9 research outputs found
Homotopy Theoretic Models of Type Theory
We introduce the notion of a logical model category which is a Quillen model
category satisfying some additional conditions. Those conditions provide enough
expressive power that one can soundly interpret dependent products and sums in
it. On the other hand, those conditions are easy to check and provide a wide
class of models some of which are listed in the paper.Comment: Corrected version of the published articl
Smash products for secondary homotopy groups
We construct a smash product operation on secondary homotopy groups yielding
the structure of a lax symmetric monoidal functor. Applications on cup-one
products, Toda brackets and Whitehead products are considered. In particular we
prove a formula for the crossed effect of the cup-one product operation on
unstable homotopy groups of spheres which was claimed by
Barratt-Jones-Mahowald.Comment: We give a clearer description of the tensor product of symmetric
sequences of quadratic pair module
PPARÎł Controls Dectin-1 Expression Required for Host Antifungal Defense against Candida albicans
We recently showed that IL-13 or peroxisome proliferator activated receptor Îł (PPARÎł) ligands attenuate Candida albicans colonization of the gastrointestinal tract. Here, using a macrophage-specific Dectin-1 deficient mice model, we demonstrate that Dectin-1 is essential to control fungal gastrointestinal infection by PPARÎł ligands. We also show that the phagocytosis of yeast and the release of reactive oxygen intermediates in response to Candida albicans challenge are impaired in macrophages from Dectin-1 deficient mice treated with PPARÎł ligands or IL-13. Although the Mannose Receptor is not sufficient to trigger antifungal functions during the alternative activation of macrophages, our data establish the involvement of the Mannose Receptor in the initial recognition of non-opsonized Candida albicans by macrophages. We also demonstrate for the first time that the modulation of Dectin-1 expression by IL-13 involves the PPARÎł signaling pathway. These findings are consistent with a crucial role for PPARÎł in the alternative activation of macrophages by Th2 cytokines. Altogether these data suggest that PPARÎł ligands may be of therapeutic value in esophageal and gastrointestinal candidiasis in patients severely immunocompromised or with metabolic diseases in whom the prevalence of candidiasis is considerable