Project description:Osteoarthritis (OA) and rheumatoid arthritis (RA) are joint diseases that are associated with pain and lost quality of life. No disease modifying OA drugs are currently available. RA treatments are better established but are not always effective and can cause immune suppression. Here, an MMP13-selective siRNA conjugate (Albumin-binding siMMP13<(EG18L)2) was developed that, when delivered intravenously, docks onto endogenous albumin and promotes preferential accumulation in articular cartilage and synovia of post-traumatic OA (PTOA) and RA (K/BxN) joints. MMP13 expression was diminished upon intravenous delivery of MMP13 siRNA conjugates, consequently decreasing multiple histological and molecular markers of disease severity, while also reducing clinical manifestations such as swelling (RA) and joint pressure sensitivity (RA and OA). Importantly, MMP13 silencing provided more comprehensive OA treatment efficacy than standard of care (steroids) or experimental MMP inhibitors. These data demonstrate the utility of albumin ‘hitchhiking’ for drug delivery to arthritic joints, and establish the therapeutic utility of systemically delivered anti-MMP13 siRNA conjugates in OA and RA.
Project description:To development of our gene expression, we have employed whole rhesus monkey genome microarray expression profiling as a discovery platform to identify genes with the potential to induce immune response. The peripheral blood from rhesus macaques, who were immunized in groups of three with the capsular polysaccharide (CPS antigen), carrier protein tetanus toxoid (TT) or conjugate vaccine via intramuscular injection (i.m.) in the anterolateral thigh on days 0, 30 and 60 using the formulations, were obtained on days 0, 30, 60 and 90. PBMCs were collected for microarray assays. Dynamic expression variations of eight genes (KLRC1, LGALS13, LTB4DH, NUAK1, VNN2, GALNT3, LOC710050 and LOC716305) were maintained in Hib conjugate vaccine group throughout experiment comparing with the CPS antigen group and carrier protein TT group.
Project description:Carrier proteins are chemically linked to poorly immunogenic antigens to generate conjugate vaccines, which have significantly improved immunization strategies in recent decades. CRM197, a genetically detoxified diphtheria toxin (DT) mutant carrying the G52E mutation, is a widely used carrier protein as it retains lysine residues for antigen conjugation. In the past, CRM197 has been expressed in Corynebacterium diphtheriae, but low yields and high costs have prompted the exploration of alternative expression systems. Although high-yield expression and native refolding of CRM197 in E. coli are challenging due to its reducing cytoplasm, recent advances have enabled the production of soluble and well-folded recombinant CRM197 proteins, namely EcoCRM® and EcoCRM®(-Met). In this study, we use Hydrogen/Deuterium eXchange Mass Spectrometry (HDX-MS) to compare the structural dynamics of EcoCRM® and EcoCRM®(-Met) with DT wild-type. Our HDX-MS data show that the presence of the N-terminal methionine does not affect the structural dynamics of the two recombinant EcoCRM proteins. Furthermore, our results elucidate the molecular mechanism underlying the lack of toxicity of EcoCRM compared to DT wild-type: the G52E mutation in the CRM197 proteins exclusively alters the stability of the NAD-binding pocket and induces allosteric effects within the receptor-binding domain. Altogether, these insights support the substitution of CRM197 derived from Corynebacterium with the recombinant EcoCRM® and EcoCRM®(-Met) produced in E. coli, offering a cost-effective solution for use in conjugate vaccines.
Project description:Physiologically, albumin is produced by hepatocytes. It remains largely unknown how patients are capable of maintaining essential albumin levels even in the condition of liver failure. Here, we delineate a hierarchical regulatory network that controls albumin transcription under different pathophysiological conditions. The ALB core promoter possesses a TATA box and nucleosome-free area, which allows constitutive binding of RNA Pol II and thus initiation of transcription. In normal conditions, HNF4α and C/EBPα facilitate albumin transcription through binding to its promoter. In severely damaged livers, hepatocellular HNF4α and C/EBPα expression is often inhibited. The absence of HNF4 and C/EBPα increases hedgehog ligand biosynthesis. Hedgehog upregulates FOXA2 expression through transcription factor GLI2 binding to the FOXA2 promoter. Subsequently, FOXA2 maintains albumin expression in the hepatocytes lacking HNF4α and C/EBPα. In patients with massive hepatocyte loss, the expression of albumin is activated in liver progenitor cells. Albumin transcription in these cells is regulated by HNF4α or FOXA2. Taken together, HNF4α, C/EBPα and FOXA2 form a hierarchical regulatory network that ensures stable albumin expression even in pathophysiological conditions.