RESUMO
Las enfermedades periodontales representan un importante problema de salud que afecta los tejidos de soporte de las piezas dentarias. Dentro de ellas, las Periodontitis Agresivas se caracterizan por su rápida progresión, agregación familiar, pacientes sistémicamente sanos1 subdividiéndose en localizadas y generalizadas según la extensión del cuadro. Los microorganismos juegan un papel importante en su etiopatogenia, entre los cuales se encuentran Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum. El propósito de este trabajo fue estudiar cuáles de estos microorganismos estaba presente en 50 pacientes uruguayos con Periodontitis Agresiva. La detección se realizó con técnica convencional bacteriológica y PCR. En los cuadros generalizados se observó mayor prevalencia de F. nucleatum y P. intermedia seguido de P. gingivalis y T. forsythia. En los cuadros localizados destacaron P. intermedia, F. nucleatum y A. actinomycetemcomitans. En nuestro país se presentó una flora similar a los que figuran en otras localizaciones geográficas
Periodontal diseases are a major health problem affecting tooth-supporting tissues. Among them, aggressive periodontitis is characterized by rapid progression, family aggregation, systemically healthy patients, and is subdivided into localized and generalized according to the extent of the disease. Microbiota plays a major role in the etiopathogenesis of these diseases, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Fusobacterium nucleatum. The aim of this work was to study the prevalence of these microorganisms in 50 Uruguayan patients with aggressive periodontitis. Detection was conducted with conventional bacteriological techniques and PCR. In the generalized disorders, a higher prevalence of F. nucleatum and P. intermedia was observed, although P. gingivalis and T. forsythia were also important. In the localized disorders, P. intermedia, F. nucleatum and A. actinomycetemcomitans were the main ones. A similar flora to other geographical locations was present in our country
Assuntos
Humanos , Periodontite Agressiva/diagnóstico , Uruguai , NoxasRESUMO
AIM: We evaluated a novel approach combining the use of attenuated Salmonella immunotherapy with a Toll-like receptor agonist, imiquimod, in B16F1 melanoma-bearing mice. MATERIALS & METHODS: B16F1 melanoma-bearing mice were daily treated with topical imiquimod in combination with one intratumoral injection of attenuated Salmonella enterica serovar Typhimurium LVR01. RESULTS: The combined therapy resulted in retarded tumor growth and prolonged survival. Combination treatment led to an enhancement in the expression of pro-inflammatory cytokines and chemokines in the tumor microenvironment, with a Th1-skewed profile, resulting in a broad antitumor response. The induced immunity was effective in controlling the occurrence of metastasis. CONCLUSION: Salmonella LVR01 immunotherapy in combination with imiquimod is a novel approach that could be considered as an effective antimelanoma therapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Imunoterapia/métodos , Melanoma Experimental/terapia , Salmonella typhi/imunologia , Receptor 7 Toll-Like/agonistas , Animais , Antineoplásicos/uso terapêutico , Morte Celular , Linhagem Celular Tumoral , Feminino , Imiquimode/uso terapêutico , Melanoma Experimental/imunologia , Melanoma Experimental/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Viabilidade Microbiana , Metástase Neoplásica/prevenção & controle , Salmonella typhi/fisiologia , Análise de Sobrevida , Resultado do Tratamento , Carga Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologiaRESUMO
We have previously shown that Salmonella immunotherapy is effective to treat B-cell non-Hodgkin lymphoma (B-NHL) in mice. However, this model involves animals with high tumor burden, whereas in the clinics B-NHL patients are usually treated with chemotherapy (CHOP: cyclophosphamide, doxorubicin, vincristine, and prednisone) as first-line therapy prior to immunotherapy. Recently, we have described a NHL-B preclinical model using CHOP chemotherapy to achieve MRD in immunocompetent animals that closely resemble patients' conditions. In this work, we assessed the efficacy of Salmonella immunotherapy in B-NHL-bearing mice undergoing chemotherapy. Salmonella administration significantly delayed tumor growth and prolonged survival of chemotherapy-treated NHL-bearing animals. Mice receiving the CHOP-Salmonella combined therapy showed increased numbers of tumor-infiltrating leukocytes and a different profile of cytokines and chemokines expressed in the tumor microenvironment. Further, Salmonella immunotherapy in CHOP-treated animals also enhanced NK cells cytotoxic activity as well as induced systemic lymphoma-specific humoral and cellular responses. Chemotherapy treatment profoundly impacted on the general health status of recipient animals, but those receiving Salmonella showed significantly better overall body condition. Altogether, the results clearly demonstrated that Salmonella immunotherapy could be safely used in individuals under CHOP treatment, resulting in a better prognosis. These results give strong support to consider Salmonella as a neoadjuvant therapy in a clinical setting.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Imunoterapia/métodos , Linfoma não Hodgkin/terapia , Salmonella/imunologia , Animais , Linhagem Celular Tumoral , Quimiocinas/análise , Ciclofosfamida/uso terapêutico , Intervalo Livre de Doença , Doxorrubicina/uso terapêutico , Feminino , Células Matadoras Naturais/imunologia , Ativação Linfocitária/imunologia , Linfoma não Hodgkin/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Prednisona/uso terapêutico , Resultado do Tratamento , Microambiente Tumoral/imunologia , Vincristina/uso terapêuticoRESUMO
