Ptaquiloside from bracken (Pteridium spp.) inhibits tumour-infiltrating CD8(+) T cells in HPV-16 transgenic mice

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Carlos Santos (Author) Other; Pedro Ferreirinha (Author) Other; Hugo Sousa (Author) Other; Joana Ribeiro (Author) Other; Margarida M. S. M. Bastos (Author) FEUP; Tiago Neto (Author) Other; Paula A. Oliveira (Author) Other; Rui Medeiros (Author) Other; Manuel Vilanova (Author) Other; Rui M. Gil da Costa (Author) FEUP

Journal

Title: Food and Chemical Toxicology

Vol. 97

Pages: 277-285

ISSN: 0278-6915

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 19 Citations

Scopus - 21 Citations

Associated Projects

LEPABE - Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia

Other information

Authenticus ID: P-00K-X67

DOI: 10.1016/j.fct.2016.09.019

Abstract (EN): Bracken is a fern with worldwide distribution. Exposure to bracken toxins such as ptaquiloside is hypothesized to increase the risk of papillomavirus-related cancers of the upper digestive tract. Ptaquiloside is thought to be an immunosupressor, thus allowing for the development of viral lesions. We have used a human papillomavirus type 16-transgenic (K14-HPV16) mouse model to study the effects of ptaquiloside on tumour-infiltrating CD8(+) T lymphocytes, which are critical players in anti-tumour immunity. HPV16(+/-) mice received ptaquiloside (0.5 mg/mouse/week) for 10 weeks. These were then euthanized at 30 weeks of age, along with age-matched untreated controls. Skin samples were enzymatically digested and CD8(+) T cells analysed for CD107a and CD44 surface expression. Ptaquilosideexposed HPV16(+/-) mice showed a significantly decreased percentage (P < 0.05) of CD8(+)CD107(+) and CD8(+)CD44 T cells when compared with untreated HPV16(+/)- animals. Histologically, 100% of ptaqui-losidetreated mice showed diffuse epidermal dysplasia, compared with 50% of the untreated mice. These findings suggest that ptaquiloside exerts an immunosuppressive role by decreasing CD8(+) T cell activation and degranulation in HPV-induced lesions. Given the key role of CD8(+) T lymphocytes against HPV-induced lesions, this effect is likely to contribute for viral persistence, tumour progression and increased aggressiveness in patients with HPV-related malignancies.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9