Células T reguladoras em sangue periférico de cães portadores de mastocitoma cutâneo

• Autor(a) principal: Chaves, Mônica Ribeiro Sant'Anna [UNESP]
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/121880
• topic: Cão; Cão - Doenças; Mastocitoma; Celulas T; Citometria de fluxo; Mastocytoma

Mast cell tumor is a neoplastic proliferation of mast cells which is the most frequent cutaneous tumor in dogs. Its extremely variable biological behavior makes the prognostic and therapeutic determination more difficult, which demands the search for more reliable prognostic indicators. The regulatory T cells (Tregs) are a subset of T lymphocytes that express CD4 and CD25, and are transcribed by Foxp3 factor. The Tregs, through their immunosuppressive potential, regulate the immune responses in several diseases. Regarding the oncological aspects, they are responsible for the limitation of the antitumoral immune response, promoting an immunological tolerance to the neoplastic mast cells. In this context, the current study had the objective to quantify, through flow cytometry, the expression of Tregs and the Treg/CD8+ ratio in the peripheral blood of dogs with cutaneous mast cell tumor (n = 18) at diagnosis. Such variables were also evaluated in different histologic grades of mast cell tumor, according to the grading system proposed by Kiupel et al. (2011). The results indicated that dogs with mast cell tumor (8,99 ± 1,15) showed significantly higher percentage (p<0,01) of Tregs when compared to healthy dogs (4,71 ± 0,51). There was not difference in the quantities of Tregs for dogs with high (5,55 ± 1,16) and low (4,96 ± 0,70) grade mast cell tumor. Dogs with mast cell tumor (0,27 ± 0,04) also presented significantly higher Treg/CD8+ ratio (p = 0,04) when compared to control dogs (0,12 ± 0,01). It was concluded that the mast cell tumor in dogs increases Tregs in the peripheral blood, and also leads to a higher Treg/CD8+ ratio