Doutoramento / PhD Degree / The immune evasion mechanisms of pathogenic trypanosomatids involve a multitude of
phenomena such as the polyclonal activation of lymphocytes, cytokine modulation and
the enhanced detoxification of oxygen reactive species. A trypanothione-cascade seems
to be involved in the detoxification process. We have recently described and
characterized a tryparedoxin (LiTXN1) involved in the Leishmania infantum
cytoplasmatic hydroperoxide metabolism. LiTXN1 is a secreted protein upregulated in
the infectious form of the parasite, suggesting that it can play an important role during
infection. In the present study, we investigated whether the recombinant LiTXN1
(rLiTXN1) would affect T and B cell functions in a murine model. We observed a
significant increase of CD69 surface marker on the B-cell population in total spleen and
on isolated B-cells from BALB/c mice after in vitro rLiTXN1 stimulus. Activated Bcells
underwent further proliferation, as measured by an increased [3H]-thymidine
incorporation. Cytokine quantification showed a dose-dependent upregulation of IL-10
secretion. B-cells were identified as a source. Furthermore, intraperitoneal injection of
rLiTXN1 into BALB/c mice triggered the production of elevated levels of rLiTXN1
specific antibodies, predominantly of the IgM, IgG1 and IgG3 isotypes, with a
minimum reactivity against other heterologous antigens. Taken together, our data
suggest that rLiTXN1 could participate in the immunopathological processes by
targeting the B-cells effector functions with subsequent IL-10 secretion and specific
antibodies production.
| Identifer | oai:union.ndltd.org:up.pt/oai:repositorio-aberto.up.pt:10216/7369 |
| Date | 28 September 2007 |
| Creators | Oliveira, Ricardo Jorge Dinis |
| Publisher | Faculdade de Farmácia da Universidade do Porto, FFUP |
| Source Sets | Universidade do Porto |
| Language | Portuguese |
| Detected Language | English |
| Type | Tese |
| Format | application/pdf, application/pdf |
| Rights | openAccess |
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