Synthetic Peptides Elicit Humoral Response against Porcine Reproductive and Respiratory Syndrome Virus in Swine

• Published in: Vaccines (Basel) 2024-06, Vol.12 (6), p.652
• Main Authors: Perez-Duran, Francisco, Calderon-Rico, Fernando, Franco-Correa, Luis Enrique, Zamora-Aviles, Alicia Gabriela, Ortega-Flores, Roberto, Durand-Herrera, Daniel, Bravo-Patiño, Alejandro, Cortes-Vieyra, Ricarda, Hernandez-Morales, Ilane, Nuñez-Anita, Rosa Elvira
• Format: Article
• Language: English
• Subjects: Animal diseases; Antibodies; B-cells; Care and treatment; CD2; CD21; Cell activation; Cell-mediated immunity; Cytokines; Epitopes; Genomes; GP5; Health aspects; Hogs; Immune response (humoral); Immunization; Immunogenicity; Immunoreactivity; Inoculation; Lymphocytes B; Peptides; Physiological aspects; Porcine reproductive and respiratory syndrome; Proteins; PRRS; Respiratory diseases; Swine; Synthetic peptides; Vaccines; Viruses
• ISSN: 2076-393X; 2076-393X
• DOI: 10.3390/vaccines12060652

The aim of this study was to analyze the immunogenic response elicited in swine by two synthetic peptides derived from GP5 to understand the role of lineal B epitopes in the humoral and B-cell-mediated response against the porcine reproductive and respiratory syndrome virus (PRRSV). For inoculation, twenty-one-day-old pigs were allocated into six groups: control, vehicle, vaccinated (Ingelvac-PRRSV, MLV ), non-vaccinated and naturally infected, GP5-B and GP5-B3. At 2 days post-immunization (dpi), the GP5-B3 peptide increased the serum concentrations of cytokines associated with activate adaptive cellular immunity, IL-1β (1.15 ± 1.15 to 10.17 ± 0.94 pg/mL) and IL-12 (323.8 ± 23.3 to 778.5 ± 58.11 pg/mL), compared to the control group. The concentration of IgGs anti-GP5-B increased in both cases at 21 and 42 dpi compared to that at 0 days (128.3 ± 8.34 ng/mL to 231.9 ± 17.82 and 331 ± 14.86 ng/mL), while IgGs anti-GP5-B3 increased at 21 dpi (105.1 ± 19.06 to 178 ± 15.09 ng/mL) and remained at the same level until 42 dpi. Also, antibody-forming/Plasma B cells (CD2+/CD21-) increased in both cases (9.85 ± 0.7% to 13.67 ± 0.44 for GP5-B and 15.72 ± 1.27% for GP5-B3). Furthermore, primed B cells (CD2-/CD21+) from immunized pigs showed an increase in both cases (9.62 ± 1.5% to 24.51 ± 1.3 for GP5-B and 34 ± 2.39% for GP5-B3) at 42 dpi. Conversely the naïve B cells from immunized pigs decreased compared with the control group (8.84 ± 0.63% to 6.25 ± 0.66 for GP5-B and 5.78 ± 0.48% for GP5-B3). Importantly, both GP5-B and GP5-B3 peptides exhibited immunoreactivity against serum antibodies from the vaccinated group, as well as the non-vaccinated and naturally infected group. In conclusion, GP5-B and GP5-B3 peptides elicited immunogenicity mediated by antigen-specific IgGs and B cell activation.