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Updated: Jun 9, 2025
Intralymphatic Immunotherapy and Vaccination in Mice
Published on: February 2, 2014
Delayed reinforcement of costimulation improves the efficacy of mRNA vaccines in mice
Sarah Sanchez1, Tanushree Dangi1, Bakare Awakoaiye1
1Department of Microbiology-Immunology, and.
Abstract:
mRNA vaccines have demonstrated efficacy during the COVID-19 pandemic and are now being investigated for multiple diseases. However, concerns linger about the durability of immune responses, and the high incidence of breakthrough infections among vaccinated individuals highlights the need for improved mRNA vaccines. In this study, we investigated the effects of reinforcing costimulation via 4-1BB, a member of the TNF receptor superfamily, on immune responses elicited by mRNA vaccines. We first immunized mice with mRNA vaccines, followed by treatment with 4-1BB costimulatory antibodies to reinforce the 4-1BB pathway at different time points after vaccination. Consistent with prior studies, reinforcing 4-1BB costimulation on the day of vaccination did not result in a substantial improvement in vaccine responses. However, reinforcing 4-1BB costimulation on day 4 after vaccination, when 4-1BB expression levels were highest, resulted in a profound improvement in CD8+ T cell responses associated with enhanced protection against pathogen challenges. A similar clinical benefit was observed in a therapeutic cancer vaccine model. We also report time-dependent effects with OX40, another costimulatory molecule of the TNF receptor superfamily. These findings demonstrate that delayed reinforcement of costimulation may exert an immunologic benefit, providing insights for the development of more effective mRNA vaccines for infectious diseases and cancer.
Insights
Delayed costimulation with 4-1BB antibodies significantly enhances mRNA vaccine-induced CD8+ T cell responses and protection. This strategy improves vaccine efficacy for infectious diseases and cancer by boosting immune memory.
Area of Science:
- Immunology
- Vaccinology
- Molecular Biology
Background:
- mRNA vaccines show promise but require improved durability and reduced breakthrough infections.
- Costimulatory molecules, like 4-1BB, are crucial for robust T cell responses.
- Optimizing the timing of costimulatory signals is key to enhancing vaccine efficacy.
Purpose of the Study:
- To investigate the impact of reinforcing the 4-1BB costimulatory pathway at different time points on mRNA vaccine-induced immune responses.
- To determine if delayed costimulation can overcome limitations in current mRNA vaccine technology.
- To explore the potential of this strategy for both infectious disease and cancer vaccines.
Main Methods:
- Mice were immunized with mRNA vaccines and subsequently treated with 4-1BB costimulatory antibodies at various intervals post-vaccination.
- Immune responses, particularly CD8+ T cell activity, were analyzed.
- Protection against pathogen challenges and therapeutic cancer vaccine models were assessed.
Main Results:
- Reinforcing 4-1BB costimulation on the day of vaccination showed minimal benefit.
- Delayed reinforcement on day 4 post-vaccination, coinciding with peak 4-1BB expression, led to a significant improvement in CD8+ T cell responses.
- Enhanced protection was observed in both infectious disease and cancer models.
- Time-dependent effects were also noted for OX40 costimulation.
Conclusions:
- Delayed reinforcement of costimulation, specifically via 4-1BB, offers a potent strategy to enhance mRNA vaccine immunogenicity and protective efficacy.
- This approach provides valuable insights for developing next-generation mRNA vaccines against infectious diseases and cancer.
- Optimizing the timing of immune system stimulation is critical for maximizing vaccine effectiveness.