BACKGROUND: Non-Hodgkin lymphomas (NHL) are the most frequent hemato-oncological malignancies. Despite recent major advances in treatment, a substantial proportion of patients relapses highlighting the need for new therapeutic modalities. Promissory results obtained in pre-clinical studies are usually not translated when moving into clinical trials. Pre-clinical studies are mainly conducted in animals with high tumor burden; instead patients undergo chemotherapy as first line of treatment and most likely are under remission when immunotherapies are applied. Thus, an animal model that more closely resembles patients' conditions would be a valuable tool. METHODS: BALB/c mice were injected subcutaneously with A20 lymphoma cells and after tumor development different doses of chemotherapy were assessed to find optimal conditions for minimal residual disease (MRD) establishment. Tumor growth and survival, as well as drugs side effects, were all evaluated. Complete lymphoma remission was monitored in vivo using positron emission tomography (PET), and the results were correlated with histology. Immunological status was assessed by splenocytes proliferation assays in NHL-complete remission mice and by analyzing tumor cell infiltrates and chemokines/cytokines gene expression in the tumor microenvironment of animals with residual lymphoma. RESULTS: Two cycles of CHOP chemotherapy at days 25 and 35 post-tumor implantation induced complete remission for around 20 days. PET showed to be a suitable follow-up technique for MRD condition with 85.7 and 75% of sensibility and specificity respectively. Proliferative responses upon mitogen stimulation were similar in animals that received chemotherapy and wild type mice. Tumors from animals with residual lymphoma showed higher numbers of CD4+ and CD8+ and similar numbers of NK, neutrophils and Tregs infiltrating cells as compared with non-treated animals. Gene expression of several cytokines as well as an array of chemokines associated with migration of activated T cells to tumor sites was upregulated in the tumor microenvironment of animals that received chemotherapy treatment. CONCLUSIONS: We established a NHL-B pre-clinical model using standard chemotherapy to achieve MRD in immunocompetent animals. The MRD condition is maintained for approximately 20 days providing a therapeutic window of time where new immunotherapies can be tested in conditions closer to the clinics.
Assuntos
Linfoma não Hodgkin/patologia , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proliferação de Células , Quimiocinas/genética , Quimiocinas/metabolismo , Modelos Animais de Doenças , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/genética , Linfoma não Hodgkin/imunologia , Camundongos Endogâmicos BALB C , Neoplasia Residual/tratamento farmacológico , Neoplasia Residual/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Padrões de Referência , Indução de Remissão , Baço/patologia , Análise de Sobrevida , Resultado do TratamentoRESUMO
Despite the efficacy of current immune-chemotherapy for treatment of B-cell non-Hodgkin lymphoma, a substantial proportion of patients relapse, highlighting the need for new therapeutic modalities. The use of live microorganisms to develop anti-tumoural therapies has evolved since Coley's toxin and is now receiving renewed attention. Salmonella Typhimurium has been shown to be highly effective as an anti-tumour agent in many solid cancer models, but it has not been used in haemato-oncology. Here, we report that intra-tumoural administration of LVR01 (attenuated S. Typhimurium strain with safety profile) elicits local and systemic anti-tumour immunity, resulting in extended survival in a lymphoma model. LVR01 induces intra-tumoural recruitment of neutrophils and activated CD8(+) T cells, as well as increasing the natural killer cell activation status. Furthermore, a systemic specific anti-tumour response with a clear T helper type 1 profile was observed. This approach is an alternative therapeutic strategy for lymphoma patients that could be easily moved into clinical trials.
Assuntos
Imunoterapia/métodos , Linfoma de Células B/imunologia , Salmonella typhimurium/imunologia , Animais , Morte Celular/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Epitopos/imunologia , Feminino , Imunidade Humoral , Interferon gama/genética , Interferon gama/metabolismo , Leucócitos/imunologia , Leucócitos/patologia , Linfoma de Células B/genética , Linfoma de Células B/metabolismo , Linfoma de Células B/mortalidade , Linfoma de Células B/patologia , Linfoma de Células B/terapia , Camundongos , Baço/citologia , Baço/imunologia , Baço/microbiologiaRESUMO
Genomic islands are DNA regions containing variable genetic information related to secondary metabolism. Frequently, they have the ability to excise from and integrate into replicons through site-specific recombination. Thus, they are usually flanked by short direct repeats that act as attachment sites, and contain genes for an integrase and an excisionase which carry out the genetic exchange. These mobility events would be at the basis of the horizontal transfer of genomic islands among bacteria.Microcin H47 is a ribosomally-synthesized antibacterial peptide that belongs to the group of chromosome-encoded microcins. The 13 kb-genetic system responsible for its production resides in the chromosome of the Escherichia coli H47 strain and is flanked by extensive and imperfect direct repeats. In this work, both excision and integration of the microcin H47 system were experimentally detected. The analyses were mainly performed in E. coli K12 cells carrying the microcin system cloned in a multicopy plasmid. As expected of a site-specific recombination event, the genetic exchange also occurred in a context deficient for homologous recombination. The DNA sequence of the attachment sites resulting from excision were hybrid between the sequences of the direct repeats. Unexpectedly, different hybrid attachment sites appeared which resulted from recombination in four segments of identity between the direct repeats. Genes encoding the trans-acting proteins responsible for the site-specific recombination were shown to be absent in the microcin H47 system. Therefore, they should be provided by the remaining genetic context, not only in the H47 strain but also in E. coli K12 cells, where both excision and integration occurred. Moreover, a survey of the attachment sites in data banks revealed that they are widely spread among E. coli strains. It is concluded that the microcin system is a small island -H47 genomic island- that would employ a parasitic strategy for its mobility.