Cryptococcosis Inhibits the Immune Response of Dendritic Cells Through the snhg1-miR-145a-3p-Bcl2 Axis

Objectives: Dendritic cells are one of the first host cells that cryptococcus encounters. However, the correlations among cryptococcus, dendritic cells, and long noncoding RNA remain unclear. This study was undertaken to investigate the effects of long noncoding RNAs on dendritic cells with cryptococcus infection. Materials and Methods: We treated dendritic cells with cryptococcus and then detected expression of CD80, CD86, and major histocompatibility complex class II in dendritic cells with a real-time fluorescent quantitative polymerase chain reaction assay. We used next-generation sequencing and bioinformatics analysis to determine the competitive endogenous RNA mechanisms, confirmed via real-time polymerase chain reaction, dual luciferase reporter, and RNA-binding protein immunoprecipitation assays. Results: After treatment of dendritic cells with 1 x 10(8) CFU/ mL cryptococcus for 12 hours, dendritic cell viability was normal, whereas mRNA expression levels of CD80, CD86, and major histocompatibility complex class II in dendritic cells were substantially increased. With next-generation sequencing, we discovered 4 small nucleolar RNA host genes (snhg1, snhg3, snhg4, and snhg16) in cryptococcus-treated dendritic cells compared with wild-type dendritic cells. Bioinformatics analysis combined with real-time polymerase chain reaction led us to speculate that cryptococcus may affect the maturation and apoptosis of dendritic cells by regulating snhg1-miR-145a-3p-Bcl2. Further polymerase chain reaction, dual luciferase reporter, and RNA-binding protein immunoprecipitation experiments revealed that snhg1 acted as a sponge for miR-145a-3p to inhibit the expression of miR-145a-3p and that miR-145a-3p promoted the expression of Bcl2 by directly targeting the 3'-UTR of Bcl2. Functional recovery experiments showed that cryptococcus promoted the maturation and apoptosis and inhibited the proliferation of dendritic cells through the snhg1-Bcl2 pathway. Conclusions: This study lays a foundation for the further understanding of the pathogenic role of snhg1-miR-145a-3p-Bcl2 axis in cryptococcosis.