Abstract
Outer membrane protein 25 (OMP25), a virulence factor from Brucella, plays an important role in maintaining the structural stability of Brucella. Mitogen-activated protein kinase (MAPK) signal pathway widely exists in eukaryotic cells. In this study, human trophoblast cell line HPT-8 and BALB/c mice were infected with Brucella abortus 2308 strain (S2308) and 2308ΔOmp25 mutant strain. The expression of cytokines and activation of MAPK signal pathway were detected. We found that the expressions of tumor necrosis factor-α, interleukin-1, and interleukin-10 (IL-10) were increased in HPT-8 cells infected with S2308 and 2308ΔOmp25 mutant. S2308 also activated p38 phosphorylation protein, extracellular-regulated protein kinases (ERK), and Jun-N-terminal kinase (JNK) from MAPK signal pathway. 2308ΔOmp25 could not activate p38, ERK, and JNK branches. Immunohistochemistry experiments showed that S2308 was able to activate phosphorylation of p38 and ERK in BABL/c mice. However, 2308ΔOmp25 could weakly activate phosphorylation of p38 and ERK. These results suggest that Omp25 played an important role in the process of Brucella activation of the MAPK signal pathway.
Highlights
Brucella spp. are Gram-negative facultative intracellular pathogens that can cause diseases of worldwide significance [1, 2]
To detect the expression level of cytokines, we collected supernatant from HPT-8 cells infected with S2308 and 2308ΔOmp25 and monitored expression levels of cytokine tumor necrosis factor-α (TNF-α), IL-1, and IL-10 by ELISA
Supernatant from HPT-8 cells infected with S2308 produced higher amounts of TNF-α (Figure 1A), IL-1 (Figure 1B), and IL-10 (Figure 1C) than did supernatant from uninfected cells (P < 0.05) and this difference increased with time
Summary
Brucella spp. are Gram-negative facultative intracellular pathogens that can cause diseases of worldwide significance [1, 2]. Infection in humans can cause fever or arthritis [4, 5]. It resulted in heavy economic losses [6]. There are three groups of major outer membrane proteins (Omps) in Brucella [7]. Group 1 Omps consist of two major Omps: Omp and Omp. Group 3 Omps consist of two major Omps: outer membrane protein 25 (Omp25) and Omp. Omp was a primary protein that was released by Brucella when it invaded host cells [8]. Omp was involved in attachment or invasion to the host cells and intracellular survival or reproduction of Brucella, which plays an important role in Brucella virulence.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
