Brucella Immune Escape: TLR Subversion, Antigen Presentation Destruction and T Cell Disorder

Brucellosis is a severe zoonotic disease caused by Brucella infection, which remains prevalent in several regions worldwide and poses a significant public health challenge. The host deploys complex immune mechanisms to combat the pathogen, including the recognition of pathogenic signals, secretion of inflammatory factors, and activation of innate and adaptive immune responses. Brucella, as a facultative intracellular pathogen, replicates within host cells and establishes chronic infections through diverse immune evasion strategies. These include subversion of Toll-like receptor (TLR) signaling, disruption of antigen presentation, and interference with T cell responses. This review focuses on Brucella species with significant human infectivity, such as B. melitensis and B. abortus, summarizing their interactions with the host immune system. Recent studies have highlighted TLR pathway inhibition, antigen presentation impairment, and T cell dysregulation as key mechanisms of immune evasion. Understanding these processes is crucial for elucidating Brucella pathogenesis and developing novel therapeutic and vaccine strategies against brucellosis.