This will benefit to put the transmission dynamics of DENV into perspective, so as to stop or postpone the potential indigenous outbreak in Beijing. Electronic supplementary material Below is the link to the electronic supplementary material. Supplementary material 1 (PDF 427?kb)(426K, pdf) Acknowledgements This study was supported by the National Natural Science Foundation of China (Grant Nos. at Capital Medical University or college. In the present study, a total of 961 healthy students, lived in Beijing, were recruited and their serum specimens were collected in 2019. Socio-demographics of individuals, including gender, birth 12 months and travel history, were recorded and analyzed anonymously (Supplementary Table?1). Of 961 enrolled subjects, 344 were male and 617 were female, with male to female ratio of 1 1:1.79. The age (years of birth) of subjects were grouped into the two groups, 21-year-old (1998) with 236 individuals (24.6%) and 20-year-old (1999) with 725 individuals (75.4%). First of all, we verified the seroprevalence of anti-DENV antibodies by ELISA (The details of the experiment were shown in Supplementary Materials and Methods). Overall, 1.5% (14/961) of serum samples were seropositive for anti-DENV IgG. Similarly, there were 1.2% (4/344) and 1.6% (10/617) of anti-DENV IgG seropositivity for male and female subjects, respectively, and they were not significantly different with each other ( em P /em ?=?0.570). In addition, there was no association between seroprevalence of anti-DENV IgG and years of birth ( em P /em ?=?0.784, Supplementary Table?1). Theoretically, individuals with anti-DENV IgG experienced experienced at least one DENV contamination since there is currently no dengue vaccine available in China. As expected, all 14 IgG seropositive individuals experienced ever traveled to southern China (SC, including Guangdong, Yunnan, Guangxi or Fujian) or Southeast Asia (SEA), implying a history of DENV exposure (data not shown). Then, we further detected serotype-specific neutralizing antibody (nAb) titers by PRNT50 (The details of the experiment were shown in Supplementary Materials and Methods). Of the 14 anti-DENV IgG seropositive subjects, 92.9% (13/14) had at least one detectable serotype-specific nAb. Anti-DENV1, -DENV2, -DENV3, and -DENV4 nAb seropositivity was found in 50.0% (7/14), 35.7% (5/14), 57.1% (8/14), and 7.1% (1/14) of them, respectively (Fig.?1A, Table?1). As a matter of fact, four closely-related DENV serotypes had been isolated from both large-scale and sporadic dengue outbreaks in China (Qiu em et al. /em 1993; Lai em et al. /em 2015), and the possibility of DENV1C4 prevalence in China shows no significant difference. Moreover, most nAb titers against any serotype of DENV were just 1:20, implying the previous contamination experienced likely occurred quite a while ago. Only two subjects (No. 3072 and No. 3107) had titers of 1 1:40 and 1:160 against DENV1, respectively (Table?1). Open in a separate windows Fig.?1 Identification for serotype specificity in anti-DENV nAb seropositive participants ( em n /em ?=?14). A Bar chart displayed the percentages of each serotype in anti-DENV nAb seropositivity, the serum samples were from participants with anti-DENV IgG seropositivity. Anti-DENV nAb seropositivity was defined as using a PRNT50 titer??1:10. B Pie chart represented summarized results of the number of positive serotypes in anti-DENV IgG positive subjects. Table?1 Seroprevalence of anti-DENV nAb among all anti-DENV IgG antibody positive participants ( Refametinib (RDEA-119, BAY 86-9766) em n /em ?=?14). thead th align=”left” rowspan=”3″ colspan=”1″ Participant no. /th th align=”left” rowspan=”3″ colspan=”1″ Age (12 months of birth) /th th align=”left” rowspan=”3″ colspan=”1″ Gender /th th align=”left” colspan=”4″ rowspan=”1″ Seroprevalence of anti-DENV nAb /th th align=”left” rowspan=”3″ colspan=”1″ Positive serotype of DENV /th th align=”left” colspan=”4″ rowspan=”1″ Titers of anti-DENV nAb /th th align=”left” rowspan=”1″ colspan=”1″ DENV1 /th th align=”left” rowspan=”1″ colspan=”1″ DENV2 /th th align=”left” rowspan=”1″ colspan=”1″ DENV3 /th th align=”left” rowspan=”1″ colspan=”1″ DENV4 /th /thead 305220 (1999)Female ?1:10 ?1:101:20 ?1:10DENV3307220 (1999)Female1:40 ?1:10 ?1:10 ?1:10DENV1309920 (1999)Male ?1:101:20 ?1:10 ?1:10DENV2310320 (1999)Female1:20 ?1:10 ?1:10 ?1:10DENV1310720 (1999)Female1:160 ?1:101:10 ?1:10DENV1, DENV3315020 (1999)Male ?1:101:101:20 ?1:10DENV2, DENV3346120 (1999)Female ?1:10 ?1:10 ?1:10 ?1:10None348220 (1999)Female1:101:20 ?1:10 ?1:10DENV1, DENV2350520 (1999)Female ?1:10 ?1:101:20 ?1:10DENV3359120 (1999)Male ?1:101:201:20 ?1:10DENV2, DENV3361621 (1998)Male ?1:101:201:20 ?1:10DENV2, DENV3363120 (1999)Female1:20 ?1:101:10 ?1:10DENV1, DENV3440420 (1999)Female1:201:10 ?1:101:10DENV1, DENV2, DENV4446821 (1998)Female1:20 ?1:10 ?1:10 ?1:10DENV1 Open in a separate window Additionally, 42.9% (6/14), 42.9% (6/14) and 7.1% (1/14) of serum samples were nAb positive for one, two or three serotypes, respectively (Fig.?1B). Half of the seropositive subjects were detected neutralized for at least two serotypes, suggesting that this detectable cross-neutralization may exist between serotypes, or they had probably experienced infections with multiple DENV serotypes. Interestingly, nAb was not detected in one anti-DENV IgG seropositive sample, suggesting a better specificity of PRNT50 Mouse monoclonal to CD37.COPO reacts with CD37 (a.k.a. gp52-40 ), a 40-52 kDa molecule, which is strongly expressed on B cells from the pre-B cell sTage, but not on plasma cells. It is also present at low levels on some T cells, monocytes and granulocytes. CD37 is a stable marker for malignancies derived from mature B cells, such as B-CLL, HCL and all types of B-NHL. CD37 is involved in signal transduction than ELISA. Taken together, the overall low seroprevalence displayed in our study presented an average poor force of contamination in Beijing, and seropositive individuals probably resulted from travel in endemic regions. Moreover, the low DENV seroprevalence among adults reveals that there are adequate preconditions for DENV reservations and potential indigenous transmission in Beijing. First, according to the data released from Beijing Center for Disease Control and Prevention, em Culex /em , the vector of Japanese encephalitis computer virus, is still a predominant vector species in Beijing, but in the mean time, the proportion of em A. albopictus /em , in Beijing has increased from 7% in 2013 to 14% in 2017, implying the increased risk of dengue transmission. Second, imported cases have been reported annually in Beijing since 2001 (Lai em et al. /em 2015), and epidemiological data show that the average probability of dengue Refametinib (RDEA-119, BAY 86-9766) importation from SEA into Beijing increased from 0.38 in 2005 to 0.77 in 2015 (Lai em et al. /em 2018). Third, asymptomatic dengue accounted for the most proportion of dengue, and the subclinical individuals can be the main source of contamination Refametinib (RDEA-119, BAY 86-9766) (Duong em et al. /em 2015; Ten Bosch em et.