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ABSTRACT: While the tree shrew (Tupaia belangeri chinensis) is an excellent animal model for studying the mechanisms of human diseases, but few studies examine interleukin-2 (IL-2), an important immune factor in disease model evaluation. In this study, a 465 bp of the full-length IL-2 cDNA encoding sequence was cloned from the RNA of tree shrew spleen lymphocytes, which were then cultivated and stimulated with ConA (concanavalin). Clustal W 2.0 was used to compare and analyze the sequence and molecular characteristics, and establish the similarity of the overall structure of IL-2 between tree shrews and other mammals. The homology of the IL-2 nucleotide sequence between tree shrews and humans was 93%, and the amino acid homology was 80%. The phylogenetic tree results, derived through the Neighbour-Joining method using MEGA5.0, indicated a close genetic relationship between tree shrews, Homo sapiens, and Macaca mulatta. The three-dimensional structure analysis showed that the surface charges in most regions of tree shrew IL-2 were similar to between tree shrews and humans; however, the N-glycosylation sites and local structures were different, which may affect antibody binding. These results provide a fundamental basis for the future study of IL-2 monoclonal antibody in tree shrews, thereby improving their utility as a model.
Zoological Research 04/2013; 34(2):121-6.
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ABSTRACT: Tupaia belangeri are small mammals with a squirrel-like appearance; they were formerly classified under the primates order despite the lack of derived features characteristic of primates. Given that T. belangeri are easy to raise, cheap to maintain, and have a small body size, a high reproductive rate, and close affinity to primates, these animals would be used as an alternative to primates in biomedical research. Three-month old T. belangeri chineses were infected with enterovirus 71 (EV71) via three different routes, namely, oral administration, nasal dripping, and tail intravenous injection, to study the infection in infant T. belangeri and find a feasible scheme to make them an ideal animal model of EV71 in place of primates. Daily activities were regularly observed, body temperatures were measured, and blood tests were conducted. Blood and fecal samples were regularly collected. The infection was examined via the neutralizing antibody test, reverse transcription polymerase chain reaction (RT-PCR), Real-Time PCR, and pathological analysis. The temperature, as well as the white blood cell count and the number of lymphocytes, increased four days after infection. Virus loads were determined in all three groups, and the peak appeared on, before, or after the tenth day, respectively. Thus, oral administration proved to be the best route. The highest serum antibody titer obtained was 1:16. Acute paralysis with urinary retention manifested after about two weeks, and pathological changes were observed in the brain, heart, lung, spleen, kidney, and other tissues. In conclusion, T. belangeri chineses can infected with EV71 via oral administration, nasal dripping, and tail intravenous injection. Therefore, T. belangeri are potential EV71 animal models for further studies on the mechanism of pathogenesis or vaccine evaluation.
Zoological Research 02/2012; 33(1):7-13.
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ABSTRACT: Virological testing and monitoring is a fundamental part of quality control of experimental animals. However, there are few papers regarding the spectrum and status of natural infection in wild tree shrews with human and animal pathogenic viruses. Using enzyme-linked immunosorbent adsorption assay (ELISA), we tested sixty wild tree shrews captured from Qinglong, an outskirt region of Kunming, Yunnan Province, China for eleven viruses, including herpes simplex virus, coxsackie virus, influenza virus, HAV, HBV, HCV, HDV, dengue virus, hemorrhagic fever virus and measles virus. Our results showed that, in the serum samples, 22/60 (36.7%) and 1/60 (1.67%) were antibody positive for herpes simplex virus and coxsackie virus, respectively, and 4/60 (6.7%) were antigen positive for rotavirus in the feces. The remaining species of viruses were negative in these tree shrews. Based on these results, we propose that herpes simplex virus, coxsackie virus and cotavirus should be listed as top priority for routine virological monitoring of tree shrews.
Zoological Research 02/2011; 32(1):66-9.
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ABSTRACT: Hepatitis C virus is a prevalent and globally distributed human pathogen that seriously harmful to public health. However, the development of therapy and vaccine was impeded by the lack of suit small animal models. Herein, we introduce the characters of HCV replication. Taken the HCV cellular receptors as the viewpoint, the potentiality of tupaia as hepatitis C animal model is discussed at the molecular level by comparing of present animal model.
Zoological Research 02/2011; 32(1):97-103.
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ABSTRACT: The use of tree shrews (Tupaia belangeri) in human disease studies demands essential research tools, in particular cellular markers and their monoclonal antibodies for immunological studies. Here we cloned the full-length cDNAs encoding CD3E from total RNA of the spleen, liver and peripheral blood of tree shrews and analyzed their structural characteristics in comparison with other mammals by Discovery Studio software. The results showed that the open reading frame sequence of tree shrew CD3E was 582 bp, encoding 194 amino acids. The overall structure of tree shrew CD3E protein was similar to its counterparts of other mammals, intracellular and transmembrane domain highly conserved. However, detailed analysis revealed two potential glycosylation sites and different surface charges in the extracellular domain. Availability of the entire open-reading-frame and related sequence information would therefore facilitate the preparation of monoclonal antibodies against tree shrew CD3 and further studies for its function.
Zoological Research 10/2010; 31(5):483-9.
