Role of Globotriaosylceramide in Physiology and Pathology.

At first glance, the biological function of globoside (Gb) clusters appears to be that of glycosphingolipid (GSL) receptors for bacterial toxins that mediate host-pathogen interaction. Indeed, certain bacterial toxin families have been evolutionarily arranged so that they can enter eukaryotic cells through GSL receptors. A closer look reveals this molecular arrangement allocated on a variety of eukaryotic cell membranes, with its role revolving around physiological regulation and pathological processes. What makes Gb such a ubiquitous functional arrangement? Perhaps its peculiarity is underpinned by the molecular structure itself, the nature of Gb-bound ligands, or the intracellular trafficking unleashed by those ligands. Moreover, Gb biological conspicuousness may not lie on intrinsic properties or on its enzymatic synthesis/degradation pathways. The present review traverses these biological aspects, focusing mainly on globotriaosylceramide (Gb3), a GSL molecule present in cell membranes of distinct cell types, and proposes a wrap-up discussion with a phylogenetic view and the physiological and pathological functional alternatives.

In vivo neutralization of bee venom lethality by IgY antibodies.

Bee venom is a complex mixture of molecules, among which melittin and phospholipase A2 (PLA2) are the toxic components involved in envenoming accidents with multiple honeybee stings. Traditionally, the treatment of envenomings has been based on the administration of specific antibodies to neutralize the deleterious effects of toxins. An alternative to mammalian polyclonal antibodies is the use of egg yolk immunoglobulins (IgY) due to their advantages regarding animal welfare and lower costs of production as compared to the conventional production methods. In this work, a novel composition containing specific IgY antibodies was developed. After four immunizations, IgY extracted from the egg yolks was able to recognize several components of the bee venom, including melittin and PLA2. The performance of IgY to neutralize the lethal activity was evaluated in a mouse model by using one median lethal dose (LD50) of the bee venom. The effective dose of the IgY extract was determined as 30.66 µg/mg. These results demonstrate the feasibility to produce IgY-based antivenoms to treat envenomings by multiple bee stings.