Protective efficacy evaluation of immunogenic protein AHA_3793 of Aeromonas hydrophila as vaccine candidate for largemouth bass Micropterus salmoides

Aeromonas hydrophila is a Gram-negative pathogen that can infect various fish,including largemouth bass(Micropterus salmoides),which have caused huge economic losses.In present study,largemouth bass anti-A.hydrophila antibodies were produced,then a highly immunogenic outer membrane proteins,AHA_3793,was identified by combined western blotting and mass spectrometry analysis.Moreover,AHA_3793 was expressed,and its immunogenicity was further verified by western blotting.Subsequently,the protective efficacy of AHA_3793 were evaluated in largemouth bass.The results showed that rAHA_3793 could produce a relative percentage survival(RPS)of 61.76% for largemouth bass against A.hydrophila challenge.ELISA analysis showed the specific serum antibodies of largemouth bass against rAHA_3793 and A.hydrophila in vaccinated group in weeks 4 and 5 after immunization were significantly higher than those in control group,which suggested that rAHA_3793 induced production of specific serum antibodies against rAHA_3793 and A.hydrophila.The qRT-PCR analysis showed that expressions of CD4-2 and MHC Ⅱα were also significantly up-regulated after immunization.These results collectively demonstrated that rAHA_3793 could induce a strong humoral immune response of largemouth bass,and then produce high immune protection ef fects against A.hydrophila infection.

浅析生猪养殖用地政策

文章介绍了近年来,国家出台的支持生猪生产发展的新政策及各地的经验和做法,分析了生猪养殖用地面临的新情况新问题,提出了一些合理化建议。

Characterization and comparison of two C-type lectins with novel key motifs from mud crab Scylla paramamosain

As an important pattern recognition receptor(PRR)in the innate immune system,C-type lectin plays an important role in the innate immune process of invertebrates.Two C-type lectins Sp CTL-C and Sp CTL-D were characterized from mud crab(Scylla paramamosain).The predicted Sp CTL-C and Sp CTL-D proteins both contain a single carbohydrate-recognition domain(CRD)with key motif Gln-Pro-Ala(QPA)and Met-Pro-Ala(MPA),respectively.Sp CTL-C and Sp CTL-D transcripts distributed in all examined tissues,and the expression level was the highest in hepatopancreas.As PRR,the purifi ed recombinant proteins r Sp CTL-C and r Sp CTL-D have high affi nity for three kinds of pathogen-associated molecular patterns(PAMPs):β-glucan,lipopolysaccharide,and peptidoglycan.Besides,r Sp CTL-D can bind to all nine microorganisms tested,while r Sp CTL-C can bind to seven microorganisms except for Staphylococcus aureus and Micrococcus luteus.Both r Sp CTL-C and r Sp CTL-D showed agglutination activity towards fungi Pichia pastoris and Saccharomyces cerevisiae.However,r Sp CTL-C and r Sp CTL-D exhibited diff erent antimicrobial activities:r Sp CTL-D has a certain inhibitory eff ect on the growth of Vibrio fl uvialis and M.luteus,while r Sp CTL-C has no obvious inhibitory activity.The results show that r Sp CTL-C and r Sp CTL-D had better phagocytosis-promoting eff ect on M.luteus than the negative control.Meanwhile,both r Sp CTL-C and r Sp CTL-D had certain encapsulation-promoting activity.Collectively,two C-type lectins with novel key motifs make an important impact as PRR in immune response towards pathogens.At the same time,they play diff erent functions in the innate immunity of mud crab S.paramamosain.

Electric-field-controlled highly regioselective thiocyanation of N-containing heterocycles

Achieving highly regioselective synthesis in organic chemistry is challenging due to the uncontrollable orientation between reacting partners.External electric fields(EEFs)can influence the reactivity and selectivity of the substrate by causing directional adsorption.However,scalable and efficient techniques for using EEFs as“smart catalysts”have been lacking,hindering their application.In this study,we present a novel method for modifying the regioselectivity of quinoxaline-2(1H)-ones by functionalizing their C7-position using the electric double layer(EDL)theory.This approach led to moderate to good yields of the corresponding C7-thiocyanation products.DFT calculations and control experiments demonstrated that EEFs could reverse the regioselectivity of quinoxaline-2(1H)-ones,allowing the C7-thiocyanation to proceed via a radical reaction mechanism.Additionally,the resulting 7-thiocyano-1-methylquinoxaline-2(1H)-ones exhibited promising AIE properties.Our work showcases a promising strategy for achieving highly regioselective functionalization by aligning the electric field with the desired reaction/bond axis.

On-demand assembly of polymeric nanoparticles for longer-blood-circulation and disassembly in tumor for boosting sonodynamic therapy

Sonodynamic therapy (SDT) is one of the promising strategies for tumor therapy, but its application is usually hindered by fast clearance in blood-circulation, abnormal tumor microenvironment, and inefficient generation of reactive oxygen species. To solve these problems, we proposed an on-demand assembly-disassembly strategy, where the assembly is favorable for longer-blood-circulation and then the disassembly in tumor is favorable for boosting SDT. Hematoporphyrin monomethyl ether (HMME) as the model of organic sonosensitizers were conjugated with hyaluronic acid (HA). Then HA-HMME was mixed with catalase (CAT) and assembled into polymeric nanoparticles (CAT@HA-HMME NPs) with size of ~80 nm. CAT@HA-HMME NPs exhibit good biocompatibility and a longer blood half-time (t1/2 = 4.17 h) which is obviously longer than that (~0.82 h) of HMME molecules. After HA receptor-mediated endocytosis of cancer cells, CAT@HA-HMME NPs can be cleaved by endogenous hyaluronidase, resulting in the on-demand disassembly in tumor to release HA-HMME molecules and CAT. The CAT catalyzes the endogenous H_(2)O_(2) into O_(2) to relieve the hypoxic microenvironment, and the released HA-HMME exhibits a higher ROS generation ability, greatly boosting SDT for the inhibition of tumor growth. Therefore, the on-demand assembly-disassembly strategy may provide some insight in the design and development of nanoagents for tumor therapy.