Bacterial immune systems
摘要
Bacterial immune systems encompass the multi-layered defense mechanisms that bacteria develop against bacteriophages and mobile genetic elements, such as plasmids. This review covers bacterial innate defense systems (surface defenses, superinfection exclusion, restriction–modification, abortive infection, and toxin–antitoxin systems), CRISPR-Cas-mediated adaptive immunity, and the escape strategies used by phages to overcome these defenses (genome modifications, anti-restriction proteins, and anti-CRISPR factors). Emerging evidence also highlights the role of outer membrane vesicles (OMVs) in anti-phage defense and their translational potential as vaccine and delivery platforms. In this context, a better understanding of bacterial defense systems contributes to the development of biotechnology and medical applications such as CRISPR technologies, diagnostic approaches, and phage therapy.