We sought to develop an IL-33 vaccine and evaluate its efficacy in a mouse model of asthma. The full-length molecules of putative mature IL-33 were inserted into the immunodominant epitope region of hepatitis B core antigen using gene recombination techniques. The expressed chimeric protein presented as virus-like particles (VLPs) under observation using an electron microscopy. To investigate immunization characteristics of the VLPs, mice were immunized by using different doses, adjuvants, and routes. The VLPs induced sustained and high titers of IL-33-specific IgG and IgA even without the use of a conventional adjuvant, and the lowered ratio of IgG1/IgG2a in vaccinated mice indicated a shift from Th2 to Th1-like responses. To assess the vaccine effects on blocking the signaling of IL-33/ST2 pathway, mice receiving 3 vaccinations subjected to intraperitoneal sensitization and intranasal challenge with ovalbumin (OVA). Control animals received carrier or PBS in place of the vaccine. Immunization with the VLPs significantly suppressed inflammatory cell number and IL-33 level in BALF. OVA -induced goblet cell hyperplasia and lung tissue inflammatory cell infiltration were significantly suppressed in vaccinated mice. Our data indicate that IL-33 molecule-based vaccine, which may block IL-33/ST2 signaling pathway on a persistent basis, holds potential for treatment of asthma and, by extension, other diseases where overexpressed IL-33 plays a pivotal role in pathogenesis.
Two versions of an optimized gene that encodes human papilloma virus type 16 major protein L1 were designed according to the codon usage frequency of Pichia pastoris. Y16 was highly expressed in both P. pastoris and Hansenula polymorpha. M16 expression was as efficient as that of Y16 in P. pastoris, but merely detectable in H. polymorpha even though transcription levels of M16 and Y16 were similar. H. polymorpha had a unique codon usage frequency that contains many more rare codons than Saccharomyces cerevisiae or P. pastoris. These findings indicate that even codon-optimized genes that are expressed well in S. cerevisiae and P. pastoris may be inefficiently expressed in H. polymorpha; thus rare codons must be avoided when universal optimized gene versions are designed to facilitate expression in a variety of yeast expression systems, especially H. polymorpha is involved.
Acinetobacter baumannii is considered the prototypical example of a multi- or pan- drug-resistant bacterium. It has been increasingly implicated as a major cause of nosocomial and community-associated infections. This study proposed to evaluate the efficacy of immunological approaches to prevent and treat A. baumannii infections.
A novel cathelicidin-like antimicrobial peptide was identified by mining genome of panda. This peptide (cathelicidin-AM) was synthesized. It showed potential antimicrobial activities against wide spectrum of microorganisms including Gram-negative and -positive bacteria, and fungi. It had similar antimicrobial abilities against both standard and clinically isolated drug-resistant strains. Cathelicidin-AM could rapidly exert its antibacterial activities. It just took less than 1h to kill all Staphylococcus sciuri at the concentration of 2, 4 or 10 times of minimal inhibitory concentration (MIC) while clindamycin took 6h. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis indicated that cathelicidin-AM killed bacteria by directly affecting bacterial cell wall and membrane. Phylogenetic analysis revealed that the panda cathelicidin had the nearest evolution relationship with dog cathelicidin. The current work provides a novel cathelicidin-like peptide with strong antimicrobial abilities.
Direct-acting fibrin(ogen)olytic agents such as plasmin have been proved to contain effective and safety thrombolytic potential. Unfortunately, plasmin is ineffective when administered by the intravenous route because it was neutralized by plasma antiplasmin. Direct-acting fibrin(ogen)olytic agents with resistance against antiplasmin will brighten the prospect of anti-thrombosis. As reported in Compendium of Materia Medica, the insect of Eupolyphaga sinensis Walker has been used as traditional anti-thrombosis medicine without bleeding risk for several hundreds years. Currently, we have identified a fibrin(ogen)olytic protein (Eupolytin1) containing both fibrin(ogen)olytic and plasminogen-activating (PA) activities from the beetle, E. sinensis.
The question of how amphibians can protect themselves from reactive oxygen species when exposed to the sun in an oxygen-rich atmosphere is important and interesting, not only from an evolutionary viewpoint, but also as a primer for researchers interested in mammalian skin biology, in which such peptide systems for antioxidant defense are not well studied. The identification of an antioxidant peptide named antioxidin-RL from frog (Odorrana livida) skin in this report supports the idea that a peptide antioxidant system may be a widespread antioxidant strategy among amphibian skins. Its ability to eliminate most of the 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical tested within 2 s, which is much faster than the commercial antioxidant factor butylated hydroxytoluene, suggests that it has a potentially large impact on redox homeostasis in amphibian skins. Cys10 is proven to be responsible for its rapid radical scavenging function and tyrosines take part in the binding of antioxidin-RL to radicals according to our nuclear magnetic resonance assay.
Much attention has been paid on amphibian peptides for their wide-ranging pharmacological properties, clinical potential, and gene-encoded origin. More than 300 antimicrobial peptides (AMPs) from amphibians have been studied. Peptidomics and genomics analysis combined with functional test including microorganism killing, histamine-releasing, and mast cell degranulation was used to investigate antimicrobial peptide diversity. Thirty-four novel AMPs from skin secretions of Rana nigrovittata were identified in current work, and they belong to 9 families, including 6 novel families. Other three families are classified into rugosin, gaegurin, and temporin family of amphibian AMP, respectively. These AMPs share highly conserved preproregions including signal peptides and spacer acidic peptides, while greatly diversified on mature peptides structures. In this work, peptidomics combined with genomics analysis was confirmed to be an effective way to identify amphibian AMPs, especially novel families. Some AMPs reported here will provide leading molecules for designing novel antimicrobial agents.
It is generally agreed that reactive oxygen species (ROS) contribute to skin aging, skin disorders, and skin diseases. Skin possesses an extremely efficient antioxidant system. This antioxidant activity is conferred by two systems: antioxidant enzymes and small molecules that can scavenge ROS by donating electrons. No gene-encoded secreted ROS scavengers have been reported. Amphibian skin is a multifunctional organ acting in defense, respiration, and water regulation, although it seems susceptible. Amphibian skins are easily harmed by biological or non-biological attacks such as microorganism infection or radiation injury. Among vertebrates, skins of amphibian are exposed to more dangers of radiation injury than others. Radiation toxicity occurs by directly attacking the genetic material and/or by generating ROS. In addition, amphibian skin respiration and inflammatory response also induce ROS generation. It is rational to hypothesize that amphibian skins should have potent free radical scavenging and radioprotective ability for their survival. Rana pleuraden is distributed in Southwest of China; it lives in the subtropical plateau (altitude around 2300 m) where there is strong ultraviolet radiation and long duration of sunshine. By peptidomics and genomics approaches, a large amount of antioxidant peptides belonging to 11 different groups with variable structures were isolated from the skin secretions of R. pleuraden. Their free radical scavenging and anti-inflammatory abilities were studied. All of these peptide share highly homologous preproregions, although mature antioxidant peptides have very divergent primary structures, suggesting the possibility of a common ancestor. Some peptides were also found to have multifunctional properties, such as combined antioxidant, anti-inflammatory, and antimicrobial activities. According to our knowledge, no gene-encoded specific antioxidant peptides have been reported except metallothionein. Our work possibly reveals a new skin antioxidant system. The current work also provides a large amount of peptide candidates with medical-pharmaceutical significance.
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