Abstract： Objective　To elucidate the antigenic antibody reaction of recombinant expression of non-structural protein 1 (NS1) of Japanese encephalitis (JE) virus with various mosquito-borne flaviviruses, including JE virus, and the antigenic antibody reaction of serum samples of patients infected with JE virus in acute stage. Methods　In this study, Escherichia coli prokaryotic expression vector (pET) system was used to recombinant express Japanese encephalitis virus NS1 gene. Western Blot assay was performed to detect the antibody responses of the recombinantly expressed protein against a variety of mosquito-transmitted flaviviruses, including JE virus, as well as antigen-antibody reactions of serum from patients with acute JE virus infection. Results　The NS1 gene expression product of JE virus (P3 strain) was in the form of an inclusion body, and the denatured and renatured expression product was displayed as a single band in the denatured gel (polyacrylamide gel electrophoresis, PAGE), with a molecular weight of about 45 000. The results of further antigen-antibody analysis showed that the antigen/antibody hybridization reaction of the expression product with polyclonal or monoclonal antibody of JE virus (mosquito isolates, encephalitis isolates) and serum samples of patients with acute JE virus infection could be completely consistent. The recombinant product showed negative antigen/antibody hybridization reactions with mosquito-transmitted flaviviruses, such as dengue virus and yellow fever virus polyclonal antibodies, but positive reactions with polyclonal antibodies to West Nile virus and Murray Valley encephalitis virus. Conclusions　In this study, the recombinant expression of the NS1 protein of JE virus was successfully obtained, and the antigen/antibody reaction between the recombinant protein and samples of patients infected with mosquito-borne flavivirus and JE virus was analyzed. The study results provide important basic data for elucidating the antigen-antibody reaction between the NS1 protein of JE virus and mosquito-borne flavivirus. The recombinant expression protein obtained in this study provides an important material basis for further research on the function of JE virus NS1 protein.

Objective To investigate the effect and mechanism of suberoylanilide hydroxamic acid (SAHA) on the fear extinction in mice with chronic social defeat stress (SD). Methods Fifty-six male C57BL/6J mice aged 7-8 weeks were randomly divided into control group,social defeat group,control-SAHA group and social defeat-SAHA group to investigate the effect of SAHA and social defeat group,social defeat-AAV BDNF group and social defeat-AAV blank group to investigate the effect of BDNF. Fear extinction in mice was evaluated by fear conditioning test (FC). The levels of BDNF and HDAC2 in mice hippocampus were detected by Western blot (WB). The expression of BDNF-overexpressing virus in hippocampus of mice was detected by immunofluorescence assay. Results (1) Compared with control group,fear extinction in the social defeat group was significantly decreased (P<0. 05). Compared with control group, the level of HDAC2(0. 50±0. 02) in the social defeat group was significantly increased (P<0. 001),while the level of BDNF(0. 16 ± 0. 03) was significantly decreased (P<0. 001) in the social defeat group. ( 2) After using SAHA,fear extinction of mice significantly improved (P<0. 05). Compared with control group,the level of HDAC2 (0. 26±0. 02) in the control-SAHA group was significantly decreased(P<0. 001),and the level of BDNF (0. 40±0. 03) was significantly increased (P<0. 001). Compared with social defeat group,the level of HDAC2 (0. 39±0. 03) in the social defeat-SAHA group was significantly decreased (P<0. 001),and the lev-el of BDNF (0. 28±0. 01) was significantly increased (P<0. 001). (3)After injection BDNF-overexpressing virus,fear extinction was significantly improved(P<0. 05). Conclusion SAHA can enhance fear extinction in mice with chronic social defeat stress and its mechanism may be related to the up-regulation of BDNF ex-pression in hippocampus by inhibiting HDAC2 in hippocampal.

Objective: To understand the situation of ticks carrying pathogens in border areas of Heilongjiang province. Methods: From 2009 to 2018, tick specimens were collected in Yichun, Daxing′anling area and Jiamusi in Heilongjiang province. A total of 2 530 ticks were studied, including 800 Ixodes persulcatus and 1 730 Dermacentor silvarum. Tick-borne encephalitis virus (TBEV), severe fever with thrombocytopenia syndrome virus (SFTSV), omsk hemorrhagic fever virus (OHFV), langat virus (LGTV), powassan virus (POWV) were detected by real-time RT-PCR. Spotted fever group rickettsia (SFGR) and Borrelia burgdorferi sensulato (B.b.s.l) were detected by PCR in ticks collected from Jiamusi area. Results: All tick speciments collected were negative for TBEV, SFTSV, OHFV, LGTV and POWV. Tick specimens from Jiamusi carried SFGR and B. b.s.l.with positive rates of 59.5% and 8.9%. Conclusions The ticks in border areas of Heilongjiang province carry spotted fever group rickettsia and Borrelia burgdorferi, and the carrying rate of spotted fever group rickettsia is high. The monitoring and control of ticks and tick-borne diseases should be strengthened.

Objective: To analyze the epidemiological characteristics and distribution characteristics of tick-borne encephalitis in China in 2014, and to provide scientific basis for formulating specific prevention and control measures. Methods: The epidemic data were obtained from the "infectious disease report information management system" , using Excel 2016, GIS and other software to summarize and analyze the cases of tick borne encephalitis (TBE) reported, using the number of cases, incidence, composition ratio and other indicators to analyze and describe the TBE epidemiological characteristics in China in 2014. Results: In 2014, a total of 322 cases of TBE were reported in 9 provinces in China, with an annual incidence of 0.024/100, 000 and 1 death of patient. The provinces with high number of cases were Jilin province, Inner mongolia autonomous region and Heilongjiang province, and the number of cases in the other six provinces is no more than two. TBE was distributed in spring and summer, and it is concentrated in May to July. The age of the affected population was mostly concentrated in 40-49 years old, the male-female ratio was 1.6∶1 (198/124), and the patients were dominantly farmers, household and unemployed workers, and forestry workers, they accounted for 49.40% (159/322), 26.40% (85/322) and 18.60% (60/322) of the national TBE cases respectively. The three hospitals that reported the most TBE cases in 2014 were Inner mongolia forestry general hospital, Jiangyuan People′s hospital of Baishan city, Jilin province and Mudanjiang forestry central hospital of Heilongjiang province. The number of reported cases in these three hospitals accounted for 68.6% of the whole country. The laboratory diagnosis rate of Inner mongolia forestry general hospital was the highest (91.9%). Conclusions In 2014, the incidence of TBE in China has continued to rise compared with the previous two years. The geographical focus is mainly on the forest areas of Daxing′anling, Xiaoxing′anling and Changbai Mountain.