Evaluation of Vaccine-Induced Immunity Against Bacterial Infection in a Mouse Model
Transcript
To study vaccine-induced immunity, take an injection filled with an acellular pertussis vaccine. The vaccine contains antigenic proteins of a respiratory disease-causing bacteria — Bordetella pertussis, and adjuvants that extend the antigen exposure for a sustained immune response.
Inject the vaccine intramuscularly into an anesthetized mouse.
Post-injection, the resident antigen-presenting cells, APCs, capture and process the antigenic proteins into peptides, presenting them on their surface. These APCs then migrate to nearby lymph nodes and interact with T cells, initiating their activation and differentiation into effector T cells.
These effector T cells circulate and migrate to various organs, including the lungs, where they reside as resident memory T cells or TRM cells, leading to immunization.
Post-immunization, intranasally administer an antibiotic-resistant strain of live Bordetella pertussis. These bacteria enter the lung tissue and activate TRM cells. The activated TRM cells secrete inflammatory cytokines that recruit the immune cells to cause bacterial clearance.
Harvest the mouse's lung tissue and homogenize it to obtain a single-cell suspension. Spread the diluted cell suspension on an antibiotic-containing agar plate and incubate it to allow bacterial colony formation.
The tissue extract from an immunized mouse exhibits fewer colonies compared to that from a non-immunized mouse, confirming vaccine-induced immunity against Bordetella pertussis.
