Expression of hypoallergenic Der f 2 derivatives with altered intramolecular disulphide bonds induces the formation of novel ER-derived protein bodies in transgenic rice seeds

House dust mites (HDM) are the most common source of indoor allergens and are associated with allergic diseases worldwide. To benefit allergic patients, safer and non-invasive mucosal routes of oral administration are considered to be the best alternative to conventional allergen-specific immunotherapy. In this study, transgenic rice was developed expressing derivatives of the major HDM allergen Der f 2 with reduced Der f 2-specific IgE reactivity by disrupting intramolecular disulphide bonds in Der f 2. These derivatives were produced specifically as secretory proteins in the endosperm tissue of seeds under the control of the endosperm-specific glutelin GluB-1 promoter. Notably, modified Der f 2 derivatives aggregated in the endoplasmic reticulum (ER) lumen and were deposited in a unique protein body (PB)-like structure tentatively called the Der f 2 body. Der f 2 bodies were characterized by their intracellular localization and physico-chemical properties, and were distinct from ER-derived PBs (PB-Is) and protein storage vacuoles (PB-IIs). Unlike ER-derived organelles such as PB-Is, Der f 2 bodies were rapidly digested in simulated gastric fluid in a manner similar to that of PB-IIs. Oral administration in mice of transgenic rice seeds containing Der f 2 derivatives encapsulated in Der f 2 bodies suppressed Der f 2-specific IgE and IgG production compared with that in mice fed non-transgenic rice seeds, and the effect was dependent on the type of Der f 2 derivative expressed. These results suggest that engineered hypoallergenic Der f 2 derivatives expressed in the rice seed endosperm could serve as a basis for the development of viable strategies for the oral delivery of vaccines against HDM allergy.

The cell biology of TRIM5α

The tripartite motif (TRIM)-containing proteins are involved in many cellular functions such as cell signaling, apoptosis, cell differentiation, and immune modulation. TRIM5 proteins, including TRIM5α and TRIM-Cyp, are known to possess antiretroviral activity against many different retroviruses. Besides being retroviral restriction factors, TRIM5 proteins participate in other cellular functions that have recently emerged in the study of TRIM5α. In this review, we discuss properties of TRIM5α such as cytoplasmic body formation, protein turnover, and trafficking. Also, we discuss recent insights into innate immune modulation mediated by TRIM5α, highlighting the various functions TRIM5α has in cellular processes.

Autoantibodies to GW bodies and other autoantigens in primary biliary cirrhosis

Autoantibodies to intracellular targets in mitochondria and nuclei are serological hallmarks of primary biliary cirrhosis (PBC). One of the most recently identified cellular targets of PBC autoantibodies is a novel cytoplasmic structure referred to as GW bodies [GWB, G (glycine) W (tryptophan)-containing bodies (GWB)]. GWB are indentified as discrete cytoplasmic domains that are involved in mRNA processing via the RNA interference (RNAi) pathway. Key components of GWB include the proteins GW182, Ago2, RNA-associated protein 55 (RAP55) and Ge-1/Hedls. The primary objective was to study the frequency and clinical association of antibodies directed to GWB components, in 109 PBC patients. Autoantibodies to mitochondrial antigen-pyruvate dehydrogenase complex (M2), branched-chain 2-oxo-acid dehydrogenase complex and 2-oxo glutarate dehydrogenase complex (3E-BPO), gp210, sp100, promyelocytic leukaemia cell antigen (PML) and liver kidney microsomal-1 antigen (LKM-1) were detected by a line immunoassay and antibodies to GWB (GW182, RAP55, Ge-1, GW2, GW3) and glutamate receptor interacting protein (GRIP)-associated protein-1 (GRASP-1), by an addressable laser bead immunoassay (ALBIA). The most common GWB autoantigen targets were: RAP55-28%, GW182-12%, GW2-2% and antibodies to GRASP-1-17%. By comparison, the frequency of reactivity to established PBC autoantigens was: gp210, 27%; sp100, 27% and PML, 17%. None of the autoantibodies were associated with differences in Mayo risk score or liver decompensation. This study is the first study to show that antibodies to RAP55, GW182 and GRASP-1 are the most common GWB targets in PBC.

Dendritic Cell Aggresome-Like-Induced Structure Formation and Delayed Antigen Presentation Coincide in Influenza Virus-Infected Dendritic Cells

Influenza virus infection induces maturation of murine dendritic cells (DCs), which is most important for the initiation of an immune response. However, in contrast to EL-4 and MC57 cells, DCs present viral CTL epitopes with a delay of up to 10 h. This delay in Ag presentation coincides with the up-regulation of MHC class I molecules as well as costimulatory molecules on the cell surface and the accumulation of newly synthesized ubiquitinated proteins in large cytosolic structures, called DC aggresome-like-induced structures (DALIS). These structures were observed previously after LPS-induced maturation of DCs, and it was speculated that they play a role in the regulation of MHC class I Ag presentation. Our findings provide the first evidence for a connection between DC maturation, MHC class I-restricted Ag presentation, and DALIS formation, which is further supported by the observation that DALIS contain ubiquitinated influenza nucleoprotein.