Plant-Derived Chimeric Virus Particles for the Diagnosis of Primary Sjögren Syndrome

Plants are ideal for the production of protein-based nanomaterials because they synthesize and assemble complex multimeric proteins that cannot be expressed efficiently using other platforms. Plant viruses can be thought of as self-replicating proteinaceous nanomaterials generally stable and easily produced in high titers. We used Potato virus X (PVX) chimeric virus particles (CVPs) and Cowpea mosaic virus (CPMV) empty virus-like particles (eVLPs) to display a linear peptide (lipo) derived from human lipocalin , which is immunodominant in Sjögren’s syndrome (SjS) and is thus recognized by autoantibodies in SjS patient serum. These virus-derived nanoparticles (VNPs) were thus used to develop a diagnostic assay for SjS based on a direct enzyme linked immunosorbent assay (ELISA) format. We found that PVX-lipo formulations were more sensitive than the chemically synthesized immunodominant peptide and equally specific when used to distinguish between healthy individuals and SjS patients. Our novel assay therefore allows the diagnosis of SjS using a simple, low-invasive serum test, contrasting with the invasive labial biopsy required for current tests. Our results demonstrate that nanomaterials based on plant viruses can be used as diagnostic reagents for SjS, and could also be developed for the diagnosis of other diseases

Immunolocalisation of P2Y receptors in the rat eye

Nucleotides present an important role in ocular physiology which has been demonstrated by recent works that indicate their involvement in many ocular processes. P2Y are important among P2 receptors since they can control tear production, corneal wound healing, aqueous humour dynamics and retinal physiology. Commercial antibodies have allowed us to investigate the distribution of P2Y receptors in the cornea, anterior and posterior chamber of the eye and retina. The P2Y1 receptor was present mainly in cornea, ciliary processes, and trabecular meshwork. The P2Y2 receptors were present in cornea, ciliary processes and retinal pigmented epithelium. P2Y4 was present in cornea, ciliary processes, photoreceptors, outer plexiform layer and ganglion cell layer. The P2Y6 presented almost an identical distribution as the P2Y4 receptor. The P2Y11 was also detectable in the retinal pigmented epithelium. The detailed distribution of the receptors clearly supports the recent findings indicating the relevant role of nucleotides in the ocular function

Bioactive titaminates from molecular layer deposition

Organic–inorganic hybrid materials are an emerging class of materials suitable for deposition by the molecular layer deposition (MLD) technique. Their toolbox is now expanded to include linkers of amino acids, which when combined with titanium form materials that can be termed titaminates, based on the amine and carboxylates present in the amino acids being used as linkers. This is a class of compounds with high potential as bioactive materials, containing essential amino acids and biocompatible titanium. The films have been prepared by combining titanium tetra-isopropoxide (TTIP) with glycine and L-aspartic acid. L-Arginine has also been used, however, without success. Hybrid films of TTIP and succinic acid were also investigated as a comparison to L-aspartic acid due to their structural similarities. All systems show self-limiting growth with a reduction in the growth rate with increasing temperature. The as-deposited films are amorphous, have low surface roughness, exhibit a hydrophilic nature as measured by a goniometer, and bear indications of some porosity towards water. Films based on glycine and L-aspartic acid have been used as substrates for growth of epithelial cells (rat goblet cells) where their proliferation has been monitored. The cell proliferation was significantly increased on these substrates compared to uncoated coverslips

Interaction of IFN-γ with Cholinergic Agonists to Modulate Rat and Human Goblet Cell Function

Goblet cells populate wet-surfaced mucosa including the conjunctiva of the eye, intestine, and nose, among others. These cells function as part of the innate immune system by secreting high molecular weight mucins that interact with environmental constituents including pathogens, allergens, and particulate pollutants. Herein we determined whether IFN-γ, a Th1 cytokine increased in dry eye, alters goblet cell function. Goblet cells from rat and human conjunctiva were cultured. Changes in intracellular [Ca2+] ([Ca2+]i), high molecular weight glycoconjugate secretion, and proliferation were measured after stimulation with IFN-γ with or without the cholinergic agonist carbachol. IFN-γ itself increased [Ca2+]i in rat and human goblet cells and prevented the increase in [Ca2+]i caused by carbachol. Carbachol prevented IFN-γ-mediated increase in [Ca2+]i. This cross-talk between IFN-γ and muscarinic receptors may be partially due to use of the same Ca2+i reservoirs, but also from interaction of signaling pathways proximal to the increase in [Ca2+]i. IFN-γ blocked carbachol-induced high molecular weight glycoconjugate secretion and reduced goblet cell proliferation. We conclude that increased levels of IFN-γ in dry eye disease could explain the lack of goblet cells and mucin deficiency typically found in this pathology. IFN-γ could also function similarly in respiratory and gastrointestinal tracts