Host B-cell receptors and antibodies specific for tetanus toxoid, diphtheria toxoid, pertussis toxin, and filamentous hemagglutinin (BCR/Ab (Tdap-specific))

This target encompasses the repertoire of host B-cell receptors (BCRs) and secreted antibodies that specifically recognize and bind to the primary antigens used in Tdap and DTaP vaccines: tetanus toxoid, diphtheria toxoid, pertussis toxin (PT), and filamentous hemagglutinin (FHA). These BCRs are membrane-bound immunoglobulins on the surface of B lymphocytes that, upon ligation with their cognate antigens, trigger the adaptive immune response necessary for long-term protection against Clostridium tetani, Corynebacterium diphtheriae, and Bordetella pertussis (CDC, 2020). The biological role of this target system is to produce high-affinity IgG antibodies that neutralize the potent exotoxins responsible for the clinical manifestations of tetanus and diphtheria. Additionally, the system targets pertussis-specific proteins like PT and FHA to mitigate the severity and transmission of respiratory infection (StatPearls, 2023). In clinical practice, these receptors and antibodies are the primary targets of active immunization strategies, where vaccines serve as the agents that stimulate the expansion of these specific immune cell populations. Therapeutic antibodies, such as tetanus immune globulin, also interact with these pathways by providing immediate passive immunity. Monitoring the efficacy of these interactions is typically performed by measuring serum antibody titers, which serve as established correlates of protection for tetanus and diphtheria (WHO, 2017).

Other names

Tdap-specific B-cell receptorsAnti-tetanus/diphtheria/pertussis antibodiesTetanus-Diphtheria-Pertussis specific BCRsAnti-TT/DT/PT/FHA antibodiesHost immunoglobulins specific for Tdap antigens

Vaccines act as exogenous antigens that bind to and cross-link specific B-cell receptors (BCRs), initiating signal transduction that leads to B-cell proliferation, affinity maturation, and differentiation into memory B cells and antibody-secreting plasma cells (PubMed: 25135873). The resulting antibodies neutralize bacterial toxins (tetanospasmin, diphtheria toxin, and pertussis toxin) by blocking their binding to host cell receptors and facilitate the clearance of Bordetella pertussis by binding to filamentous hemagglutinin (FHA) to prevent bacterial adhesion (StatPearls: 2023).