B-cell receptor specific for Haemophilus influenzae type b polyribosyl-ribitol phosphate (Anti-PRP BCR)

The B-cell receptor (BCR) and its secreted antibody form (paratope) specific for the polyribosyl-ribitol phosphate (PRP) capsular polysaccharide are the primary mediators of adaptive immunity against Haemophilus influenzae type b (Hib) (CDC, 2022). Hib is a major cause of invasive bacterial infections such as meningitis and pneumonia in children, with the PRP capsule serving as its essential virulence factor by inhibiting phagocytosis (WHO, 2013). Vaccines targeting this BCR, specifically conjugate vaccines, link the PRP carbohydrate to a protein carrier to induce a T-cell dependent immune response, leading to high-affinity antibody production and immunological memory (PubMed: 12732859). The resulting anti-PRP antibodies provide protection by coating the bacterial surface, which enables opsonophagocytosis and complement-mediated killing (PubMed: 10450739). Clinical efficacy is typically monitored by measuring serum anti-PRP IgG levels, where specific thresholds correlate with short-term and long-term protection (StatPearls, 2023). This target is unique in that it represents the specific recognition site of the host immune system that must be engaged to prevent life-threatening invasive disease.

Other names

Anti-polyribosyl-ribitol phosphate antibodyAnti-Hib PRP antibodyHaemophilus influenzae type b specific B-cell receptorHib-specific antibody paratopeAnti-PRP BCR

Hib conjugate vaccines act as antigens that bind to the B-cell receptor (BCR) paratope, triggering B-cell activation, proliferation, and differentiation into plasma cells that secrete anti-PRP antibodies (PubMed: 12732859). These antibodies then bind to the PRP capsule of the bacteria, facilitating opsonization and clearance by the immune system (CDC, 2022).