Sialic acid-binding adhesin (SabA) (SabA)

The Sialic acid-binding adhesin (SabA) is a major outer membrane protein of Helicobacter pylori that plays a pivotal role in the bacterium's ability to colonize and persist within the human stomach (UniProt A5LGD1). While other adhesins like BabA mediate initial attachment to healthy tissue, SabA is specifically adapted to bind to inflamed gastric mucosa by recognizing sialylated glycans, such as sialyl-Lewis X (sLeX), which are upregulated during chronic infection (Mahdavi et al., 2002). This binding not only facilitates stable colonization but also enables H. pylori to interact with and activate host immune cells, such as neutrophils, contributing to the inflammatory environment (Unemo et al., 2005). Consequently, SabA is strongly associated with the development of chronic gastritis, peptic ulcers, and gastric adenocarcinoma (Wikipedia). As a therapeutic target, SabA is being explored for the development of anti-adhesion agents and vaccines designed to disrupt bacterial attachment and promote clearance (Ace Therapeutics). Experimental strategies include the use of sialylated oligosaccharides or multivalent glycan conjugates to competitively inhibit SabA-receptor interactions. However, the effectiveness of such therapies is challenged by the high genetic plasticity of H. pylori; the sabA gene is subject to frequent phase variation through slipped-strand mispairing, allowing the bacteria to rapidly switch expression on or off to evade host defenses or therapeutic pressure (Bonsor & Sundberg, 2019). Understanding these regulatory mechanisms is essential for developing durable treatments against H. pylori-related diseases.

Other names

SabAHopPOuter membrane protein 17OMP17Sialic acid-binding adhesinHemagglutinin

Inhibition of bacterial attachment to the gastric mucosa by blocking the interaction between the SabA adhesin and host sialylated glycans, such as sialyl-Lewis X (sLeX).