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| Author(s): |
Renata Ricardi
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2010-06-18 |
| Examining board members: |
Eliana Faquim de Lima Mauro;
Anderson de Sá Nunes;
Sandra Coccuzzo Sampaio
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| Advisor: | Eliana Faquim de Lima Mauro |
| Abstract | |
The venom of the rattlesnake Crotalus durissus terrificus (C.d.terrificus) changes the coagulation system and presents neurotoxic, myotoxic and immunosuppressive effect. The venom and its main fraction, crotoxin (CTX) inhibited both the cellular and humoral response. This effect is not due to induction of cell death. The objective was to investigate the immunosuppressive mechanisms of CTX. CTX induces production of IL-10, TGF-<font face=\"Symbol\">β and prostaglandin E2 (PGE2) by cells of mice that received it. Lower secretion of IFN-<font face=\"Symbol\">γ and IL-12 was observed in the cultured cells from mice immunized that received CTX. CTX promotes increased expression of the enzyme indoleamine 2,3 dioxygenase and generation of regulatory T cells in mice immunized with OVA and receiving the toxin. CTX was able to inhibit the expression of CD40, CD80, CD86 and MHC II in mice immunized and in dendritic cells (DCs) purified from these animals. In cultures of DCs, CTX increased secretion of IL-10, TGF-<font face=\"Symbol\">β and PGE 2 and lower IL-12. (AU) | |