Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

<p>Despite aggressive surgical resection, cytotoxic chemotherapy, and external beam radiotherapy, most cases of glioblastoma (GBM) remain recalcitrant. These outcomes necessitate novel developmental therapeutics that spare normal tissue. Immunotherapy is a promising novel adjuvant treatment that can harness the cytotoxic capacity of the immune system against tumor-associated antigens with exquisite specificity. To circumvent the challenges associated with the advancement of adoptive cellular immunotherapy, we developed a novel treatment platform, which leverages the use of commercially available and clinically translatable nanoparticles (NPs) that can be combined with tumor derived RNA to peripherally activate T cells against GBM antigens. Although cancer vaccines have suffered from weak immunogenicity, we have advanced a NP vaccine formulation that can reshape a host’s immune profile through combinatorial delivery of RNAs encoding for tumor antigens and RNAs encoding for immunomodulatory molecules to mediate long-lived T cell persistence. </p><p>We sought to assess if vaccination with amplified tumor derived RNA encapsulated in lipophilic NPs could be assembled to transfect antigen presenting cells (APCs) in vivo and induce therapeutic anti-tumor immunity in pre-clinical murine tumor models. We hypothesized that RNA encapsulated nanoliposomes would localize to reticuloendothelial organs such as the spleen and liver, transfect APCs therein and induce peripheral antigen specific T cell immunity against GBM. Since activated T cells can cross the blood brain barrier and exert their effector functions against GBM antigens, peripheral transfection of APCs by RNA-NPs represents an attractive vaccination approach for priming endogenous immunity against refractory brain tumors.</p><p>We screened several translatable NP formulations for their ability to transfect dendritic cells (DCs) in vitro with GFP mRNA. We demonstrated that the NP DOTAP was the most promising translatable formulation compared to alternative cationic liposomal preparations and linear polyethylenimine NPs with and without DC targeting mannose receptors. RNA-NP vaccines formulated in DOTAP were shown to induce in vivo gene expression and preserve RNA stability over time. We determined that intravenous (IV) injection of RNA-NPs was requisite for inducing functional antigen specific immunity, which was superior to standard peptide vaccines formulated in complete Freund’s adjuvant (CFA). IV administered RNA-NPs localized to splenic and hepatic white blood cells (WBCs); these cells expanded antigen specific T cells when transferred to naïve immunocompetent mice. RNA-NPs induced increased percentages of B7 co-stimulatory molecules, but also elicited compensatory PD-L1 expression. We enhanced the immunogenicity and anti-tumor efficacy of RNA-NP vaccines by combining RNA-NPs with immune checkpoint blockade against PD-L1. We also enhanced the immunogenicity and efficacy of this platform by simply combining mRNAs encoding for immunomodulatory cytokines (i.e. GM-CSF). Finally, we demonstrated that RNA-NP vaccines mediate anti-tumor efficacy against intracranial and subcutaneous melanomas and engender therapeutic anti-tumor efficacy in a cellular immunotherapy model against a radiation/temozolomide resistant invasive murine high-grade glioma.</p><p>GBM remains invariably associated with poor patient outcomes thus necessitating development of more targeted therapeutics. Clinically translatable RNA-NPs form stable complexes making them amenable to overnight shipping. They induce potent immune responses when administered systemically and mediate robust anti-tumor efficacy that can be enhanced through co-delivery of immunomodulatory RNAs. </p><p>This technology can simultaneously bypass the complexity of cellular therapeutics while cutting down the time to generation of personalized vaccines. Since RNA-NP vaccines can be made within days from a tumor biopsy, providing near immediate immune induction against GBM, these formulations can provide a more feasible and effective therapy with a wide range of applicability for all malignancies that can be targeted using RNA obtained from surgical resection of solid tumors.</p> / Dissertation

Ly49 receptors are the canonical natural killer cell class-I major histocompatibility complex receptors expressed in mice. They have a well-defined role in natural killer cell self/non-self discrimination and in the developmental licensing of functional natural killer cells. In this thesis, I report two novel aspects of Ly49 receptor biology. First, I show that their expression may be regulated by specific nucleosome occupancy on AML-1 binding sites within the distal Ly49 promoter. This finding sheds light on a potential regulatory pathway that has thus far been unexplored in studies of the Ly49 receptor family, and highlights the Ly49 family as an ideal model system in which to study the impact of nucleosome occupancy in general. Second, I show that Ly49 receptors have a central and indispensable role in the emerging phenomenon known as adaptive natural killer cell memory. Natural killer cells have recently been observed displaying adaptive, long-lived, antigen specific memory responses comparable to T cell memory responses, but no explanatory mechanism has been discovered to describe how adaptive memory is possible in these ‘innate’ immune cells. Using Ly49-deficient mice, I show that the inhibitory, self-specific Ly49 receptors Ly49C and Ly49I are required for adaptive memory responses to chemical haptens or protein antigens. Moreover, I show that Ly49C/I binding capabilities are required during all stages of the memory response, as is antigen presentation in the context of class I major histocompatibility complex, again analogous to T cell memory responses. I present initial findings implicating these Ly49 receptors as key components of the antigen recognition process itself, and propose a mechanism based in evolutionarily ancient immunology to explain how this specificity could arise. Finally, I demonstrate that Ly49-dependent natural killer cell memory is capable of mediating powerful anti-cancer vaccination effects using an aggressive model of melanoma. Together, these findings in Ly49 family expression regulation and its functional role in adaptive NK cell responses open several new avenues of study in Ly49 receptor biology and natural killer cell immunology.

