[Expression and bioinformatic analysis of miR-29 family, target gene IFN-γ in CD4(+) T cells from subjects with latent tuberculosis infection].

Objective To investigate the effect of latent and active pulmonary tuberculosis(TB) on expression of miR-29 family and target gene IFN-γ in CD4 + T cells.Methods Subjects from two hospitals of Weifang were enrolled from March 2012 to December 2012 and divided into three groups:active TB group (30 cases),latent tuberculosis infection (LTBI) group (25 cases) and healthy control group (30 cases).CD4 + T cells in blood were collected from the three groups.Levels of miR-29a,miR-29b and miR-29c were measured by nucleic acid hybridization and RT-qPCR.Expression of IFN-γwas analyzed by RT-qPCR.Target genes of miR-29 family were predicted with both TargetScan and PicTar.GO annotation and pathway overrepresentation were further analyzed with David database and Cytoscape.Results Levels of miR-29a,miR-29b and miR-29c showed significant differences among the three groups(P ＜0.05):levels of miR-29b and miR-29c in the active TB group (561.63 ± 65.36,281.85 ± 42.78) were higher than the healthy controls(260.74 ± 38.69,128.21 ± 19.98),but lower than the LTBI group (2030.29 ± 321.68,620.93 ±79.14) ; expression of miR-29a in the healthy control group(913.95 ± 104.73) were higher than the active TB group(323.37 ± 54.38),but lower than the LTBI group (4782.13 ± 567.81).Level of IFN-γ showed significant differences among the three groups (P ＜ 0.05):level of IFN-γin the LTBI group (0.45 ± 0.09)were lower than the healthy controls (1.00),but higher than the active TB group (0.11 ± 0.03).The target genes of miR-29 family mainly existed in molecular function such as extracellular matrix structural constituent and transcription regulator activity.In KEGG pathway,the gene set mostly existed in signaling pathway such as Focal adhesion,ECM-receptor interaction and mTOR signaling pathway.Conclusion The expression of miR-29 family was increased and target gene IFN-γ in CD4 + T cells was decreased by latent and active pulmonary TB,which might play important role in alteration of signal pathway. Key words: Latent tuberculosis ;  Computational biology ;  MiR-29 ;  IFN-γ