Structure and IgE Cross-Reactivity among Cashew, Pistachio, Walnut, and Peanut Vicilin-Buried Peptides.

Peanut and tree-nut allergies are frequently comorbid for reasons not completely understood. Vicilin-buried peptides (VBPs) are an emerging family of food allergens whose conserved structural fold could mediate peanut/tree-nut co-allergy. Peptide microarrays were used to identify immunoglobulin E (IgE) epitopes from the N-terminus of the vicilin allergens Ara h 1, Ana o 1, Jug r 2, and Pis v 3 using serum from three patient diagnosis groups: monoallergic to either peanuts or cashew/pistachio, or dual allergic.

Host Sex Modulates the Energetics of Pathogen Proliferation and Its Dependence on Environmental Resources.

AbstractSex differences in immunity are predicted to underlie much of the frequently observed sex differences in the prevalence or severity of infection. We propose the additional hypothesis that differences in the ability of males and females to acquire and use resources will also affect how readily a pathogen can convert host energy into transmission stages, thereby contributing to sex differences in infection dynamics. To test this we manipulated the resource environment of male and female by altering the availability of food and then exposed hosts to a bacterial pathogen.

Structure, Immunogenicity, and IgE Cross-Reactivity among Walnut and Peanut Vicilin-Buried Peptides.

Vicilin-buried peptides (VBPs) from edible plants are derived from the N-terminal leader sequences (LSs) of seed storage proteins. VBPs are defined by a common α-hairpin fold mediated by conserved CxxxCxCxxxC motifs. Here, peanut and walnut VBPs were characterized as potential mediators of both peanut/walnut allergenicity and cross-reactivity despite their low (∼17%) sequence identity.

Epitopes with similar physicochemical properties contribute to cross reactivity between peanut and tree nuts.

Many individuals with peanut (PN) allergy have severe reactions to tree nuts (TN) such as walnuts or cashews. Although allergenic proteins in TN and PN have overall low identity, they share discrete sequences similar in physicochemical properties (PCP) to known IgE epitopes. Here, PCP-consensus peptides (cp, 13 aa and 31 aa) were identified from an alignment of epitope rich regions of walnut vicilin, Jug r 2, leader sequence (J2LS) and cross-reactive epitopes in the 2S albumins of peanut and synthesized.

Host sexual dimorphism affects the outcome of within-host pathogen competition.

Natural infections often consist of multiple pathogens of the same or different species. When coinfections occur, pathogens compete for access to host resources and fitness is determined by how well a pathogen can reproduce compared to its competitors. Yet not all hosts provide the same resource pool.

Erratum: The impact of host sex on the outcome of co-infection.

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.

The impact of host sex on the outcome of co-infection.

Males and females vary in many characteristics that typically underlie how well a host is able to fight infection, such as body-size, immune capacity, or energy availability. Although well studied in the context of sexual signalling, there is now growing recognition that these differences can influence aspects of pathogen evolution as well. Here we consider how co-infection between multiple pathogen strains is shaped by male-female differences.

The evolution of sexual dimorphism and its potential impact on host-pathogen coevolution.

Sex and infection are intimately linked. Many diseases are spread by sexual contact, males are thought to evolve exaggerated sexual signals to demonstrate their immune robustness, and pathogens have been shown to direct the evolution of recombination. In all of these examples, infection is influencing the evolution of male and female fitness, but less is known about how sex differences influence pathogen fitness.