K. Babiarová Ph.D. Thesis ABSTRACT Cancer immunotherapy is concerned generally with the activation of cancer immunity specific for tumor antigens (TA) produced by cancer cells. My PhD thesis focused on the development of different types of cancer vaccines expressing various TA and predominantly on the determination of the efficacy of these vaccines. For studying TA-specific cancer cellular immunity in mice immunized with these vaccines, I used mainly the ELISPOT-IFNγ assay. First, DNA, recombinant vaccinia virus (rVACV) and peptide vaccines against WT1 positive tumors were prepared. They consist of a fragment of WT1 protein with motifs predicted to bind to Db murine MHC class I. The administration of peptide vaccines by tattoo delivery in combination with unmethylated CpG motifs and anti-TGFβ monoclonal antibody was the most effective. Next, I was interested in the immunotherapy of chronic myeloid leukemia (CML). Hruskova et al. prepared the mouse polyomavirus-like particles (MPyV-VLP) carrying the junction region of BCR-ABL fusion protein (1). In our laboratory, there were constructed the other types of CML vaccines with the expression of the junction region of BCR-ABL fusion protein, such as DNA or rVACV, too. Prepared vaccines failed to induce effective cancer immune response. It seems that BCR-ABL...

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

Thesis (Ph.D. in Immunology) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 133-156). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;

Introdução: A imunoterapia intravesical com o bacilo de Calmette-Guérin (BCG) é o tratamento adjuvante de escolha no câncer superficial de bexiga. Recentemente, os estudos do mecanismo imunoterápico do BCG têm permitido identificar as reações imunológicas e os genes associados ao efeito antitumoral, possibilitando a produção de vacinas recombinantes, possivelmente mais efetivas e com menos efeitos colaterais. Com esses objetivos, associou-se o componente pertussis (S1PT) ao BCG, criando uma variante recombinante (rBCG-S1PT) com capacidade para promover uma resposta imune direcionada ao tipo T helper 1 (Th1), o que poderá elevar a eficácia antitumoral do imunoterápico. Objetivo: Avaliar comparativamente o efeito antitumoral do rBCG-S1PT e do BCG no modelo experimental de carcinoma urotelial de bexiga. Métodos: O estabelecimento do modelo murino ortotópico e singênico de tumor vesical foi realizado através da implantação transuretral das células tumorais de bexiga da linhagem MB49 de camundongo C57BL/6. Experimento I Os animais (modelo experimental) foram divididos em três grupos, os quais receberam 4 aplicações semanais de rBCG-S1PT, BCG, ou soro fisiológico (grupo controle), por via intravesical. Após 7 dias da última aplicação, foram extraídos o baço e a bexiga, com o intuito de inferir o peso tumoral. Em seguida, as bexigas foram submetidas à avaliação do padrão de resposta imunológica e exame anátomo-patológico e imunohistoquímico. Experimento II Realizado como descrito no Experimento I, porém os animais foram acompanhados por 60 dias para análise de sobrevida. Experimento III Este ensaio foi realizado como descrito anteriormente, porém não foi realizada a implantação tumoral, para controle dos achados imunológicos e anátomo-patológicos. Resultados: A taxa média de implantação tumoral foi de aproximadamente 90% dos animais inoculados. Obtivemos redução das médias dos pesos vesicais dos grupos BCG e rBCG-S1PT (p<0,001). Nos dois grupos tratados com os imunoterápicos observou-se aumento significativo da expressão de TNF-, a qual foi mais intensa com o uso do rBCGS1PT (p<0,05). A IL-10 também teve aumento significante de sua expressão no grupo BCG recombinante (p<0,01). Os esplenócitos provenientes dos camundongos que foram tratados com imunoterápicos diminuíram a viabilidade das células tumorais MB49, sendo que este efeito foi mais intenso no grupo rBCG-S1PT. O grupo de animais tratados com rBCG-S1PT apresentou aumento significativo da sobrevida em relação aos outros grupos (Experimento II). As aplicações dos imunoterápicos em animais sem tumor (experimento III) não revelaram diferenças histológicas em relação ao grupo controle e o padrão de resposta imunológica encontrado sugere uma tendência