Anamnestic anti-pZP CD4+ and CD8+ T-cell responses in PBMC from pony mares immunized with either native pZP, a recombinant zona pellucida vaccine or adjuvanted saline (controls)
This study aimed to investigate pZP-specific anamnestic responses of helper (CD4+) and cytotoxic (CD8+) T-lymphocytes in peripheral blood mononuclear cells (PBMC) harvested from mares before and after treatment with native porcine zona pellucida (pZP), recombinant pZP3 and pZP4 antigens (reZP) or adjuvanted saline. Mares were randomly assigned to pZP, reZP and control groups (n=7 per group). Treatments consisted of a primary vaccination or saline (V1; Day 0) incorporating Freund’s modified complete adjuvant, followed by a single booster (V2; Day 35) incorporating Freund’s incomplete adjuvant. PBMC were isolated and cryopreserved on Day 0 (immediately prior to V1) and Day 70 (five weeks post V2). Relative proliferation of T-lymphocytes in response to pZP antigen was assessed using carboxyfluorescein diacetate succinimidyl ester dilution with immunophenotyping, analysed via flow cytometry (Accuri C6).