Tonsil explants as a human in vitro model to study vaccine responses

Area of Science:

• Immunology
• Vaccinology
• Tissue Engineering

Background:

• Influenza viruses rapidly mutate, challenging vaccine efficacy and necessitating improved vaccine design strategies.
• Current influenza vaccine strain selection relies on animal models with limited predictive value for human immune responses.
• Developing effective vaccines against highly mutable viruses like influenza remains a significant global health challenge.

Purpose of the Study:

• To develop and validate a human in vitro vaccination model using tonsil tissue.
• To establish a platform for testing vaccine candidates and improving vaccine design.
• To assess the model's capacity for generating de novo immune responses.

Main Methods:

• Human tonsil tissue explants were cultured in 3D perfusion bioreactors.
• The in vitro system was exposed to various vaccines, protein antigens, and antigen combinations.
• Immune responses, including B cell activation and antibody production, were analyzed.

Main Results:

• Perfusion bioreactor cultures demonstrated superior tissue viability, metabolic activity, and immune responses compared to static cultures.
• The in vitro vaccination system successfully responded to diverse vaccine types and antigens.
• Multivalent immunization with distinct H3N2 influenza strains induced broader B cell activation and enhanced antibody cross-reactivity.

Conclusions:

• Perfusion-cultured tonsil tissue represents a valuable human in vitro model for immunology research.
• This model shows potential for application in the selection and optimization of vaccine candidates.
• The developed system offers a promising alternative for pre-clinical vaccine evaluation.