Development of a peptide-based vaccine using a T cell epitope derived from SARS-CoV-2

Area of Science:

• Immunology
• Vaccinology
• Cardiovascular Research

Background:

• Follicular helper T (Tfh) cells are crucial for antibody production and vaccine efficacy.
• Inducing Tfh cell responses is key for developing effective vaccines against various diseases.
• A specific Tfh epitope from SARS-CoV-2 spike protein can activate Tfh cells.

Purpose of the Study:

• To evaluate a peptide vaccine conjugated with a SARS-CoV-2 Tfh epitope for treating experimental hypertension.
• To assess the vaccine's ability to activate Tfh cells, germinal center B cells, and induce antibodies against Angiotensin II (Ang II).

Main Methods:

• A peptide vaccine was designed by conjugating the SARS-CoV-2 Tfh epitope with Ang II.
• The vaccine's efficacy was tested in a mouse model of experimental hypertension.
• Immune responses, including Tfh cell activation, B cell responses, and antibody production, were analyzed.
• The impact of prior SARS-CoV-2 spike priming on vaccine efficacy was investigated.
• Human peripheral blood mononuclear cells from COVID-19 mRNA vaccinated individuals were tested for Tfh epitope activation.

Main Results:

• The Tfh-Ang II vaccine effectively suppressed hypertension in mice.
• Vaccination activated Tfh cells and germinal center B cells, leading to anti-Ang II antibodies.
• No induction of Ang II-specific autoreactive T cells was observed.
• Antibody production was enhanced by prior SARS-CoV-2 spike priming.
• Tfh epitope activated human immune cells from individuals vaccinated with COVID-19 mRNA vaccines.

Conclusions:

• The SARS-CoV-2 spike-derived universal Tfh epitope holds potential for peptide-based vaccine development.
• This strategy may offer a novel approach for treating hypertension and potentially other autoimmune or inflammatory conditions.
• The findings suggest a broader applicability of this Tfh epitope in vaccine design.