Abstract: Objective To screen and clarify the mechanism of long non-coding RNA CD48-AS (lncRNA CD48-AS) and the antisense complementary molecule CD48 in the process of N-3-oxododecanoyl-L-homoserine lactone (3-O-C12- HSL) hampering the maturation of human monocyte-induced dendritic cells (Mo-DCs). Methods Mo-DCs were extracted from the peripheral blood of healthy individuals, and the immature Mo-DCs were divided into three groups for lncRNA chip analysis: the negative control group (0.1% DMSO), the lipopolysaccharide (LPS) positive control group (100 μg/L LPS) and the treatment group (100 μg/L LPS+40 μmol/L 3-O-C12-HSL). The natural antisense lncRNA expressed more than 5 times in the lncRNA expression profile were screened for Cluster analysis. The natural antisense lncRNA CD48-AS was screened. Immature Mo-DCs were divided into the negative control group, the LPS positive control group, and the 3-O-C12-HSL treatment group (5, 10, 25 μmol/L 3-O-C12-HSL). The expression of lncRNA CD48-AS and antisense molecule CD48 were measured using quantitative PCR in each group. The complementary regions of lncRNA CD48-AS and CD48 and the protein coding function of lncRNA CD48-AS were analyzed through bioinformatics. Whether lncRNA CD48-AS affected the expression of CD48 by forming a dimer with CD48 was verified through the ribonuclease protection experiment (RPA). Preliminary experiments were carried out on the localization of lncRNA CD48-AS in cells. Results The lncRNA expression profile of Mo-DCs showed specific changes after 3-O-C12-HSL treatment. 3-O-C12-HSL down-regulated the expression of lncRNA CD48-AS and its antisense target molecule CD48 induced by LPS. Bioinformatics analysis showed that lncRNA CD48-AS was a non-coding RNA without protein coding function. lncRNA CD48-AS may form RNA dimers with CD48 to reduce the degradation of CD48 by RNase and increase the expression of CD48. lncRNA CD48-AS was mainly located in the nucleus in Mo-DCs, with less expression in cytoplasm. Conclusion 3-O-C12-HSL can inhibit the maturation of Mo-DCs by down-regulating lncRNA CD48-AS and then affecting the expression of CD48.

Key words: RNA, long noncoding, dendritic cells, lipopolysaccharides, CD48 antigen, computational biology, N-3- oxododecanoyl-L-homoserine lactone, lncRNA CD48-AS