Differentially expressed genes of human microvascular endothelial cells in response to anti-dengue virus NS1 antibodies by suppression subtractive hybridization.

It has been previously shown that anti-dengue virus (DENV) nonstructural protein NS1 antibodies could act as autoantibodies that direct against one or more of the host's own proteins, which has potential implications for dengue hemorrhagic fever pathogenesis. In the present study, we have employed suppression subtractive hybridization (SSH) to identify the differentially expressed genes from human microvascular endothelial cells (HMEC-1) in response to anti-dengue virus type 2 NS1 antibodies (anti-DENV2 NS1 Abs). A total of 35 clones from the SSH cDNA library were randomly selected for further analysis using bioinformatics tools after vector screening. After searching for sequence homology in NCBI GenBank database with BLASTN and BLASTX programs, 23 obtained sequences with significant matches (E-values < 1 x 10(-4)) in the SSH library. The predicted genes in the subtracted library include immune response molecules (CD59 antigen preproprotein preproprotein, MURR1), signal transduction molecules (Nuclear casein kinase and cyclin-dependent kinase substrate 1), calcium-binding proteins (S100A6, Annexin A2 isoform 1/2), and cell-membrane component (Yip1 domain family). From these clones, 5 upregulated genes were selected for differential expression profiling by real-time RT-PCR to confirm their upregulated status. The results confirmed their differential upregulation, and thus verified the success of SSHs and the likely involvement of these genes in dengue pathogenesis.