à resposta Th1. Conclusão: Obtivemos sucesso no estabelecimento do modelo murino ortotópico singênico de tumor vesical. O imunoterápico rBCG-S1PT apresentou mais benefícios no tratamento do tumor vesical ortotópico em camundongos em relação ao BCG, como também maior redução da viabilidade das células tumorais in vitro. A cepa rBCG-S1PT apresentou elevação significativamente maior das citocinas da resposta imune Th1 em relação aos demais grupos. Concluimos, então, que os dados apresentados sugerem a possibilidade deste recombinante proporcionar melhor controle clínico do tumor vesical em humanos que a imunoterapia com BCG / Introduction: The intravesical immunotherapy with bacillus Calmette-Guérin (BCG) is the adjuvant treatment of choice in superficial bladder cancer. Recently, studies of the mechanism of BCG have identified the immune reactions favorable and the genes responsible for the antitumor effect, enabling the production of recombinant vaccines, possibly more effective and with fewer side effects. With those goals, the pertussis toxin (S1PT) was combined to BCG, creating a recombinant variant (rBCG-S1PT) with the capacity to promote an immune response targeted to the T helper type 1 (Th1), which may increase the effectiveness of its antitumor effect. Objective: Compare the antitumor effects of rBCG-S1PT and BCG in an experimental model of bladder cancer. Methods: The development of the animal model of bladder cancer was conducted by transurethral instillation of bladder tumor cell line MB49 of the mouse strain C57BL/6, setting the orthotopic and syngeneic murine model. Experiment I - The animal models were divided into three groups, which received 4 weekly intravesical applications of rBCG-S1PT, BCG, or saline (SF - control group). After 7 days of the last instillation, splenectomy was performed for splenocyte culture and the bladders extracted and weighed in order to infer the tumor weight. Then, the bladders were divided into two pieces. The first was used for molecular analysis to assess the pattern of immune response. The second was sent to histopathological analysis. Experiment II - Held as described in Experiment I, but the animals were monitored for 60 days for analysis of survival. Experiment III - This test was carried out as previously described (Experiment I), but with no tumor cells instillation. Results: The rate of tumor implantation was 90% of the animals submitted to tumor inoculation. We obtained reduction of the average weights of bladder in groups BCG and rBCG-S1PT ((p<0,001). In both groups treated with immunotherapy, there was an increase of expression of interleukins TNF-, which was more intense in the group treated with rBCG-S1PT (p<0,05). There was also increased expression of IL-10 in the recombinant BCG (p<0,01). The splenocytes from animals that received immunotherapies had reduced tumor cells viability, more intensely demonstrated in the rBCG-S1PT group. The analysis of survival showed a significant increase in the group of animals treated with rBCGS1PT (Experiment II). The instillation of immunotherapeutic agents in animals without tumor did not demonstrate histological differences when compared to the control group and the immunological response pattern was similar to that of Experiment I (Experiment III). Conclusion: The establishment of the syngeneic orthotopic animal model was successful. The immunotherapy with rBCG-S1PT demonstrated more benefits than BCG in the treatment of bladder cancer in mice, reducing the bladder weight, increasing survival, and reducing tumor cells viability in vitro. The immune response obtained with the rBCG-S1PT expressed higher cytokines related to Th1. All this data may indicate that this recombinant agent may promote better bladder tumor control than BCG imunotherapy

