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| Author(s): |
Luana Silva Soares
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Ribeirão Preto. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC) |
| Defense date: | 2011-12-12 |
| Examining board members: |
Celio Lopes Silva;
Kelen Cristina Ribeiro Malmegrim de Farias;
Anderson de Sá Nunes
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| Advisor: | Celio Lopes Silva |
| Abstract | |
In 1993, the World Health Organization declared tuberculosis (TB) as a global emergence due to its epidemical relevance and the need to improve its control. Nowadays, TB still remains a public health problem and requires the development of more effective vaccines and therapies. In this sense, the Laboratory of Genetic Vaccines from the School of Medicine of Ribeirão Preto studies, for more than ten years, the efficiency of the genetic vaccine DNAhsp65 in TB prophylaxis and therapy. In order to complement the knowledge about the immune mechanisms triggered by DNAhsp65 vaccine and by its association with conventional drugs used in TB, our aim in this work was to characterize natural killer (NK), natural killer T (NKT) and gamma-delta (??) T cells in the immunotherapy of experimental tuberculosis with the DNAhsp65 vaccine, in the treatment with rifampicin and isoniazid drugs and in the association DNAhsp65-drugs. Initially, BALB/c mice were infected with Mtb strain H37Rv on day 0, and on days 1, 7, 15, 30 and 70 after infection, infected animals or not (control) were euthanized for lung cell analysis by flow cytometry. On day 30 after infection, infected animals received the following treatment: DNAhsp65 vaccine, pVAX1 vector, rifampicin and isoniazid drugs, or drugs in association with DNAhsp65. Ten days after the end of treatment, animals were euthanized for lung and lymph node cell analysis by flow cytometry, immunohistochemistry and real time PCR. Infected animals showed a significant increase of NK (CD3-CD49b+), NKT (CD3+CD49b+) and ?? (CD3+??+) T cells in the first week of infection and this difference compared to control animals remained until 70 days after infection. Within the lung NK cell population, we observed a predominance of CD11bhighCD27low phenotype in all animals. In infected animals, we verified a significant increase of the following NK cell subpopulations: CD11bhighCD27high and CD11blowCD27high on days 7 and 15, and only on day 15 after infection, respectively. Within the lung ?? T cell population, there was a predominance of CD27- ?? T cell in control and infected animals in the different experimental times. In infected animals and subsequently vaccinated with DNAhsp65, we verified a significant increase in ?? T cells producing IFN-? and IL-17 in the lungs. Although we have not seen any differences in NK and NKT cells in this group, NK cells showed higher expression of FasL molecule related to induced cell death by apoptosis. In DNAhsp65-drugs and drugs groups, we observed an increase in lung ?? T cells frequency, as well as increase in NK cells producing IL-10 and expressing CD69, an activation marker. Our results confirm the effectiveness of DNAhsp65 vaccine and its association with drugs in Mtb infected animals and suggest a modulation in the immune response through unconventional T cells such as NK, NKT and ?? T cells. These findings should be taken into consideration in the design of new therapeutic and prophylactic strategies for TB. (AU) | |
| FAPESP's process: | 09/04544-0 - Characterization of Natural Killer and gamma-delta T cells in the immunotherapy of experimental tuberculosis with DNAhsp65 genetic vaccine. |
| Grantee: | Luana Silva Soares |
| Support Opportunities: | Scholarships in Brazil - Master |