Université Nantes Angers Le Mans

About: Université Nantes Angers Le Mans is a education organization based out in Nantes, France. It is known for research contribution in the topics: Geology & Finite element method. The organization has 434 authors who have published 249 publications receiving 7208 citations. The organization is also known as: PRES Universite Nantes Angers Le Mans.

Cancer: a missing link in ecosystem functioning?

Abstract: Cancer is a disease that affects the majority of metazoan species and, before directly causing host death, is likely to influence the competitive abilities of individuals, their susceptibility to pathogens, their vulnerability to predators, and their ability to disperse. Despite the potential importance of these ecological impacts, cancer is rarely incorporated into model ecosystems. We describe here the diversity of ways in which oncogenic phenomena, from precancerous lesions to generalized metastatic cancers, may affect ecological processes that govern biotic interactions. We argue that oncogenic phenomena, despite their complexity, can have significant and sometimes predictable ecological consequences. Our aim is to provide a new perspective on the ecological and evolutionary significance of cancer in wildlife, and to stimulate research on this topic.

β2-Adrenoreceptor Agonist Inhibits Antigen Cross-Presentation by Dendritic Cells

Abstract: Despite widespread usage of β-adrenergic receptor (AR) agonists and antagonists in current clinical practice, our understanding of their interactions with the immune system is surprisingly sparse. Among the AR expressed by dendritic cells (DC), β2-AR can modify in vitro cytokine release upon stimulation. Because DC play a pivotal role in CD8(+) T cell immune responses, we examined the effects of β2-AR stimulation on MHC class I exogenous peptide presentation and cross-presentation capacities. We demonstrate that β2-AR agonist-exposed mature DC display a reduced ability to cross-present protein Ags while retaining their exogenous peptide presentation capability. This effect is mediated through the nonclassical inhibitory G (Gαi/0) protein. Moreover, inhibition of cross-presentation is neither due to reduced costimulatory molecule expression nor Ag uptake, but rather to impaired phagosomal Ag degradation. We observed a crosstalk between the TLR4 and β2-AR transduction pathways at the NF-κB level. In vivo, β2-AR agonist treatment of mice inhibits Ag protein cross-presentation to CD8(+) T cells but preserves their exogenous MHC class I peptide presentation capability. These findings may explain some side effects on the immune system associated with stress or β-agonist treatment and pave the way for the development of new immunomodulatory strategies.