ABSTRACT
@#ObjectiveTo establish models of Dengue virus type Ⅲ（DENV-3,DV-3）infection and antibody dependent enhancement(ADE)infection at the acute monocytic leukemia cells(THP-1),investigate the differential expression of long non-coding RNAs(LncRNAs),map the competitive endogenous RNA(CeRNA)regulatory network and predict the translation function of LncRNAs.MethodsThe culture supernatant was harvested 6 d after C6/36 cells were infected with DENV-3,the virus titer was determined by CCID50,and the type and full-length genome amplification were identified by PCR;The DENV-3 standard plasmid was amplified,identified by PCR,and the standard curve was drawn;THP-1 cells were divided into negative control group(THP-1),direct infection group(DV-3),ADE group and blank control group[1640(-)]. After 48 h of infection,the total RNA was extracted and the copy number of intracellular virus nucleic acid was measured;Through the whole transcriptome sequencing technology,the CeRNA regulatory network was constructed for the top five up-regulated and down-regulated LncRNAs in THP-1 vs DENV3,THP-1 vs ADE,DENV3 vs ADE groups,and the functions of their coding proteins were analyzed.ResultsC6/36 cells infected with DENV-3 for 3 d showed obvious cell fusion,vacuoles and abscission;The virus had a titer of about 1. 0 × 104. 64PFU/mL and was identified as DENV-3 by PCR specific primers,of which the complete gene sequence was obtained;The number of viral nucleic acid copies in ADE group was significantly higher than those in DV-3 group and blank control group;In THP-1 vs DENV-3,the expression of cytohesin interacting protein(CYTIP)was predicted to be up-regulated;In THP-1 vs ADE,the expression of kinesin family5A(KIF5A)was predicted to be down-regulated;In DENV-3 vs ADE,the expression of cluster differentiation antigen 9(CD9)and insulin like growth factor 2(IGF2)was predicted to be up-regulated. All of these differential LncRNAs had open reading frames(ORFs). Except Lnc-SH3BP1 and Lnc-RPL41,all of the other LncRNAs had internal ribosome binding site(IRES).ConclusionIn DENV-3 infection of THP-1 cells and ADE infection mediated by DENV-3,the expression of LncRNAs has changed significantly,and may regulate the process of infection through a variety of biological functions,which is helpful for a deeper understanding of the mechanism of ADE infection.