Sneaky tactics: Ingenious immune evasion mechanisms of Bartonella

ABSTRACT

Gram-negative Bartonella species are facultative intracellular bacteria that can survive in the harsh intracellular milieu of host cells. They have evolved strategies to evade detection and degradation by the host immune system, which ensures their proliferation in the host. Following infection, Bartonella alters the initial immunogenic surface-exposed proteins to evade immune recognition via antigen or phase variation. The diverse lipopolysaccharide structures of certain Bartonella species allow them to escape recognition by the host pattern recognition receptors. Additionally, the survival of mature erythrocytes and their resistance to lysosomal fusion further complicate the immune clearance of this species. Certain Bartonella species also evade immune attacks by producing biofilms and anti-inflammatory cytokines and decreasing endothelial cell apoptosis. Overall, these factors create a challenging landscape for the host immune system to rapidly and effectively eradicate the Bartonella species, thereby facilitating the persistence of Bartonella infections and creating a substantial obstacle for therapeutic interventions. This review focuses on the effects of three human-specific Bartonella species, particularly their mechanisms of host invasion and immune escape, to gain new perspectives in the development of effective diagnostic tools, prophylactic measures, and treatment options for Bartonella infections.

KEYWORDS:

• Bartonella
• antigen variation
• intracellular survival
• biofilm
• apoptosis

Acknowledgements

Figure 1 was created using Biorender.com.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Original idea: Xiaoxing You; Data acquisition and interpretation: Yixuan Xi, Lu Liu, Feichen Xiu, and Xinchao Yi; Writing: Yixuan Xi; Review and editing: Xinru Li, Hongliang Chen, and Xiaoxing You. All authors agree to be accountable for all aspects of this work.

Data Availability statement

No data were generated or analysed in this work.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the Natural Science Foundation of Hunan Province, China (2021JJ70002 and 2022JJ30488) and Hunan Science and Technology innovation project (2021SK50302).