As células tumorais prosperam como consequência da capacidade de resistir aos mecanismos de morte celular e de evasão da vigilância imunológica. Nós propomos que, em cânceres que possuem o supressor de tumor p53 selvagem, a remediação de ambas dessas defesas pode ser promovida pela transferência genica combinada de vetores adenovirais portadores dos transgenes de p19Arf (proteína supressora de tumor, parceira funcional de p53) e de interferon-beta (IFNbeta, citocina imunomoduladora). De fato, em resultados anteriores, notamos que a transdução combinada (p19Arf/IFNbeta), mas não os tratamentos individuais, em células de melanoma murino B16F10 resulta em aumento massivo de morte celular. Porém a capacidade destas células em processo de morte de desencadear imunidade antitumoral não foi analisada. Nesta tese e em estudos complementares, buscamos investigar os mecanismos moleculares de morte celular envolvidos na resposta imune estimulada por p19Arf/IFNbeta e explorar sua aplicação como imunoterapia do câncer. Inicialmente, em modelo de vacinação profilática, revelamos que o tratamento combinado em células B16F10 promove a expressão de IL-15, ULBP1, dos receptores de morte FAS/APO1 e KILLER/DR5, assim como uma resposta de células natural killer que rejeitam estas células tratadas quando inoculadas em camundongos imunocompetentes singênicos. Após desafio tumoral no flanco oposto, a progressão desses tumores foi fortemente reduzida devido ao engajamento de linfócitos T CD4+ e CD8+, que apresentaram produção aumentada das citocinas IFN-? e TNF-alfa e medeiam proteção antitumoral de longo prazo. Em seguida, explorando um contexto de imunização diferente, a transferência de gênica in situ foi realizada em carcinoma heterotópico de pulmão e exibiu proteção significativa contra um desafio tumoral secundário, apenas quando o tumor primário foi tratado com p19Arf/IFNbeta. Análise de transcriptoma destes tumores indicou uma assinatura quimiotáxica de neutrófilos e linfócitos T CD8+ através das quimiocinas CCL3, CXCL3 e da IL-1beta. Em apoio destas observações, análises mecanicistas in vitro revelaram que células tratadas com p19Arf/IFNbeta ativam programas apoptóticos de p53 e antivirais de IFNbeta, enquanto sucumbem a um processo de morte por necroptose que também libera moléculas de morte celular imunogênica (MCI), calreticulina, ATP e HMGB1. No entanto, procurando potencializar ainda mais o benefício terapêutico dos nossos vetores, exploramos sua associação com o quimioterápico imunogênico doxorrubicina (Dox), que também é indutor de MCI. E nesta associação, percebemos que a Dox aumenta não apenas os níveis de morte celular, mas também a imunogenicidade das células tratadas, proporcionando em um modelo de vacina terapêutica, um controle tumoral superior em camundongos que já portavam antes da vacinação tumores B16F10 ou MCA205. Além disso, a associação in situ destas terapias restaurou a eficácia de uma dose sub-terapêutica de Dox, que em contraste com sua dose terapêutica, não prejudica a função cardíaca. Finalmente, também exploramos a associação com o bloqueio dos pontos de controle imunológicos PD-1 ou CTLA-4, que no modelo de vacina terapêutica, sua associação induziu maior rejeição completa de tumores B16F10. Em conclusão, aqui apresentamos evidências sobre a capacidade da combinação p19Arf/IFNbeta de induzir morte celular e estimulação imunológica. E ressaltamos seu potencial como uma estratégia de imunoterapia do câncer / Cancer cells thrive as a consequence of resisting cell death mechanisms and escaping from immune surveillance. We propose that, in cancers that harbor the wild-type tumor suppressor p53, remediation of both of these defenses can be achieved by harnessing the adenoviral vector mediated gene transfer of p19Arf (tumor suppressor protein, p53 functional partner) together with interferon-beta (IFNbeta, immunomodulatory cytokine). Indeed, in our initial observations, it was noticed that combined-transduction (p19Arf/IFNbeta), but not the individual treatments, of B16F10 mouse melanoma cells results in massive cell death levels. Yet, the capability of these dying cells to unleash antitumor immunity was not investigated. Here in this thesis and in complementary studies, we sought to investigate the molecular mechanisms of cell death involved in the p19Arf/IFNbeta immune stimulation and explore its potential as a mediator of cancer immunotherapy. First, in a prophylactic B16F10 vaccine model, we revealed that the dual treatment led to the up-regulation of IL-15, ULBP1, FAS/APO1 and KILLER/DR5 death receptors, plus a natural killer cell response that completely rejects treated cells when inoculated in syngeneic immunocompetent mice. Whereas, upon