Rabies vaccination induces a CD4+ TEM and CD4+CD8+ TEMRA TH1 phenotype in dogs

Area of Science:

• Immunology
• Veterinary Medicine
• Vaccinology

Background:

• Canine rabies vaccines provide protection but their impact on cell-mediated immunity is not well understood.
• Understanding adaptive immune responses is key to improving vaccine efficacy.

Purpose of the Study:

• To characterize the cell-mediated immune response in dogs following rabies vaccination.
• To investigate the phenotype and longevity of T cells specific to rabies vaccine antigens.

Main Methods:

• Analysis of blood and spleen samples from vaccinated dogs.
• Ex vivo restimulation with recombinant rabies virus glycoprotein (RABV-G) and nucleoprotein (RABV-N).
• Flow cytometry to identify T cell subsets (CD4+, CD4+CD8+ DP) and their phenotypes (TH1, TEM, TEMRA).

Main Results:

• RABV-G induced higher antibody titers and IFNγ production than RABV-N.
• RABV-G stimulated robust proliferation of CD4+ and CD4+CD8+ double-positive (DP) T cells, dependent on MHC class II.
• RABV-G-specific CD4+ and DP T cells exhibited TH1 and effector memory phenotypes, persisting for over 1000 days post-vaccination.

Conclusions:

• Rabies vaccination elicits robust and long-lasting antigen-specific T cell responses in dogs.
• The study provides the first detailed characterization of canine T cell phenotypes following rabies vaccination.
• RABV-G is a key antigen driving adaptive cell-mediated immunity in canine rabies vaccines.