ABSTRACT
The pathogenesis of cerebral malaria is biologically complex and involves multi-factorial mechanisms such as microvascular congestion, immunopathology by the pro-inflammatory cytokine and endothelial dysfunction. Recent data have suggested that a pleiotropic T-cell immunomodulatory protein (TIP) could effectively mediate inflammatory cytokines of mammalian immune response against acute graft-versus-host disease in animal models. In this study, we identified a conserved homologue of TIP in Plasmodium berghei (PbTIP) as a membrane protein in Plasmodium asexual stage. Compared with PBS control group, the pathology of experimental cerebral malaria (ECM) in rPbTIP intravenous injection (i.v.) group was alleviated by the downregulation of pro-inflammatory responses, and rPbTIP i.v. group elicited an expansion of regulatory T-cell response. Therefore, rPbTIP i.v. group displayed less severe brain pathology and feverish mice in rPbTIP i.v. group died from ECM. This study suggested that PbTIP may be a novel promising target to alleviate the severity of ECM.
Subject(s)
Animals , Mice , Brain , Cytokines , Down-Regulation , Estrogens, Conjugated (USP) , Graft vs Host Disease , Injections, Intravenous , Malaria, Cerebral , Membrane Proteins , Models, Animal , Pathology , Plasmodium berghei , Plasmodium , Staphylococcal Protein A , T-LymphocytesABSTRACT
Objective To construct 2 recombinant plasmids carrying cassette chromosome recombinase C(ccrC)and ccrAB respectively and introduce the plasmids into methicillin-resistant Staphlococcus aureus(MRSA)strain 81/0432,and to observe the precise excision of Staphylococcal cassette chromosome mec(SCCmec)island from bacterial chromosome.Methods ccrC and ccrAB genes were amplified with chromosomal DNAs isolated from MRSA strains 81/0342 and N31S as PCR templates.We constructed recombinant plasmids pSR5C and pSR2AB by cloning ccrC and ccrAB genes into temperature-sensitive plasmid pYI3,after introducing them into MRSA strains 81/0432 and N315 by electroporation.PCR was performed to identify SCCmec excision from the bacterial chromosome.The transformants were serial passaged for 10 days,and then the drug resistance of these rransformants was detected by replica experiment.Results The fragment length of ccrC gene was 1.9 kb,smaller than the fragment length of ccrAB from N315.The recombinant plasmids of pSR5C and pSR2AB were successfully constructed.After these 2 recombinant plasmids were introduced into MRSA strain 81/0342,type-V SCCmec island was excised from the chromosome and formed a closed circular structure in the bacteria.However,type-Ⅱ SCCmec island could be excised only in N31S strain after the expression of pSR2AB.Replica experiment verified that transformed strains of 0342(pSR2AB),0342(pSR5C),and N315 (pSR2AB)were mostly susceptible to ceftizoxim or tobramycin after the excision of SCCmec island.Conclusion cciC could serve as a recombinase as ccrAB,which could mediate precise excision of SCCmec island from the chromosome of type-V MRSA strain.This study shows that type-V SCCmec island is widely disseminated between Staphylococcus aweus strains in community setting.
ABSTRACT
To study the kinetics in vivo of a Hantaan virus DNA vaccine, we constructed a fusion DNA vaccine,pEGFP/S, by cloning the S segment of Hantavirus into the vector, pEGFP-C1, which encodes Green fluorescent protein EGFP. In this report, we provide evidence that pEGFP/S was distributed and persistently expressed for more than 60 days in several organs after inoculation. Our findings suggest that the persistent immune responses induced by a Hantaan virus DNA vaccine are likely due to the plasmid pEGFP/S deposited in vivo, which acts as a booster immunization.
ABSTRACT
The present report is concerned with the surface structure of the metacercaria of Pa-ragonimus iloktsuenensis as visualized with the scanning electron microscopy. The meta-cercariae were obtained from the liver of tne Sesarma dehaani collected in Yingkou county, Liaoning Province.The tegumental spines of the metacercaria are single-pointed and densely distributed over the entire body and are slightly different in size and shape in different parts of the body. On the forebody of the ventral surface, a vertical ridgeline can be seen in the middle of the spines.In addition to the short spines, there are two circles of non-ciliated papillae on both lips of the oral and the ventral suckers. Around the oral sucker, there are 12 papillae on the outer circle and 6 on the inner circle; around the ventral sucker, there are 6 papillae on both the outer and inner circles. No sensory papillae were found around the ventral sucker. On each side of the anterior part of the ventral side, 8 to 10 pairs of papillae are arranged in two rows.