Table 3.
Evasion mechanisms of Brucella virulence factors.
| Name | Type | Proposed function |
|---|---|---|
| VceA | T4SS effector | Inhibit autophagy and inflammatory factors (TNF-α and IL-1β) production. Promote apoptosis (Zhang et al., 2019). |
| VceC | T4SS effector | Induce inflammatory response through the IRE1 pathway (Keestra-Gounder et al., 2016). Induce unfolded protein response and regulate apoptosis (Byndloss et al., 2019; Zhi et al., 2019). |
| BtpA | T4SS effector | Inhibit inflammatory response and NF-κB activation through multiple pathways (Radhakrishnan et al., 2009; Sengupta et al., 2010; Chaudhary et al., 2012; Alaidarous et al., 2014; Jakka et al., 2017). |
| BtpB | T4SS effector | Inhibit autophagy and the inflammatory response of the TLR signaling pathway. Induce apoptosis (Li et al., 2022). |
| BspJ | T4SS effector | Inhibit apoptosis (Ma et al., 2020). |
| BspG | T4SS effector | Inhibit apoptosis (Ma et al., 2022a). |
| BspF | T4SS effector | Inhibit apoptosis (Lin et al., 2023). |
| LPS | Lipopolysaccharide | Inhibit recognition with the complement system. Evade TLR4 identification and attenuate the inflammatory response (Lapaque et al., 2006). Induce PMN cell death (Barquero-Calvo et al., 2015). |
| Omp16 | Lipoprotein | Maintain the integrity and activity of the Brucella outer membrane (Zhi et al., 2020). Induce the production of inflammatory factors (Giambartolomei et al., 2004). |
| Omp19 | Lipoprotein | Maintain the outer membrane properties of Brucella (Tibor et al., 2002). Evade the protease hydrolysis system (Pasquevich et al., 2019). Induce the production of inflammatory factors (Giambartolomei et al., 2004). Interact with TLR2 and inhibit MHC-II antigen presentation. |
| Omp25 | Outer membrane protein | Inhibit apoptosis (Ma et al., 2015). Affect the autophagy mechanism (Jiao et al., 2020). Regulate miRNA to inhibit TNF-α production (Luo et al., 2017). Restrict NF-κB nuclear translocation in DC cells and inhibit secretion of pro-inflammatory factors (Degos et al., 2020). Inhibit the cGAS/STING signaling pathway and interfere with IFN-β production (Li et al., 2021). Inhibit LPS-induced IL-12 production (Cui et al., 2017). |
| Omp31 | Outer membrane protein | Inhibit the classical apoptotic pathway and the mitochondrial apoptotic pathway (Zhang et al., 2016). Inhibit NF-κB p65 signal pathway and TNF-α expression (Wang et al., 2021a). |
| Flagella | Failure to recognize with TLR5 (Terwagne et al., 2013). |