TLR9 and infection: Since the NF-κB pathway and MAPK pathway can be activated by TLR9 and TLR2 signaling pathways after Brucella infection [29], we first infected cells with 2308WT and 2308ΔbspF strains, alongside an NI control group, and collected cell samples at 48 h after infection to detect the phosphorylation of p65, p38, JNK, and Extracellular regulated protein kinases (ERK) (p-p65,p-p38, p-pJNK, and p-ERK) in RAW264.7 cells.