma B16F10 cells expressing CEA (B16F10-CEA). Cytotoxic T lymphocytes (CTL) from uP/PS-scFv6.C4 immunized mice lysed B16F10-CEA (56.7%) and B16F10 expressing scFv6.C4 (B16F10-scFv6.C4) (46.7%) cells, against CTL from uP-immunized mice (10%). After the last immunization, 5 x 10(5) B16F10-CEA cells were injected into the left flank. All mice immunized with the uP empty vector died within 40 days, but uP/PS-scFv6.C4 vaccinated mice (40%) remained free of tumor for more than 100 days. Splenocytes obtained from uP/PS-scFv6.C4 vaccinated mice showed higher T-cell proliferative activity than those from uP vaccinated mice. Collectively, DNA vaccination with the uP-PS/scFv6.C4 plasmid vector was able to give rise to specific humoral and cellular responses, which were sufficient to retard growth and/or eliminate the injected B16F10-CEA cells.
- ItemAcesso aberto (Open Access)Propionibacterium acnes Enhances the Immunogenicity of HIVBr18 Human Immunodeficiency Virus-1 Vaccine(Frontiers Media Sa, 2018) Teixeira, Daniela [UNIFESP]; Ishimura, Mayari Eika [UNIFESP]; Apostolico, Juliana de Souza [UNIFESP]; Viel, Jacqueline Miyuki [UNIFESP]; Passarelli, Victor Cabelho [UNIFESP]; Cunha-Neto, Edecio; Rosa, Daniela Santoro [UNIFESP]; Longo-Maugeri, Ieda Maria [UNIFESP]Immunization of BALB/c mice with HIVBr18, a DNA vaccine containing 18 CD4(+) T cell epitopes from human immunodeficiency virus (HIV), induced specific CD4(+) and CD8(+) T cell responses in a broad, polyfunctional and persistent manner. With the aim of increasing the immunogenicity of this vaccine, the effect of Propionibacterium acnes as an adjuvant was evaluated. The adjuvant effects of this bacterium have been extensively demonstrated in both experimental and clinical settings. Herein, administration of two doses of HIVBr18, in the presence of P. acnes, increased the proliferation of HIV-1-specific CD4(+) and CD8(+) T lymphocytes, the polyfunctional profile of CD4(+) T cells, the production of IFN-gamma, and the number of recognized vaccine-encoded peptides. One of the bacterial components responsible for most of the adjuvant effects observed was a soluble polysaccharide extracted from the P. acnes cell wall. Furthermore, within 10 weeks after immunization, the proliferation of specific T cells and production of IFN-gamma were maintained when the whole bacterium was administered, demonstrating a greater effect on the longevity of the immune response by P. acnes. Even with fewer immunization doses, P. acnes was found to be a potent adjuvant capable of potentiating the effects of the HIVBr18 vaccine. Therefore, P. acnes may be a potential adjuvant to aid this vaccine in inducing immunity or for therapeutic use.
- ItemSomente MetadadadosStrain-specific protective immunity following vaccination against experimental Trypanosoma cruzi infection(Elsevier B.V., 2009-09-18) Haolla, Filipe Augusto Bettencourt [UNIFESP]; Claser, Carla [UNIFESP]; Alencar, Bruna Cunha Gondim de [UNIFESP]; Tzelepis, Fanny [UNIFESP]; Vasconcelos, Jose Ronnie Carvalho de [UNIFESP]; Oliveira, Gabriel de; Silverio, Jaline Coutinho; Machado, Alexandre Vieira; Lannes-Vieira, Joseli; Bruna-Romero, Oscar; Gazzinelli, Ricardo Tostes; Santos, Ricardo Ribeiro dos; Soares, Milena Botelho Pereira; Rodrigues, Mauricio Martins [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Fiocruz MS; Universidade Federal de Minas Gerais (UFMG); Univ Massachusetts; Hosp Sao RafaelImmunisation with Amastigote Surface Protein 2 (asp-2) and trans-sialidase (ts) genes induces protective immunity in highly susceptible A/Sn mice, against infection with parasites of the Y strain of Trypanosoma cruzi. Based on immunological and biological strain variations in T cruzi parasites, our goal was to validate our vaccination results using different parasite strains. Due to the importance of the CD8(+) T cells in protective immunity, we initially determined which strains expressed the immunodominant H-2K(k)-restricted epitope TEWETGQI. We tested eight strains, four of which elicited immune responses to this epitope (Y, G, Colombian and Colombia). We selected the Colombian and Colombia strains for our studies. A/Sn mice were immunised with different regimens using both T. cruzi genes (asp-2 and ts) simultaneously and subsequently challenged with blood trypomastigotes. Immune responses before the challenge were confirmed by the presence of specific antibodies and peptide-specific T cells. Genetic vaccination did not confer protective immunity against acute infection with a lethal dose of the Colombian strain. in contrast, we observed a drastic reduction in parasitemia and a significant increase in survival, following challenge with an otherwise lethal dose of the Colombia strain. in many surviving animals with late-stage chronic infection, we observed alterations in the heart's electrical conductivity, compared to naive mice. in summary, we concluded that immunity against T cruzi antigens, similar to viruses and bacteria, may be strain-specific and have a negative impact on vaccine development. (c) 2009 Elsevier B.V. All rights reserved.