a contralateral tumor challenge, progression was strongly reduced by engaging both CD4+ and CD8+ T cells, which displayed augmented production of IFN-? and TNF-alpha cytokines and provided long term antitumor protection. Next, exploring different immunization context, in situ gene transfer in a heterotopic lung carcinoma exhibited significant protection against a secondary tumor challenge only when the primary tumor was treated with p19Arf/IFNbeta. Transcriptome analysis of these treated tumors indicated a chemotaxic signature of neutrophils and CD8+ T cells with the involvement of CCL3, CXCL3 chemokines and IL-1beta. Moreover, in support of this evidence, mechanistic in vitro studies revealed that p19Arf/IFNbeta treated cells reactivate p53 apoptotic and IFNbeta antiviral programs, while succumbing to a necroptosis cell death processes that also releases immunogenic cell death (ICD) molecules, calreticulin, ATP and HMGB1. Yet, aiming to potentiate therapeutic benefit of our vectors, we explored their association with doxorubicin (Dox) immunogenic chemotherapy, which is also an inducer of ICD. And in this setting, this association with Dox enhances not only cell death levels but also immunogenicity of treated cells, providing superior tumor control in a therapeutic vaccine model, where mice were already bearing B16F10 tumors or MCA205 sarcomas before vaccination. Moreover, associated use of these therapies in situ rescued efficacy of a sub-therapeutic dose of Dox, which in contrast to its therapeutic dose, does not impair cardiac function. Finally, we also evaluated the association with PD-1 or CTLA-4 checkpoint blockade immunotherapy, which in the therapeutic vaccine model induced full tumor rejection in a greater number of mice. In sum, here we provide compelling evidence for the ability of the p19Arf/IFNbeta combined gene transfer to promote cell death and immunogenic stimuli and underscored its potential to be applied as a cancer immunotherapy strategy

Introdução: A imunoterapia intravesical com o bacilo de Calmette-Guérin (BCG) é o tratamento adjuvante de escolha no câncer superficial de bexiga. Recentemente, os estudos do mecanismo imunoterápico do BCG têm permitido identificar as reações imunológicas e os genes associados ao efeito antitumoral, possibilitando a produção de vacinas recombinantes, possivelmente mais efetivas e com menos efeitos colaterais. Com esses objetivos, associou-se o componente pertussis (S1PT) ao BCG, criando uma variante recombinante (rBCG-S1PT) com capacidade para promover uma resposta imune direcionada ao tipo T helper 1 (Th1), o que poderá elevar a eficácia antitumoral do imunoterápico. Objetivo: Avaliar comparativamente o efeito antitumoral do rBCG-S1PT e do BCG no modelo experimental de carcinoma urotelial de bexiga. Métodos: O estabelecimento do modelo murino ortotópico e singênico de tumor vesical foi realizado através da implantação transuretral das células tumorais de bexiga da linhagem MB49 de camundongo C57BL/6. Experimento I Os animais (modelo experimental) foram divididos em três grupos, os quais receberam 4 aplicações semanais de rBCG-S1PT, BCG, ou soro fisiológico (grupo controle), por via intravesical. Após 7 dias da última aplicação, foram extraídos o baço e a bexiga, com o intuito de inferir o peso tumoral. Em seguida, as bexigas foram submetidas à avaliação do padrão de resposta imunológica e exame anátomo-patológico e imunohistoquímico. Experimento II Realizado como descrito no Experimento I, porém os animais foram acompanhados por 60 dias para análise de sobrevida. Experimento III Este ensaio foi realizado como descrito anteriormente, porém não foi realizada a implantação tumoral, para controle dos achados imunológicos e anátomo-patológicos. Resultados: A taxa média de implantação tumoral foi de aproximadamente 90% dos animais inoculados. Obtivemos redução das médias dos pesos vesicais dos grupos BCG e rBCG-S1PT (p<0,001). Nos dois grupos tratados com os imunoterápicos observou-se aumento significativo da expressão de TNF-, a qual foi mais intensa com o uso do rBCGS1PT (p<0,05). A IL-10 também teve aumento significante de sua expressão no grupo BCG recombinante (p<0,01). Os esplenócitos provenientes dos camundongos que foram tratados com