Comparative Gene Expression Analysis within Mouse Macrophage for Identifying Critical Pathways in Macrophage and Brucella suis Interaction

Abstract

Background: Brucella spp. are Gram-negative bacteria that cause a zoonotic disease called brucellosis in humans as well as many animals. Brucella suis (B.suis) is one of the greatest threats to the human health and food safety. Studying macrophage and B. suis interaction is critical for understanding the chronic infection mechanism. However, the interaction mechanisms, especially for molecular events triggered by B. suis infected macrophage, such as biological pathways, are still obscure. Objectives: We will use gene set enrichment analysis (GSEA) to microarray in an attempt to find critical pathways in the interaction of macrophage and B. suis. Methods: We applied a standardized microarray preprocessing and GSEA to 2 independent macrophage and B. suis interaction studies including smooth virulent B. suis strain 1330 (S1330) data sets and rough attenuated B. suis strain VTRS1 (VTRS1) data sets. Integrative analysis was used to find critical pathways for 2 independent macrophage and B. suis interaction data sets. Results: The results demonstrated that for S1330 data sets, 8 and 13 common up- and down- regulated pathways were found in 4 interaction stages including 4h, 8h, 24h, and 48h post macrophage infected S1330 B. suis, and for VTRS1 data sets, we found 30 and 19 common up- and down- regulated pathways. Comparing the results of S1330 and VTRS1 data sets, 6 and 8 common up- and down- regulated pathways were identified. Conclusions: The study of macrophage and B. suis interaction through pathway analysis highlighted genes weakly connected to the phenotype, and discovered common critical pathways in the process of macrophages and different phenotypes of B. suis interaction. The identified pathways will shed light on the understanding of the functional events within macrophage post infected B. suis.