1.Expression and characterization of anticoagulant activity of salivary protein alALP from Asian tiger mosquito Aedes albopictus
Li, X.P. ; Lin, D. ; Zhang, Y. ; Chen, S.Q. ; Bai, H.Q. ; Zhang, S.N. ; Liu, W.Q. ; Liang, S.H.
Tropical Biomedicine 2020;37(No.1):116-126
Several bioactive molecules isolated from the saliva of blood-sucking arthropods, such as mosquitoes, have been shown to exhibit potential anticoagulant function. We have previously identified a 30kDa allergen named Aegyptin-like protein (alALP), which is highly homologous to Aegyptin, from the salivary glands of female Aedes albopictus (Asian tiger mosquito). In this study, we identified the conserved functional domain of alALP by using bioinformatic tools, and expressed the His-tagged alALP recombinant protein in sf9 insect cells by generation and transfection of a baculoviral expression plasmid carrying the fulllength cDNA of alALP. We purified this recombinant protein and examined its function on the inhibition of blood coagulation. The results showed that the purified His-alALP prolonged the Activated Partial Thromboplastin Time (APTT), Prothrombin Time (PT) and Thrombin Time (TT) in vitro as well as the Bleeding Time (BT) in vivo, which suggest that alALP could be a novel anticoagulant.
2.Parasitological and molecular detection of human fascioliasis in a young man from Guizhou, China
Chen, M.X. ; Zhang, R.L. ; Xu, X.N. ; Yu, Q. ; Huang, D.N. ; Liu, W. ; Chen, S.H. ; Song, P. ; Lu, Y. ; Cai, Y.C. ; Ai, L. ; Chen, J.X.
Tropical Biomedicine 2020;37(No.1):50-57
A 24-year-old man born in Guizhou province was diagnosed with obstructive jaundice and bile duct stones in 2013. Four living trematodes were found during laparotomy and cholecystectomy. Based on the morphology and molecular genetics analysis of internal transcribed spacer and pcox1 genes of the flatworm specimens, the trematodes from the patient were confirmed to be Fasciola hepatica. This report provided the clinical and molecular diagnosis information on human fascioliasis, which is an emerging sanitary problem still ignored in China. Human fascioliasis constantly occurs due to climatic changes and frequency of human travel. Therefore, it deserves more attention from physicians working in both developing and developed countries.
3.Dendritic cell TLR4 induces Th1-type immune response against Cryptosporidium parvum infection
Xu, Q.M. ; Fang, F. ; Wu, S.H. ; Shi, Z.Q. ; Liu, Z. ; Zhao, Y.J. ; Zheng, H.W. ; Lu, G.X. ; Kong, H.R. ; Wang, G.J. ; Ai, L. ; Chen, M.X. ; Chen, J.X.
Tropical Biomedicine 2021;38(No.1):172-179
The objective of this study was to investigate the mechanism of Toll-like receptor (TLR4)-
mediated dendritic cell (DC) immune against Cryptosporidium parvum infection. C. parvum
sporozoites were labeled with 5,6-carboxyfluorescein diacetate succinimidyl ester. Murine
bone marrow-derived DCs were isolated, and divided into TLR4 antibody blocking (TAB;
infected with 2 × 105 labeled sporozoites and 0.5 μg TLR4 blocking antibody), TLR4 antibody
unblocking (TAU; infected with 2 × 105 labeled sporozoites), and blank control (BC; with 1.5
mL Roswell Park Memorial Institute 1640 medium) groups. The adhesion of Cryptosporidium
sporozoites to DCs and CD11c+ levels were examined by fluorescence microscopy and flow
cytometry. Male KM mice were orally injected with C. parvum. The proliferation of T lymphocytes
in spleen, expression of cytokines in peripheral blood, and TLR4 distribution features in
different organs were further determined by immunohistochemistry. A significantly higher
expression of CD11c+ and higher C. parvum sporozoite adhesion were found in the TAU group
compared with other groups. The expression of CD4+CD8-
/CD8+CD4- in the spleen were
obviously differences between the TAB and TAU groups. The expression of TLR4, interleukin
IL-4, IL-12, IL-18 and IFN-γ improved in the TAU group compared with TAB group. Higher
expression of TLR4 was detected in the lymph nodes of mice in the TAU group, with pathological
changes in the small intestine. Hence, TLR4 could mediate DCs to recognize C. parvum,
inducing Th1 immune reaction to control C. parvum infection.
4.microRNAs expression profiles in Schistosoma japonicum of different sex 14 and 28 days post-infection
Ai, L. ; Hu, W. ; Zhang, R.L. ; Huang, D.N. ; Chen, S.H. ; Xu, B. ; Li, H. ; Cai, Y.C. ; Lu, Y. ; Zhou, X.N. ; Chen, M.X. ; Chen, J.X.
Tropical Biomedicine 2020;37(No.4):947-962
Different miRNAs are involved in the life cycles of Schistosoma japonicum. The
aim of this study was to examine the expression profile of miRNAs in individual S. japonicum
of different sex before and after pairing (18 and 24 dpi). The majority of differential expressed
miRNAs were highly abundant at 14 dpi, except for sja-miR-125b and sja-miR-3505, in both
male and female. Moreover, it was estimated that sja-miR-125b and sja-miR-3505 might be
related to laying eggs. sja-miR-2a-5p and sja-miR-3484-5p were expressed at 14 dpi in males
and were significantly clustered in DNA topoisomerase III, Rap guanine nucleotide exchange
factor 1 and L-serine/L-threonine ammonia-lyase. Target genes of sja-miR-2d-5p, sja-miR-31-
5p and sja-miR-125a, which were expressed at 14 dpi in males but particularly females, were
clustered in kelch-like protein 12, fructose-bisphosphate aldolase, class I, and heat shock
protein 90 kDa beta. Predicted target genes of sja-miR-3483-3p (expressed at 28 dpi in
females but not in males) were clustered in 26S proteasome regulatory subunit N1, ATPdependent RNA helicase DDX17. Predicted target genes of sja-miR-219-5p, which were
differentially expressed at 28 dpi in females but particularly males, were clustered in DNA
excision repair protein ERCC-6, protein phosphatase 1D, and ATPase family AAA domaincontaining protein 3A/B. Moreover, at 28 dpi, eight miRNAs were significantly up-regulated in
females compared to males. The predicted target genes of these miRNAs were significantly
clustered in heat shock protein 90 kDa beta, 26S proteasome regulatory subunit N1, and
protein arginine N-methyltransferase 1. To sum up, differentially expressed miRNAs may
have an essential role and provide necessary information on clarifying this trematode’s growth,
development, maturation, and infection ability to mammalian hosts in its complex life cycle,
and may be helpful for developing new drug targets and vaccine candidates for schistosomiasis.