imunoterápicos diminuíram a viabilidade das células tumorais MB49, sendo que este efeito foi mais intenso no grupo rBCG-S1PT. O grupo de animais tratados com rBCG-S1PT apresentou aumento significativo da sobrevida em relação aos outros grupos (Experimento II). As aplicações dos imunoterápicos em animais sem tumor (experimento III) não revelaram diferenças histológicas em relação ao grupo controle e o padrão de resposta imunológica encontrado sugere uma tendência à resposta Th1. Conclusão: Obtivemos sucesso no estabelecimento do modelo murino ortotópico singênico de tumor vesical. O imunoterápico rBCG-S1PT apresentou mais benefícios no tratamento do tumor vesical ortotópico em camundongos em relação ao BCG, como também maior redução da viabilidade das células tumorais in vitro. A cepa rBCG-S1PT apresentou elevação significativamente maior das citocinas da resposta imune Th1 em relação aos demais grupos. Concluimos, então, que os dados apresentados sugerem a possibilidade deste recombinante proporcionar melhor controle clínico do tumor vesical em humanos que a imunoterapia com BCG / Introduction: The intravesical immunotherapy with bacillus Calmette-Guérin (BCG) is the adjuvant treatment of choice in superficial bladder cancer. Recently, studies of the mechanism of BCG have identified the immune reactions favorable and the genes responsible for the antitumor effect, enabling the production of recombinant vaccines, possibly more effective and with fewer side effects. With those goals, the pertussis toxin (S1PT) was combined to BCG, creating a recombinant variant (rBCG-S1PT) with the capacity to promote an immune response targeted to the T helper type 1 (Th1), which may increase the effectiveness of its antitumor effect. Objective: Compare the antitumor effects of rBCG-S1PT and BCG in an experimental model of bladder cancer. Methods: The development of the animal model of bladder cancer was conducted by transurethral instillation of bladder tumor cell line MB49 of the mouse strain C57BL/6, setting the orthotopic and syngeneic murine model. Experiment I - The animal models were divided into three groups, which received 4 weekly intravesical applications of rBCG-S1PT, BCG, or saline (SF - control group). After 7 days of the last instillation, splenectomy was performed for splenocyte culture and the bladders extracted and weighed in order to infer the tumor weight. Then, the bladders were divided into two pieces. The first was used for molecular analysis to assess the pattern of immune response. The second was sent to histopathological analysis. Experiment II - Held as described in Experiment I, but the animals were monitored for 60 days for analysis of survival. Experiment III - This test was carried out as previously described (Experiment I), but with no tumor cells instillation. Results: The rate of tumor implantation was 90% of the animals submitted to tumor inoculation. We obtained reduction of the average weights of bladder in groups BCG and rBCG-S1PT ((p<0,001). In both groups treated with immunotherapy, there was an increase of expression of interleukins TNF-, which was more intense in the group treated with rBCG-S1PT (p<0,05). There was also increased expression of IL-10 in the recombinant BCG (p<0,01). The splenocytes from animals that received immunotherapies had reduced tumor cells viability, more intensely demonstrated in the rBCG-S1PT group. The analysis of survival showed a significant increase in the group of animals treated with rBCGS1PT (Experiment II). The instillation of immunotherapeutic agents in animals without tumor did not demonstrate histological differences when compared to the control group and the immunological response pattern was similar to that of Experiment I (Experiment III). Conclusion: The establishment of the syngeneic orthotopic animal model was successful. The immunotherapy with rBCG-S1PT demonstrated more benefits than BCG in the treatment of bladder cancer in mice, reducing the bladder weight, increasing survival, and reducing tumor cells viability in vitro. The immune response obtained with the rBCG-S1PT expressed higher cytokines related to Th1. All this data may indicate that this recombinant agent may promote better bladder tumor control than BCG imunotherapy